The invention relates to novel bispecific antigen binding molecules, comprising (a) at least one moiety capable of specific binding to OX40, and (b) at least one moiety capable of specific binding to epithelial cell adhesion molecule (EpCAM). The invention further relates to methods of producing these molecules and to methods of using the same.

BACKGROUND

Several members of the tumor necrosis factor receptor (TNFR) family function after initial T cell activation to sustain T cell responses and thus have pivotal roles in the organization and function of the immune system. CD27, 4-1BB (CD137), OX40 (CD134), HVEM, CD30, and GITR can have costimulatory effects on T cells, meaning that they sustain T-cell responses after initial T cell activation (Watts T.H. (2005) Annu. Rev. Immunol. 23, 23-68). The effects of these costimulatory TNFR family members can often be functionally, temporally, or spatially segregated from those of CD28 and from each other. The sequential and transient regulation of T cell activation/survival signals by different costimulators may function to allow longevity of the response while maintaining tight control of T cell survival. Depending on the disease condition, stimulation via costimulatory TNF family members can exacerbate or ameliorate disease.

Despite these complexities, stimulation or blockade of TNFR family costimulators shows promise for several therapeutic applications, including cancer, infectious disease, transplantation, and autoimmunity. Among several costimulatory molecules, the tumor necrosis factor (TNF) receptor family member OX40 (CD 134) plays a key role in the survival and homeostasis of effector and memory T cells (Croft M. et al. (2009), Immunological Reviews 229, 173-191). OX40 (CD134) is expressed in several types of cells and regulates immune responses against infections, tumors and self-antigens and its expression has been demonstrated on the surface of T-cells, NKT-cells and NK-cells as well as neutrophils (Baumann R. et al. (2004), Eur. J. Immunol. 34, 2268-2275) and shown to be strictly inducible or strongly upregulated in response to various stimulatory signals. Functional activity of the molecule has been demonstrated in every OX40-expressing cell type suggesting complex regulation of OX40-mediated activity in vivo. Combined with T- cell receptor triggering, OX40 engagement on T-cells by its natural ligand or agonistic antibodies leads to synergistic activation of the PI3K and NFKB signalling pathways (Song J. et al. (2008) J. Immunology 180(11), 7240-7248). In turn, this results in enhanced proliferation, increased cytokine receptor and cytokine production and better survival of activated T-cells. In addition to its co-stimulatory activity in effector CD4 ⁺ or CD8 ⁺ T-cells, OX40 triggering has been recently shown to inhibit the development and immunosuppressive function of T regulatory cells. This effect is likely to be responsible, at least in part, for the enhancing activity of OX40 on anti-tumor or anti-microbial immune responses. Given that OX40 engagement can expand T- cell populations, promote cytokine secretion, and support T-cell memory, agonists including antibodies and soluble forms of the ligand OX40L have been used successfully in a variety of preclinical tumor models (Weinberg et al. (2000), J. Immunol. 164, 2160-2169).

The available pre-clinical and clinical data clearly demonstrate that there is a high clinical need for effective agonists of costimulatory TNFR family members such as OX40 and 4- IBB that are able to induce and enhance effective endogenous immune responses to cancer. However, almost never are the effects limited to a single cell type or acting via a single mechanism and studies designed to elucidate inter- and intracellular signaling mechanisms have revealed increasing levels of complexity. Thus, there is a need of "targeted" agonists that preferably act on a single cell type. The antigen binding molecules of the invention combine a moiety capable of preferred binding to tumor-specific or tumor-associated targets with a moiety capable of agonistic binding to costimulatory TNF receptors. The antigen binding molecules of this invention may be able to trigger TNF receptors not only effectively, but also very selectively at the desired site thereby reducing undesirable side effects. Epithelial cell adhesion molecule (EpCAM) - also known as tumor-associated calcium signal transducer 1 (TACSTD1), 17-1A and CD326 - is a type I ~ 40 kDa transmembrane glycoprotein that is highly expressed in epithelial cancers, and at lower levels in normal simple epithelia. The structure and function of EpCAM is reviewed, for example, in Schnell et al., Biochimica et Biophysica Acta - Biomembranes (2013), 1828(8): 1989-2001; Trzpis et al. Am J Pathol. (2007) 171(2): 386-395 and Baeuerle and Gires, Br. J. Cancer, (2007) 96:417-423.

EpCAM is expressed at the baso lateral membrane, and plays a role in calcium- independent homophilic cell adhesion. The mature EpCAM molecule (after processing to remove the 23 amino acid signal peptide) comprises an N-terminal, 242 amino acid extracellular domain comprising an epidermal growth factor-like repeat region, a human thyroglobulin (TY) repeat region and a cysteine-poor region, a single-pass 23 amino acid transmembrane domain and a C- terminal, 26 amino acid cytoplasmic domain comprising two binding sites for a-actinin and a NPXY internalization motif.

EpCAM is frequently overexpressed in cancers of epithelial origin and is expressed by cancer stem cells, and is therefore a molecule of significant interest for therapy and diagnosis. The extracellular domain EpCAM can be cleaved to yield the soluble extracellular domain molecule EpEX, and the intracellular molecule EpICD. EpICD has been shown to associate with other proteins to form a nuclear complex which upregulates the expression of genes promoting cell proliferation (Maetzel et al, Nat Cell Biol (2009) 11(2): 162-171). EpCAM may also be involved in the epithelial to mesenchymal cell transition (EMT), and may contribute to the formation of large metastases (Imrich et al, Cell Adh Migr. (2012) 6(1): 30-38).

Several clinical trials have been conducted for the use of anti-EpCAM antibodies to treat various carcinomas (reviewed e.g. in Munz et al., Cancer Cell Int. (2010) 10:44, and Baeuerle and Gires, supra).

SUMMARY OF THE INVENTION The present invention provides a bispecific antigen binding molecule, comprising

(a) at least one moiety capable of specific binding to OX40 comprising an antibody light chain variable region (VL) and an antibody heavy chain variable region (VH), and

(b) at least one moiety capable of specific binding to epithelial cell adhesion molecule

(EpCAM) comprising an antibody light chain variable region (VL) and an antibody heavy chain variable region (VH).

The novel bispecific antigen binding molecules of the present invention are able to trigger OX40 very selectively at the site where EpCAM is expressed, due to their binding capability towards EpCAM. Side effects may therefore be drastically reduced.

In some embodiments, the bispecific antigen binding molecule additionally comprises (c) a Fc region composed of a first and a second subunit capable of stable association.

In some embodiments, the moiety capable of specific binding to OX40 binds to a polypeptide comprising, or consisting of, the amino acid sequence of SEQ ID NO: l .

In some embodiments, the moiety capable of specific binding to EpCAM binds to a polypeptide comprising, or consisting of, the amino acid sequence of SEQ ID NO:49. In some embodiments, the moiety capable of specific binding to OX40 comprises a heavy chain variable domain (VH) comprising

(i) a CDR-H1 comprising an amino acid sequence selected from the group consisting of SEQ ID NO:4 and SEQ ID NO:5,

(ii) a CDR-H2 comprising an amino acid sequence selected from the group consisting of SEQ ID NO:6 and SEQ ID NO:7, and (iii) a CDR-H3 comprising an amino acid sequence selected from the group consisting of SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO: 10, SEQ ID NO: l l, SEQ ID NO: 12, SEQ ID NO: 13 and SEQ ID NO: 14,

and a light chain variable domain (VL) comprising

(iv) a CDR-L1 comprising an amino acid sequence selected from the group consisting of

SEQ ID NO: 15, SEQ ID NO: 16 and SEQ ID NO: 17,

(v) a CDR-L2 comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 18, SEQ ID NO: 19 and SEQ ID NO:20, and

(vi) a CDR-L3 comprising an amino acid sequence selected from the group consisting of SEQ ID NO:21, SEQ ID NO:22, SEQ ID NO:23, SEQ ID NO:24, SEQ ID NO:25 and SEQ ID

NO:26.

In some embodiments, the moiety capable of specific binding to OX40 comprises a heavy chain variable region (VH) comprising an amino acid sequence that is at least about 95%, 96%, 97%), 98%o, 99%) or 100% identical to an amino acid sequence selected from the group consisting of SEQ ID NO:33, SEQ ID NO: 35, SEQ ID NO:37, SEQ ID NO:39, SEQ ID NO:41, SEQ ID NO:43 and SEQ ID NO:45 and a light chain variable region (VL) comprising an amino acid sequence that is at least about 95%>, 96%>, 97%>, 98%>, 99%> or 100% identical to an amino acid sequence selected from the group consisting of SEQ ID NO:34, SEQ ID NO: 36, SEQ ID NO:38, SEQ ID NO:40, SEQ ID NO:42, SEQ ID NO:44 and SEQ ID NO:46. In some embodiments, the moiety capable of specific binding to OX40 comprises

(i) a VH comprising the amino acid sequence of SEQ ID NO:33 and a VL comprising the amino acid sequence of SEQ ID NO:34,

(ii) a VH comprising the amino acid sequence of SEQ ID NO:35 and a VL comprising the amino acid sequence of SEQ ID NO:36,

(iii) a VH comprising the amino acid sequence of SEQ ID NO:37 and a VL comprising the amino acid sequence of SEQ ID NO:38,

(iv) a VH comprising the amino acid sequence of SEQ ID NO:39 and a VL comprising the amino acid sequence of SEQ ID NO:40,

(v) a VH comprising the amino acid sequence of SEQ ID NO:41 and a VL comprising the amino acid sequence of SEQ ID NO:42,

(vi) a VH comprising the amino acid sequence of SEQ ID NO:43 and a VL comprising the amino acid sequence of SEQ ID NO:44, or

(vii) a VH comprising the amino acid sequence of SEQ ID NO:45 and a VL comprising the amino acid sequence of SEQ ID NO:46. In some embodiments, the moiety capable of specific binding to EpCAM comprises a

VH comprising (i) a CDR-H1 comprising the amino acid sequence SEQ ID NO:51 ,

(ii) a CDR-H2 comprising the amino acid sequence SEQ ID NO:52, and

(iii) a CDR-H3 comprising the amino acid sequence SEQ ID NO:53,

and a VL comprising

(iv) a CDR-L1 comprising the amino acid sequence SEQ ID NO:54,

(v) a CDR-L2 comprising the amino acid sequence SEQ ID NO:55, and

(vi) a CDR-L3 comprising the amino acid sequence SEQ ID NO:56.

In some embodiments, the moiety capable of specific binding to EpCAM comprises a VH comprising an amino acid sequence that is at least about 95%, 96%>, 97%, 98%>, 99% or 100% identical to the amino acid sequence of SEQ ID NO:63, and a VL comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: 64.

In some embodiments, the moiety capable of specific binding to EpCAM comprises a VH comprising the amino acid sequence of SEQ ID NO:63 and a VL comprising the amino acid sequence of SEQ ID NO:64.

In some embodiments, the bispecific antigen binding molecule comprises

(i) at least one moiety capable of specific binding to OX40, comprising a VH comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to an amino acid sequence selected from the group consisting of SEQ ID NO:33, SEQ ID NO: 35, SEQ ID NO:37, SEQ ID NO:39, SEQ ID NO:41 , SEQ ID NO:43 and SEQ ID NO:45 and a VL comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to an amino acid sequence selected from the group consisting of SEQ ID NO:34, SEQ ID NO: 36, SEQ ID NO:38, SEQ ID NO:40, SEQ ID NO:42, SEQ ID NO:44 and SEQ ID NO:46, and

(ii) at least one moiety capable of specific binding to EpCAM, comprising a VH comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100%) identical to the amino acid sequence of SEQ ID NO: 63 and a VL comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:64. In some embodiments, the bispecific antigen binding molecule comprises

(i) at least one moiety capable of specific binding to OX40, comprising a VH comprising the amino acid sequence of SEQ ID NO: 35 and a VL comprising the amino acid sequence of SEQ ID NO: 36, and (ii) at least one moiety capable of specific binding to EpCAM, comprising a VH comprising the amino acid sequence of SEQ ID NO:63 and a VL comprising the amino acid sequence of SEQ ID NO: 64.

In some embodiments, the moiety capable of specific binding to OX40 binds to a polypeptide comprising, or consisting of, the amino acid sequence of SEQ ID NO:2.

In some embodiments, the moiety capable of specific binding to EpCAM binds to a polypeptide comprising, or consisting of, the amino acid sequence of SEQ ID NO:50.

In some embodiments, the moiety capable of specific binding to OX40 comprises a VH comprising

(i) a CDR-H1 comprising the amino acid sequence SEQ ID NO:27,

(ii) a CDR-H2 comprising the amino acid sequence SEQ ID NO:28, and

(iii) a CDR-H3 comprising the amino acid sequence SEQ ID NO:29,

and a VL comprising

(iv) a CDR-L1 comprising the amino acid sequence SEQ ID NO:30,

(v) a CDR-L2 comprising the amino acid sequence SEQ ID NO:31 , and

(vi) a CDR-L3 comprising the amino acid sequence SEQ ID NO:32.

In some embodiments, the moiety capable of specific binding to OX40 comprises a VH comprising an amino acid sequence that is at least about 95%, 96%>, 97%, 98%>, 99% or 100% identical to the amino acid sequence of SEQ ID NO:47, and a VL comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:48.

In some embodiments, the moiety capable of specific binding to OX40 comprises a VH comprising the amino acid sequence of SEQ ID NO:47 and a VL comprising the amino acid sequence of SEQ ID NO:48.

In some embodiments, the moiety capable of specific binding to EpCAM comprises a VH comprising

(i) a CDR-H1 comprising the amino acid sequence SEQ ID NO:57,

(ii) a CDR-H2 comprising the amino acid sequence SEQ ID NO:58, and

(iii) a CDR-H3 comprising the amino acid sequence SEQ ID NO:59,

and a VL comprising

(iv) a CDR-L1 comprising the amino acid sequence SEQ ID NO:60,

(v) a CDR-L2 comprising the amino acid sequence SEQ ID NO:61 , and

(vi) a CDR-L3 comprising the amino acid sequence SEQ ID NO: 62. In some embodiments, the moiety capable of specific binding to EpCAM comprises a VH comprising an amino acid sequence that is at least about 95%, 96%>, 97%, 98%>, 99% or 100% identical to the amino acid sequence of SEQ ID NO:65, and a VL comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: 66.

In some embodiments, the moiety capable of specific binding to EpCAM comprises a VH comprising the amino acid sequence of SEQ ID NO:65 and a VL comprising the amino acid sequence of SEQ ID NO:66.

In some embodiments, the bispecific antigen binding molecule comprises

(i) at least one moiety capable of specific binding to OX40, comprising a VH comprising the amino acid sequence of SEQ ID NO:47 and a VL comprising the amino acid sequence of SEQ ID NO:48, and

(ii) at least one moiety capable of specific binding to EpCAM, comprising a VH comprising the amino acid sequence of SEQ ID NO:65 and a VL comprising the amino acid sequence of SEQ ID NO:66.

In some embodiments, the Fc region is an IgG, particularly an IgGl Fc region or an IgG4 Fc region.

In some embodiments, the Fc region comprises one or more amino acid substitution that reduces the binding affinity of the antibody to an Fc receptor and/or effector function. In some embodiments, the Fc region is (i) of human IgGl subclass with the amino acid mutations L234A, L235A and P329G (numbering according to Kabat EU index), or (ii) of mouse IgGl subclass with the amino acid mutations D265A and P329G (numbering according to Kabat EU index).

In some embodiments, the Fc region comprises a modification promoting the association of the first and second subunit of the Fc region.

In some embodiments, the first subunit of the Fc region comprises knobs and the second subunit of the Fc region comprises holes according to the knobs into holes method.

In some embodiments, (i) the first subunit of the Fc region comprises the amino acid substitutions S354C and T366W (numbering according to Kabat EU index) and the second subunit of the Fc region comprises the amino acid substitutions Y349C, T366S and Y407V

(numbering according to Kabat EU index), or (ii) the first subunit of the Fc region comprises the amino acid substitutions K392D and K409D (numbering according to Kabat EU index) and the second subunit of the Fc region comprises the amino acid substitutions E356K and D399K (numbering according to Kabat EU index).

In some embodiments, the bispecific antigen binding molecule comprises

(a) at least two Fab fragments capable of specific binding to OX40 connected to a Fc region, and

(b) at least one moiety capable of specific binding to EpCAM connected to the C- terminus of the Fc region.

In some embodiments, the bispecific antigen binding molecule comprises

(a) two light chains and two heavy chains of an antibody comprising two Fab fragments capable of specific binding to OX40, and a Fc region, and

(b) a VH and a VL of a moiety capable specific binding to EpCAM, wherein the VH is connected to the C-terminus of one of the two heavy chains of (a), and wherein the VL is connected to the C-terminus of the other of the two heavy chains of (a).

In some embodiments, the bispecific antigen binding molecule comprises

(a) two light chains and two heavy chains of an antibody comprising two Fab fragments capable of specific binding to OX40, and a Fc region, and

(b) two Fab fragments capable of specific binding to EpCAM, wherein one of the Fab fragments is connected to the C-terminus of one of the two heavy chains of (a), and the other of the Fab fragments is connected to the C-terminus of the other of the two heavy chains of (a). In some embodiments, the bispecific antigen binding molecule comprises

(a) two heavy chains, each heavy chain comprising a VH and CHI domain of a Fab fragment capable of specific binding to OX40 and a Fc region subunit,

(b) two light chains, each light chain comprising a VL and CL domain of a Fab fragment capable of specific binding to OX40, and

(c) a VH and a VL of a moiety capable specific binding to EpCAM, wherein the VH is connected to the C-terminus of one of the two heavy chains of (a), and wherein the VL is connected to the C-terminus of the other of the two heavy chains of (a).

In some embodiments, the bispecific antigen binding molecule comprises

(a) two heavy chains, each heavy chain comprising a VH and CHI domain of a Fab fragment capable of specific binding to OX40, and a Fc region subunit,

(b) two light chains, each light chain comprising a VL and CL domain of a Fab fragment capable of specific binding to OX40, (c) two Fab fragments capable of specific binding to EpCAM, wherein one of the Fab fragments is connected to the C-terminus of one of the two heavy chains of (a), and the other of the Fab fragments is connected to the C-terminus of the other of the two heavy chains of (a).

In some embodiments, the two Fab fragments capable of specific binding to EpCAM are crossover Fab fragments each comprising a VL-CHl chain and a VH-CL chain, and wherein one of the VL-CHl chains is connected to the C-terminus of one of the two heavy chains of (a), and the other of the VL-CHl chains is connected to the C-terminus of the other of the two heavy chains of (a).

In some embodiments, the bispecific antigen binding molecule comprises four Fab fragments capable of specific binding to OX40.

In some embodiments, each of the two heavy chains of (a) comprises two VH domains and two CHI domains of a Fab fragment capable of specific binding to OX40.

In some embodiments, one or more of the Fab fragments capable of specific binding to OX40 comprises

a CL domain comprising an arginine (R) at amino acid at position 123 (EU numbering) and a lysine (K) at amino acid at position 124 (EU numbering), and

a CHI domain comprising a glutamic acid (E) at amino acid at position 147 (EU numbering) and a glutamic acid (E) at amino acid at position 213 (EU numbering).

The present invention also provides a bispecific antigen binding molecule, comprising a first heavy chain comprising the amino acid sequence of SEQ ID NO: 183,

a second heavy chain comprising the amino acid sequence of SEQ ID NO: 184, and four light chains, each comprising the amino acid sequence of SEQ ID NO: 182.

The present invention also provides a bispecific antigen binding molecule, comprising two heavy chains, each comprising the amino acid sequence of SEQ ID NO: 186, two light chains, each comprising the amino acid sequence of SEQ ID NO: 187, and four light chains, each comprising the amino acid sequence of SEQ ID NO: 185.

The present invention also provides a bispecific antigen binding molecule, comprising a first heavy chain comprising the amino acid sequence of SEQ ID NO: 192,

a second heavy chain comprising the amino acid sequence of SEQ ID NO: 193, and four light chains, each comprising the amino acid sequence of SEQ ID NO: 191.

The present invention also provides a polynucleotide encoding the bispecific antigen binding molecule of the present invention. The present invention also provides a expression vector comprising the polynucleotide of the invention.

The present invention also provides a host cell comprising the polynucleotide of the invention, or the expression vector of the invention.

The present invention also provides a method of producing a bispecific antigen binding molecule, comprising culturing the host cell of the invention under conditions suitable for the expression of the bispecific antigen binding molecule, and isolating the bispecific antigen binding molecule.

The present invention also provides a pharmaceutical composition comprising the bispecific antigen binding molecule of the invention and at least one pharmaceutically acceptable excipient.

The present invention also provides the bispecific antigen binding molecule of the invention, or the pharmaceutical composition of the invention, for use as a medicament.

The present invention also provides the bispecific antigen binding molecule of the invention, or the pharmaceutical composition of the invention, for use

(i) in stimulating T cell response,

(ii) in supporting survival of activated T cells,

(iii) in the treatment of infections,

(iv) in the treatment of cancer,

(v) in delaying progression of cancer, or

(vi) in prolonging the survival of a patient suffering from cancer.

The present invention also provides the bispecific antigen binding molecule of the invention, or the pharmaceutical composition of the invention, for use in the treatment of cancer.

The present invention also provides the use of the bispecific antigen binding molecule of the invention, or the pharmaceutical composition of the invention, in the manufacture of a medicament for the treatment of cancer.

The present invention also provides a method of treating an individual having cancer comprising administering to the individual an effective amount of the bispecific antigen binding molecule of the invention, or the pharmaceutical composition of the invention.

The present invention also provides the bispecific antigen binding molecule of the invention, or the pharmaceutical composition of the invention, for use in up-regulating or prolonging cytotoxic T cell activity. The present invention also provides the use of the bispecific antigen binding molecule of the invention, or the pharmaceutical composition of the invention, in the manufacture of a medicament for up-regulating or prolonging cytotoxic T cell activity.

The present invention also provides method of up-regulating or prolonging cytotoxic T cell activity in an individual having cancer, comprising administering to the individual an effective amount of the bispecific antigen binding molecule of the invention, or the

pharmaceutical composition of the invention.

In some embodiments in accordance with various aspects of the present invention the individual is a mammal, particularly a human. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows the monomeric form of Fc-linked human OX40 antigen ECD that was used for the preparation of anti-human OX40 antibodies.

Figure 2A shows a schematic representation of the bispecific, tetravalent anti- OX40, monovalent anti EpCAM hu/muIgGl P329GLALA/DAPG kih 4+1 construct. Figure 2B shows a schematic representation of the bispecific, tetravalent anti-human OX40, bivalent anti-human EpCAM hulgGI P329GLALA kih 4+2 construct. Charged residues are depicted as stars.

Figures 3A to 3D show the binding of the bispecific, tetravalent anti-murine OX40, monovalent anti-murine EpCAM (4+1 muEpCAM); monospecific, tetravalent anti-murine OX40, non-targeted (4+1 control); or monospecific, bivalent anti-murine EpCAM IgG (muEpCAM IgG) to resting and activated murine CD4+ and CD8+ T cells. Figure 3A shows binding to activated CD4+ T cells, Figure 3B shows binding to activated CD8+ T cells, Figure 3C shows binding to resting CD4+ T cells, and Figure 3D shows binding to resting CD8+ T cells. Binding is shown as the median of fluorescence intensity (MFI) of PE-conjugated AffmiPure anti-mouse IgG Fcy- fragment-specific goat IgG F(ab")2 fragment, which is used as secondary detection antibody. MFI was measured by flow cytometry and baseline corrected by subtracting the MFI of the blank control. The x-axis shows the concentration of the antigen binding molecules. All of the antigen binding molecules comprising an OX40-binding domain bind to activated, OX40-expressing mouse CD4+ and CD8+ T cells. OX40 is not expressed on resting mouse CD4+ and CD8+ T cells (Figure 3C and 3D). After activation, OX40 is up-regulated on CD4+ and CD8+ T cells (Figure 3A and 3B).

Figure 4 shows the binding of the bispecific, tetravalent anti-murine OX40, monovalent anti-murine EpCAM (4+1 muEpCAM); bispecific, tetravalent anti-murine OX40, non-targeted (4+1 control); or monospecific, bivalent anti-murine EpCAM IgG (muEpCAM IgG) molecules to CT26muEpCAM and CT26muFAP cells. Figure 4A shows binding to CT26muEpCAM cells, which stably express murine EpCAM. Figure 4B shows binding to CT26muFAP cells, which stably express murine FAP, and which do not express murine EpCAM. Binding is shown as the median of fluorescence intensity (MFI) of FITC-labeled anti-mouse IgG Fey-specific goat IgG F(ab")2 fragment, which is used as secondary detection antibody. MFI was measured by flow cytometry and baseline corrected by subtracting the MFI of the blank control. The x-axis shows the concentration of the antigen binding molecules. The antigen binding molecules comprising a murine EpCAM-binding domain bind to CT26muEpCAM cells, but not to the CT26muFAP cells

Figures 5A to 5D show rescue of suboptimal TCR restimulation of preactivated murine CD4+ and CD8+ T cells with the bispecific, tetravalent anti-murine OX40, monovalent anti- murine EpCAM (4+1 muEpCAM); monospecific, tetravalent anti-murine OX40, non-targeted (4+1 control); or monospecific, bivalent anti-murine EpCAM IgG (muEpCAM IgG) molecules, in the presence of crosslinking by CT26muEpCAM cells, as determined by analysis of cell size and cell number. Figure 5A shows CD4+ T cell size as determined by forward scatter (FSC), Figure 5B shows CD8+ T cell size as determined by FSC, Figure 5C shows CD4+ T cell event count, and Figure 5D shows CD8+ T cell event count. Values were baseline-corrected to values for samples containing only the anti-murine CD3 (and not the OX40/EpCAM-targeted constructs).

Figures 6A to 6D show rescue of suboptimal TCR restimulation of preactivated murine CD4+ and CD8+ T cells with the bispecific, tetravalent anti-murine OX40, monovalent anti- murine EpCAM (4+1 muEpCAM); monospecific, tetravalent anti-murine OX40, non-targeted (4+1 control); or monospecific, bivalent anti-murine EpCAM IgG (muEpCAM IgG) molceules, in the presence of crosslinking by CT26muEpCAM cells, as determined by analysis for CD25 expression. Figure 6A shows the percentage of CD25+ cells within the CD4+ T cell population, Figure 6B shows the percentage of CD25+ cells within the CD8+ T cell population, Figure 6C shows the mean fluorescence intensity (MFI) for CD25 expressed on CD4+ T cells, and Figure 6D shows the MFI for CD25 expressed on CD8+ T cells. Values were baseline-corrected to values for samples containing only the anti-murine CD3 (and not the OX40/EpCAM-targeted constructs). Figures 7A to 7D show the binding of the bispecific, tetravalent anti-human OX40, bivalent or monovalent anti-human EpCAM (i.e. 4+2 or 4+1 format); monospecific, tetravalent anti-human OX40, non-targeted (4+1 control); or monospecific, bivalent anti-human EpCAM IgG (huEpCAM IgG) molecules to resting and activated human CD4+ and CD8+ T cells. Figure 7A shows binding to activated CD4+ T cells, Figure 7B shows binding to activated CD8+ T cells Figure 7C shows binding to resting CD4+ T cells, and Figure 7D shows binding to resting CD8+ T cells. Binding is shown as the median of fluorescence intensity (MFI) of FITC conjugated anti-human IgG F(ab') ₂ -fragment-specific goat IgG F(atT)2 fragment, which is used as secondary detection antibody. MFI was measured by flow cytometry and baseline corrected by subtracting the MFI of the blank control. The x-axis shows the concentration of the antigen binding molecules. All of the antigen binding molecules comprising an OX40-binding domain bind to activated, OX40 expressing human CD4+ T cells, and to a lower extent to activated human CD8+ T cells. OX40 is not expressed on resting human PBMCs (Figure 7C and 7D). After activation, OX40 is up-regulated on CD4+ and CD8+ T cells (Figure 7 A and 7B). OX40 expression on human CD8+ T cells is lower than on CD4+ T cells.

Figure 8 shows analysis of expression of human EpCAM on KATO-III,

NIH/3T3huEpCAM clone 44 cells and HeLa_huOX40_NFkB_Lucl reporter cells as determined by flow cytometry. Binding to huEpCAM was analysed by flow cytometry using by PE conjugated anti-huEpCAM antibody clone EBA-1 on the three cell lines tested.

HeLa_huOX40_NFkB_Lucl reporter cells are negative for human EpCAM, NIH/3T3huEpCAM clone 44 cells express human EpCAM, and KATO-III cells express high levels of human

EpCAM.

Figures 9A and 9B show the binding of the bispecific, tetravalent anti-human OX40, monovalent anti-human EpCAM (4+1 huEpCAM); bispecific, tetravalent anti-human OX40, bivalent anti-human EpCAM (4+2 huEpCAM); monospecific, tetravalent anti-murine OX40, non-targeted (4+1 control); and monospecific, bivalent anti-human EpCAM IgG (huEpCAM IgG) molecules to KATO-II cells and A549 NLR cells. Figure 9A shows binding to KATO-II cells, which express human EpCAM. Figure 9B shows binding to A549 NLR cells, which do not express human EpCAM. Binding is shown as the median of fluorescence intensity (MFI) of FITC conjugated anti-human IgG F(ab')2-fragment-specific goat IgG F(ab ^" )2 fragment, which is used as secondary detection antibody. MFI was measured by flow cytometry and baseline corrected by subtracting the MFI of the blank control. The x-axis shows the concentration of the antigen binding molecules.

Figures 10A to 10D show activation of NFKB by the bispecific, tetravalent anti-human OX40, monovalent anti-human EpCAM (4+1 huEpCAM); bispecific, tetravalent anti-human OX40, bivalent anti-human EpCAM (4+2 huEpCAM); monospecific, tetravalent anti-murine OX40, non-targeted (4+1 control); and monospecific, bivalent anti-human EpCAM IgG

(huEpCAM IgG) molecules. Figure 10A shows NFKB activation in OX40 ⁺ HeLa reporter cells by antigen binding molecules in the absence of crosslinking. Figure 10B shows NFKB activation in OX40 ⁺ HeLa reporter cells by antigen binding molecules in the presence of crosslinking by anti- human Fc specific secondary antibody. Figure IOC shows NFKB activation in OX40 ⁺ HeLa reporter cells by antigen binding molecules in the presence of crosslinking by 3T3huEpCAM cells. NF-KB-mediated luciferase activity was characterized by plotting the emitted relative light units (RLUs), measured during 500 ms, versus the concentration of the antigen binding molecule (in nM). RLUs are emitted due to luciferase-mediated oxidation of luciferin to oxyluciferin. The values were baseline-corrected by subtracting the RLUs for a 'blank control' condition. Figure 10D shows the data of Figures 10A to IOC represented as area under the curve (AUC). Figures 11A to 11D show rescue of suboptimal TCR restihulation of preactivated human

CD4+ and CD8+ T cells with the bispecific, tetravalent anti-human OX40, monovalent anti- human EpCAM (4+1 huEpCAM); bispecific, tetravalent anti-human OX40, bivalent anti-human EpCAM (4+2 huEpCAM); monospecific, tetravalent anti-human OX40, non-targeted (4+1 control); or monospecific, bivalent anti-human EpCAM IgG (huEpCAM IgG), in the presence of crosslinking by human EpCAM-expressing KATO-III cells, as determined by analysis of cell size and cell number. Figure 11A shows CD4+ T cell size as determined by forward scatter (FSC), Figure 11B shows CD8+ T cell size as determined by FSC, Figure 11C shows CD4+ T cell event count, and Figure 11D shows CD8+ T cell event count. Values were baseline- corrected to values for samples containing only the anti-human CD3 (and not the

OX40/EpCAM-targeted constructs).

Figures 12A to 12D show rescue of suboptimal TCR restihulation of preactivated human CD4+ and CD8+ T cells with the bispecific, tetravalent anti-human OX40, monovalent anti- human EpCAM (4+1 huEpCAM); monospecific, tetravalent anti-human OX40, non-targeted (4+1 control); or monospecific, bivalent anti- human EpCAM IgG (huEpCAM IgG), in the presence of crosslinking by human EpCAM-expressing KATO-III cells, as determined by analysis of CD25 expression. Figure 12A shows the percentage of CD25+ cells within the CD4+ T cell population, Figure 12B shows the percentage of CD25+ cells within the CD8+ T cell population, Figure 12C shows the mean fluorescence intensity (MFI) for CD25 expressed on CD4+ T cells, and Figure 12D shows the MFI for CD25 expressed on CD8+ T cells. Values were baseline-corrected to values for samples containing only the anti-human CD3 (and not the OX40/EpCAM-targeted constructs).

Figures 13A to 13D show rescue of suboptimal TCR restihulation of preactivated human CD4+ and CD8+ T cells with the bispecific, tetravalent anti-human OX40, monovalent anti- human EpCAM (4+1 huEpCAM); bispecific, tetravalent anti-human OX40, bivalent anti-human EpCAM (4+2 huEpCAM); monospecific, tetravalent anti-human OX40, non-targeted (4+1 control); or monospecific, bivalent anti-human EpCAM IgG (huEpCAM IgG), in the presence of crosslinking by human EpCAM-expressing 3T3huEpCAM cells, as determined by analysis of cell size and cell number. Figure 13A shows CD4+ T cell size as determined by forward scatter (FSC), Figure 13B shows CD8+ T cell size as determined by FSC, Figure 13C shows CD4+ T cell event count, and Figure 13D shows CD8+ T cell event count. Values were baseline- corrected to values for samples containing only the anti-human CD3 (and not the OX40/EpCAM-targeted constructs).

Figures 14A to 14D show rescue of suboptimal TCR restihulation of preactivated human CD4+ and CD8+ T cells with the bispecific, tetravalent anti-human OX40, monovalent anti- human EpCAM (4+1 huEpCAM); monospecific, tetravalent anti-human OX40, non-targeted (4+1 control); or monospecific, bivalent anti- human EpCAM IgG (huEpCAM IgG), in the presence of crosslinking by human EpCAM-expressing 3T3huEpCAM cells, as determined by analysis of CD25 expression. Figure 14A shows the percentage of CD25+ cells within the CD4+ T cell population, Figure 14B shows the percentage of CD25+ cells within the CD8+ T cell population, Figure 14C shows the mean fluorescence intensity (MFI) for CD25 expressed on CD4+ T cells, and Figure 14D shows the MFI for CD25 expressed on CD8+ T cells. Values were baseline-corrected to values for samples containing only the anti-human CD3 (and not the OX40/EpCAM-targeted constructs).

DETAILED DESCRIPTION OF THE INVENTION

Definitions

Unless defined otherwise, technical and scientific terms used herein have the same meaning as generally used in the art to which this invention belongs. For purposes of interpreting this specification, the following definitions will apply and whenever appropriate, terms used in the singular will also include the plural and vice versa.

As used herein, the term "antigen binding molecule" refers in its broadest sense to a molecule that specifically binds an antigenic determinant. Examples of antigen binding molecules are antibodies, antibody fragments and scaffold antigen binding proteins.

As used herein, the term "moiety capable of specific binding to epithelial cell adhesion molecule (EpCAM)" refers to a polypeptide molecule that specifically binds to EpCAM. In a particular aspect, the antigen binding moiety is able to direct the entity to which it is attached to a target site, for example to a specific type of tumor cell or tumor stroma bearing EpCAM.

Moieties capable of specific binding to EpCAM include antibodies and fragments thereof as further defined herein. In addition, moieties capable of specific binding to EpCAM include scaffold antigen binding proteins as further defined herein, e.g. binding domains which are based on designed repeat proteins or designed repeat domains (see e.g. WO 2002/020565).

In relation to an antibody or fragment thereof, the term "moiety capable of specific binding to epithelial cell adhesion molecule (EpCAM)" refers to the part of the molecule that comprises the area which specifically binds to and is complementary to part or all of EpCAM. A moiety capable of specific binding to EpCAM may be provided, for example, by one or more antibody variable domains (also called antibody variable regions). Particularly, a moiety capable of specific binding to EpCAM comprises an antibody light chain variable region (VL) and an antibody heavy chain variable region (VH). In some embodiments, the "moiety capable of specific binding to epithelial cell adhesion molecule (EpCAM)" may be an scFv, a Fab fragment or a cross-Fab fragment.

The term "moiety capable of specific binding to OX40" refers to a polypeptide molecule that specifically binds to OX40. In one aspect, the antigen binding moiety is able to activate signaling through OX40. Moieties capable of specific binding to OX40 include antibodies and fragments thereof as further defined herein. In addition, moieties capable of specific binding to OX40 include scaffold antigen binding proteins as further defined herein, e.g. binding domains which are based on designed repeat proteins or designed repeat domains (see e.g. WO

2002/020565). Particularly, a moiety capable of specific binding to OX40 comprises an antibody light chain variable region (VL) and an antibody heavy chain variable region (VH). In a particular aspect, the "moiety capable of specific binding to OX40" may be a Fab fragment, a cross-Fab fragment or an scFv.

The term "antibody" herein is used in the broadest sense and encompasses various antibody structures, including but not limited to monoclonal antibodies, polyclonal antibodies, monospecific and multispecific antibodies (e.g., bispecific antibodies), and antibody fragments so long as they exhibit the desired antigen-binding activity.

The term "monoclonal antibody" as used herein refers to an antibody obtained from a population of substantially homogeneous antibodies, i.e., the individual antibodies comprising the population are identical and/or bind the same epitope, except for possible variant antibodies, e.g. containing naturally occurring mutations or arising during production of a monoclonal antibody preparation, such variants generally being present in minor amounts. In contrast to polyclonal antibody preparations, which typically include different antibodies directed against different determinants (epitopes), each monoclonal antibody of a monoclonal antibody preparation is directed against a single determinant on an antigen. The term "monospecific" antibody as used herein denotes an antibody that has one or more binding sites each of which bind to the same epitope of the same antigen. The term

"bispecific" means that the antigen binding molecule is able to specifically bind to at least two distinct antigenic determinants. A bispecific antigen binding molecule comprises at least two antigen binding sites, each of which is specific for a different antigenic determinant. In certain embodiments the bispecific antigen binding molecule is capable of simultaneously binding two antigenic determinants, particularly two antigenic determinants expressed on two distinct cells. For example, the antigen binding molecules of the present invention are bispecific, comprising a moiety capable of specific binding to OX40, and a moiety capable of specific binding to EpCAM.

The term "valent" as used within the current application denotes the presence of a specified number of binding sites in an antigen binding molecule. As such, the terms "bivalent", "terra valent", and "hexavalent" denote the presence of two binding sites, four binding sites, and six binding sites, respectively, in an antigen binding molecule. Valency of an antigen binding molecule may also be expressed in relation to the number of binding sites for a given antigenic determinant. For example, in some embodiments the antigen binding molecules of the present invention are tetravalent with respect to OX40, and bivalent with respect to EpCAM (i.e. 4+2).

The terms "full length antibody", "intact antibody", and "whole antibody" are used herein interchangeably to refer to an antibody having a structure substantially similar to a native antibody structure. "Native antibodies" refer to naturally occurring immunoglobulin molecules with varying structures. For example, native IgG-class antibodies are heterotetrameric

glycoproteins of about 150,000 daltons, composed of two light chains and two heavy chains that are disulfide-bonded. From N- to C-terminus, each heavy chain has a variable region (VH), also called a variable heavy domain or a heavy chain variable domain, followed by three constant domains (CHI, CH2, and CH3), also called a heavy chain constant region. Similarly, from N- to C-terminus, each light chain has a variable region (VL), also called a variable light domain or a light chain variable domain, followed by a light chain constant domain (CL), also called a light chain constant region. The heavy chain of an antibody may be assigned to one of five types, called a (IgA), δ (IgD), ε (IgE), γ (IgG), or μ (IgM), some of which may be further divided into subtypes, e.g. γΐ (IgGl), γ2 (IgG2), γ3 (IgG3), γ4 (IgG4), al (IgAl) and a2 (IgA2). The light chain of an antibody may be assigned to one of two types, called kappa (κ) and lambda (λ), based on the amino acid sequence of its constant domain.

An "antibody fragment" refers to a molecule other than an intact antibody that comprises a portion of an intact antibody that binds the antigen to which the intact antibody binds.

Examples of antibody fragments include but are not limited to Fv, Fab, Fab', Fab'-SH, F(ab') ₂ ; diabodies, triabodies, tetrabodies, cross-Fab fragments; linear antibodies; single-chain antibody molecules (e.g. scFv); and single domain antibodies. For a review of certain antibody fragments, see Hudson et al, Nat Med 9, 129-134 (2003). For a review of scFv fragments, see e.g.

Pluckthun, in The Pharmacology of Monoclonal Antibodies, vol. 113, Rosenburg and Moore eds., Springer- Verlag, New York, pp. 269-315 (1994); see also WO 93/16185; and U.S. Patent Nos. 5,571,894 and 5,587,458. For discussion of Fab and F(ab')2 fragments comprising salvage receptor binding epitope residues and having increased in vivo half-life, see U.S. Patent No.

5,869,046. Diabodies are antibody fragments with two antigen-binding sites that may be bivalent or bispecific, see, for example, EP 404,097; WO 1993/01161; Hudson et al, Nat Med 9, 129-134 (2003); and Hollinger et al, Proc Natl Acad Sci USA 90, 6444-6448 (1993). Triabodies and tetrabodies are also described in Hudson et al, Nat Med 9, 129-134 (2003). Single-domain antibodies are antibody fragments comprising all or a portion of the heavy chain variable domain or all or a portion of the light chain variable domain of an antibody. In certain embodiments, a single-domain antibody is a human single-domain antibody (Domantis, Inc., Waltham, MA; see e.g. U.S. Patent No. 6,248,516 Bl). Antibody fragments can be made by various techniques, including but not limited to proteolytic digestion of an intact antibody as well as production by recombinant host cells (e.g. E. coli or phage), as described herein. Papain digestion of intact antibodies produces two identical antigen-binding fragments, called "Fab" fragments containing each the heavy- and light-chain variable domains and also the constant domain of the light chain and the first constant domain (CHI) of the heavy chain. As used herein, Thus, the term "Fab fragment" refers to an antibody fragment comprising a light chain fragment comprising a VL and a constant domain of a light chain (CL), and a VH and a first constant domain (CHI) of a heavy chain. Fab' fragments differ from Fab fragments by the addition of a few residues at the carboxy terminus of the heavy chain CHI domain including one or more cysteins from the antibody hinge region. Fab'-SH are Fab' fragments wherein the cysteine residue(s) of the constant domains bear a free thiol group. Pepsin treatment yields an F(ab') ₂ fragment that has two antigen-combining sites (two Fab fragments) and a part of the Fc region. According to the present invention, the term "Fab fragment" also includes "cross-Fab fragments" or "crossover Fab fragments" as defined below.

The term "cross-Fab fragment" or "xFab fragment" or "crossover Fab fragment" refers to a Fab fragment, wherein either the variable regions or the constant regions of the heavy and light chain are exchanged. Two different chain compositions of a cross-Fab molecule are possible and comprised in the bispecific antibodies of the invention: On the one hand, the variable regions of the Fab heavy and light chain are exchanged, i.e. the crossover Fab molecule comprises a peptide chain composed of the light chain variable region (VL) and the heavy chain constant region (CHI), and a peptide chain composed of the heavy chain variable region (VH) and the light chain constant region (CL). This crossover Fab molecule is also referred to as CrossFab (VLVH). On the other hand, when the constant regions of the Fab heavy and light chain are exchanged, the crossover Fab molecule comprises a peptide chain composed of the heavy chain variable region (VH) and the light chain constant region (CL), and a peptide chain composed of the light chain variable region (VL) and the heavy chain constant region (CHI). This crossover Fab molecule is also referred to as CrossFab (CLCHI). A "single chain Fab fragment" or "scFab" is a polypeptide consisting of an antibody heavy chain variable domain (VH), an antibody constant domain 1 (CHI), an antibody light chain -Invariable domain (VL), an antibody light chain constant domain (CL) and a linker, wherein said antibody domains and said linker have one of the following orders in N-terminal to C-terminal direction: a) VH-CH1 -linker- VL-CL, b) VL-CL-linker-VH-CHl, c) VH-CL-linker-VL-CHl or d) VL-CH1 -linker- VH-CL; and wherein said linker is a polypeptide of at least 30 amino acids, preferably between 32 and 50 amino acids. Said single chain Fab fragments are stabilized via the natural disulfide bond between the CL domain and the CHI domain. In addition, these single chain Fab molecules might be further stabilized by generation of interchain disulfide bonds via insertion of cysteine residues (e.g. position 44 in the variable heavy chain and position 100 in the variable light chain according to Kabat numbering). A "crossover single chain Fab fragment" or "x-scFab" is a is a polypeptide consisting of an antibody heavy chain variable domain (VH), an antibody constant domain 1 (CHI), an antibody light chain variable domain (VL), an antibody light chain constant domain (CL) and a linker, wherein said antibody domains and said linker have one of the following orders in N- terminal to C-terminal direction: a) VH-CL-linker-VL-CHl and b) VL-CH1 -linker- VH-CL; wherein VH and VL form together an antigen-binding site which binds specifically to an antigen and wherein said linker is a polypeptide of at least 30 amino acids. In addition, these x-scFab molecules might be further stabilized by generation of interchain disulfide bonds via insertion of cysteine residues (e.g. position 44 in the variable heavy chain and position 100 in the variable light chain according to Kabat numbering). A "single-chain variable fragment (scFv)" is a fusion protein of the variable regions of the heavy (V _H ) and light chains (V _L ) of an antibody, connected with a short linker peptide of ten to about 25 amino acids. The linker is usually rich in glycine for flexibility, as well as serine or threonine for solubility, and can either connect the N-terminus of the V _H with the C-terminus of the V _L , or vice versa. This protein retains the specificity of the original antibody, despite removal of the constant regions and the introduction of the linker. scFv antibodies are, e.g. described in Houston, J.S., Methods in Enzymol. 203 (1991) 46-96). In addition, antibody fragments comprise single chain polypeptides having the characteristics of a VH, namely being able to assemble together with a VL, or of a VL, namely being able to assemble together with a VH to a functional antigen binding site and thereby providing the antigen binding property of full length antibodies.

"Scaffold antigen binding proteins" are known in the art, for example, fibronectin and designed ankyrin repeat proteins (DARPins) have been used as alternative scaffolds for antigen- binding domains, see, e.g., Gebauer and Skerra, Engineered protein scaffolds as next-generation antibody therapeutics. Curr Opin Chem Biol 13:245-255 (2009) and Stumpp et al., Darpins: A new generation of protein therapeutics. Drug Discovery Today 13: 695-701 (2008). In one aspect of the invention, a scaffold antigen binding protein is selected from the group consisting of CTLA-4 (Evibody), Lipocalins (Anticalin), a Protein A-derived molecule such as Z-domain of Protein A (Affibody), an A-domain (Avimer/Maxibody), a serum transferrin (trans-body); a designed ankyrin repeat protein (DARPin), a variable domain of antibody light chain or heavy chain (single-domain antibody, sdAb), a variable domain of antibody heavy chain (nanobody, aVH), V _NAR fragments, a fibronectin (AdNectin), a C-type lectin domain (Tetranectin); a variable domain of a new antigen receptor beta- lactamase (V _NAR fragments), a human gamma- crystallin or ubiquitin (Affilin molecules); a kunitz type domain of human protease inhibitors, microbodies such as the proteins from the knottin family, peptide aptamers and fibronectin (adnectin). CTLA-4 (Cytotoxic T Lymphocyte-associated Antigen 4) is a CD28-family receptor expressed on mainly CD4 ⁺ T-cells. Its extracellular domain has a variable domain- like Ig fold. Loops corresponding to CDRs of antibodies can be substituted with heterologous sequence to confer different binding properties. CTLA-4 molecules engineered to have different binding specificities are also known as Evibodies (e.g. US7166697B1). Evibodies are around the same size as the isolated variable region of an antibody (e.g. a domain antibody). For further details see Journal of Immunological Methods 248 (1-2), 31-45 (2001). Lipocalins are a family of extracellular proteins which transport small hydrophobic molecules such as steroids, bilins, retinoids and lipids. They have a rigid beta-sheet secondary structure with a number of loops at the open end of the conical structure which can be engineered to bind to different target antigens. Anticalins are between 160-180 amino acids in size, and are derived from lipocalins. For further details see Biochim Biophys Acta 1482: 337-350 (2000), US7250297B1 and US20070224633. An affibody is a scaffold derived from Protein A of Staphylococcus aureus which can be engineered to bind to antigen. The domain consists of a three-helical bundle of approximately 58 amino acids. Libraries have been generated by randomization of surface residues. For further details see Protein Eng. Des. Sel. 2004, 17, 455-462 and EP 1641818A1. Avimers are multidomain proteins derived from the A-domain scaffold family. The native domains of approximately 35 amino acids adopt a defined disulfide bonded structure. Diversity is generated by shuffling of the natural variation exhibited by the family of A-domains. For further details see Nature Biotechnology 23(12), 1556 - 1561 (2005) and Expert Opinion on Investigational Drugs 16(6), 909-917 (June 2007). A transferrin is a monomeric serum transport glycoprotein.

Transferrins can be engineered to bind different target antigens by insertion of peptide sequences in a permissive surface loop. Examples of engineered transferrin scaffolds include the Trans- body. For further details see J. Biol. Chem 274, 24066-24073 (1999). Designed Ankyrin Repeat Proteins (DARPins) are derived from Ankyrin which is a family of proteins that mediate attachment of integral membrane proteins to the cytoskeleton. A single ankyrin repeat is a 33 residue motif consisting of two alpha-helices and a beta-turn. They can be engineered to bind different target antigens by randomizing residues in the first alpha-helix and a beta-turn of each repeat. Their binding interface can be increased by increasing the number of modules (a method of affinity maturation). For further details see J. Mol. Biol. 332, 489-503 (2003), PNAS 100(4), 1700-1705 (2003) and J. Mol. Biol. 369, 1015-1028 (2007) and US20040132028Al . A single- domain antibody is an antibody fragment consisting of a single monomeric variable antibody domain. The first single domains were derived from the variable domain of the antibody heavy chain from camelids (nanobodies or V _H H fragments). Furthermore, the term single-domain antibody includes an autonomous human heavy chain variable domain (aVH) or V _NAR fragments derived from sharks. Fibronectin is a scaffold which can be engineered to bind to antigen.

Adnectins consists of a backbone of the natural amino acid sequence of the 10th domain of the 15 repeating units of human fibronectin type III (FN3). Three loops at one end of the .beta.- sandwich can be engineered to enable an Adnectin to specifically recognize a therapeutic target of interest. For further details see Protein Eng. Des. Sel. 18, 435- 444 (2005), US20080139791, WO2005056764 and US6818418B1. Peptide aptamers are combinatorial recognition molecules that consist of a constant scaffold protein, typically thioredoxin (TrxA) which contains a constrained variable peptide loop inserted at the active site. For further details see Expert Opin. Biol. Ther. 5, 783-797 (2005). Microbodies are derived from naturally occurring microproteins of 25-50 amino acids in length which contain 3-4 cysteine bridges - examples of microproteins include KalataBI and conotoxin and knottins. The microproteins have a loop which can beengineered to include upto 25 amino acids without affecting the overall fold of the

microprotein. For further details of engineered knottin domains, see WO2008098796.

An "antigen binding molecule that binds to the same epitope" as a reference molecule refers to an antigen binding molecule that blocks binding of the reference molecule to its antigen in a competition assay by 50% or more, and conversely, the reference molecule blocks binding of the antigen binding molecule to its antigen in a competition assay by 50% or more.

The term "antigen binding domain" or "antigen-binding site" refers to the part of an antigen binding molecule that comprises the area which specifically binds to and is

complementary to part or all of an antigen. Where an antigen is large, an antigen binding molecule may only bind to a particular part of the antigen, which part is termed an epitope. An antigen binding domain may be provided by, for example, one or more variable domains (also called variable regions). Preferably, an antigen binding domain comprises an antibody light chain variable region (VL) and an antibody heavy chain variable region (VH). As used herein, the term "antigenic determinant" is synonymous with "antigen" and

"epitope," and refers to a site (e.g. a contiguous stretch of amino acids or a conformational configuration made up of different regions of non-contiguous amino acids) on a polypeptide macromolecule to which an antigen binding moiety binds, forming an antigen binding moiety- antigen complex. Useful antigenic determinants can be found, for example, on the surfaces of tumor cells, on the surfaces of virus-infected cells, on the surfaces of other diseased cells, on the surface of immune cells, free in blood serum, and/or in the extracellular matrix (ECM). The proteins useful as antigens herein can be any native form the proteins from any vertebrate source, including mammals such as primates (e.g. humans) and rodents (e.g. mice and rats), unless otherwise indicated. In a particular embodiment the antigen is a human protein. Where reference is made to a specific protein herein, the term encompasses the "full-length", unprocessed protein as well as any form of the protein that results from processing in the cell. The term also encompasses naturally occurring variants of the protein, e.g. splice variants or allelic variants.

By "specific binding" is meant that the binding is selective for the antigen and can be discriminated from unwanted or non-specific interactions. The ability of an antigen binding molecule to bind to a specific antigen can be measured either through an enzyme-linked immunosorbent assay (ELISA) or other techniques familiar to one of skill in the art, e.g. Surface Plasmon Resonance (SPR) technique (analyzed on a BIAcore instrument) (Liljeblad et al., Glyco J 17, 323-329 (2000)), and traditional binding assays (Heeley, Endocr Res 28, 217-229 (2002)). In one embodiment, the extent of binding of an antigen binding molecule to an unrelated protein is less than about 10% of the binding of the antigen binding molecule to the antigen as measured, e.g. by SPR. In certain embodiments, an molecule that binds to the antigen has a dissociation constant (Kd) of < 1 μΜ, < 100 nM, < 10 nM, < 1 nM, < 0.1 nM, < 0.01 nM, or < 0.001 nM (e.g. 10 ^~8 M or less, e.g. from 10 ^~8 M to 10 ^~13 M, e.g. from 10 ^"9 M to 10 ^~13 M).

"Affinity" or "binding affinity" refers to the strength of the sum total of non-covalent interactions between a single binding site of a molecule (e.g. an antibody) and its binding partner (e.g. an antigen). Unless indicated otherwise, as used herein, "binding affinity" refers to intrinsic binding affinity which reflects a 1 : 1 interaction between members of a binding pair (e.g.

antibody and antigen). The affinity of a molecule X for its partner Y can generally be represented by the dissociation constant (Kd), which is the ratio of dissociation and association rate constants (koff and kon, respectively). Thus, equivalent affinities may comprise different rate constants, as long as the ratio of the rate constants remains the same. Affinity can be measured by common methods known in the art, including those described herein. A particular method for measuring affinity is Surface Plasmon Resonance (SPR).

An "affinity matured" antibody refers to an antibody with one or more alterations in one or more hypervariable regions (HVRs), compared to a parent antibody which does not possess such alterations, such alterations resulting in an improvement in the affinity of the antibody for antigen.

The term "epithelial cell adhesion molecule (EpCAM)" refers to any native EpCAM from any vertebrate source, including mammals such as primates (e.g. humans) non-human primates (e.g. cynomolgus monkeys) and rodents (e.g. mice and rats), unless otherwise indicated. The term encompasses "full-length," unprocessed EpCAM as well as any form of EpCAM that results from processing in the cell. The term also encompasses naturally occurring variants of EpCAM, e.g., splice variants or allelic variants. In one embodiment, the antigen binding molecule of the invention is capable of specific binding to human, mouse and/or cynomolgus EpCAM. The amino acid sequence of human EpCAM is shown in UniProt (www.uniprot.org) accession no. P16422 (version 167, SEQ ID NO:68), or NCBI (www.ncbi.nlm.nih.gov/) RefSeq NP 002345.2. The amino acid sequence of mouse EpCAM is shown in UniProt

(www.uniprot.org) accession no. Q99JW5 (version 111, SEQ ID NO:75), or NCBI

(www.ncbi.nlm.nih.gov ) RefSeq NP_032558.2.

In certain embodiments, the antigen binding molecule of the present invention comprises a moiety capable of specific binding to the extracellular domain (ECD) of EpCAM. In some embodiments, a moiety capable of specific binding to EpCAM binds to SEQ ID NO:49. In some embodiments, a moiety capable of specific binding to EpCAM binds to SEQ ID NO:50.

The term "variable region" or "variable domain" refers to the domain of an antibody heavy or light chain that is involved in binding the antigen binding molecule to antigen. The variable domains of the heavy chain and light chain (VH and VL, respectively) of a native antibody generally have similar structures, with each domain comprising four conserved framework regions (FRs) and three hypervariable regions (HVRs). See, e.g., Kindt et al, Kuby Immunology, 6th ed., W.H. Freeman and Co., page 91 (2007). A single VH or VL may be sufficient to confer antigen-binding specificity. The term "hypervariable region" or "HVR," as used herein refers to each of the regions of an antibody variable domain which are hypervariable in sequence and/or form structurally defined loops ("hypervariable loops"). Generally, native four-chain antibodies comprise six HVRs; three in the VH (HI, H2, H3), and three in the VL (LI, L2, L3). HVRs generally comprise amino acid residues from the hypervariable loops and/or from the "complementarity determining regions" (CDRs), the latter being of highest sequence variability and/or involved in antigen recognition. Exemplary hypervariable loops occur at amino acid residues 26-32 (LI), 50- 52 (L2), 91-96 (L3), 26-32 (HI), 53-55 (H2), and 96-101 (H3). (Chothia and Lesk, J. Mol. Biol. 196:901-917 (1987).) Exemplary CDRs (CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2, and CDR-H3) occur at amino acid residues 24-34 of LI, 50-56 of L2, 89-97 of L3, 31-35B of HI, 50-65 of H2, and 95-102 of H3. (Kabat et al., Sequences of Proteins of Immunological Interest, 5th Ed. Public Health Service, National Institutes of Health, Bethesda, MD (1991).)

Hypervariable regions (HVRs) are also referred to as complementarity determining regions (CDRs), and these terms are used herein interchangeably in reference to portions of the variable region that form the antigen binding regions. This particular region has been described by Kabat et al, U.S. Dept. of Health and Human Services, "Sequences of Proteins of Immunological Interest" (1983) and by Chothia et al, J. Mol. Biol. 196:901-917 (1987), where the definitions include overlapping or subsets of amino acid residues when compared against each other.

Nevertheless, application of either definition to refer to a CDR of an antibody or variants thereof is intended to be within the scope of the term as defined and used herein. The appropriate amino acid residues which encompass the CDRs as defined by each of the above cited references are set forth below in Table A as a comparison. The exact residue numbers which encompass a particular CDR will vary depending on the sequence and size of the CDR. Those skilled in the art can routinely determine which residues comprise a particular CDR given the variable region amino acid sequence of the antibody.

TABLE A. CDR Definitions ¹

1 Numbering of all CDR definitions in Table A is according to the numbering

conventions set forth by Kabat et al. (see below).

2 "AbM" with a lowercase "b" as used in Table A refers to the CDRs as

defined by Oxford Molecular's "AbM" antibody modeling software.

Kabat et al. also defined a numbering system for variable region sequences that is applicable to any antibody. One of ordinary skill in the art can unambiguously assign this system of "Kabat numbering" to any variable region sequence, without reliance on any experimental data beyond the sequence itself. As used herein, "Kabat numbering" refers to the numbering system set forth by Kabat et al, U.S. Dept. of Health and Human Services, "Sequence of Proteins of Immunological Interest" (1983). Unless otherwise specified, references to the numbering of specific amino acid residue positions in an antibody variable region are according to the Kabat numbering system.

With the exception of CDRl in VH, CDRs generally comprise the amino acid residues that form the hypervariable loops. CDRs also comprise "specificity determining residues," or "SDRs," which are residues that contact antigen. SDRs are contained within regions of the CDRs called abbreviated-CDRs, or a-CDRs. Exemplary a-CDRs (a-CDR-Ll, a-CDR-L2, a-CDR-L3, a- CDR-H1 , a-CDR-H2, and a-CDR-H3) occur at amino acid residues 31-34 of LI , 50-55 of L2, 89-96 of L3, 31-35B of HI, 50-58 of H2, and 95-102 of H3. (See Almagro and Fransson, Front. Biosci. 13: 1619-1633 (2008).) Unless otherwise indicated, HVR residues and other residues in the variable domain (e.g., FR residues) are numbered herein according to Kabat et al., supra.

"Framework" or "FR" refers to variable domain residues other than hypervariable region (HVR) residues. The FR of a variable domain generally consists of four FR domains: FR1, FR2, FR3, and FR4. Accordingly, the HVR and FR sequences generally appear in the following sequence in VH (or VL): FR1-H1(L1)-FR2-H2(L2)-FR3-H3(L3)-FR4.

The term "chimeric" antibody refers to an antibody in which a portion of the heavy and/or light chain is derived from a particular source or species, while the remainder of the heavy and/or light chain is derived from a different source or species. The "class" of an antibody refers to the type of constant domain or constant region possessed by its heavy chain. There are five major classes of antibodies: IgA, IgD, IgE, IgG, and IgM, and several of these may be further divided into subclasses (isotypes), e.g. IgGi, IgG ₂ , IgG ₃ , IgG ₄ , IgAi, and IgA ₂ . The heavy chain constant domains that correspond to the different classes of immunoglobulins are called α, δ, ε, γ, and μ respectively. A "humanized" antibody refers to a chimeric antibody comprising amino acid residues from non-human HVRs and amino acid residues from human FRs. In certain embodiments, a humanized antibody will comprise substantially all of at least one, and typically two, variable domains, in which all or substantially all of the HVRs (e.g., CDRs) correspond to those of a non- human antibody, and all or substantially all of the FRs correspond to those of a human antibody. A humanized antibody optionally may comprise at least a portion of an antibody constant region derived from a human antibody. A "humanized form" of an antibody, e.g., a non-human antibody, refers to an antibody that has undergone humanization. Other forms of "humanized antibodies" encompassed by the present invention are those in which the constant region has been additionally modified or changed from that of the original antibody to generate the properties according to the invention, especially in regard to Clq binding and/or Fc receptor (FcR) binding.

A "human" antibody is one which possesses an amino acid sequence which corresponds to that of an antibody produced by a human or a human cell or derived from a non-human source that utilizes human antibody repertoires or other human antibody-encoding sequences. This definition of a human antibody specifically excludes a humanized antibody comprising non- human antigen-binding residues.

The term "Fc domain" or "Fc region" herein is used to define a C-terminal region of an antibody heavy chain that contains at least a portion of the constant region. The term includes native sequence Fc regions and variant Fc regions. An IgG Fc region comprises an IgG CH2 and an IgG CH3 domain. The "CH2 domain" of a human IgG Fc region usually extends from an amino acid residue at about position 231 to an amino acid residue at about position 340. In one embodiment, a carbohydrate chain is attached to the CH2 domain. The CH2 domain herein may be a native sequence CH2 domain or variant CH2 domain. The "CH3 domain" comprises the stretch of residues C-terminal to a CH2 domain in an Fc region (i.e. from an amino acid residue at about position 341 to an amino acid residue at about position 447 of an IgG). The CH3 region herein may be a native sequence CH3 domain or a variant CH3 domain (e.g. a CH3 domain with an introduced "protuberance" ("knob") in one chain thereof and a corresponding introduced "cavity" ("hole") in the other chain thereof; see US Patent No. 5,821,333, expressly incorporated herein by reference). Such variant CH3 domains may be used to promote heterodimerization of two non- identical antibody heavy chains as herein described. In one embodiment, a human IgG heavy chain Fc region extends from Cys226, or from Pro230, to the carboxyl-terminus of the heavy chain. However, the C-terminal lysine (Lys447) of the Fc region may or may not be present. Unless otherwise specified herein, numbering of amino acid residues in the Fc region or constant region is according to the EU numbering system, also called the EU index, as described in Kabat et al, Sequences of Proteins of Immunological Interest, 5th Ed. Public Health Service, National Institutes of Health, Bethesda, MD, 1991.

The "knob-into-hole" technology is described e.g. in US 5,731,168; US 7,695,936;

Ridgway et al, Prot Eng 9, 617-621 (1996) and Carter, J Immunol Meth 248, 7-15 (2001). Generally, the method involves introducing a protuberance ("knob") at the interface of a first polypeptide and a corresponding cavity ("hole") in the interface of a second polypeptide, such that the protuberance can be positioned in the cavity so as to promote heterodimer formation and hinder homodimer formation. Protuberances are constructed by replacing small amino acid side chains from the interface of the first polypeptide with larger side chains (e.g. tyrosine or tryptophan). Compensatory cavities of identical or similar size to the protuberances are created in the interface of the second polypeptide by replacing large amino acid side chains with smaller ones (e.g. alanine or threonine). The protuberance and cavity can be made by altering the nucleic acid encoding the polypeptides, e.g. by site-specific mutagenesis, or by peptide synthesis. In a specific embodiment a knob modification comprises the amino acid substitution T366W in one of the two subunits of the Fc domain, and the hole modification comprises the amino acid substitutions T366S, L368A and Y407V in the other one of the two subunits of the Fc domain. In a further specific embodiment, the subunit of the Fc domain comprising the knob modification additionally comprises the amino acid substitution S354C, and the subunit of the Fc domain comprising the hole modification additionally comprises the amino acid substitution Y349C. Introduction of these two cysteine residues results in the formation of a disulfide bridge between the two subunits of the Fc region, thus further stabilizing the dimer (Carter, J Immunol Methods 248, 7-15 (2001)). A "region equivalent to the Fc region of an immunoglobulin" is intended to include naturally occurring allelic variants of the Fc region of an immunoglobulin as well as variants having alterations which produce substitutions, additions, or deletions but which do not decrease substantially the ability of the immunoglobulin to mediate effector functions (such as antibody- dependent cellular cytotoxicity). For example, one or more amino acids can be deleted from the N-terminus or C-terminus of the Fc region of an immunoglobulin without substantial loss of biological function. Such variants can be selected according to general rules known in the art so as to have minimal effect on activity (see, e.g., Bowie, J. U. et al, Science 247: 1306-10 (1990)).

The term "effector functions" refers to those biological activities attributable to the Fc region of an antibody, which vary with the antibody isotype. Examples of antibody effector functions include: Clq binding and complement dependent cytotoxicity (CDC), Fc receptor binding, antibody-dependent cell-mediated cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP), cytokine secretion, immune complex-mediated antigen uptake by antigen presenting cells, down regulation of cell surface receptors (e.g. B cell receptor), and B cell activation.

Fc receptor binding dependent effector functions can be mediated by the interaction of the Fc-region of an antibody with Fc receptors (FcRs), which are specialized cell surface receptors on hematopoietic cells. Fc receptors belong to the immunoglobulin superfamily, and have been shown to mediate both the removal of antibody-coated pathogens by phagocytosis of immune complexes, and the lysis of erythrocytes and various other cellular targets (e.g. tumor cells) coated with the corresponding antibody, via antibody dependent cell mediated cytotoxicity (ADCC) (see e.g. Van de Winkel, J.G. anderson, C.L., J. Leukoc. Biol. 49 (1991) 511-524). FcRs are defined by their specificity for immunoglobulin isotypes: Fc receptors for IgG antibodies are referred to as FcyR. Fc receptor binding is described e.g. in Ravetch, J.V. and Kinet, J.P., Annu. Rev. Immunol. 9 (1991) 457-492; Capel, P.J., et al, Immunomethods 4 (1994) 25-34; de Haas, M., et al, J. Lab. Clin. Med. 126 (1995) 330-341; and Gessner, J.E., et al, Ann. Hematol. 76 (1998) 231-248.

Cross-linking of receptors for the Fc-region of IgG antibodies (FcyR) triggers a wide variety of effector functions including phagocytosis, antibody-dependent cellular cytotoxicity, and release of inflammatory mediators, as well as immune complex clearance and regulation of antibody production. In humans, three classes of FcyR have been characterized, which are:

- FcyRI (CD64) binds monomeric IgG with high affinity and is expressed on macrophages, monocytes, neutrophils and eosinophils. Modification in the Fc-region IgG at least at one of the amino acid residues E233-G236, P238, D265, N297, A327 and P329 (numbering according to EU index of Kabat) reduce binding to FcyRI. IgG2 residues at positions 233-236, substituted into IgGl and IgG4, reduced binding to FcyRI by 10 ³ -fold and eliminated the human monocyte response to antibody-sensitized red blood cells (Armour, K.L., et al, Eur. J. Immunol. 29 (1999) 2613-2624).

-FcyRII (CD32) binds complexed IgG with medium to low affinity and is widely expressed. This receptor can be divided into two sub-types, FcyRII A and FcyRIIB. FcyRII A is found on many cells involved in killing (e.g. macrophages, monocytes, neutrophils) and seems able to activate the killing process. FcyRIIB seems to play a role in inhibitory processes and is found on B cells, macrophages and on mast cells and eosinophils. On B-cells it seems to function to suppress further immunoglobulin production and isotype switching to, for example, the IgE class. On macrophages, FcyRIIB acts to inhibit phagocytosis as mediated through FcyRIIA. On eosinophils and mast cells the B-form may help to suppress activation of these cells through IgE binding to its separate receptor. Reduced binding for FcyRIIA is found e.g. for antibodies comprising an IgG Fc-region with mutations at least at one of the amino acid residues E233- G236, P238, D265, N297, A327, P329, D270, Q295, A327, R292, and K414 (numbering according to EU index of Kabat).

- FcyRIII (CD 16) binds IgG with medium to low affinity and exists as two types. FcyRIIIA is found on NK cells, macrophages, eosinophils and some monocytes and T cells and mediates ADCC. Fc γ RIIIB is highly expressed on neutrophils. Reduced binding to FcyRIIIA is found e.g. for antibodies comprising an IgG Fc-region with mutation at least at one of the amino acid residues E233-G236, P238, D265, N297, A327, P329, D270, Q295, A327, S239, E269, E293, Y296, V303, A327, K338 and D376 (numbering according to EU index of Kabat).

Mapping of the binding sites on human IgGl for Fc receptors, the above mentioned mutation sites and methods for measuring binding to FcyRI and FcyRIIA are described in Shields, R.L., et al. J. Biol. Chem. 276 (2001) 6591-6604.

The term "ADCC" or "antibody-dependent cellular cytotoxicity" is a function mediated by Fc receptor binding and refers to lysis of target cells by an antibody as reported herein in the presence of effector cells. The capacity of the antibody to induce the initial steps mediating ADCC is investigated by measuring their binding to Fey receptors expressing cells, such as cells, recombinantly expressing FcyRI and/or FcyRIIA or NK cells (expressing essentially FcyRIIIA). In particular, binding to FcyR on NK cells is measured. An "activating Fc receptor" is an Fc receptor that following engagement by an Fc region of an antibody elicits signaling events that stimulate the receptor-bearing cell to perform effector functions. Activating Fc receptors include FcyRIIIa (CD 16a), FcyRI (CD64), FcyRIIa (CD32), and FcaRI (CD89). A particular activating Fc receptor is human FcyRIIIa (see UniProt accession no. P08637, version 141). The "Tumor Necrosis factor receptor superfamily" or "TNF receptor superfamily" currently consists of 27 receptors. It is a group of cytokine receptors characterized by the ability to bind tumor necrosis factors (TNFs) via an extracellular cysteine-rich domain (CRD). These pseudorepeats are defined by intrachain disulphides generated by highly conserved cysteine residues within the receptor chains. With the exception of nerve growth factor (NGF), all TNFs are homologous to the archetypal TNF-alpha. In their active form, the majority of TNF receptors form trimeric complexes in the plasma membrame. Accordingly, most TNF receptors contain transmembrane domains (TMDs). Several of these receptors also contain intracellular death domains (DDs) that recruit caspase-interacting proteins following ligand binding to initiate the extrinsic pathway of caspase activation. Other TNF superfamily receptors that lack death domains bind TNF receptor-associated factors and activate intracellular signaling pathways that can lead to proliferation or differentiation. These receptors can also initiate apoptosis, but they do so via indirect mechanisms. In addition to regulating apoptosis, several TNF superfamily receptors are involved in regulating immune cell functions such as B cell homeostasis and activation, natural killer cell activation, and T cell co-stimulation. Several others regulate cell type-specific responses such as hair follicle development and osteoclast development. Members of the TNF receptor superfamily include the following: Tumor necrosis factor receptor 1 (1A) (TNFRSF1A, CD120a), Tumor necrosis factor receptor 2 (IB) (TNFRSF1B, CD120b),

Lymphotoxin beta receptor (LTBR, CD 18), OX40 (TNFRSF4, CD 134), CD40 (Bp50), Fas receptor (Apo-1, CD95, FAS), Decoy receptor 3 (TR6, M68, TNFRSF6B), CD27 (S152, Tp55), CD30 (Ki-1, TNFRSF8), 4- IBB (CD137, TNFRSF9), DR4 (TRAILR1, Apo-2, CD261, TNFRSF10A), DR5 (TRAILR2, CD262, TNFRSF10B), Decoy Receptor 1 (TRAILR3, CD263, TNFRSF10C), Decoy Receptor 2 (TRAILR4, CD264, TNFRSF10D), RANK (CD265,

TNFRSF11A), Osteoprotegerin (OCIF, TR1, TNFRSF1 IB), TWEAK receptor (Fnl4, CD266, TNFRSF12A), TACI (CD267, TNFRSF13B), BAFF receptor (CD268, TNFRSF13C),

Herpesvirus entry mediator (HVEM, TR2, CD270, TNFRSF14), Nerve growth factor receptor (p75NTR, CD271 , NGFR), B-cell maturation antigen (CD269, TNFRSF 17), Glucocorticoid- induced TNFR-related (GITR, AITR, CD357, TNFRSF 18), TROY (TNFRSF 19), DR6 (CD358, TNFRSF21), DR3 (Apo-3, TRAMP, WS-1, TNFRSF25) and Ectodysplasin A2 receptor (XEDAR, EDA2R).

Several members of the tumor necrosis factor receptor (TNFR) family function after initial T cell activation to sustain T cell responses. The term "costimulatory TNF receptor family member" or "costimulatory TNF family receptor" refers to a subgroup of TNF receptor family members, which are able to costimulate proliferation and cytokine production of T-cells. The term refers to any native TNF family receptor from any vertebrate source, including mammals such as primates (e.g. humans), non-human primates (e.g. cynomolgus monkeys) and rodents (e.g. mice and rats), unless otherwise indicated. In specific embodiments of the invention, costimulatory TNF receptor family members are selected from the group consisting of OX40 (CD134), 4-1BB (CD137), CD27, HVEM (CD270), CD30, and GITR, all of which can have costimulatory effects on T cells. More particularly, the antigen binding molecule of the present invention comprises at least moiety capable of specific binding to the costimulatory TNF receptor family member OX40.

Further information, in particular sequences, of the TNF receptor family members may be obtained from publically accessible databases such as Uniprot (www.uniprot.org). For instance, the human costimulatory TNF receptors have the following amino acid sequences: human OX40 (UniProt accession no. P43489, SEQ ID NO:67), human 4-lBB (UniProt accession no. Q07011, SEQ ID NO:69), human CD27 (UniProt accession no. P26842, SEQ ID NO:70), human HVEM (UniProt accession no. Q92956, SEQ ID NO:71), human CD30 (UniProt accession no. P28908, SEQ ID NO:72), and human GITR (UniProt accession no. Q9Y5U5, SEQ ID NO:73).

The term "OX40", as used herein, refers to any native OX40 from any vertebrate source, including mammals such as primates (e.g. humans) and rodents (e.g., mice and rats), unless otherwise indicated. The term encompasses "full-length," unprocessed OX40 as well as any form of OX40 that results from processing in the cell. The term also encompasses naturally occurring variants of OX40, e.g., splice variants or allelic variants. The amino acid sequence of an exemplary human OX40 is shown in SEQ ID NO:67 (Uniprot P43489, version 112) and the amino acid sequence of an exemplary murine OX40 is shown in SEQ ID NO: 74 (Uniprot P47741, version 101).

The terms "anti-OX40 antibody", "anti-OX40", "OX40 antibody and "an antibody that specifically binds to OX40" refer to an antibody that is capable of binding OX40 with sufficient affinity such that the antibody is useful as a diagnostic and/or therapeutic agent in targeting OX40. In one embodiment, the extent of binding of an anti-OX40 antibody to an unrelated, non- OX40 protein is less than about 10% of the binding of the antibody to OX40 as measured, e.g., by a radioimmunoassay (RIA) or flow cytometry (FACS). In certain embodiments, an antibody that binds to OX40 has a dissociation constant ( K _D ) of < ΙμΜ, < 100 nM, < 10 nM, < 1 nM, < 0.1 nM, < 0.01 nM, or < 0.001 nM (e.g. 10 ^"6 M or less, e.g. from 10 ^"68 M to 10 ^"13 M, e.g., from 10 ^"8 M to 10 ^"10 M).

The terms terms "anti-EpCAM antibody" and "an antibody that binds to EpCAM" refer to an antibody that is capable of binding to epithelial cell adhesion molecule (EpCAM) with sufficient affinity such that the antibody is useful as a diagnostic and/or therapeutic agent in targeting EpCAM. In one embodiment, the extent of binding of an anti-EpCAM antibody to an unrelated, non-EpCAM protein is less than about 10% of the binding of the antibody to EpCAM as measured, e.g., by a radioimmunoassay (RIA). In certain embodiments, an antibody that binds to EpCAM has a dissociation constant (KD) of < ΙμΜ, < 100 nM, < 10 nM, < 5 nM, < 2 nM, < 1 nM, < 0.1 nM, < 0.01 nM, or < 0.001 nM (e.g., 10-8 M or less, e.g., from 10-8 M to 10-13 M, e.g., from 10-9 M to 10-13 M, e.g., from 10 nM to 0.1 nM, e.g., from 5 nM to 0.1 nM, e.g., from 2 nM to 0.1 nM). In certain embodiments, an anti-EpCAM antibody binds to an epitope of EpCAM that is conserved among EpCAM from different species. In certain embodiments, an antibody that binds to an epitope of EpCAM is specific for the extracellular domain (ECD) of EpCAM. In certain embodiments an antibody specific for SEQ ID NO:49 is provided. In certain embodiments an antibody specific for SEQ ID NO:50 is provided.

The term "peptide linker" refers to a peptide comprising one or more amino acids, typically about 2 to 20 amino acids. Peptide linkers are known in the art or are described herein. Suitable, non-immunogenic linker peptides are, for example, (G ₄ S) _n , (SG4) _n or G4(SG4) _n peptide linkers, wherein "n" is generally a number between 1 and 10, typically between 2 and 4, in particular 2, i.e. the peptides selected from the group consisting of GGGGS (SEQ ID NO:76) GGGGSGGGGS (SEQ ID NO:77), SGGGGSGGGG (SEQ ID NO:78) and

GGGGSGGGGSGGGG (SEQ ID NO:80), but also include the sequences GSPGSSSSGS (SEQ ID NO:82), (G4S) ₃ (SEQ ID NO:79), (G4S) ₄ (SEQ ID NO:81), GSGSGSGS (SEQ ID NO:83), GSGSGNGS (SEQ ID NO:84), GGSGSGSG (SEQ ID NO:85), GGSGSG (SEQ ID NO:86), GGSG (SEQ ID NO:87), GGSGNGSG (SEQ ID NO:88), GGNGSGSG (SEQ ID NO:89) and GGNGSG (SEQ ID NO:90). Peptide linkers of particular interest are (G4S) (SEQ ID NO:76), (G ₄ S) ₂ or GGGGSGGGGS (SEQ ID NO:77) and GSPGSSSSGS (SEQ ID NO:82).

The term "amino acid" as used within this application denotes the group of naturally occurring carboxy a-amino acids comprising alanine (three letter code: ala, one letter code: A), arginine (arg, R), asparagine (asn, N), aspartic acid (asp, D), cysteine (cys, C), glutamine (gin, Q), glutamic acid (glu, E), glycine (gly, G), histidine (his, H), isoleucine (ile, I), leucine (leu, L), lysine (lys, K), methionine (met, M), phenylalanine (phe, F), proline (pro, P), serine (ser, S), threonine (thr, T), tryptophan (trp, W), tyrosine (tyr, Y), and valine (val, V). By "fused" or "connected" is meant that the components (e.g. a heavy chain of an antibody and a Fab fragment) are linked by peptide bonds, either directly or via one or more peptide linkers.

"Percent (%) amino acid sequence identity" with respect to a reference polypeptide (protein) sequence is defined as the percentage of amino acid residues in a candidate sequence that are identical with the amino acid residues in the reference polypeptide sequence, after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity, and not considering any conservative substitutions as part of the sequence identity. Alignment for purposes of determining percent amino acid sequence identity can be achieved in various ways that are within the skill in the art, for instance, using publicly available computer software such as BLAST, BLAST-2, ALIGN. SAWI or Megalign (DNASTAR) software. Those skilled in the art can determine appropriate parameters for aligning sequences, including any algorithms needed to achieve maximal alignment over the full length of the sequences being compared. For purposes herein, however, % amino acid sequence identity values are generated using the sequence comparison computer program ALIGN-2. The ALIGN- 2 sequence comparison computer program was authored by Genentech, Inc., and the source code has been filed with user documentation in the U.S. Copyright Office, Washington D.C., 20559, where it is registered under U.S. Copyright Registration No. TXU510087. The ALIGN-2 program is publicly available from Genentech, Inc., South San Francisco, California, or may be compiled from the source code. The ALIGN-2 program should be compiled for use on a UNIX operating system, including digital UNIX V4.0D. All sequence comparison parameters are set by the ALIGN-2 program and do not vary. In situations where ALIGN-2 is employed for amino acid sequence comparisons, the % amino acid sequence identity of a given amino acid sequence A to, with, or against a given amino acid sequence B (which can alternatively be phrased as a given amino acid sequence A that has or comprises a certain % amino acid sequence identity to, with, or against a given amino acid sequence B) is calculated as follows:

100 times the fraction X/Y where X is the number of amino acid residues scored as identical matches by the sequence alignment program ALIGN-2 in that program's alignment of A and B, and where Y is the total number of amino acid residues in B. It will be appreciated that where the length of amino acid sequence A is not equal to the length of amino acid sequence B, the % amino acid sequence identity of A to B will not equal the % amino acid sequence identity of B to A. Unless specifically stated otherwise, all % amino acid sequence identity values used herein are obtained as described in the immediately preceding paragraph using the ALIGN-2 computer program.

In certain embodiments, amino acid sequence variants of the antigen binding molecules provided herein are contemplated. For example, it may be desirable to improve the binding affinity and/or other biological properties of the antigen binding molecules. Amino acid sequence variants of the antigen binding molecules may be prepared by introducing appropriate modifications into the nucleotide sequence encoding the molecules, or by peptide synthesis. Such modifications include, for example, deletions from, and/or insertions into and/or substitutions of residues within the amino acid sequences of the antibody. Any combination of deletion, insertion, and substitution can be made to arrive at the final construct, provided that the final construct possesses the desired characteristics, e.g., antigen-binding. Sites of interest for substitutional mutagenesis include the HVRs and Framework (FRs). Conservative substitutions are provided in Table B under the heading "Preferred Substitutions" and further described below in reference to amino acid side chain classes (1) to (6). Amino acid substitutions may be introduced into the molecule of interest and the products screened for a desired activity, e.g., retained/improved antigen binding, decreased immunogenicity, or improved ADCC or CDC.

TABLE B

Amino acids may be grouped according to common side-chain properties:

(1) hydrophobic: Norleucine, Met, Ala, Val, Leu, He;

(2) neutral hydrophilic: Cys, Ser, Thr, Asn, Gin;

(3) acidic: Asp, Glu;

(4) basic: His, Lys, Arg;

(5) residues that influence chain orientation: Gly, Pro;

(6) aromatic: Trp, Tyr, Phe. Non-conservative substitutions will entail exchanging a member of one of these classes for another class.

The term "amino acid sequence variants" includes substantial variants wherein there are amino acid substitutions in one or more hypervariable region residues of a parent antigen binding molecule (e.g. a humanized or human antibody). Generally, the resulting variant(s) selected for further study will have modifications (e.g., improvements) in certain biological properties (e.g., increased affinity, reduced immunogenicity) relative to the parent antigen binding molecule and/or will have substantially retained certain biological properties of the parent antigen binding molecule. An exemplary substitutional variant is an affinity matured antibody, which may be conveniently generated, e.g., using phage display-based affinity maturation techniques such as those described herein. Briefly, one or more HVR residues are mutated and the variant antigen binding molecules displayed on phage and screened for a particular biological activity (e.g. binding affinity). In certain embodiments, substitutions, insertions, or deletions may occur within one or more HVRs so long as such alterations do not substantially reduce the ability of the antigen binding molecule to bind antigen. For example, conservative alterations (e.g., conservative substitutions as provided herein) that do not substantially reduce binding affinity may be made in HVRs. A useful method for identification of residues or regions of an antibody that may be targeted for mutagenesis is called "alanine scanning mutagenesis" as described by Cunningham and Wells (1989) Science, 244: 1081-1085. In this method, a residue or group of target residues (e.g., charged residues such as Arg, Asp, His, Lys, and Glu) are identified and replaced by a neutral or negatively charged amino acid (e.g., alanine or polyalanine) to determine whether the interaction of the antibody with antigen is affected. Further substitutions may be introduced at the amino acid locations demonstrating functional sensitivity to the initial substitutions. Alternatively, or additionally, a crystal structure of an antigen-antigen binding molecule complex to identify contact points between the antibody and antigen. Such contact residues and neighboring residues may be targeted or eliminated as candidates for substitution. Variants may be screened to determine whether they contain the desired properties.

Amino acid sequence insertions include amino- and/or carboxyl-terminal fusions ranging in length from one residue to polypeptides containing a hundred or more residues, as well as intrasequence insertions of single or multiple amino acid residues. Examples of terminal insertions include bispecific antigen binding molecules of the invention with an N-terminal methionyl residue. Other insertional variants of the molecule include the fusion to the N- or C- terminus to a polypeptide which increases the serum half-life of the bispecific antigen binding molecules. In certain embodiments, the bispecific antigen binding molecules provided herein are altered to increase or decrease the extent to which the antibody is glycosylated. Glycosylation variants of the molecules may be conveniently obtained by altering the amino acid sequence such that one or more glycosylation sites is created or removed. Where the bispecific antigen binding molecule comprises an Fc region, the carbohydrate attached thereto may be altered. Native antibodies produced by mammalian cells typically comprise a branched, biantennary oligosaccharide that is generally attached by an N-linkage to Asn297 of the CH2 domain of the Fc region. See, e.g., Wright et al. TIBTECH 15:26-32 (1997). The oligosaccharide may include various carbohydrates, e.g., mannose, N-acetyl glucosamine (GlcNAc), galactose, and sialic acid, as well as a fucose attached to a GlcNAc in the "stem" of the biantennary oligosaccharide structure. In some embodiments, modifications of the oligosaccharide in the antigen binding molecule may be made in order to create variants with certain improved properties. In one aspect, variants of bispecific antigen binding molecules or antibodies of the invention are provided having a carbohydrate structure that lacks fucose attached (directly or indirectly) to an Fc region. Such fucosylation variants may have improved ADCC function, see e.g. US Patent Publication Nos. US 2003/0157108 (Presta, L.) or US 2004/0093621 (Kyowa Hakko Kogyo Co., Ltd). In another aspect, variants of the bispecific antigen binding molecules or antibodies of the invention are provided with bisected oligosaccharides, e.g., in which a biantennary

oligosaccharide attached to the Fc region is bisected by GlcNAc. Such variants may have reduced fucosylation and/or improved ADCC function., see for example WO 2003/011878

(Jean-Mairet et al); US Patent No. 6,602,684 (Umana et al); and US 2005/0123546 (Umana et al.). Variants with at least one galactose residue in the oligosaccharide attached to the Fc region are also provided. Such antibody variants may have improved CDC function and are described, e.g., in WO 1997/30087 (Patel et al); WO 1998/58964 (Raju, S.); and WO 1999/22764 (Raju, S.).

In certain aspects, it may be desirable to create cysteine engineered variants of the bispecific antigen binding molecules of the invention, e.g., "thioMAbs," in which one or more residues of the molecule are substituted with cysteine residues. In particular aspects, the substituted residues occur at accessible sites of the molecule. By substituting those residues with cysteine, reactive thiol groups are thereby positioned at accessible sites of the antibody and may be used to conjugate the antibody to other moieties, such as drug moieties or linker-drug moieties, to create an immunoconjugate. In certain aspects, any one or more of the following residues may be substituted with cysteine: V205 (Kabat numbering) of the light chain; Al 18 (EU numbering) of the heavy chain; and S400 (EU numbering) of the heavy chain Fc region.

Cysteine engineered antigen binding molecules may be generated as described, e.g., in U.S. Patent No. 7,521,541. The term "polynucleotide" refers to an isolated nucleic acid molecule or construct, e.g. messenger RNA (mRNA), virally-derived RNA, or plasmid DNA (pDNA). A polynucleotide may comprise a conventional phosphodiester bond or a non-conventional bond (e.g. an amide bond, such as found in peptide nucleic acids (PNA). The term "nucleic acid molecule" refers to any one or more nucleic acid segments, e.g. DNA or RNA fragments, present in a polynucleotide.

By "isolated" nucleic acid molecule or polynucleotide is intended a nucleic acid molecule, DNA or RNA, which has been removed from its native environment. For example, a

recombinant polynucleotide encoding a polypeptide contained in a vector is considered isolated for the purposes of the present invention. Further examples of an isolated polynucleotide include recombinant polynucleotides maintained in heterologous host cells or purified (partially or substantially) polynucleotides in solution. An isolated polynucleotide includes a polynucleotide molecule contained in cells that ordinarily contain the polynucleotide molecule, but the polynucleotide molecule is present extrachromosomally or at a chromosomal location that is different from its natural chromosomal location. Isolated RNA molecules include in vivo or in vitro RNA transcripts of the present invention, as well as positive and negative strand forms, and double-stranded forms. Isolated polynucleotides or nucleic acids according to the present invention further include such molecules produced synthetically. In addition, a polynucleotide or a nucleic acid may be or may include a regulatory element such as a promoter, ribosome binding site, or a transcription terminator. By a nucleic acid or polynucleotide having a nucleotide sequence at least, for example,

95% "identical" to a reference nucleotide sequence of the present invention, it is intended that the nucleotide sequence of the polynucleotide is identical to the reference sequence except that the polynucleotide sequence may include up to five point mutations per each 100 nucleotides of the reference nucleotide sequence. In other words, to obtain a polynucleotide having a nucleotide sequence at least 95% identical to a reference nucleotide sequence, up to 5% of the nucleotides in the reference sequence may be deleted or substituted with another nucleotide, or a number of nucleotides up to 5% of the total nucleotides in the reference sequence may be inserted into the reference sequence. These alterations of the reference sequence may occur at the 5' or 3' terminal positions of the reference nucleotide sequence or anywhere between those terminal positions, interspersed either individually among residues in the reference sequence or in one or more contiguous groups within the reference sequence. As a practical matter, whether any particular polynucleotide sequence is at least 80%, 85%, 90%, 95%, 96%, 97%, 98% or 99% identical to a nucleotide sequence of the present invention can be determined conventionally using known computer programs, such as the ones discussed above for polypeptides (e.g.

ALIGN-2). The term "expression cassette" refers to a polynucleotide generated recombinantly or synthetically, with a series of specified nucleic acid elements that permit transcription of a particular nucleic acid in a target cell. The recombinant expression cassette can be incorporated into a plasmid, chromosome, mitochondrial DNA, plastid DNA, virus, or nucleic acid fragment. Typically, the recombinant expression cassette portion of an expression vector includes, among other sequences, a nucleic acid sequence to be transcribed and a promoter. In certain

embodiments, the expression cassette of the invention comprises polynucleotide sequences that encode bispecific antigen binding molecules of the invention or fragments thereof.

The term "vector" or "expression vector" is synonymous with "expression construct" and refers to a DNA molecule that is used to introduce and direct the expression of a specific gene to which it is operably associated in a target cell. The term includes the vector as a self-replicating nucleic acid structure as well as the vector incorporated into the genome of a host cell into which it has been introduced. The expression vector of the present invention comprises an expression cassette. Expression vectors allow transcription of large amounts of stable mRNA. Once the expression vector is inside the target cell, the ribonucleic acid molecule or protein that is encoded by the gene is produced by the cellular transcription and/or translation machinery. In one embodiment, the expression vector of the invention comprises an expression cassette that comprises polynucleotide sequences that encode bispecific antigen binding molecules of the invention or fragments thereof. The terms "host cell", "host cell line," and "host cell culture" are used interchangeably and refer to cells into which exogenous nucleic acid has been introduced, including the progeny of such cells. Host cells include "transformants" and "transformed cells," which include the primary transformed cell and progeny derived therefrom without regard to the number of passages. Progeny may not be completely identical in nucleic acid content to a parent cell, but may contain mutations. Mutant progeny that have the same function or biological activity as screened or selected for in the originally transformed cell are included herein. A host cell is any type of cellular system that can be used to generate the bispecific antigen binding molecules of the present invention. Host cells include cultured cells, e.g. mammalian cultured cells, such as CHO cells, BHK cells, NSO cells, SP2/0 cells, YO myeloma cells, P3X63 mouse myeloma cells, PER cells, PER.C6 cells or hybridoma cells, yeast cells, insect cells, and plant cells, to name only a few, but also cells comprised within a transgenic animal, transgenic plant or cultured plant or animal tissue.

An "effective amount" of an agent refers to the amount that is necessary to result in a physiological change in the cell or tissue to which it is administered. A "therapeutically effective amount" of an agent, e.g. a pharmaceutical composition, refers to an amount effective, at dosages and for periods of time necessary, to achieve the desired therapeutic or prophylactic result. A therapeutically effective amount of an agent for example eliminates, decreases, delays, minimizes or prevents adverse effects of a disease. An "individual" or "subject" is a mammal. Mammals include, but are not limited to, domesticated animals (e.g. cows, sheep, cats, dogs, and horses), primates (e.g. humans and non- human primates such as monkeys), rabbits, and rodents (e.g. mice and rats). Particularly, the individual or subject is a human.

The term "pharmaceutical composition" refers to a preparation which is in such form as to permit the biological activity of an active ingredient contained therein to be effective, and which contains no additional components which are unacceptably toxic to a subject to which the formulation would be administered.

A "pharmaceutically acceptable excipient" refers to an ingredient in a pharmaceutical composition, other than an active ingredient, which is nontoxic to a subject. A pharmaceutically acceptable excipient includes, but is not limited to, a buffer, a stabilizer, or a preservative.

The term "package insert" is used to refer to instructions customarily included in commercial packages of therapeutic products, that contain information about the indications, usage, dosage, administration, combination therapy, contraindications and/or warnings concerning the use of such therapeutic products. As used herein, "treatment" (and grammatical variations thereof such as "treat" or

"treating") refers to clinical intervention in an attempt to alter the natural course of the individual being treated, and can be performed either for prophylaxis or during the course of clinical pathology. Desirable effects of treatment include, but are not limited to, preventing occurrence or recurrence of disease, alleviation of symptoms, diminishment of any direct or indirect

pathological consequences of the disease, preventing metastasis, decreasing the rate of disease progression, amelioration or palliation of the disease state, and remission or improved prognosis. In some embodiments, the molecules of the invention are used to delay development of a disease or to slow the progression of a disease.

The term "cancer" as used herein refers to proliferative diseases, such as lymphomas, lymphocytic leukemias, lung cancer, non-small cell lung (NSCL) cancer, bronchioloalviolar cell lung cancer, bone cancer, pancreatic cancer, skin cancer, cancer of the head or neck, cutaneous or intraocular melanoma, uterine cancer, ovarian cancer, rectal cancer, cancer of the anal region, stomach cancer, gastric cancer, colon cancer, breast cancer, uterine cancer, carcinoma of the fallopian tubes, carcinoma of the endometrium, carcinoma of the cervix, carcinoma of the vagina, carcinoma of the vulva, Hodgkin's Disease, cancer of the esophagus, cancer of the small intestine, cancer of the endocrine system, cancer of the thyroid gland, cancer of the parathyroid gland, cancer of the adrenal gland, sarcoma of soft tissue, cancer of the urethra, cancer of the penis, prostate cancer, cancer of the bladder, cancer of the kidney or ureter, renal cell carcinoma, carcinoma of the renal pelvis, mesothelioma, hepatocellular cancer, biliary cancer, neoplasms of the central nervous system (CNS), spinal axis tumors, brain stem glioma, glioblastoma

multiforme, astrocytomas, schwanomas, ependymonas, medulloblastomas, meningiomas, squamous cell carcinomas, pituitary adenoma and Ewings sarcoma, including refractory versions of any of the above cancers, or a combination of one or more of the above cancers. Bispecific antigen binding molecules of the invention

The invention provides novel bispecific antigen binding molecules with particularly advantageous properties such as producibility, stability, binding affinity, biological activity, targeting efficiency and reduced toxicity.

The present invention provides a bispecific antigen binding molecule, comprising

(a) at least one moiety capable of specific binding to OX40 comprising an antibody light chain variable region (VL) and an antibody heavy chain variable region (VH), and

(b) at least one moiety capable of specific binding to epithelial cell adhesion molecule (EpCAM) comprising an antibody light chain variable region (VL) and an antibody heavy chain variable region (VH). In some embodiments, the bispecific antigen binding molecule additionally comprises (c) a

Fc region composed of a first and a second subunit capable of stable association.

In particular aspects, the bispecific antigen binding molecules of the present invention are characterized by agonistic binding to OX40. Bispecific antigen binding molecules binding to OX40

In one aspect, the invention provides bispecific antigen binding molecules, wherein the moiety capable of specific binding to OX40 binds to a polypeptide comprising, or consisting of, the amino acid sequence of SEQ ID NO: 1. In one aspect, provided is a bispecific antigen binding molecule, comprising at least one moiety capable of specific binding to OX40, wherein said moiety comprises a VH comprising (i) a CDR-H1 comprising an amino acid sequence selected from the group consisting of SEQ ID NO:4 and SEQ ID NO:5, (ii) a CDR-H2 comprising an amino acid sequence selected from the group consisting of SEQ ID NO:6 and SEQ ID NO:7, and

(iii) a CDR-H3 comprising an amino acid sequence selected from the group consisting of SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 13 and SEQ ID NO: 14,

and a VL comprising

(iv) a CDR-L1 comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 15, SEQ ID NO: 16 and SEQ ID NO: 17,

(v) a CDR-L2 comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 18, SEQ ID NO: 19 and SEQ ID NO:20, and

(vi) a CDR-L3 comprising an amino acid sequence selected from the group consisting of SEQ ID NO:21, SEQ ID NO:22, SEQ ID NO:23, SEQ ID NO:24, SEQ ID NO:25 and SEQ ID NO:26.

In particular, provided is a bispecific antigen binding molecule, comprising at least one moiety capable of specific binding to OX40, wherein said moiety comprises

(a) a VH comprising CDR-H1 comprising the amino acid sequence of SEQ ID NO:4, CDR-H2 comprising the amino acid sequence of SEQ ID NO:6, CDR-H3 comprising the amino acid sequence of SEQ ID NO: 8 and a VL comprising CDR-L1 comprising the amino acid sequence of SEQ ID NO: 15, CDR-L2 comprising the amino acid sequence of SEQ ID NO: 18 and CDR-L3 comprising the amino acid sequence of SEQ ID NO:21,

(b) a VH comprising CDR-H1 comprising the amino acid sequence of SEQ ID NO:4, CDR-H2 comprising the amino acid sequence of SEQ ID NO:6, CDR-H3 comprising the amino acid sequence of SEQ ID NO: 9 and a VL comprising CDR-L1 comprising the amino acid sequence of SEQ ID NO : 15 , CDR-L2 comprising the amino acid sequence of SEQ ID NO : 18 and CDR-L3 comprising the amino acid sequence of SEQ ID NO:22,

(c) a VH comprising CDR-H1 comprising the amino acid sequence of SEQ ID NO:4, CDR-H2 comprising the amino acid sequence of SEQ ID NO:6, CDR-H3 comprising the amino acid sequence of SEQ ID NO: 10 and a VL comprising CDR-L1 comprising the amino acid sequence of SEQ ID NO: 15, CDR-L2 comprising the amino acid sequence of SEQ ID NO: 18 and CDR-L3 comprising the amino acid sequence of SEQ ID NO:23,

(d) a VH comprising CDR-H1 comprising the amino acid sequence of SEQ ID NO:4, CDR-H2 comprising the amino acid sequence of SEQ ID NO:6, CDR-H3 comprising the amino acid sequence of SEQ ID NO: l 1 and a VL comprising CDR-L1 comprising the amino acid sequence of SEQ ID NO: 15, CDR-L2 comprising the amino acid sequence of SEQ ID NO: 18 and CDR-L3 comprising the amino acid sequence of SEQ ID NO:24, (e) a VH comprising CDR-H1 comprising the amino acid sequence of SEQ ID NO:5, CDR-H2 comprising the amino acid sequence of SEQ ID NO:7, CDR-H3 comprising the amino acid sequence of SEQ ID NO: 12 and a VL comprising CDR-L1 comprising the amino acid sequence of SEQ ID NO: 16, CDR-L2 comprising the amino acid sequence of SEQ ID NO: 19 and CDR-L3 comprising the amino acid sequence of SEQ ID NO:25,

(f) a VH comprising CDR-H1 comprising the amino acid sequence of SEQ ID NO:5, CDR-H2 comprising the amino acid sequence of SEQ ID NO:7, CDR-H3 comprising the amino acid sequence of SEQ ID NO: 13 and a VL comprising CDR-L1 comprising the amino acid sequence of SEQ ID NO: 16, CDR-L2 comprising the amino acid sequence of SEQ ID NO: 19 and CDR-L3 comprising the amino acid sequence of SEQ ID NO:25, or

(g) a VH comprising CDR-H1 comprising the amino acid sequence of SEQ ID NO:5, CDR-H2 comprising the amino acid sequence of SEQ ID NO:7, CDR-H3 comprising the amino acid sequence of SEQ ID NO: 14 and a VL comprising CDR-L1 comprising the amino acid sequence of SEQ ID NO: 17, CDR-L2 comprising the amino acid sequence of SEQ ID NO:20 and CDR-L3 comprising the amino acid sequence of SEQ ID NO:26.

In one aspect, the invention provides a bispecific antigen binding molecule, comprising at least one moiety capable of specific binding to OX40, wherein said moiety comprises a VH comprising CDR-H1 comprising the amino acid sequence of SEQ ID NO:4, CDR-H2 comprising the amino acid sequence of SEQ ID NO:6, CDR-H3 comprising the amino acid sequence of SEQ ID NO: 9 and a VL comprising CDR-L1 comprising the amino acid sequence of SEQ ID NO: 15, CDR-L2 comprising the amino acid sequence of SEQ ID NO: 18 and CDR- L3 comprising the amino acid sequence of SEQ ID NO:22.

In another aspect, the invention provides a bispecific antigen binding molecule, wherein the moiety capable of specific binding to OX40 comprises a VH comprising an amino acid sequence that is at least about about 95%, 96%, 97%, 98%, 99% or 100% identical to an amino acid sequence selected from the group consisting of SEQ ID NO:33, SEQ ID NO: 35, SEQ ID NO:37, SEQ ID NO:39, SEQ ID NO:41 , SEQ ID NO:43 and SEQ ID NO:45 and a VL comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to an amino acid sequence selected from the group consisting of SEQ ID NO:34, SEQ ID NO: 36, SEQ ID NO:38, SEQ ID NO:40, SEQ ID NO:42, SEQ ID NO:44 and SEQ ID NO:46.

Particularly, provided is a bispecific antigen binding molecule, wherein the moiety capable of specific binding to OX40 comprises

(i) a VH comprising the amino acid sequence of SEQ ID NO:33 and a VL comprising the amino acid sequence of SEQ ID NO:34, (ii) a VH comprising the amino acid sequence of SEQ ID NO:35 and a VL comprising the amino acid sequence of SEQ ID NO:36,

(iii) a VH comprising the amino acid sequence of SEQ ID NO:37 and a VL comprising the amino acid sequence of SEQ ID NO:38,

(iv) a VH comprising the amino acid sequence of SEQ ID NO:39 and a VL comprising the amino acid sequence of SEQ ID NO:40,

(v) a VH comprising the amino acid sequence of SEQ ID NO:41 and a VL comprising the amino acid sequence of SEQ ID NO:42,

(vi) a VH comprising the amino acid sequence of SEQ ID NO:43 and a VL comprising the amino acid sequence of SEQ ID NO:44, or

(vii) a VH comprising the amino acid sequence of SEQ ID NO:45 and a VL comprising the amino acid sequence of SEQ ID NO:46.

In a particular aspect, provided is a bispecific antigen binding molecule, wherein the moiety capable of specific binding to OX40 comprises a VH comprising the amino acid sequence of SEQ ID NO:35 and a VL comprising the amino acid sequence of SEQ ID NO:36.

In one aspect, the invention provides bispecific antigen binding molecules, wherein the moiety capable of specific binding to OX40 binds to a polypeptide comprising, or consisting of, the amino acid sequence of SEQ ID NO:2.

In one aspect, provided is a bispecific antigen binding molecule, comprising at least one moiety capable of specific binding to OX40, wherein said moiety comprises a VH comprising

(i) a CDR-H1 comprising the amino acid sequence SEQ ID NO:27,

(ii) a CDR-H2 comprising the amino acid sequence SEQ ID NO:28, and

(iii) a CDR-H3 comprising the amino acid sequence SEQ ID NO:29,

and a VL comprising

(iv) a CDR-L1 comprising the amino acid sequence SEQ ID NO:30,

(v) a CDR-L2 comprising the amino acid sequence SEQ ID NO:31, and

(vi) a CDR-L3 comprising the amino acid sequence SEQ ID NO:32.

In another aspect, the invention provides a bispecific antigen binding molecule, wherein the moiety capable of specific binding to OX40 comprises a VH comprising an amino acid sequence that is at least about about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:47, and a VL comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:48. Particularly, provided is a bispecific antigen binding molecule, wherein the moiety capable of specific binding to OX40 comprises a VH comprising the amino acid sequence of SEQ ID NO:47 and a VL comprising the amino acid sequence of SEQ ID NO:48. Bispecific antigen binding molecules binding to EpCAM

In one aspect, the invention provides bispecific antigen binding molecules, wherein the moiety capable of specific binding to epithelial cell adhesion molecule (EpCAM) binds to a polypeptide comprising, or consisting of, the amino acid sequence of SEQ ID NO:49. In one aspect, provided is a bispecific antigen binding molecule, comprising at least one moiety capable of specific binding to EpCAM, wherein said moiety comprises a VH comprising

(i) a CDR-H1 comprising the amino acid sequence SEQ ID NO:51,

(ii) a CDR-H2 comprising the amino acid sequence SEQ ID NO:52, and

(iii) a CDR-H3 comprising the amino acid sequence SEQ ID NO:53,

and a VL comprising

(iv) a CDR-L1 comprising the amino acid sequence SEQ ID NO:54,

(v) a CDR-L2 comprising the amino acid sequence SEQ ID NO:55, and

(vi) a CDR-L3 comprising the amino acid sequence SEQ ID NO:56.

In another aspect, provided is a bispecific antigen binding molecule, wherein the moiety capable of specific binding to EpCAM comprises a VH comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:63, and a VL comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:64.

Particularly provided is a bispecific antigen binding molecule, wherein the moiety capable of specific binding to EpCAM comprises a VH comprising the amino acid sequence of SEQ ID NO: 63 and a VL comprising the amino acid sequence of SEQ ID NO: 64.

In one aspect, the invention provides bispecific antigen binding molecules, wherein the moiety capable of specific binding to epithelial cell adhesion molecule (EpCAM) binds to a polypeptide comprising, or consisting of, the amino acid sequence of SEQ ID NO:50. In one aspect, provided is a bispecific antigen binding molecule, comprising at least one moiety capable of specific binding to EpCAM, wherein said moiety comprises a VH comprising

(i) a CDR-H1 comprising the amino acid sequence SEQ ID NO:57,

(ii) a CDR-H2 comprising the amino acid sequence SEQ ID NO:58, and

(iii) a CDR-H3 comprising the amino acid sequence SEQ ID NO:59,

and a VL comprising (iv) a CDR-L1 comprising the amino acid sequence SEQ ID NO:60,

(v) a CDR-L2 comprising the amino acid sequence SEQ ID NO:61, and

(vi) a CDR-L3 comprising the amino acid sequence SEQ ID NO:62.

In another aspect, the invention provides a bispecific antigen binding molecule, wherein the moiety capable of specific binding to EpCAM comprises a VH comprising an amino acid sequence that is at least about about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:65, and a VL comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:66. Particularly, provided is a bispecific antigen binding molecule, wherein the moiety capable of specific binding to EpCAM comprises a VH comprising the amino acid sequence of SEQ ID NO: 65 and a VL comprising the amino acid sequence of SEQ ID NO: 66.

Bispecific antigen binding molecules binding to OX40 and EpCAM

In a further aspect, provided is a bispecific antigen binding molecule, wherein (i) the moiety capable of specific binding to OX40 comprises a VH comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:33, SEQ ID NO: 35, SEQ ID NO:37, SEQ ID NO:39, SEQ ID NO:41, SEQ ID NO:43 and SEQ ID NO:45 and a VL comprising an amino acid sequence that is at least about 95%>, 96%>, 97%>, 98%>, 99%> or 100% identical to an amino acid sequence selected from the group consisting of SEQ ID NO:34, SEQ ID NO: 36, SEQ ID NO:38, SEQ ID NO:40, SEQ ID NO:42, SEQ ID NO:44 and SEQ ID NO:46, and

(ii) the moiety capable of specific binding to EpCAM comprises a VH comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:63, and a VL comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:64.

In a particular aspect, provided is a bispecific antigen binding molecule, wherein

(a) the moiety capable of specific binding to OX40 comprises a VH comprising the amino acid sequence of SEQ ID NO:33 and a VL comprising the amino acid sequence of SEQ ID NO:34 and the moiety capable of specific binding to EpCAM comprises a VH comprising the amino acid sequence of SEQ ID NO: 63 and a VL comprising the amino acid sequence of SEQ ID NO:64,

(b) the moiety capable of specific binding to OX40 comprises a VH comprising the amino acid sequence of SEQ ID NO:35 and a VL comprising the amino acid sequence of SEQ ID NO:36 and the moiety capable of specific binding to EpCAM comprises a VH comprising the amino acid sequence of SEQ ID NO: 63 and a VL comprising the amino acid sequence of SEQ ID NO:64,

(c) the moiety capable of specific binding to OX40 comprises a VH comprising the amino acid sequence of SEQ ID NO:37 and a VL comprising the amino acid sequence of SEQ ID NO:38 and the moiety capable of specific binding to EpCAM comprises a VH comprising the amino acid sequence of SEQ ID NO: 63 and a VL comprising the amino acid sequence of SEQ ID NO:64,

(d) the moiety capable of specific binding to OX40 comprises a VH comprising the amino acid sequence of SEQ ID NO:39 and a VL comprising the amino acid sequence of SEQ ID NO:40 and the moiety capable of specific binding to EpCAM comprises a VH comprising the amino acid sequence of SEQ ID NO: 63 and a VL comprising the amino acid sequence of SEQ ID NO:64,

(e) the moiety capable of specific binding to OX40 comprises a VH comprising the amino acid sequence of SEQ ID NO:41 and a VL comprising the amino acid sequence of SEQ ID NO:42 and the moiety capable of specific binding to EpCAM comprises a VH comprising the amino acid sequence of SEQ ID NO: 63 and a VL comprising the amino acid sequence of SEQ ID NO:64,

(f) the moiety capable of specific binding to OX40 comprises a VH comprising the amino acid sequence of SEQ ID NO:43 and a VL comprising the amino acid sequence of SEQ ID NO:44 and the moiety capable of specific binding to EpCAM comprises a VH comprising the amino acid sequence of SEQ ID NO: 63 and a VL comprising the amino acid sequence of SEQ ID NO:64,

(g) the moiety capable of specific binding to OX40 comprises a VH comprising the amino acid sequence of SEQ ID NO:45 and a VL comprising the amino acid sequence of SEQ ID NO:46 and the moiety capable of specific binding to EpCAM comprises a VH comprising the amino acid sequence of SEQ ID NO:63 and a VL comprising the amino acid sequence of SEQ ID NO:64.

In a particular aspect, the invention provides a bispecific antigen binding molecule, wherein

the moiety capable of specific binding to OX40 comprises a VH comprising the amino acid sequence of SEQ ID NO:35 and a VL comprising the amino acid sequence of SEQ ID NO:36, and

the moiety capable of specific binding to EpCAM comprises a VH comprising the amino acid sequence of SEQ ID NO: 63 and a VL comprising the amino acid sequence of SEQ ID NO:64.

In a further aspect, provided is a bispecific antigen binding molecule, wherein (i) the moiety capable of specific binding to OX40 comprises a VH comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:47, and a VL comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:48 and

(ii) the moiety capable of specific binding to EpCAM comprises a VH comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:65, and a VL comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:66. In a particular aspect, provided is a bispecific antigen binding molecule, wherein the moiety capable of specific binding to OX40 comprises a VH comprising the amino acid sequence of SEQ ID NO:47 and a VL comprising the amino acid sequence of SEQ ID NO:48, and

the moiety capable of specific binding to EpCAM comprises a VH comprising the amino acid sequence of SEQ ID NO: 65 and a VL comprising the amino acid sequence of SEQ ID NO:66.

Bispecific antigen binding molecules having tetravalent binding to OX40, and monovalent binding to EpCAM (4+1 format) In one aspect, the bispecific antigen binding molecule is tetravalent for OX40 and monovalent for EpCAM.

In one aspect, the bispecific antigen binding molecule of the invention comprises

(a) four Fab fragments capable of specific binding to OX40 connected to a Fc region, and

(b) a moiety capable of specific binding to EpCAM comprising an antibody light chain variable region (VL) and an antibody heavy chain variable region (VH) connected to the C- terminus of the Fc region.

In one aspect, the bispecific antigen binding molecule of the invention comprises

(a) two light chains and two heavy chains of an antibody comprising four Fab fragments capable of specific binding to OX40, and a Fc region, and

(b) a VH and a VL of a moiety capable specific binding to EpCAM, wherein the VH is connected to the C-terminus of one of the two heavy chains of (a), and wherein the VL is connected to the C-terminus of the other of the two heavy chains of (a).

In one aspect, the bispecific antigen binding molecule of the invention comprises (a) two heavy chains, each heavy chain comprising two VH domains and two CHI domains of a Fab fragment capable of specific binding to OX40 and a Fc region subunit,

(b) four light chains, each light chain comprising a VL and CL domain of a Fab fragment capable of specific binding to OX40, and

(c) a VH and a VL of a moiety capable specific binding to EpCAM, wherein the VH is connected to the C-terminus of one of the two heavy chains of (a), and wherein the VL is connected to the C-terminus of the other of the two heavy chains of (a).

In some embodiments in accordance with various aspects of the present invention, the VH of a moiety capable specific binding to EpCAM is connected to the C-terminus of one of the two heavy chains of (a) via a peptide linker. In some embodiments in accordance with various aspects of the present invention, the VL of a moiety capable specific binding to EpCAM is connected to the C-terminus of one of the two heavy chains of (a) via a peptide linker. In particular embodiments, the peptide linker is (G4S) ₄ (SEQ ID NO:81).

In a particular aspect, the invention provides a bispecific antigen binding molecule comprising a first heavy chain comprising the amino acid sequence of SEQ ID NO: 183, a second heavy chain comprising the amino acid sequence of SEQ ID NO: 184, and a light chain comprising the amino acid sequence of SEQ ID NO: 182.

In a particular aspect, the invention provides a bispecific antigen binding molecule comprising

a first heavy chain comprising the amino acid sequence of SEQ ID NO: 183,

a second heavy chain comprising the amino acid sequence of SEQ ID NO: 184, and four light chains, each comprising the amino acid sequence of SEQ ID NO: 182.

In a particular aspect, the invention provides a bispecific antigen binding molecule comprising a first heavy chain comprising the amino acid sequence of SEQ ID NO: 192, a second heavy chain comprising the amino acid sequence of SEQ ID NO: 193, and a light chain comprising the amino acid sequence of SEQ ID NO: 191.

In a particular aspect, the invention provides a bispecific antigen binding molecule comprising

a first heavy chain comprising the amino acid sequence of SEQ ID NO: 192,

a second heavy chain comprising the amino acid sequence of SEQ ID NO: 193, and four light chains, each comprising the amino acid sequence of SEQ ID NO: 191.

In one aspect, the bispecific antigen binding molecule of the invention comprises a first and a second heavy chain and four light chains that form a first, a second, a third, a forth, and a fifth antigen binding moiety, wherein the first, the second, the third, and the fourth antigen binding moiety each are capable of specific binding to OX40 and the fifth antigen binding moiety is capable of specific binding to EpCAM, wherein

(i) the first polypeptide chain comprises in amino (N)-terminal to carboxyl (C)-terminal direction, VH(OX40), CHI, VH(OX40), CHI, CH2, CH3 (Fc knob) and VH(EpCAM),

(ii) the second polypeptide chain comprises in N-terminal to C-terminal direction, VH(OX40), CHI, VH(OX40), CHI, CH2, CH3(Fc hole) and VL(EpCAM), and

(iii) four light chains comprise in N-terminal to C-terminal direction VL(OX40) and CL.

In another aspect, the bispecific antigen binding molecule of the invention comprises a first and a second heavy chain and four light chains that form a first, a second, a third, a forth, and a fifth antigen binding moiety, wherein the first, the second, the third, and the fourth antigen binding moiety each are capable of specific binding to OX40 and the fifth antigen binding moiety is capable of specific binding to EpCAM, wherein

(i) the first polypeptide chain comprises in amino (N)-terminal to carboxyl (C)-terminal direction, VH(OX40), CHI, VH(OX40), CHI, CH2, CH3 (Fc knob) and VL(EpCAM),

(ii) the second polypeptide chain comprises in N-terminal to C-terminal direction, VH(OX40), CHI, VH(OX40), CHI, CH2, CH3(Fc hole) and VH(EpCAM), and

(iii) the four light chains comprise in N-terminal to C-terminal direction VL(Ox40) and CL.

Bispecific antigen binding molecules having tetravalent binding to OX40, and bivalent binding to EpCAM (4+2 format)

In one aspect, the bispecific antigen binding molecule is tetravalent for OX40 and bivalent for EpCAM.

In one aspect, the bispecific antigen binding molecule of the invention comprises

(a) four Fab fragments capable of specific binding to OX40 connected to a Fc region, and (b) a moiety capable of specific binding to EpCAM comprising an antibody light chain variable region (VL) and an antibody heavy chain variable region (VH) connected to the C- terminus of the Fc region.

In one aspect, the bispecific antigen binding molecule of the invention comprises

(a) four light chains and two heavy chains of an antibody comprising four Fab fragments capable of specific binding to OX40, and a Fc region, and

(b) two Fab fragments capable of specific binding to EpCAM, wherein one of the Fab fragments is connected to the C-terminus of one of the two heavy chains of (a), and the other of the Fab fragments is connected to the C-terminus of the other of the two heavy chains of (a).

In one aspect, the bispecific antigen binding molecule of the invention comprises (a) two heavy chains, each heavy chain comprising two VH domains and two CHI domains of a Fab fragment capable of specific binding to OX40 and a Fc region subunit,

(b) four light chains, each light chain comprising a VL and CL domain of a Fab fragment capable of specific binding to OX40, and

(c) two Fab fragments capable of specific binding to EpCAM, wherein one of the Fab fragments is connected to the C-terminus of one of the two heavy chains of (a), and the other of the Fab fragments is connected to the C-terminus of the other of the two heavy chains of (a).

In some embodiments, the two Fab fragments capable of specific binding to EpCAM are crossover Fab fragments each comprising a VL-CHl chain and a VH-CL chain, and wherein one of the VL-CHl chains is connected to the C-terminus of one of the two heavy chains of (a), and the other of the VL-CHl chains is connected to the C-terminus of the other of the two heavy chains of (a).

In some embodiments in accordance with various aspects of the present invention, Fab fragments capable of specific binding to EpCAM are connected to the C-terminus of the heavy chains of (a) via a peptide linker. In some embodiments in accordance with various aspects of the present invention, the VL-CHl chain of a crossover Fab fragment capable of specific binding to EpCAM is connected to the C-terminus of one of the two heavy chains of (a) via a peptide linker. In particular embodiments, the peptide linker is (G4S) ₄ (SEQ ID NO:81).

In a particular aspect, the invention provides a bispecific antigen binding molecule comprising two heavy chains, each comprising the amino acid sequence of SEQ ID NO: 186, a first light chain comprising the amino acid sequence of SEQ ID NO: 185, and a second light chain comprising the amino acid sequence of SEQ ID NO: 187.

In a particular aspect, the invention provides a bispecific antigen binding molecule comprising

two heavy chains, each comprising the amino acid sequence of SEQ ID NO: 186, two light chains, each comprising the amino acid sequence of SEQ ID NO: 187, and four light chains, each comprising the amino acid sequence of SEQ ID NO: 185.

In one aspect, the bispecific antigen binding molecule of the invention comprises a first and a second heavy chain and six light chains that form a first, a second, a third, a forth, a fifth, and a sixth antigen binding moiety, wherein the first, the second, the third, and the fourth antigen binding moiety each are capable of specific binding to OX40, and wherein the fifth and the sixth antigen binding moiety each are capable of specific binding to EpCAM, wherein

(i) the first and the second polypeptide chains comprise in amino (N)-terminal to carboxyl (C)- terminal direction, VH(OX40), CHI *, VH(OX40), CHI *, CH2, CH3, VL(EpCAM) and CHI, (ii) four light chains comprise in N-terminal to C-terminal direction VL(OX40) and CL*, and (iii) two light chains comprise in N-terminal to C-terminal direction VH(EpCAM) and CL and wherein CHI * and CL* comprise amino acid mutations to allow better pairing.

Fc region modifications reducing Fc receptor binding and/or effector function

In embodiments in accordance with various aspects of the present invention, the bispecific antigen binding molecules further comprise a Fc region composed of a first and a second subunit capable of stable association.

In certain aspects, one or more amino acid modifications may be introduced into the Fc region of an antibody provided herein, thereby generating an Fc region variant. The Fc region variant may comprise a human Fc region sequence (e.g., a human IgGl, IgG2, IgG3 or IgG4 Fc region) comprising an amino acid modification (e.g. a substitution) at one or more amino acid positions.

The Fc region confers favorable pharmacokinetic properties to the bispecific antibodies of the invention, including a long serum half-life which contributes to good accumulation in the target tissue and a favorable tissue-blood distribution ratio. At the same time it may, however, lead to undesirable targeting of the bispecific antibodies of the invention to cells expressing Fc receptors rather than to the preferred antigen-bearing cells. Accordingly, in particular

embodiments the Fc region of the bispecific antibodies of the invention exhibits reduced binding affinity to an Fc receptor and/or reduced effector function, as compared to a native IgG Fc region, in particular an IgGl Fc region or an IgG4 Fc region. More particularly, the Fc region is an IgGl Fc region.

In one such aspect the Fc region (or the bispecific antigen binding molecule of the invention comprising said Fc region) exhibits less than 50%, preferably less than 20%, more preferably less than 10% and most preferably less than 5% of the binding affinity to an Fc receptor, as compared to a native IgGl Fc region (or the bispecific antigen binding molecule of the invention comprising a native IgGl Fc region), and/or less than 50%, preferably less than

20%, more preferably less than 10% and most preferably less than 5% of the effector function, as compared to a native IgGl Fc region (or the bispecific antigen binding molecule of the invention comprising a native IgGl Fc region). In one aspect, the Fc region (or the bispecific antigen binding molecule of the invention comprising said Fc region) does not substantially bind to an Fc receptor and/or induce effector function. In a particular aspect the Fc receptor is an Fey receptor. In one aspect, the Fc receptor is a human Fc receptor. In one aspect, the Fc receptor is an activating Fc receptor. In a specific aspect, the Fc receptor is an activating human Fey receptor, more specifically human FcyRIIIa, FcyRI or FcyRIIa, most specifically human FcyRIIIa. In one aspect, the Fc receptor is an inhibitory Fc receptor. In a specific aspect, the Fc receptor is an inhibitory human Fey receptor, more specifically human FcyRIIB. In one aspect the effector function is one or more of CDC, ADCC, ADCP, and cytokine secretion. In a particular aspect, the effector function is ADCC. In one aspect, the Fc region domain exhibits substantially similar binding affinity to neonatal Fc receptor (FcRn), as compared to a native IgGl Fc region.

Substantially similar binding to FcRn is achieved when the Fc region (or the bispecific antigen binding molecule of the invention comprising said Fc region) exhibits greater than about 70%, particularly greater than about 80%, more particularly greater than about 90% of the binding affinity of a native IgGl Fc region (or the bispecific antigen binding molecule of the invention comprising a native IgGl Fc region) to FcRn.

In a particular aspect, the Fc region is engineered to have reduced binding affinity to an Fc receptor and/or reduced effector function, as compared to a non-engineered Fc region. In a particular aspect, the Fc region of the bispecific antigen binding molecule of the invention comprises one or more amino acid mutation that reduces the binding affinity of the Fc region to an Fc receptor and/or effector function. Typically, the same one or more amino acid mutation is present in each of the two subunits of the Fc region. In one aspect, the amino acid mutation reduces the binding affinity of the Fc region to an Fc receptor. In another aspect, the amino acid mutation reduces the binding affinity of the Fc region to an Fc receptor by at least 2-fold, at least 5-fold, or at least 10-fold. In one aspect, the bispecific antigen binding molecule of the invention comprising an engineered Fc region exhibits less than 20%, particularly less than 10%, more particularly less than 5% of the binding affinity to an Fc receptor as compared to bispecific antibodies of the invention comprising a non-engineered Fc region. In a particular aspect, the Fc receptor is an Fey receptor. In other aspects, the Fc receptor is a human Fc receptor. In one aspect, the Fc receptor is an inhibitory Fc receptor. In a specific aspect, the Fc receptor is an inhibitory human Fey receptor, more specifically human FcyRIIB. In some aspects the Fc receptor is an activating Fc receptor. In a specific aspect, the Fc receptor is an activating human Fey receptor, more specifically human FcyRIIIa, FcyRI or FcyRIIa, most specifically human FcyRIIIa. Preferably, binding to each of these receptors is reduced. In some aspects, binding affinity to a complement component, specifically binding affinity to Clq, is also reduced. In one aspect, binding affinity to neonatal Fc receptor (FcRn) is not reduced. Substantially similar binding to FcRn, i.e. preservation of the binding affinity of the Fc region to said receptor, is achieved when the Fc region (or the bispecific antigen binding molecule of the invention comprising said Fc region) exhibits greater than about 70% of the binding affinity of a non- engineered form of the Fc region (or the bispecific antigen binding molecule of the invention comprising said non-engineered form of the Fc region) to FcRn. The Fc region, or the bispecific antigen binding molecule of the invention comprising said Fc region, may exhibit greater than about 80% and even greater than about 90% of such affinity. In certain embodiments the Fc region of the bispecific antigen binding molecule of the invention is engineered to have reduced effector function, as compared to a non-engineered Fc region. The reduced effector function can include, but is not limited to, one or more of the following: reduced complement dependent cytotoxicity (CDC), reduced antibody-dependent cell-mediated cytotoxicity (ADCC), reduced antibody-dependent cellular phagocytosis (ADCP), reduced cytokine secretion, reduced immune complex-mediated antigen uptake by antigen-presenting cells, reduced binding to NK cells, reduced binding to macrophages, reduced binding to monocytes, reduced binding to

polymorphonuclear cells, reduced direct signaling inducing apoptosis, reduced dendritic cell maturation, or reduced T cell priming.

Antibodies with reduced effector function include those with substitution of one or more of Fc region residues 238, 265, 269, 270, 297, 327 and 329 (U.S. Patent No. 6,737,056). Such Fc mutants include Fc mutants with substitutions at two or more of amino acid positions 265, 269, 270, 297 and 327, including the so-called "DANA" Fc mutant with substitution of residues 265 and 297 to alanine (US Patent No. 7,332,581). Certain antibody variants with improved or diminished binding to FcRs are described, (e.g. U.S. Patent No. 6,737,056; WO 2004/056312, and Shields, R.L. et al, J. Biol. Chem. 276 (2001) 6591-6604). In one aspect of the invention, the Fc region comprises an amino acid substitution at a position of E233, L234, L235, N297, P331 and P329. In some aspects, the Fc region comprises the amino acid substitutions L234A and L235A ("LALA"). In one such embodiment, the Fc region is an IgGl Fc region, particularly a human IgGl Fc region. In one aspect, the Fc region comprises an amino acid substitution at position P329. In a more specific aspect, the amino acid substitution is P329A or P329G, particularly P329G. In one embodiment the Fc region comprises an amino acid substitution at position P329 and a further amino acid substitution selected from the group consisting of E233P, L234A, L235A, L235E, N297A, N297D or P331S. In more particular embodiments the Fc region comprises the amino acid mutations L234A, L235A and P329G ("P329G LALA"). The "P329G LALA" combination of amino acid substitutions almost completely abolishes Fey receptor binding of a human IgGl Fc region, as described in PCT Patent Application No. WO 2012/130831 Al . Said document also describes methods of preparing such mutant Fc regions and methods for determining its properties such as Fc receptor binding or effector functions. such antibody is an IgGl with mutations L234A and L235A or with mutations L234A, L235A and P329G (numbering according to EU index of Kabat et al, Kabat et al, Sequences of Proteins of Immunological Interest, 5th Ed. Public Health Service, National Institutes of Health, Bethesda, MD, 1991).

In one aspect of the invention, the Fc region comprises an amino acid substitution at positions D265, and P329. In some aspects, the Fc region comprises the amino acid substitutions D265A and P329G ("DAPG") in the CH2 domain. In one such embodiment, the Fc region is an IgGl Fc region, particularly a mouse IgGl Fc region. DAPG mutations are described e.g. in WO 2016/030350 Al, and can be introduced in CH2 regions of heavy chains to abrogate binding of antigen binding molecules to murine Fc gamma receptors.

In one aspect, the Fc region is an IgG4 Fc region. In a more specific embodiment, the Fc region is an IgG4 Fc region comprising an amino acid substitution at position S228 (Kabat numbering), particularly the amino acid substitution S228P. In a more specific embodiment, the Fc region is an IgG4 Fc region comprising amino acid substitutions L235E and S228P and P329G. This amino acid substitution reduces in vivo Fab arm exchange of IgG4 antibodies (see Stubenrauch et al, Drug Metabolism and Disposition 38, 84-91 (2010)).

Antibodies with increased half lives and improved binding to the neonatal Fc receptor (FcRn), which is responsible for the transfer of maternal IgGs to the fetus (Guyer, R.L. et al, J. Immunol. 117 (1976) 587-593, and Kim, J.K. et al, J. Immunol. 24 (1994) 2429-2434), are described in US 2005/0014934. Those antibodies comprise an Fc region with one or more substitutions therein which improve binding of the Fc region to FcRn. Such Fc variants include those with substitutions at one or more of Fc region residues: 238, 256, 265, 272, 286, 303, 305, 307, 311, 312, 317, 340, 356, 360, 362, 376, 378, 380, 382, 413, 424 or 434, e.g., substitution of Fc region residue 434 (US Patent No. 7,371,826). See also Duncan, A.R. and Winter, G., Nature 322 (1988) 738-740; US 5,648,260; US 5,624,821; and WO 94/29351 concerning other examples of Fc region variants.

Binding to Fc receptors can be easily determined e.g. by ELISA, or by Surface Plasmon Resonance (SPR) using standard instrumentation such as a BIAcore instrument (GE Healthcare), and Fc receptors such as may be obtained by recombinant expression. A suitable such binding assay is described herein. Alternatively, binding affinity of Fc regions or cell activating bispecific antigen binding molecules comprising an Fc region for Fc receptors may be evaluated using cell lines known to express particular Fc receptors, such as human NK cells expressing Fcyllla receptor. Effector function of an Fc region, or bispecific antibodies of the invention comprising an Fc region, can be measured by methods known in the art. A suitable assay for measuring ADCC is described herein. Other examples of in vitro assays to assess ADCC activity of a molecule of interest are described in U.S. Patent No. 5,500,362; Hellstrom et al. Proc Natl Acad Sci USA 83, 7059-7063 (1986) and Hellstrom et al, Proc Natl Acad Sci USA 82, 1499- 1502 (1985); U.S. Patent No. 5,821,337; Bruggemann et al, J Exp Med 166, 1351-1361 (1987). Alternatively, non-radioactive assays methods may be employed (see, for example, ACTI™ nonradioactive cytotoxicity assay for flow cytometry (CellTechnology, Inc. Mountain View, CA); and CytoTox 96 ^® non-radioactive cytotoxicity assay (Promega, Madison, WI)). Useful effector cells for such assays include peripheral blood mononuclear cells (PBMC) and Natural Killer (NK) cells. Alternatively, or additionally, ADCC activity of the molecule of interest may be assessed in vivo, e.g. in a animal model such as that disclosed in Clynes et al, Proc Natl Acad Sci USA 95, 652-656 (1998).

The following section describes preferred aspects of the bispecific antigen binding molecules of the invention comprising Fc region modifications reducing Fc receptor binding and/or effector function. In one aspect, the invention relates to the bispecific antigen binding molecule (a) at least one moiety capable of specific binding to OX40, (b) at least one moiety capable of specific binding to EpCAM, and (c) a Fc region composed of a first and a second subunit capable of stable association, wherein the Fc region comprises one or more amino acid substitution that reduces the binding affinity of the antibody to an Fc receptor, in particular towards Fey receptor. In another aspect, the invention relates to the bispecific antigen binding molecule comprising (a) at least one moiety capable of specific binding to OX40, (b) at least one moiety capable of specific binding to EpCAM, and (c) a Fc region composed of a first and a second subunit capable of stable association, wherein the Fc region comprises one or more amino acid substitution that reduces effector function. In particular aspect, the Fc region is of human IgGl subclass with the amino acid mutations L234A, L235A and P329G (numbering according to Kabat EU index). In particular aspect, the Fc region is of mouse IgGl subclass with the amino acid mutations D265 A and P329G.

Fc region modifications promoting heterodimerization

The bispecific antigen binding molecules of the invention comprise different antigen- binding sites, fused to one or the other of the two subunits of the Fc region, thus the two subunits of the Fc region may be comprised in two non-identical polypeptide chains. Recombinant co- expression of these polypeptides and subsequent dimerization leads to several possible

combinations of the two polypeptides. To improve the yield and purity of the bispecific antibodies of the invention in recombinant production, it will thus be advantageous to introduce in the Fc region of the bispecific antigen binding molecules of the invention a modification promoting the association of the desired polypeptides.

Accordingly, in particular aspects the invention relates to the bispecific antigen binding molecule comprising (a) at least one moiety capable of specific binding to OX40, (b) at least one moiety capable of specific binding to EpCAM, and (c) a Fc region composed of a first and a second subunit capable of stable association, wherein the Fc region comprises a modification promoting the association of the first and second subunit of the Fc region. The site of most extensive protein-protein interaction between the two subunits of a human IgG Fc region is in the CH3 domain of the Fc region. Thus, in one aspect said modification is in the CH3 domain of the Fc region. In a specific aspect said modification is a so-called "knob-into-hole" modification, comprising a "knob" modification in one of the two subunits of the Fc region and a "hole" modification in the other one of the two subunits of the Fc region. Thus, the invention relates to the bispecific antigen binding molecule comprising (a) at least one moiety capable of specific binding to OX40, (b) at least one moiety capable of specific binding to EpCAM, and (c) a Fc region composed of a first and a second subunit capable of stable association, wherein the first subunit of the Fc region comprises knobs and the second subunit of the Fc region comprises holes according to the knobs into holes method. In a particular aspect, the first subunit of the Fc region comprises the amino acid substitutions S354C and T366W (EU numbering) and the second subunit of the Fc region comprises the amino acid substitutions Y349C, T366S and Y407V (numbering according to Kabat EU index).

The knob-into-hole technology is described e.g. in US 5,731,168; US 7,695,936; Ridgway et al, Prot Eng 9, 617-621 (1996) and Carter, J Immunol Meth 248, 7-15 (2001). Generally, the method involves introducing a protuberance ("knob") at the interface of a first polypeptide and a corresponding cavity ("hole") in the interface of a second polypeptide, such that the

protuberance can be positioned in the cavity so as to promote heterodimer formation and hinder homodimer formation. Protuberances are constructed by replacing small amino acid side chains from the interface of the first polypeptide with larger side chains (e.g. tyrosine or tryptophan). Compensatory cavities of identical or similar size to the protuberances are created in the interface of the second polypeptide by replacing large amino acid side chains with smaller ones (e.g. alanine or threonine).

Accordingly, in one aspect, in the CH3 domain of the first subunit of the Fc region of the bispecific antigen binding molecules of the invention an amino acid residue is replaced with an amino acid residue having a larger side chain volume, thereby generating a protuberance within the CH3 domain of the first subunit which is positionable in a cavity within the CH3 domain of the second subunit, and in the CH3 domain of the second subunit of the Fc region an amino acid residue is replaced with an amino acid residue having a smaller side chain volume, thereby generating a cavity within the CH3 domain of the second subunit within which the protuberance within the CH3 domain of the first subunit is positionable. The protuberance and cavity can be made by altering the nucleic acid encoding the polypeptides, e.g. by site-specific mutagenesis, or by peptide synthesis. In a specific aspect, in the CH3 domain of the first subunit of the Fc region the threonine residue at position 366 is replaced with a tryptophan residue (T366W), and in the CH3 domain of the second subunit of the Fc region the tyrosine residue at position 407 is replaced with a valine residue (Y407V). In one aspect, in the second subunit of the Fc region additionally the threonine residue at position 366 is replaced with a serine residue (T366S) and the leucine residue at position 368 is replaced with an alanine residue (L368A). In yet a further aspect, in the first subunit of the Fc region additionally the serine residue at position 354 is replaced with a cysteine residue (S354C), and in the second subunit of the Fc region additionally the tyrosine residue at position 349 is replaced by a cysteine residue (Y349C). Introduction of these two cysteine residues results in formation of a disulfide bridge between the two subunits of the Fc region, further stabilizing the dimer (Carter (2001), J Immunol Methods 248, 7-15). In a particular aspect, the first subunit of the Fc region comprises the amino acid substitutions S354C and T366W (EU numbering) and the second subunit of the Fc region comprises the amino acid substitutions Y349C, T366S and Y407V (numbering according to Kabat EU index). In a further aspect, the first subunit of the Fc region comprises aspartic acid residues (D) at positions 392 and 409, and the second subunit of the Fc region comprises lysine residues (K) at positions 356 and 399. In some embodiments, in the first subunit of the Fc region the lysine residues at positions 392 and 409 are replaced with aspartic acid residues (K392D, K409D), and in the second subunit of the Fc region the glutamate residue at position 356 and the aspartic acid residue at position 399 are replaced with lysine residues (E356K, D399K). "DDK " knob-into- hole technology is described e.g. in WO 2014/131694 Al, and favours the assembly of the heavy chains bearing subunits providing the complementary amino acid residues.

In an alternative aspect, a modification promoting association of the first and the second subunit of the Fc region comprises a modification mediating electrostatic steering effects, e.g. as described in PCT publication WO 2009/089004. Generally, this method involves replacement of one or more amino acid residues at the interface of the two Fc region subunits by charged amino acid residues so that homodimer formation becomes electrostatically unfavorable but

heterodimerization electrostatically favorable.

The C-terminus of the heavy chain of the bispecific antibody as reported herein can be a complete C-terminus ending with the amino acid residues PGK. The C-terminus of the heavy chain can be a shortened C-terminus in which one or two of the C terminal amino acid residues have been removed. In one preferred aspect, the C-terminus of the heavy chain is a shortened C- terminus ending PG. In one aspect of all aspects as reported herein, a bispecific antibody comprising a heavy chain including a C-terminal CH3 domain as specified herein, comprises the C-terminal glycine- lysine dipeptide (G446 and K447, numbering according to Kabat EU index). In one embodiment of all aspects as reported herein, a bispecific antibody comprising a heavy chain including a C-terminal CH3 domain, as specified herein, comprises a C-terminal glycine residue (G446, numbering according to Kabat EU index). Modifications in the Fab domains

In one aspect, the invention relates to a bispecific antigen binding molecule comprising (a) a first Fab fragment capable of specific binding to OX40, (b) a second Fab fragment capable of specific binding to EpCAM, and (c) a Fc region composed of a first and a second subunit capable of stable association, wherein in one of the Fab fragments either the variable domains VH and VL or the constant domains CHI and CL are exchanged. The bispecific antibodies are prepared according to the Crossmab technology.

Multispecific antibodies with a domain replacement/exchange in one binding arm

(CrossMabVH-VL or CrossMabCH-CL) are described in detail in WO2009/080252 and

Schaefer, W. et al, PNAS, 108 (201 1) 11187-1191. They clearly reduce the byproducts caused by the mismatch of a light chain against a first antigen with the wrong heavy chain against the second antigen (compared to approaches without such domain exchange).

In one aspect, the invention relates to a bispecific antigen binding molecule comprising (a) a first Fab fragment capable of specific binding to OX40, (b) a second Fab fragment capable of specific binding to EpCAM, and (c) a Fc region composed of a first and a second subunit capable of stable association, wherein in one of the Fab fragments the constant domains CL and CHI are replaced by each other so that the CHI domain is part of the light chain and the CL domain is part of the heavy chain. More particularly, in the second Fab fragment capable of specific binding to EpCAM the constant domains CL and CHI are replaced by each other so that the CHI domain is part of the light chain and the CL domain is part of the heavy chain.

In a particular aspect, the invention relates a bispecific antigen binding molecule comprising (a) a first Fab fragment capable of specific binding to OX40, (b) a second Fab fragment capable of specific binding to EpCAM, wherein the constant domains CL and CHI are replaced by each other so that the CHI domain is part of the light chain and the CL domain is part of the heavy chain. Such a molecule is called a monvalent bispecific antigen binding molecule.

In another aspect, the invention relates to a bispecific antigen binding molecule, comprising (a) two light chains and two heavy chains of an antibody comprising two Fab fragments capable of specific binding to OX40 and the Fc region, and (b) two additional Fab fragments capable of specific binding to EpCAM, wherein said additional Fab fragments are each connected via a peptide linker to the C-terminus of the heavy chains of (a). In a particular aspect, the additional Fab fragments are Fab fragments, wherein the variable domains VL and VH are replaced by each other so that the VH is part of the light chain and the VL is part of the heavy chain. Thus, in a particular aspect, the invention comprises a bispecific, antigen binding molecule, comprising (a) two light chains and two heavy chains of an antibody comprising two Fab fragments capable of specific binding to OX40 and the Fc region, and (b) two additional Fab fragments capable of specific binding to EpCAM, wherein said two additional Fab fragments capable of specific binding to a EpCAM are crossover Fab fragments wherein the variable domains VL and VH are replaced by each other and the VL-CH chains are each connected via a peptide linker to the C-terminus of the heavy chains of (a).

In another aspect, and to further improve correct pairing, the bispecific antigen binding molecule comprising (a) a first Fab fragment capable of specific binding to OX40, (b) a second Fab fragment capable of specific binding to EpCAM, and (c) a Fc region composed of a first and a second subunit capable of stable association, can contain different charged amino acid substitutions (so-called "charged residues"). These modifications are introduced in the crossed or non-crossed CHI and CL domains. In a particular aspect, the invention relates to a bispecific antigen binding molecule, wherein in one of CL domains the amino acid at position 123 (EU numbering) has been replaced by arginine (R) and the amino acid at position 124 (EU numbering) has been substituted by lysine (K) and wherein in one of the CHI domains the amino acids at position 147 (EU numbering) and at position 213 (EU numbering) have been substituted by glutamic acid (E).

More particularly, the invention relates to a bispecific antigen binding molecule

comprising a Fab, wherein in the CL domain the amino acid at position 123 (EU numbering) has been replaced by arginine (R) and the amino acid at position 124 (EU numbering) has been substituted by lysine (K), and wherein in the CHI domain the amino acids at position 147 (EU numbering) and at position 213 (EU numbering) have been substituted by glutamic acid (E).

Accordingly, in some embodiments one or more of the Fab fragments (e.g. Fab fragments capable of specific binding to OX40) of the bispecific antigen binding molecule of the present invention comprise a CL domain comprising an arginine (R) at amino acid at position 123 (EU numbering) and a lysine (K) at amino acid at position 124 (EU numbering), and a CHI domain comprising a glutamic acid (E) at amino acid at position 147 (EU numbering) and a glutamic acid (E) at amino acid at position 213 (EU numbering). Polynucleotides

The invention further provides isolated polynucleotides encoding a bispecific antigen binding molecule of the invention as described herein, or a fragment thereof.

The isolated polynucleotides encoding bispecific antigen binding molecules of the invention may be expressed as a single polynucleotide that encodes the entire antigen binding molecule or as multiple (e.g., two or more) polynucleotides that are co-expressed. Polypeptides encoded by polynucleotides that are co-expressed may associate through, e.g., disulfide bonds or other means to form a functional antigen binding molecule. For example, the light chain portion of a moiety capable of specific binding to EpCAM may be encoded by a separate polynucleotide from the heavy chain portion of the capable of specific binding to EpCAM. When co-expressed, the heavy chain polypeptides will associate with the light chain polypeptides to form the moiety capable of specific binding to EpCAM. Similarly, the light chain portion of a moiety capable of specific binding to OX40 may be encoded by a separate polynucleotide from the heavy chain portion of the capable of specific binding to OX40. When co-expressed, the heavy chain polypeptides will associate with the light chain polypeptides to form the moiety capable of specific binding to OX40.

In certain embodiments the polynucleotide or nucleic acid is DNA. In other embodiments, a polynucleotide of the present invention is R A, for example, in the form of messenger R A (mR A). RNA of the present invention may be single stranded or double stranded. According to another aspect of the invention, there is provided an isolated polynucleotide encoding a bispecific antigen binding molecule as defined herein before or a fusion polypeptide as described herein before. The invention further provides a vector, particularly an expression vector, comprising the isolated polynucleotide of the invention and a host cell comprising the isolated polynucleotide or the vector of the invention. In some embodiments the host cell is a eukaryotic cell, particularly a mammalian cell.

In another aspect, provided is a method for producing the bispecific antigen binding molecule of the invention, comprising the steps of (i) culturing the host cell of the invention under conditions suitable for expression of said antigen binding molecule, and (ii) isolating said bispecific antigen binding molecule. The invention also encompasses a bispecific antigen binding molecule produced by the method of the invention.

Recombinant Methods

Bispecific antigen binding molecules of the invention may be obtained, for example, by solid-state peptide synthesis (e.g. Merrifield solid phase synthesis) or recombinant production. For recombinant production one or more polynucleotide encoding the antigen binding molecule or polypeptide fragments thereof, e.g., as described above, is isolated and inserted into one or more vectors for further cloning and/or expression in a host cell. Such polynucleotide may be readily isolated and sequenced using conventional procedures. In one aspect of the invention, a vector, preferably an expression vector, comprising one or more of the polynucleotides of the invention is provided. Methods which are well known to those skilled in the art can be used to construct expression vectors containing the coding sequence of the bispecific antigen binding molecule (fragment) along with appropriate transcriptional/translational control signals. These methods include in vitro recombinant DNA techniques, synthetic techniques and in vivo recombination/genetic recombination. See, for example, the techniques described in Maniatis et al, MOLECULAR CLONING: A LABORATORY MANUAL, Cold Spring Harbor Laboratory, N.Y. (1989); and Ausubel et al, CURRENT PROTOCOLS IN MOLECULAR BIOLOGY,

Greene Publishing Associates and Wiley Interscience, N.Y. (1989). The expression vector can be part of a plasmid, virus, or may be a nucleic acid fragment. The expression vector includes an expression cassette into which the polynucleotide encoding the bispecific antigen binding molecule or polypeptide fragments thereof (i.e. the coding region) is cloned in operable association with a promoter and/or other transcription or translation control elements. As used herein, a "coding region" is a portion of nucleic acid which consists of codons translated into amino acids. Although a "stop codon" (TAG, TGA, or TAA) is not translated into an amino acid, it may be considered to be part of a coding region, if present, but any flanking sequences, for example promoters, ribosome binding sites, transcriptional terminators, introns, 5' and 3' untranslated regions, and the like, are not part of a coding region. Two or more coding regions can be present in a single polynucleotide construct, e.g. on a single vector, or in separate polynucleotide constructs, e.g. on separate (different) vectors. Furthermore, any vector may contain a single coding region, or may comprise two or more coding regions, e.g. a vector of the present invention may encode one or more polypeptides, which are post- or co-translationally separated into the final proteins via proteolytic cleavage. In addition, a vector, polynucleotide, or nucleic acid of the invention may encode heterologous coding regions, either fused or unfused to a polynucleotide encoding the bispecific antigen binding molecule of the invention or polypeptide fragments thereof, or variants or derivatives thereof. Heterologous coding regions include without limitation specialized elements or motifs, such as a secretory signal peptide or a heterologous functional domain. An operable association is when a coding region for a gene product, e.g. a polypeptide, is associated with one or more regulatory sequences in such a way as to place expression of the gene product under the influence or control of the regulatory sequence(s). Two DNA fragments (such as a polypeptide coding region and a promoter associated therewith) are "operably associated" if induction of promoter function results in the transcription of mRNA encoding the desired gene product and if the nature of the linkage between the two DNA fragments does not interfere with the ability of the expression regulatory sequences to direct the expression of the gene product or interfere with the ability of the DNA template to be transcribed. Thus, a promoter region would be operably associated with a nucleic acid encoding a polypeptide if the promoter was capable of effecting transcription of that nucleic acid. The promoter may be a cell- specific promoter that directs substantial transcription of the DNA only in predetermined cells. Other transcription control elements, besides a promoter, for example enhancers, operators, repressors, and transcription termination signals, can be operably associated with the polynucleotide to direct cell-specific transcription. Suitable promoters and other transcription control regions are disclosed herein. A variety of transcription control regions are known to those skilled in the art. These include, without limitation, transcription control regions, which function in vertebrate cells, such as, but not limited to, promoter and enhancer segments from cytomegaloviruses (e.g. the immediate early promoter, in conjunction with intron-A), simian virus 40 (e.g. the early promoter), and retroviruses (such as, e.g. Rous sarcoma virus). Other transcription control regions include those derived from vertebrate genes such as actin, heat shock protein, bovine growth hormone and rabbit a-globin, as well as other sequences capable of controlling gene expression in eukaryotic cells. Additional suitable transcription control regions include tissue-specific promoters and enhancers as well as inducible promoters (e.g. promoters inducible tetracyclins). Similarly, a variety of translation control elements are known to those of ordinary skill in the art. These include, but are not limited to ribosome binding sites, translation initiation and termination codons, and elements derived from viral systems (particularly an internal ribosome entry site, or IRES, also referred to as a CITE sequence). The expression cassette may also include other features such as an origin of replication, and/or chromosome integration elements such as retroviral long terminal repeats (LTRs), or adeno-associated viral (AAV) inverted terminal repeats (ITRs).

Polynucleotide and nucleic acid coding regions of the present invention may be associated with additional coding regions which encode secretory or signal peptides, which direct the secretion of a polypeptide encoded by a polynucleotide of the present invention. For example, if secretion of the bispecific antigen binding molecule or polypeptide fragments thereof is desired, DNA encoding a signal sequence may be placed upstream of the nucleic acid encoding a bispecific antigen binding molecule of the invention or polypeptide fragments thereof.

According to the signal hypothesis, proteins secreted by mammalian cells have a signal peptide or secretory leader sequence which is cleaved from the mature protein once export of the growing protein chain across the rough endoplasmic reticulum has been initiated. Those of ordinary skill in the art are aware that polypeptides secreted by vertebrate cells generally have a signal peptide fused to the N-terminus of the polypeptide, which is cleaved from the translated polypeptide to produce a secreted or "mature" form of the polypeptide. In certain embodiments, the native signal peptide, e.g. an immunoglobulin heavy chain or light chain signal peptide is used, or a functional derivative of that sequence that retains the ability to direct the secretion of the polypeptide that is operably associated with it. Alternatively, a heterologous mammalian signal peptide, or a functional derivative thereof, may be used. For example, the wild-type leader sequence may be substituted with the leader sequence of human tissue plasminogen activator (TP A) or mouse β-glucuronidase.

DNA encoding a short protein sequence that could be used to facilitate later purification (e.g. a histidine tag) or assist in labeling the fusion protein may be included within or at the ends of the polynucleotide encoding a bispecific antigen binding molecule of the invention or polypeptide fragments thereof.

In a further aspect of the invention, a host cell comprising one or more polynucleotides of the invention is provided. In certain embodiments a host cell comprising one or more vectors of the invention is provided. The polynucleotides and vectors may incorporate any of the features, singly or in combination, described herein in relation to polynucleotides and vectors,

respectively. In one aspect, a host cell comprises (e.g. has been transformed or transfected with) a vector comprising a polynucleotide that encodes (part of) a bispecific antigen binding molecule of the invention. As used herein, the term "host cell" refers to any kind of cellular system which can be engineered to generate the fusion proteins of the invention or fragments thereof. Host cells suitable for replicating and for supporting expression of antigen binding molecules are well known in the art. Such cells may be transfected or transduced as appropriate with the particular expression vector and large quantities of vector containing cells can be grown for seeding large scale fermenters to obtain sufficient quantities of the antigen binding molecule for clinical applications. Suitable host cells include prokaryotic microorganisms, such as E. coli, or various eukaryotic cells, such as Chinese hamster ovary cells (CHO), human embryonic kidney (HEK) cells, insect cells, or the like. For example, polypeptides may be produced in bacteria in particular when glycosylation is not needed. After expression, the polypeptide may be isolated from the bacterial cell paste in a soluble fraction and can be further purified. In addition to prokaryotes, eukaryotic microbes such as filamentous fungi or yeast are suitable cloning or expression hosts for polypeptide-encoding vectors, including fungi and yeast strains whose glycosylation pathways have been "humanized", resulting in the production of a polypeptide with a partially or fully human glycosylation pattern. See Gerngross, Nat Biotech 22, 1409-1414 (2004), and Li et al, Nat Biotech 24, 210-215 (2006). Suitable host cells for the expression of (glycosylated) polypeptides are also derived from multicellular organisms (invertebrates and vertebrates). Examples of invertebrate cells include plant and insect cells. Numerous baculoviral strains have been identified which may be used in conjunction with insect cells, particularly for transfection of Spodoptera frugiperda cells. Plant cell cultures can also be utilized as hosts. See e.g. US Patent Nos. 5,959,177, 6,040,498, 6,420,548, 7,125,978, and 6,417,429 (describing PLANTIBODIES™ technology for producing antibodies in transgenic plants). Vertebrate cells may also be used as hosts. For example, mammalian cell lines that are adapted to grow in suspension may be useful. Other examples of useful mammalian host cell lines are monkey kidney CV1 line transformed by SV40 (COS-7); human embryonic kidney line (293 or 293T cells as described, e.g., in Graham et al., J Gen Virol 36, 59 (1977)), baby hamster kidney cells (BHK), mouse Sertoli cells (TM4 cells as described, e.g., in Mather, Biol Reprod 23, 243-251 (1980)), monkey kidney cells (CV1), African green monkey kidney cells (VERO-76), human cervical carcinoma cells (HELA), canine kidney cells (MDCK), buffalo rat liver cells (BRL 3A), human lung cells (W138), human liver cells (Hep G2), mouse mammary tumor cells (MMT 060562), TRI cells (as described, e.g., in Mather et al, Annals N.Y. Acad Sci 383, 44-68 (1982)), MRC 5 cells, and FS4 cells. Other useful mammalian host cell lines include Chinese hamster ovary (CHO) cells, including dhfr- CHO cells (Urlaub et al, Proc Natl Acad Sci USA 77, 4216 (1980)); and myeloma cell lines such as YO, NS0, P3X63 and Sp2/0. For a review of certain mammalian host cell lines suitable for protein production, see, e.g., Yazaki and Wu, Methods in Molecular Biology, Vol. 248 (B.K.C. Lo, ed., Humana Press, Totowa, NJ), pp. 255-268 (2003). Host cells include cultured cells, e.g., mammalian cultured cells, yeast cells, insect cells, bacterial cells and plant cells, to name only a few, but also cells comprised within a transgenic animal, transgenic plant or cultured plant or animal tissue. In one embodiment, the host cell is a eukaryotic cell, preferably a mammalian cell, such as a Chinese Hamster Ovary (CHO) cell, a human embryonic kidney (HEK) cell or a lymphoid cell (e.g., Y0, NS0, Sp20 cell). Standard technologies are known in the art to express foreign genes in these systems. Cells expressing a polypeptide comprising either the heavy or the light chain of an antigen binding domain, may be engineered so as to also express the other of the

immunoglobulin chains such that the expressed product is an antigen binding domain that has both a heavy and a light chain.

In another aspect, provided is a method for producing the bispecific antigen binding molecule of the invention, comprising the steps of (i) culturing the host cell of the invention under conditions suitable for expression of said antigen binding molecule, and (ii) isolating said bispecific antigen binding molecule form the host cell or host cell culture medium.

The components of the bispecific antigen binding molecule are genetically fused to each other. Bispecific antigen binding molecules can be designed such that its components are fused directly to each other or indirectly through a linker sequence. The composition and length of the linker may be determined in accordance with methods well known in the art and may be tested for efficacy. Examples of linker sequences between different components of bispecific antigen binding molecules are found in the sequences provided herein. Additional sequences may also be included to incorporate a cleavage site to separate the individual components of the fusion if desired, for example an endopeptidase recognition sequence. In certain embodiments the moieties capable of specific binding to EpCAM (e.g. Fab fragments or scFv) forming part of the antigen binding molecule comprise at least an

immunoglobulin variable region capable of binding to EpCAM. Simialrly, in certain

embodiments, the moieties capable of specific binding to OX40 (e.g. Fab fragments or scFv) forming part of the antigen binding molecule comprise at least an immunoglobulin variable region capable of binding to OX40. Variable regions can form part of and be derived from naturally or non-naturally occurring antibodies and fragments thereof. Methods to produce polyclonal antibodies and monoclonal antibodies are well known in the art (see e.g. Harlow and Lane, "Antibodies, a laboratory manual", Cold Spring Harbor Laboratory, 1988). Non-naturally occurring antibodies can be constructed using solid phase-peptide synthesis, can be produced recombinantly (e.g. as described in U.S. patent No. 4,186,567) or can be obtained, for example, by screening combinatorial libraries comprising variable heavy chains and variable light chains (see e.g. U.S. Patent. No. 5,969,108 to McCafferty).

Any animal species of immunoglobulin can be used in the invention. Non-limiting immunoglobulins useful in the present invention can be of murine, primate, or human origin. If the fusion protein is intended for human use, a chimeric form of immunoglobulin may be used wherein the constant regions of the immunoglobulin are from a human. A humanized or fully human form of the immunoglobulin can also be prepared in accordance with methods well known in the art (see e. g. U.S. Patent No. 5,565,332 to Winter). Humanization may be achieved by various methods including, but not limited to (a) grafting the non-human (e.g., donor antibody) CDRs onto human (e.g. recipient antibody) framework and constant regions with or without retention of critical framework residues (e.g. those that are important for retaining good antigen binding affinity or antibody functions), (b) grafting only the non-human specificity-determining regions (SDRs or a-CDRs; the residues critical for the antibody-antigen interaction) onto human framework and constant regions, or (c) transplanting the entire non-human variable domains, but "cloaking" them with a human-like section by replacement of surface residues. Humanized antibodies and methods of making them are reviewed, e.g., in Almagro and Fransson, Front Biosci 13, 1619-1633 (2008), and are further described, e.g., in Riechmann et al, Nature 332, 323-329 (1988); Queen et al, Proc Natl Acad Sci USA 86, 10029-10033 (1989); US Patent Nos. 5,821,337, 7,527,791, 6,982,321, and 7,087,409; Jones et al, Nature 321, 522-525 (1986);

Morrison et al, Proc Natl Acad Sci 81, 6851-6855 (1984); Morrison and Oi, Adv Immunol 44, 65-92 (1988); Verhoeyen et al, Science 239, 1534-1536 (1988); Padlan, Molec Immun 31(3), 169-217 (1994); Kashmiri et al, Methods 36, 25-34 (2005) (describing SDR (a-CDR) grafting); Padlan, Mol Immunol 28, 489-498 (1991) (describing "resurfacing"); DaU'Acqua et al, Methods 36, 43-60 (2005) (describing "FR shuffling"); and Osbourn et al, Methods 36, 61-68 (2005) and Klimka et al, Br J Cancer 83, 252-260 (2000) (describing the "guided selection" approach to FR shuffling). Particular immunoglobulins according to the invention are human immunoglobulins. Human antibodies and human variable regions can be produced using various techniques known in the art. Human antibodies are described generally in van Dijk and van de Winkel, Curr Opin Pharmacol 5, 368-74 (2001) and Lonberg, Curr Opin Immunol 20, 450-459 (2008). Human variable regions can form part of and be derived from human monoclonal antibodies made by the hybridoma method (see e.g. Monoclonal Antibody Production Techniques and Applications, pp. 51-63 (Marcel Dekker, Inc., New York, 1987)). Human antibodies and human variable regions may also be prepared by administering an immunogen to a transgenic animal that has been modified to produce intact human antibodies or intact antibodies with human variable regions in response to antigenic challenge (see e.g. Lonberg, Nat Biotech 23, 1117-1125 (2005). Human antibodies and human variable regions may also be generated by isolating Fv clone variable region sequences selected from human-derived phage display libraries (see e.g., Hoogenboom et al. in Methods in Molecular Biology 178, 1-37 (O'Brien et al, ed., Human Press, Totowa, NJ, 2001); and McCafferty et al, Nature 348, 552-554; Clackson et al, Nature 352, 624-628 (1991)). Phage typically display antibody fragments, either as single-chain Fv (scFv) fragments or as Fab fragments.

In certain aspects, the moieties capable of specific binding to the relevant target (e.g. Fab fragments or scFv) comprised in the antigen binding molecules of the present invention are engineered to have enhanced binding affinity according to, for example, the methods disclosed in PCT publication WO 2012/020006 (see Examples relating to affinity maturation) or U.S. Pat. Appl. Publ. No. 2004/0132066. The ability of the antigen binding molecules of the invention to bind to a specific antigenic determinant can be measured either through an enzyme-linked immunosorbent assay (ELISA) or other techniques familiar to one of skill in the art, e.g. surface plasmon resonance technique (Liljeblad, et al, Glyco J 17, 323-329 (2000)), and traditional binding assays (Heeley, Endocr Res 28, 217-229 (2002)). Competition assays may be used to identify an antigen binding molecule that competes with a reference antibody for binding to a particular antigen. In certain embodiments, such a competing antigen binding molecule binds to the same epitope (e.g. a linear or a conformational epitope) that is bound by the reference antigen binding molecule. Detailed exemplary methods for mapping an epitope to which an antigen binding molecule binds are provided in Morris (1996) "Epitope Mapping Protocols", in Methods in Molecular Biology vol. 66 (Humana Press, Totowa, NJ). In an exemplary competition assay, immobilized antigen is incubated in a solution comprising a first labeled antigen binding molecule that binds to the antigen and a second unlabeled antigen binding molecule that is being tested for its ability to compete with the first antigen binding molecule for binding to the antigen. The second antigen binding molecule may be present in a hybridoma supernatant. As a control, immobilized antigen is incubated in a solution comprising the first labeled antigen binding molecule but not the second unlabeled antigen binding molecule. After incubation under conditions permissive for binding of the first antibody to the antigen, excess unbound antibody is removed, and the amount of label associated with immobilized antigen is measured. If the amount of label associated with immobilized antigen is substantially reduced in the test sample relative to the control sample, then that indicates that the second antigen binding molecule is competing with the first antigen binding molecule for binding to the antigen. See Harlow and Lane (1988) Antibodies: A Laboratory Manual ch.14 (Cold Spring Harbor Laboratory, Cold Spring Harbor, NY). Bispecific antigen binding molecules of the invention prepared as described herein may be purified by art-known techniques such as high performance liquid chromatography, ion exchange chromatography, gel electrophoresis, affinity chromatography, size exclusion chromatography, and the like. The actual conditions used to purify a particular protein will depend, in part, on factors such as net charge, hydrophobicity, hydrophilicity etc., and will be apparent to those having skill in the art. For affinity chromatography purification an antibody, ligand, receptor or antigen can be used to which the bispecific antigen binding molecule binds. For example, for affinity chromatography purification of fusion proteins of the invention, a matrix with protein A or protein G may be used. Sequential Protein A or G affinity

chromatography and size exclusion chromatography can be used to isolate an antigen binding molecule essentially as described in the Examples. The purity of the bispecific antigen binding molecule or fragments thereof can be determined by any of a variety of well-known analytical methods including gel electrophoresis, high pressure liquid chromatography, and the like. For example, the bispecific antigen binding molecule expressed as described in the Examples were shown to be intact and properly assembled as demonstrated by reducing and non-reducing SDS- PAGE.

The invention also encompasses a bispecific antigen binding molecule produced by the methods of the invention.

Assays The bispecific antigen binding molecules provided herein may be identified, screened for, or characterized for their physical/chemical properties and/or biological activities by various assays known in the art.

1. Affinity assays

The affinity of the bispecific antigen binding molecule provided herein for OX40 or EpCAM can be determined in accordance with the methods set forth in the Examples by surface plasmon resonance (SPR), using standard instrumentation such as a BIAcore instrument (GE Healthcare), and receptors or target proteins such as may be obtained by recombinant expression. According to one aspect, K _D is measured by surface plasmon resonance using a BIACORE® T200 machine (GE Healthcare) at 25 °C. 2. Binding assays and other assays

Binding of the bispecific antigen binding molecule provided herein to the corresponding OX40 and/or EpCAM expressing cells may be evaluated using cell lines expressing the particular receptor or target antigen, for example by flow cytometry (FACS). In one aspect, fresh peripheral blood mononuclear cells (PBMCs) expressing OX40 are used in the binding assay. These cells are used directly after isolation (naive PMBCs) or after stimulation (activated PMBCs). In another aspect, activated mouse splenocytes (expressing OX40) can be used to demonstrate binding of the bispecific antigen binding molecule of the invention to the corresponding OX40 expressing cells.

In a further aspect, cancer cell lines expressing EpCAM were used to demonstrate the binding of the antigen binding molecules to EpCAM.

In another aspect, competition assays may be used to identify an antigen binding molecule that competes with a specific antibody or antigen binding molecule for binding to EpCAM or OX40, respectively. In certain embodiments, such a competing antigen binding molecule binds to the same epitope (e.g., a linear or a conformational epitope) that is bound by a specific anti- EpCAM antibody or a specific anti-OX40 antibody. Detailed exemplary methods for mapping an epitope to which an antibody binds are provided in Morris (1996) "Epitope Mapping Protocols," in Methods in Molecular Biology vol. 66 (Humana Press, Totowa, NJ). 3. Activity assays

In one aspect, assays are provided for identifying bispecific antigen binding molecules that bind to EpCAM and to OX40 having biological activity. Biological activity may include, e.g., agonistic signalling through OX40 on cells expressing OX40. Bispecific antigen binding molecules identified by the assays as having such biological activity in vitro are also provided. In particular, a reporter cell assay detecting NF-κΒ activation in Hela cells expressing human OX40 and co-cultured with human EpCAM-expressing tumor cells is provided (see e.g.

Example 6.1).

In certain aspects, bispecific antigen binding molecules of the invention are tested for such biological activity. Assays for detecting the biological activity of the molecules of the invention are those described in Example 4 or Example 6. Furthermore, assays for detecting cell lysis (e.g. by measurement of LDH release), induced apoptosis kinetics (e.g. by measurement of Caspase 3/7 activity) or apoptosis (e.g. using the TUNEL assay) are well known in the art. In addition the biological activity of such complexes can be assessed by evaluating their effects on survival, proliferation and lymphokine secretion of various lymphocyte subsets such as NK cells, NKT-cells or γδ T-cells or assessing their capacity to modulate phenotype and function of antigen presenting cells such as dendritic cells, monocytes/macrophages or B-cells. Pharmaceutical Compositions, Formulations and Routes of Administation

In a further aspect, the invention provides pharmaceutical compositions comprising any of the bispecific antigen binding molecules provided herein, e.g., for use in any of the below therapeutic methods. In one embodiment, a pharmaceutical composition comprises a bispecific antigen binding molecule and at least one pharmaceutically acceptable excipient. In another embodiment, a pharmaceutical composition comprises any of the bispecific antigen binding molecules provided herein and at least one additional therapeutic agent, e.g., as described below.

Pharmaceutical compositions of the present invention comprise a therapeutically effective amount of one or more bispecific antigen binding molecule dissolved or dispersed in a

pharmaceutically acceptable excipient. The phrases "pharmaceutical or pharmacologically acceptable" refers to molecular entities and compositions that are generally non-toxic to recipients at the dosages and concentrations employed, i.e. do not produce an adverse, allergic or other untoward reaction when administered to an animal, such as, for example, a human, as appropriate. The preparation of a pharmaceutical composition that contains at least one bispecific antigen binding molecule and optionally an additional active ingredient will be known to those of skill in the art in light of the present disclosure, as exemplified by Remington's

Pharmaceutical Sciences, 18th Ed. Mack Printing Company, 1990, incorporated herein by reference. In particular, the compositions are lyophilized formulations or aqueous solutions. As used herein, "pharmaceutically acceptable excipient" includes any and all solvents, buffers, dispersion media, coatings, surfactants, antioxidants, preservatives (e.g. antibacterial agents, antifungal agents), isotonic agents, salts, stabilizers and combinations thereof, as would be known to one of ordinary skill in the art.

Parenteral compositions include those designed for administration by injection, e.g.

subcutaneous, intradermal, intralesional, intravenous, intraarterial intramuscular, intrathecal or intraperitoneal injection. For injection, the bispecific antigen binding molecules of the invention may be formulated in aqueous solutions, preferably in physiologically compatible buffers such as Hanks' solution, Ringer's solution, or physiological saline buffer. The solution may contain formulatory agents such as suspending, stabilizing and/or dispersing agents. Alternatively, the fusion proteins may be in powder form for constitution with a suitable vehicle, e.g., sterile pyrogen-free water, before use. Sterile injectable solutions are prepared by incorporating the fusion proteins or bispecific antigen binding molecules of the invention in the required amount in the appropriate solvent with various of the other ingredients enumerated below, as required.

Sterility may be readily accomplished, e.g., by filtration through sterile filtration membranes. Generally, dispersions are prepared by incorporating the various sterilized active ingredients into a sterile vehicle which contains the basic dispersion medium and/or the other ingredients. In the case of sterile powders for the preparation of sterile injectable solutions, suspensions or emulsion, the preferred methods of preparation are vacuum-drying or freeze-drying techniques which yield a powder of the active ingredient plus any additional desired ingredient from a previously sterile- filtered liquid medium thereof. The liquid medium should be suitably buffered if necessary and the liquid diluent first rendered isotonic prior to injection with sufficient saline or glucose. The composition must be stable under the conditions of manufacture and storage, and preserved against the contaminating action of microorganisms, such as bacteria and fungi. It will be appreciated that endotoxin contamination should be kept minimally at a safe level, for example, less that 0.5 ng/mg protein. Suitable pharmaceutically acceptable excipients include, but are not limited to: buffers such as phosphate, citrate, and other organic acids; antioxidants including ascorbic acid and methionine; preservatives (such as octadecyldimethylbenzyl ammonium chloride; hexamethonium chloride; benzalkonium chloride; benzethonium chloride; phenol, butyl or benzyl alcohol; alkyl parabens such as methyl or propyl paraben; catechol; resorcinol; cyclohexanol; 3-pentanol; and m-cresol); low molecular weight (less than about 10 residues) polypeptides; proteins, such as serum albumin, gelatin, or immunoglobulins; hydrophilic polymers such as polyvinylpyrrolidone; amino acids such as glycine, glutamine, asparagine, histidine, arginine, or lysine; monosaccharides, disaccharides, and other carbohydrates including glucose, mannose, or dextrins; chelating agents such as EDTA; sugars such as sucrose, mannitol, trehalose or sorbitol; salt-forming counter-ions such as sodium; metal complexes (e.g. Zn-protein complexes); and/or non-ionic surfactants such as polyethylene glycol (PEG). Aqueous injection suspensions may contain compounds which increase the viscosity of the suspension, such as sodium carboxymethyl cellulose, sorbitol, dextran, or the like. Optionally, the suspension may also contain suitable stabilizers or agents which increase the solubility of the compounds to allow for the preparation of highly concentrated solutions. Additionally, suspensions of the active compounds may be prepared as appropriate oily injection suspensions. Suitable lipophilic solvents or vehicles include fatty oils such as sesame oil, or synthetic fatty acid esters, such as ethyl cleats or triglycerides, or liposomes.

Active ingredients may be entrapped in microcapsules prepared, for example, by coacervation techniques or by interfacial polymerization, for example, hydroxymethylcellulose or gelatin-microcapsules and poly-(methylmethacylate) microcapsules, respectively, in colloidal drug delivery systems (for example, liposomes, albumin microspheres, microemulsions, nano- particles and nanocapsules) or in macroemulsions. Such techniques are disclosed in Remington's Pharmaceutical Sciences (18th Ed. Mack Printing Company, 1990). Sustained-release preparations may be prepared. Suitable examples of sustained-release preparations include semipermeable matrices of solid hydrophobic polymers containing the polypeptide, which matrices are in the form of shaped articles, e.g. films, or microcapsules. In particular

embodiments, prolonged absorption of an injectable composition can be brought about by the use in the compositions of agents delaying absorption, such as, for example, aluminum monostearate, gelatin or combinations thereof.

Exemplary pharmaceutically acceptable excipients herein further include insterstitial drug dispersion agents such as soluble neutral-active hyaluronidase glycoproteins (sHASEGP), for example, human soluble PH-20 hyaluronidase glycoproteins, such as rHuPH20 (HYLENEX®, Baxter International, Inc.). Certain exemplary sHASEGPs and methods of use, including rHuPH20, are described in US Patent Publication Nos. 2005/0260186 and 2006/0104968. In one aspect, a sHASEGP is combined with one or more additional glycosaminoglycanases such as chondroitinases. Exemplary lyophilized antibody formulations are described in US Patent No. 6,267,958.

Aqueous antibody formulations include those described in US Patent No. 6,171,586 and

WO2006/044908, the latter formulations including a histidine-acetate buffer.

In addition to the compositions described previously, the bispecific antigen binding molecules may also be formulated as a depot preparation. Such long acting formulations may be administered by implantation (for example subcutaneously or intramuscularly) or by

intramuscular injection. Thus, for example, the bispecific antigen binding molecules may be formulated with suitable polymeric or hydrophobic materials (for example as emulsion in a pharmaceutically acceptable oil) or ion exchange resins, or as sparingly soluble derivatives, for example, as a sparingly soluble salt. Pharmaceutical compositions comprising the bispecific antigen binding molecules of the invention may be manufactured by means of conventional mixing, dissolving, emulsifying, encapsulating, entrapping or lyophilizing processes. Pharmaceutical compositions may be formulated in conventional manner using one or more physiologically acceptable carriers, diluents, excipients or auxiliaries which facilitate processing of the proteins into preparations that can be used pharmaceutically. Proper formulation is dependent upon the route of administration chosen.

The bispecific antigen binding molecules may be formulated into a composition in a free acid or base, neutral or salt form. Pharmaceutically acceptable salts are salts that substantially retain the biological activity of the free acid or base. These include the acid addition salts, e.g. those formed with the free amino groups of a proteinaceous composition, or which are formed with inorganic acids such as for example, hydrochloric or phosphoric acids, or such organic acids as acetic, oxalic, tartaric or mandelic acid. Salts formed with the free carboxyl groups can also be derived from inorganic bases such as for example, sodium, potassium, ammonium, calcium or ferric hydroxides; or such organic bases as isopropylamine, trimethylamine, histidine or procaine. Pharmaceutical salts tend to be more soluble in aqueous and other protic solvents than are the corresponding free base forms.

The pharmaceutical compositions may also contain more than one active ingredients as necessary for the particular indication being treated, preferably those with complementary activities that do not adversely affect each other. Such active ingredients are suitably present in combination in amounts that are effective for the purpose intended. In one aspect, the pharmaceutical composition comprises a bispecific antigen binding molecule and another active anti-cancer agent.

The formulations to be used for in vivo administration are generally sterile. Sterility may be readily accomplished, e.g., by filtration through sterile filtration membranes.

Therapeutic methods and compositions

Any of the bispecific antigen binding molecules provided herein may be used in therapeutic methods. For use in therapeutic methods, the antigen binding molecules of the invention can be formulated, dosed, and administered in a fashion consistent with good medical practice. Factors for consideration in this context include the particular disorder being treated, the particular mammal being treated, the clinical condition of the individual patient, the cause of the disorder, the site of delivery of the agent, the method of administration, the scheduling of administration, and other factors known to medical practitioners.

In one aspect, the bispecific antigen binding molecules of the invention are provided for use as a medicament. In further aspects, the bispecific antigen binding molecules of the invention are provided for use in treating a disease, in particular for use in the treatment of cancer. In certain embodiments, the bispecific antigen binding molecules of the invention are provided for use in a method of treatment. In one embodiment, the invention provides a bispecific antigen binding molecule as described herein for use in the treatment of a disease in an individual in need thereof. In certain embodiments, the invention provides a bispecific antigen binding molecule for use in a method of treating an individual having a disease comprising administering to the individual a therapeutically effective amount of the bispecific antigen binding molecule. In certain embodiments the disease to be treated is cancer. In certain embodiments the disease to be treated is a proliferative disorder, particularly cancer. Examples of cancers include bladder cancer, brain cancer, head and neck cancer, pancreatic cancer, lung cancer, breast cancer, ovarian cancer, uterine cancer, cervical cancer, endometrial cancer, esophageal cancer, colon cancer, colorectal cancer, rectal cancer, gastric cancer, prostate cancer, blood cancer, skin cancer, squamous cell carcinoma, bone cancer, and kidney cancer. Other cell proliferation disorders that can be treated using a bispecific antigen binding molecule of the present invention include, but are not limited to neoplasms located in the: abdomen, bone, breast, digestive system, liver, pancreas, peritoneum, endocrine glands (adrenal, parathyroid, pituitary, testicles, ovary, thymus, thyroid), eye, head and neck, nervous system (central and peripheral), lymphatic system, pelvic, skin, soft tissue, spleen, thoracic region, and urogenital system. Also included are pre-cancerous conditions or lesions and cancer metastases. In certain embodiments the cancer is chosen from the group consisting of renal cell cancer, skin cancer, lung cancer, colorectal cancer, breast cancer, brain cancer, head and neck cancer. The subject, patient, or "individual" in need of treatment is typically a mammal, more specifically a human.

Also encompassed by the invention is the bispecific antigen binding molecule of the invention, or the pharmaceutical composition of the invention, for use in up-regulating or prolonging cytotoxic T cell activity.

In a further aspect, the invention provides for the use of a bispecific antigen binding molecule of the invention in the manufacture or preparation of a medicament for the treatment of a disease in an individual in need thereof. In one aspect, the medicament is for use in a method of treating a disease comprising administering to an individual having the disease a therapeutically effective amount of the medicament. In certain embodiments the disease to be treated is a proliferative disorder, particularly cancer. Examples of cancers include bladder cancer, brain cancer, head and neck cancer, pancreatic cancer, lung cancer, breast cancer, ovarian cancer, uterine cancer, cervical cancer, endometrial cancer, esophageal cancer, colon cancer, colorectal cancer, rectal cancer, gastric cancer, prostate cancer, blood cancer, skin cancer, squamous cell carcinoma, bone cancer, and kidney cancer. Other cell proliferation disorders that can be treated using a bispecific antigen binding molecule of the present invention include, but are not limited to neoplasms located in the: abdomen, bone, breast, digestive system, liver, pancreas, peritoneum, endocrine glands (adrenal, parathyroid, pituitary, testicles, ovary, thymus, thyroid), eye, head and neck, nervous system (central and peripheral), lymphatic system, pelvic, skin, soft tissue, spleen, thoracic region, and urogenital system. Also included are pre-cancerous conditions or lesions and cancer metastases. In certain embodiments the cancer is chosen from the group consisting of renal cell cancer, skin cancer, lung cancer, colorectal cancer, breast cancer, brain cancer, head and neck cancer. A skilled artisan readily recognizes that in many cases the bispecific antigen binding molecule may not provide a cure but may only provide partial benefit. In some embodiments, a physiological change having some benefit is also considered therapeutically beneficial. Thus, in some embodiments, an amount of bispecific antigen binding molecule that provides a physiological change is considered an "effective amount" or a "therapeutically effective amount". In any of the above embodiments the individual is preferably a mammal, particularly a human. In a further aspect, the invention provides a method for treating a disease in an individual, comprising administering to said individual a therapeutically effective amount of a bispecific antigen binding molecule of the invention. In one embodiment a composition is administered to said individual, comprising a fusion protein of the invention in a pharmaceutically acceptable form. In certain embodiments the disease to be treated is a proliferative disorder. In a particular embodiment the disease is cancer. In certain embodiments the method further comprises administering to the individual a therapeutically effective amount of at least one additional therapeutic agent, e.g. an anti-cancer agent if the disease to be treated is cancer. An "individual" according to any of the above embodiments may be a mammal, preferably a human.

For the prevention or treatment of disease, the appropriate dosage of a bispecific antigen binding molecule of the invention (when used alone or in combination with one or more other additional therapeutic agents) will depend on the type of disease to be treated, the route of administration, the body weight of the patient, the type of fusion protein, the severity and course of the disease, whether the fusion protein is administered for preventive or therapeutic purposes, previous or concurrent therapeutic interventions, the patient's clinical history and response to the fusion protein, and the discretion of the attending physician. The practitioner responsible for administration will, in any event, determine the concentration of active ingredient(s) in a composition and appropriate dose(s) for the individual subject. Various dosing schedules including but not limited to single or multiple administrations over various time-points, bolus administration, and pulse infusion are contemplated herein.

The bispecific antigen binding molecule is suitably administered to the patient at one time or over a series of treatments. Depending on the type and severity of the disease, about 1 μg/kg to 15 mg/kg (e.g. 0.1 mg/kg - 10 mg/kg) of the antigen binding molecule can be an initial candidate dosage for administration to the patient, whether, for example, by one or more separate administrations, or by continuous infusion. One typical daily dosage might range from about 1 μg/kg to 100 mg/kg or more, depending on the factors mentioned above. For repeated administrations over several days or longer, depending on the condition, the treatment would generally be sustained until a desired suppression of disease symptoms occurs. One exemplary dosage of the fusion protein would be in the range from about 0.005 mg/kg to about 10 mg/kg. In other examples, a dose may also comprise from about 1 μg/kg body weight, about 5 μg/kg body weight, about 10 μg/kg body weight, about 50 μg/kg body weight, about 100 μg/kg body weight, about 200 μg/kg body weight, about 350 μg/kg body weight, about 500 μg/kg body weight, about 1 mg/kg body weight, about 5 mg/kg body weight, about 10 mg/kg body weight, about 50 mg/kg body weight, about 100 mg/kg body weight, about 200 mg/kg body weight, about 350 mg/kg body weight, about 500 mg/kg body weight, to about 1000 mg/kg body weight or more per administration, and any range derivable therein. In examples of a derivable range from the numbers listed herein, a range of about 5 mg/kg body weight to about 100 mg/kg body weight, about 5 μg/kg body weight to about 500 mg/kg body weight etc., can be administered, based on the numbers described above. Thus, one or more doses of about 0.5 mg/kg, 2.0 mg/kg, 5.0 mg/kg or 10 mg/kg (or any combination thereof) may be administered to the patient. Such doses may be administered intermittently, e.g. every week or every three weeks (e.g. such that the patient receives from about two to about twenty, or e.g. about six doses of the bispecific antigen binding molecule). An initial higher loading dose, followed by one or more lower doses may be administered. However, other dosage regimens may be useful. The progress of this therapy is easily monitored by conventional techniques and assays.

The bispecific antigen binding molecule of the invention will generally be used in an amount effective to achieve the intended purpose. For use to treat or prevent a disease condition, the bispecific antigen binding molecules of the invention, or pharmaceutical compositions thereof, are administered or applied in a therapeutically effective amount. Determination of a therapeutically effective amount is well within the capabilities of those skilled in the art, especially in light of the detailed disclosure provided herein.

For systemic administration, a therapeutically effective dose can be estimated initially from in vitro assays, such as cell culture assays. A dose can then be formulated in animal models to achieve a circulating concentration range that includes the IC ₅₀ as determined in cell culture. Such information can be used to more accurately determine useful doses in humans.

Initial dosages can also be estimated from in vivo data, e.g., animal models, using techniques that are well known in the art. One having ordinary skill in the art could readily optimize administration to humans based on animal data.

Dosage amount and interval may be adjusted individually to provide plasma levels of the bispecific antigen binding molecules which are sufficient to maintain therapeutic effect. Usual patient dosages for administration by injection range from about 0.1 to 50 mg/kg/day, typically from about 0.5 to 1 mg/kg/day. Therapeutically effective plasma levels may be achieved by administering multiple doses each day. Levels in plasma may be measured, for example, by

HPLC.

In cases of local administration or selective uptake, the effective local concentration of the bispecific antigen binding molecules may not be related to plasma concentration. One skilled in the art will be able to optimize therapeutically effective local dosages without undue

experimentation.

A therapeutically effective dose of the bispecific antigen binding molecules described herein will generally provide therapeutic benefit without causing substantial toxicity. Toxicity and therapeutic efficacy of a fusion protein can be determined by standard pharmaceutical procedures in cell culture or experimental animals. Cell culture assays and animal studies can be used to determine the LD ₅₀ (the dose lethal to 50% of a population) and the ED ₅₀ (the dose therapeutically effective in 50% of a population). The dose ratio between toxic and therapeutic effects is the therapeutic index, which can be expressed as the ratio LD ₅ o/ED ₅ o. Bispecific antigen binding molecules that exhibit large therapeutic indices are preferred. In one

embodiment, the bispecific antigen binding molecule according to the present invention exhibits a high therapeutic index. The data obtained from cell culture assays and animal studies can be used in formulating a range of dosages suitable for use in humans. The dosage lies preferably within a range of circulating concentrations that include the ED50 with little or no toxicity. The dosage may vary within this range depending upon a variety of factors, e.g., the dosage form employed, the route of administration utilized, the condition of the subject, and the like. The exact formulation, route of administration and dosage can be chosen by the individual physician in view of the patient's condition (see, e.g., Fingl et al, 1975, in: The Pharmacological Basis of Therapeutics, Ch. 1, p. 1, incorporated herein by reference in its entirety).

The attending physician for patients treated with the bispecific antigen binding molecules of the invention will know how and when to terminate, interrupt, or adjust administration due to toxicity, organ dysfunction, and the like. Conversely, the attending physician would also know to adjust treatment to higher levels if the clinical response were not adequate (precluding toxicity). The magnitude of an administered dose in the management of the disorder of interest will vary with the severity of the condition to be treated, with the route of administration, and the like. The severity of the condition may, for example, be evaluated, in part, by standard prognostic evaluation methods. Further, the dose and perhaps dose frequency will also vary according to the age, body weight, and response of the individual patient.

Other agents and treatments

The bispecific antigen binding molecules of the invention may be administered in combination with one or more other agents in therapy. For instance, a fusion protein of the invention may be co-administered with at least one additional therapeutic agent. The term

"therapeutic agent" encompasses any agent that can be administered for treating a symptom or disease in an individual in need of such treatment. Such additional therapeutic agent may comprise any active ingredients suitable for the particular indication being treated, preferably those with complementary activities that do not adversely affect each other. In certain embodiments, an additional therapeutic agent is another anti-cancer agent.

Such other agents are suitably present in combination in amounts that are effective for the purpose intended. The effective amount of such other agents depends on the amount of fusion protein used, the type of disorder or treatment, and other factors discussed above. The bispecific antigen binding molecules are generally used in the same dosages and with administration routes as described herein, or about from 1 to 99% of the dosages described herein, or in any dosage and by any route that is empirically/clinically determined to be appropriate.

Such combination therapies noted above encompass combined administration (where two or more therapeutic agents are included in the same or separate compositions), and separate administration, in which case, administration of the bispecific antigen binding molecule of the invention can occur prior to, simultaneously, and/or following, administration of the additional therapeutic agent and/or adjuvant.

Articles of Manufacture

In another aspect of the invention, an article of manufacture containing materials useful for the treatment, prevention and/or diagnosis of the disorders described above is provided. The article of manufacture comprises a container and a label or package insert on or associated with the container. Suitable containers include, for example, bottles, vials, syringes, IV solution bags, etc. The containers may be formed from a variety of materials such as glass or plastic. The container holds a composition which is by itself or combined with another composition effective for treating, preventing and/or diagnosing the condition and may have a sterile access port (for example the container may be an intravenous solution bag or a vial having a stopper that is pierceable by a hypodermic injection needle). At least one active agent in the composition is a bispecific antigen binding molecule of the invention.

The label or package insert indicates that the composition is used for treating the condition of choice. Moreover, the article of manufacture may comprise (a) a first container with a composition contained therein, wherein the composition comprises a bispecific antigen binding molecule of the invention; and (b) a second container with a composition contained therein, wherein the composition comprises a further cytotoxic or otherwise therapeutic agent. The article of manufacture in this embodiment of the invention may further comprise a package insert indicating that the compositions can be used to treat a particular condition.

Alternatively, or additionally, the article of manufacture may further comprise a second (or third) container comprising a pharmaceutically-acceptable buffer, such as bacteriostatic water for injection (BWFI), phosphate-buffered saline, Ringer's solution and dextrose solution. It may further include other materials desirable from a commercial and user standpoint, including other buffers, diluents, filters, needles, and syringes. Table C. Sequences

SEQ Name Sequence

NO:

APvEYGWMDYWGOGTTVTVSS

34 OX40(8H9) VL DIOMTOSPSTLSASVGDRVTITCRASOSISSWLA

WYOOi PGKAPKLLIYDASSLESGVPSRFSGSGS GTEFTLTISSLOPDDFATYYCOOYLTYSRFTFG QGTKVEI

35 OX40(49B4) VH QVQLVQSGAEVKKPGSSVKVSCKASGGTFSSY

AISWVROAPGOGLEWMGGIIPIFGTANYAOKF QGRVTITAD STSTAYMELSSLRSEDTAVYYC ARE YYRGP YD Y WGOGTTVTVS S

36 OX40(49B4) VL DIOMTOSPSTLSASVGDRVTITCRASOSISSWLA

WYOOKPGKAPKLLIYDASSLESGVPSRFSGSGS GTEFTLTISSLOPDDFATYYCOOYSSOPYTFGO GT VEI

37 0X40(1 G4) VH QVQLVQSGAEVKKPGSSVKVSCKASGGTFSSY

AISWVROAPGOGLEWMGGIIPIFGTANYAOKF QGRVTITAD STSTAYMELSSLRSEDTAVYYC AREYGSMDYWGOGTTVTVSS

38 0X40(1 G4) VL DIOMTOSPSTLSASVGDRVTITCRASOSISSWLA

WYOOKPGKAPKLLIYDASSLESGVPSRFSGSGS GTEFTLTISSLOPDDFATYYCOOYISYSMLTFG QGTKVEIK

39 OX40(20B7) VH QVQLVQSGAEVKKPGSSVKVSCKASGGTFSSY

AISWVROAPGOGLEWMGGIIPIFGTANYAOKF QGRVTITADKSTSTAYMELSSLRSEDTAVYYC AR VNYPYSYWGDFDY WGOGTTVTVS S

40 OX40(20B7) VL DIOMTOSPSTLSASVGDRVTITCRASOSISSWLA

WYOOKPGKAPKLLIYDASSLESGVPSRFSGSGS GTEFTLTISSLOPDDFATYYCOOYOAFSLTFGO GTKVEIK

41 OX40(CLC-563) VH EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYA

MSWVROAPGKGLEWVSAISGSGGSTYYADSV KGRFTISRDNSKNTLYLQMNSLRAEDTAVYYC ALDVGAFDYWGOGALVTVSS

42 OX40(CLC-563) VL EIVLTOSPGTLSLSPGERATLSCRASOSVSSSYL

AWYOOKPGOAPRLLIYGASSRATGIPDRFSGSG SGTDFTLTISRLEPEDFAVYYCOOYGSSPLTFG QGTKVEIK

43 OX40(CLC-564) VH EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYA

MSWVROAPGKGLEWVSAISGSGGSTYYADSV KGRFTISRDNSKNTLYLQMNSLRAEDTAVYYC AFDVGPFDYWGOGTLVTVSS

44 OX40(CLC-564) VL EIVLTOSPGTLSLSPGERATLSCRASOSVSSSYL

AWYOOKPGOAPRLLIYGASSRATGIPDRFSGSG SGTDFTLTISRLEPEDFAVYYCOOYGSSPLTFG QGTKVEIK

45 0X40(17 A9) VH EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYA

MSWVROAPGKGLEWVSAISGSGGSTYYADSV SEQ Name Sequence

NO:

GRFTISRDNSKNTLYLQMNSLRAEDTAVYYC ARVF YRGG VSMD Y WGOGTL VTVS S

46 0X40(17 A9) VL SSELTODPAVSVALGOTVRITCOGDSLRSYYAS

WYOOKPGOAPVLVIYGKNNRPSGIPDRFSGSSS GNTASLTITGAOAEDEADYYCNSRVMPHNRVF GGGTKLTV

47 muOX40(OX86) VH QVQLKESGPGLVQPSQTLSLTCTVSGFSLTGYN

LHWVROPPGKGLEWMGRMRYDGDTYYNSVL KSRLSISRDTSKNQVFLKMNSLQTDDTAIYYCT RDGRGDSFDYWGOGVMVTVSS

48 muOX40(OX86) VL DIVMTOGALPNPVPSGESASITCRSSOSLVYKD

GOTYLNWFLORPGOSPOLLTYWMSTRASGVS DRF S GS GS GT YFTLKI SRVRAED AG V Y YC 00 V REYPFTFGSGTKLEIK

49 human EpCAM ECD Uniprot No. PI 6422, aa 24 to 265

50 murine EpCAM ECD Uniprot No. Q99JW5, aa 24 to 266

51 EpCAM(3-17I) CDR-H1 SYAIS

52 EpCAM(3-17I) CDR-H2 GIIPIFGTANYAQKFQG

53 EpCAM(3-17I) CDR-H3 GLLW

54 EpCAM(3-17I) CDR-L1 RASQSVSSNLA

55 EpCAM(3-17I) CDR-L2 GASTTAS

56 EpCAM(3-17I) CDR-L3 QQYNNWPPAYT

57 muEpCAM(G8.8) CDR-H1 NFPMA

58 muEpCAM(G8.8) CDR-H2 TISTSGGSTYYRDSVKG

59 muEpCAM(G8.8) CDR-H3 TLYILRVFYF

60 muEpCAM(G8.8) CDR-L1 LASEGISNDLA

61 muEpCAM(G8.8) CDR-L2 ATSRLQD

62 muEpCAM(G8.8) CDR-L3 QQSYKYPWT

63 [EpCAM(3-17I) VH QVQLVQSGAEVKKPGSSVKVSCKASGGTFSSY

AISWVROAPGOGLEWMGGIIPIFGTANYAOKF OGRVTITADESTSTAYMELSSLRSEDTAVYYCA RGLL WNYWGOGTLVT VS S

64 EpCAM(3-17I) VL EIVMTOSPATLSVSPGERATLSCRASOSVSSNL

AWYOOKPGOAPRLIIYGASTTASGIPARFSASG SGTDFTLTISSLOSEDFAVYYCOOYNNWPPAYT FGQGTKLEIK

65 muEpCAM(G8.8) VH EVQLAESGGGLVQPGRSMKLSCAASGFTFSNF

PMAWVROAPTKGLEWVATISTSGGSTYYRDS VKGRFTISRDNAKSTLYLQMNSLRSEDTATYY CTRTLYILRVFYFDYWGOGVMVTVSS

66 muEpCAM(G8.8) VL DIOMTOSPASLSASLGETVSIECLASEGISNDLA

WYOOKSGKSPOLLIYATSRLODGVPSRFSGSGS GTRYSLKISGMOPEDEADYFCOOSYKYPWTFG GGTKLELK

67 human OX40 UniProt no. P43489

68 human EpCAM UniProt no. PI 6422

69 human 4- IBB UniProt no. Q07011 SEQ Name Sequence NO:

70 human CD27 UniProt no. P26842

71 human HVEM UniProt no. Q92956

72 human CD30 UniProt no. P28908

73 human GITR UniProt no. Q9Y5U5

74 murine OX40 UniProt no. P47741

75 murine EpCAM UniProt no. Q99JW5

76 Petpide linker G4S GGGGS

77 Peptide linker (G4S) ₂ GGGGSGGGGS

78 Peptide linker (SG4) ₂ SGGGGSGGGG

79 Peptide linker (G ₄ S) ₃ GGGGSGGGGSGGGGS

80 Peptide linker G4(SG4) ₂ GGGGSGGGGSGGGG

81 Peptide linker (G ₄ S) ₄ GGGGSGGGGSGGGGSGGGGS

82 Peptide linker GSPGSSSSGS

83 Peptide linker GSGSGSGS

84 Peptide linker GSGSGNGS

85 Peptide linker GGSGSGSG

86 Peptide linker GGSGSG

87 Peptide linker GGSG

88 Peptide linker GGSGNGSG

89 Peptide linker GGNGSGSG

90 Peptide linker GGNGSG

nucleotide sequence see Table 2

91 Fc hole chain

nucleotide sequence see Table 2

human OX40 antigen Fc knob

92 chain

nucleotide sequence see Table 2

cynomolgus OX40 antigen Fc

93 knob chain

nucleotide sequence murine see Table 2

94 OX40 antigen Fc knob chain

Fc hole chain see Table 2

95

human OX40 antigen Fc knob see Table 2

96 chain

cynomolgus OX40 antigen Fc see Table 2

97 knob chain

murine OX40 antigen Fc knob see Table 2

98 chain

nucleotide sequence of library see Table 3

99 DP88-4

nucleotide sequence of see Table 4

100 Fab light chain Vkl 5

101 Fab light chain Vkl 5 see Table 4

102 nucleotide sequence of see Table 4

Fab heavy chain VH1 69 SEQ Name Sequence NO:

153 Nucleotide sequence see Table 13

OX40(49B4) heavy chain in

P329GLALA human IgGl

format

154 OX40(49B4) light chain in see Table 13

P329GLALA human IgGl

format

155 OX40(49B4) heavy chain in see Table 13

P329GLALA human IgGl

format

156 Nucleotide sequence see Table 13

0X40(1 G4) light chain in

P329GLALA human IgGl

format

157 Nucleotide sequence see Table 13

0X40(1 G4) heavy chain in

P329GLALA human IgGl

format

158 0X40(1 G4) light chain in see Table 13

P329GLALA human IgGl

format

159 0X40(1 G4) heavy chain in see Table 13

P329GLALA human IgGl

format

160 Nucleotide sequence see Table 13

OX40(20B7) light chain in

P329GLALA human IgGl

format

161 Nucleotide sequence see Table 13

OX40(20B7) heavy chain in

P329GLALA human IgGl

format

162 OX40(20B7) light chain in see Table 13

P329GLALA human IgGl

format

163 OX40(20B7) heavy chain in see Table 13

P329GLALA human IgGl

format

164 Nucleotide sequence see Table 13

OX40(CLC-563) light chain

in P329GLALA human IgGl

format

165 Nucleotide sequence see Table 13

OX40(CLC-563) heavy chain

in P329GLALA human IgGl

format

166 OX40(CLC-563) light chain see Table 13

The following numbered paragraphs (paras) describe aspects of the present invention:

1. A bispecific antigen binding molecule, comprising

(a) at least one moiety capable of specific binding to OX40, and

(b) at least one moiety capable of specific binding to epithelial cell adhesion molecule (EpCAM).

2. The bispecific antigen binding molecule of para 1, additionally comprising

(c) a Fc region composed of a first and a second subunit capable of stable association. 3. The bispecific antigen binding molecule of para 1 or para 2, wherein the moiety capable of specific binding to OX40 binds to a polypeptide comprising, or consisting of, the amino acid sequence of SEQ ID NO: l .

4. The bispecific antigen binding molecule of any one of paras 1 to 3, wherein the moiety capable of specific binding to EpCAM binds to a polypeptide comprising, or consisting of, the amino acid sequence of SEQ ID NO:49.

5. The bispecific antigen binding molecule of any one of paras 1 to 4, wherein the moiety capable of specific binding to OX40 comprises a VH comprising (i) a CDR-H1 comprising an amino acid sequence selected from the group consisting of SEQ ID NO:4 and SEQ ID NO:5,

(ii) a CDR-H2 comprising an amino acid sequence selected from the group consisting of SEQ ID NO:6 and SEQ ID NO:7, and

(iii) a CDR-H3 comprising an amino acid sequence selected from the group consisting of SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO: 10, SEQ ID NO: l l , SEQ ID NO: 12, SEQ ID NO: 13 and SEQ ID NO: 14,

and a VL comprising

(iv) a CDR-Ll comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 15, SEQ ID NO: 16 and SEQ ID NO: 17,

(v) a CDR-L2 comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 18, SEQ ID NO: 19 and SEQ ID NO:20, and

(vi) a CDR-L3 comprising an amino acid sequence selected from the group consisting of SEQ ID NO:21 , SEQ ID NO:22, SEQ ID NO:23, SEQ ID NO:24, SEQ ID NO:25 and SEQ ID NO:26.

6. The bispecific antigen binding molecule of any one of paras 1 to 5, wherein the moiety capable of specific binding to OX40 comprises a VH comprising an amino acid sequence that is at least about 95%, 96%, 97%>, 98%>, 99%> or 100% identical to an amino acid sequence selected from the group consisting of SEQ ID NO:33, SEQ ID NO: 35, SEQ ID NO:37, SEQ ID NO:39, SEQ ID NO:41 , SEQ ID NO:43 and SEQ ID NO:45 and a VL comprising an amino acid sequence that is at least about 95%>, 96%>, 97%>, 98%>, 99%> or 100% identical to an amino acid sequence selected from the group consisting of SEQ ID NO:34, SEQ ID NO: 36, SEQ ID NO:38, SEQ ID NO:40, SEQ ID NO:42, SEQ ID NO:44 and SEQ ID NO:46. 7. The bispecific antigen binding molecule of any one of paras 1 to 6, wherein the moiety capable of specific binding to OX40 comprises

(i) a VH comprising the amino acid sequence of SEQ ID NO:33 and a VL comprising the amino acid sequence of SEQ ID NO:34,

(ii) a VH comprising the amino acid sequence of SEQ ID NO:35 and a VL comprising the amino acid sequence of SEQ ID NO:36,

(iii) a VH comprising the amino acid sequence of SEQ ID NO:37 and a VL comprising the amino acid sequence of SEQ ID NO:38,

(iv) a VH comprising the amino acid sequence of SEQ ID NO:39 and a VL comprising the amino acid sequence of SEQ ID NO:40,

(v) a VH comprising the amino acid sequence of SEQ ID NO:41 and a VL comprising the amino acid sequence of SEQ ID NO:42,

(vi) a VH comprising the amino acid sequence of SEQ ID NO:43 and a VL comprising the amino acid sequence of SEQ ID NO:44, or (vii) a VH comprising the amino acid sequence of SEQ ID NO:45 and a VL comprising the amino acid sequence of SEQ ID NO:46.

8. The bispecific antigen binding molecule of any one of paras 1 to 7, wherein the moiety capable of specific binding to EpCAM comprises a VH comprising

(i) a CDR-H1 comprising the amino acid sequence SEQ ID NO:51 ,

(ii) a CDR-H2 comprising the amino acid sequence SEQ ID NO:52, and

(iii) a CDR-H3 comprising the amino acid sequence SEQ ID NO:53,

and a VL comprising

(iv) a CDR-L1 comprising the amino acid sequence SEQ ID NO:54,

(v) a CDR-L2 comprising the amino acid sequence SEQ ID NO:55, and

(vi) a CDR-L3 comprising the amino acid sequence SEQ ID NO:56.

9. The bispecific antigen binding molecule of any one of paras 1 to 8, wherein the moiety capable of specific binding to EpCAM comprises a VH comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:63, and a VL comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:64. 10. The bispecific antigen binding molecule of any one of paras 1 to 9, wherein the moiety capable of specific binding to EpCAM comprises a VH comprising the amino acid sequence of SEQ ID NO: 63 and a VL comprising the amino acid sequence of SEQ ID NO: 64.

1 1. The bispecific antigen binding molecule of any one of paras 1 to 10, comprising

(i) at least one moiety capable of specific binding to OX40, comprising a VH comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to an amino acid sequence selected from the group consisting of SEQ ID NO:33, SEQ ID NO: 35, SEQ ID NO:37, SEQ ID NO:39, SEQ ID NO:41 , SEQ ID NO:43 and SEQ ID NO:45 and a VL comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to an amino acid sequence selected from the group consisting of SEQ ID NO:34, SEQ ID NO: 36, SEQ ID NO:38, SEQ ID NO:40, SEQ ID NO:42, SEQ ID NO:44 and SEQ ID NO:46, and

(ii) at least one moiety capable of specific binding to EpCAM, comprising a VH comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: 63 and a VL comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:64. 12. The bispecific antigen binding molecule of any one of paras 1 to 11, comprising

(i) at least one moiety capable of specific binding to OX40, comprising a VH comprising the amino acid sequence of SEQ ID NO: 35 and a VL comprising the amino acid sequence of SEQ ID NO: 36, and

(ii) at least one moiety capable of specific binding to EpCAM, comprising a VH comprising the amino acid sequence of SEQ ID NO: 63 and a VL comprising the amino acid sequence of SEQ ID NO: 64.

13. The bispecific antigen binding molecule of para 1 or para 2, wherein the moiety capable of specific binding to OX40 binds to a polypeptide comprising, or consisting of, the amino acid sequence of SEQ ID NO:2.

14. The bispecific antigen binding molecule of any one of paras 1, 2 or 13, wherein the moiety capable of specific binding to EpCAM binds to a polypeptide comprising, or consisting of, the amino acid sequence of SEQ ID NO:50.

15. The bispecific antigen binding molecule of any one of paras 1, 2, 13 or 14, wherein the moiety capable of specific binding to OX40 comprises a VH comprising

(i) a CDR-H1 comprising the amino acid sequence SEQ ID NO:27,

(ii) a CDR-H2 comprising the amino acid sequence SEQ ID NO:28, and

(iii) a CDR-H3 comprising the amino acid sequence SEQ ID NO:29,

and a VL comprising

(iv) a CDR-L1 comprising the amino acid sequence SEQ ID NO:30,

(v) a CDR-L2 comprising the amino acid sequence SEQ ID NO:31, and

(vi) a CDR-L3 comprising the amino acid sequence SEQ ID NO:32.

16. The bispecific antigen binding molecule of any one of paras 1, 2, or 13 to 15, wherein the moiety capable of specific binding to OX40 comprises a VH comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:47, and a VL comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:48.

17. The bispecific antigen binding molecule of any one of paras 1, 2, or 13 to 16, wherein the moiety capable of specific binding to OX40 comprises a VH comprising the amino acid sequence of SEQ ID NO:47 and a VL comprising the amino acid sequence of SEQ ID NO:48.

18. The bispecific antigen binding molecule of any one of paras 1, 2, or 13 to 17, wherein the moiety capable of specific binding to EpCAM comprises a VH comprising (i) a CDR-H1 comprising the amino acid sequence SEQ ID NO:57,

(ii) a CDR-H2 comprising the amino acid sequence SEQ ID NO:58, and

(iii) a CDR-H3 comprising the amino acid sequence SEQ ID NO:59,

and a VL comprising

(iv) a CDR-L1 comprising the amino acid sequence SEQ ID NO:60,

(v) a CDR-L2 comprising the amino acid sequence SEQ ID NO:61, and

(vi) a CDR-L3 comprising the amino acid sequence SEQ ID NO: 62.

19. The bispecific antigen binding molecule of any one of paras 1, 2, or 13 to 18, wherein the moiety capable of specific binding to EpCAM comprises a VH comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO: 65, and a VL comprising an amino acid sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the amino acid sequence of SEQ ID NO:66. 20. The bispecific antigen binding molecule of any one of paras 1, 2, or 13 to 19, wherein the moiety capable of specific binding to EpCAM comprises a VH comprising the amino acid sequence of SEQ ID NO:65 and a VL comprising the amino acid sequence of SEQ ID NO:66.

21. The bispecific antigen binding molecule of any one of paras 1, 2, or 13 to 20, comprising (i) at least one moiety capable of specific binding to OX40, comprising a VH comprising the amino acid sequence of SEQ ID NO:47 and a VL comprising the amino acid sequence of SEQ ID NO:48, and

(ii) at least one moiety capable of specific binding to EpCAM, comprising a VH comprising the amino acid sequence of SEQ ID NO: 65 and a VL comprising the amino acid sequence of SEQ ID NO:66.

22. The bispecific antigen binding molecule of any one of paras 2 to 21, wherein the Fc region is an IgG, particularly an IgGl Fc region or an IgG4 Fc region.

23. The bispecific antigen binding molecule of any one of paras 2 to 22, wherein the Fc region comprises one or more amino acid substitution that reduces the binding affinity of the antibody to an Fc receptor and/or effector function.

24. The bispecific antigen binding molecule of any one of paras 2 to 23, wherein the Fc region is (i) of human IgGl subclass with the amino acid mutations L234A, L235A and P329G

(numbering according to Kabat EU index), or (ii) of mouse IgGl subclass with the amino acid mutations D265A and P329G (numbering according to Kabat EU index). 25. The bispecific antigen binding molecule of any one of paras 2 to 24, wherein the Fc region comprises a modification promoting the association of the first and second subunit of the Fc region. 26. The bispecific antigen binding molecule of any one of paras 2 to 25, wherein the first subunit of the Fc region comprises knobs and the second subunit of the Fc region comprises holes according to the knobs into holes method.

27. The bispecific antibody of any one of paras 2 to 26, wherein

(i) the first subunit of the Fc region comprises the amino acid substitutions S354C and T366W (numbering according to Kabat EU index) and the second subunit of the Fc region comprises the amino acid substitutions Y349C, T366S and Y407V (numbering according to Kabat EU index), or

(ii) the first subunit of the Fc region comprises the amino acid substitutions K392D and K409D (numbering according to Kabat EU index) and the second subunit of the Fc region comprises the amino acid substitutions E356K and D399K (numbering according to Kabat EU index).

28. The bispecific antigen binding molecule of any one of paras 1 to 27, wherein the bispecific antigen binding molecule comprises

(a) at least two Fab fragments capable of specific binding to OX40 connected to a Fc region, and (b) at least one moiety capable of specific binding to EpCAM connected to the C-terminus of the Fc region.

29. The bispecific antigen binding molecule of any one of paras 1 to 28, wherein the bispecific antigen binding molecule comprises

(a) two light chains and two heavy chains of an antibody comprising two Fab fragments capable of specific binding to OX40, and a Fc region, and

(b) a VH and a VL of a moiety capable specific binding to EpCAM, wherein the VH is connected to the C-terminus of one of the two heavy chains of (a), and wherein the VL is connected to the C-terminus of the other of the two heavy chains of (a).

30. The bispecific antigen binding molecule of any one of paras 1 to 29, wherein the bispecific antigen binding molecule comprises

(a) two light chains and two heavy chains of an antibody comprising two Fab fragments capable of specific binding to OX40, and a Fc region, and

(b) two Fab fragments capable of specific binding to EpCAM, wherein one of the Fab fragments is connected to the C-terminus of one of the two heavy chains of (a), and the other of the Fab fragments is connected to the C-terminus of the other of the two heavy chains of (a). 31. The bispecific antigen binding molecule of any one of paras 1 to 30, wherein the bispecific antigen binding molecule comprises

(a) two heavy chains, each heavy chain comprising a VH and CHI domain of a Fab fragment capable of specific binding to OX40 and a Fc region subunit,

(b) two light chains, each light chain comprising a VL and CL domain of a Fab fragment capable of specific binding to OX40, and

(c) a VH and a VL of a moiety capable specific binding to EpCAM, wherein the VH is connected to the C-terminus of one of the two heavy chains of (a), and wherein the VL is connected to the C-terminus of the other of the two heavy chains of (a).

32. The bispecific antigen binding molecule of any one of paras 1 to 28 or para 30, wherein the bispecific antigen binding molecule comprises

(a) two heavy chains, each heavy chain comprising a VH and CHI domain of a Fab fragment capable of specific binding to OX40, and a Fc region subunit,

(b) two light chains, each light chain comprising a VL and CL domain of a Fab fragment capable of specific binding to OX40,

(c) two Fab fragments capable of specific binding to EpCAM, wherein one of the Fab fragments is connected to the C-terminus of one of the two heavy chains of (a), and the other of the Fab fragments is connected to the C-terminus of the other of the two heavy chains of (a).

33. The bispecific antigen binding molecule of para 30 or para 32, wherein the two Fab fragments capable of specific binding to EpCAM are crossover Fab fragments each comprising a VL-CH1 chain and a VH-CL chain, and wherein one of the VL-CH1 chains is connected to the C-terminus of one of the two heavy chains of (a), and the other of the VL-CH1 chains is connected to the C-terminus of the other of the two heavy chains of (a).

34. The bispecific antigen binding molecule of any one of paras 1 to 33, wherein the bispecific antigen binding molecule comprises four Fab fragments capable of specific binding to OX40.

35. The bispecific antigen binding molecule of any one of paras 29 to 34, wherein each of the two heavy chains of (a) comprises two VH domains and two CHI domains of a Fab fragment capable of specific binding to OX40. 36. The bispecific antigen binding molecule of any one of paras 28 to 35, one or more of the Fab fragments capable of specific binding to OX40 comprises

a CL domain comprising an arginine (R) at amino acid at position 123 (EU numbering) and a lysine (K) at amino acid at position 124 (EU numbering), and a CHI domain comprising a glutamic acid (E) at amino acid at position 147 (EU numbering) and a glutamic acid (E) at amino acid at position 213 (EU numbering).

37. A bispecific antigen binding molecule, comprising

a first heavy chain comprising the amino acid sequence of SEQ ID NO: 183,

a second heavy chain comprising the amino acid sequence of SEQ ID NO: 184, and

four light chains, each comprising the amino acid sequence of SEQ ID NO: 182.

38. A bispecific antigen binding molecule, comprising

two heavy chains, each comprising the amino acid sequence of SEQ ID NO : 186,

two light chains, each comprising the amino acid sequence of SEQ ID NO: 187, and

four light chains, each comprising the amino acid sequence of SEQ ID NO: 185.

39. A bispecific antigen binding molecule, comprising

a first heavy chain comprising the amino acid sequence of SEQ ID NO: 192,

a second heavy chain comprising the amino acid sequence of SEQ ID NO: 193, and

four light chains, each comprising the amino acid sequence of SEQ ID NO: 191.

40. A polynucleotide encoding the bispecific antigen binding molecule of any one of paras 1 to 39.

41. An expression vector comprising the polynucleotide of para 40.

42. A host cell comprising the polynucleotide of para 40 or the expression vector of para 41.

43. A method of producing a bispecific antigen binding molecule, comprising culturing the host cell of para 42 under conditions suitable for the expression of the bispecific antigen binding molecule, and isolating the bispecific antigen binding molecule. 44. A pharmaceutical composition comprising the bispecific antigen binding molecule of any one of paras 1 to 39 and at least one pharmaceutically acceptable excipient.

45. The bispecific antigen binding molecule of any one of paras 1 to 39, or the pharmaceutical composition of para 44, for use as a medicament.

46. The bispecific antigen binding molecule of any one of paras 1 to 39, or the pharmaceutical composition of para 44, for use

(i) in stimulating T cell response, (ii) in supporting survival of activated T cells,

(iii) in the treatment of infections,

(iv) in the treatment of cancer,

(v) in delaying progression of cancer, or

(vi) in prolonging the survival of a patient suffering from cancer.

47. The bispecific antigen binding molecule of any one of paras 1 to 39, or the pharmaceutical composition of para 44, for use in the treatment of cancer. 48. Use of the bispecific antigen binding molecule of any one of paras 1 to 39, or the

pharmaceutical composition of para 44, in the manufacture of a medicament for the treatment of cancer.

49. A method of treating an individual having cancer comprising administering to the individual an effective amount of the bispecific antigen binding molecule of any one of paras 1 to 39, or the pharmaceutical composition of para 44.

50. The bispecific antigen binding molecule of any one of paras 1 to 39, or the pharmaceutical composition of para 44, for use in up-regulating or prolonging cytotoxic T cell activity.

51. Use of the bispecific antigen binding molecule of any one of paras 1 to 39, or the

pharmaceutical composition of para 44, in the manufacture of a medicament for up-regulating or prolonging cytotoxic T cell activity. 52. A method of up-regulating or prolonging cytotoxic T cell activity in an individual having cancer, comprising administering to the individual an effective amount of the bispecific antigen binding molecule of any one of paras 1 to 39, or the pharmaceutical composition of para 44.

EXAMPLES The following are examples of methods and compositions of the invention. It is understood that various other embodiments may be practiced, given the general description provided above.

Recombinant DNA techniques

Standard methods were used to manipulate DNA as described in Sambrook et al,

Molecular cloning: A laboratory manual; Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, 1989. The molecular biological reagents were used according to the manufacturer's instructions. General information regarding the nucleotide sequences of human immunoglobulin light and heavy chains is given in: Kabat, E.A. et al., (1991) Sequences of Proteins of Immunological Interest, Fifth Ed., NIH Publication No 91-3242.

DNA sequencing

DNA sequences were determined by double strand sequencing. Gene synthesis

Desired gene segments were either generated by PCR using appropriate templates or were synthesized by Geneart AG (Regensburg, Germany) from synthetic oligonucleotides and PCR products by automated gene synthesis. In cases where no exact gene sequence was available, oligonucleotide primers were designed based on sequences from closest homologues and the genes were isolated by RT-PCR from RNA originating from the appropriate tissue. The gene segments flanked by singular restriction endonuclease cleavage sites were cloned into standard cloning / sequencing vectors. The plasmid DNA was purified from transformed bacteria and concentration determined by UV spectroscopy. The DNA sequence of the subcloned gene fragments was confirmed by DNA sequencing. Gene segments were designed with suitable restriction sites to allow sub-cloning into the respective expression vectors. All constructs were designed with a 5 '-end DNA sequence coding for a leader peptide which targets proteins for secretion in eukaryotic cells.

Protein purification

Proteins were purified from filtered cell culture supernatants referring to standard protocols. In brief, antibodies were applied to a Protein A Sepharose column (GE healthcare) and washed with PBS. Elution of antibodies was achieved at pH 2.8 followed by immediate neutralization of the sample. Aggregated protein was separated from monomeric antibodies by size exclusion chromatography (Superdex 200, GE Healthcare) in PBS or in 20 mM Histidine, 150 mM NaCl pH 6.0. Monomeric antibody fractions were pooled, concentrated (if required) using e.g., a MILLIPORE Amicon Ultra (30 MWCO) centrifugal concentrator, frozen and stored at -20°C or -80°C. Part of the samples were provided for subsequent protein analytics and analytical characterization e.g. by SDS-PAGE, size exclusion chromatography (SEC) or mass spectrometry.

SDS-PAGE

The NuPAGE® Pre-Cast gel system (Invitrogen) was used according to the manufacturer's instruction. In particular, 10% or 4-12% NuPAGE® Novex® Bis-TRIS Pre-Cast gels (pH 6.4) and a NuPAGE® MES (reduced gels, with NuPAGE® Antioxidant running buffer additive) or MOPS (non-reduced gels) running buffer was used. Analytical size exclusion chromatography

Size exclusion chromatography (SEC) for the determination of the aggregation and oligomeric state of antibodies was performed by HPLC chromatography. Briefly, Protein A purified antibodies were applied to a Tosoh TSKgel G3000SW column in 300 mM NaCl, 50 mM KH ₂ PO ₄ /K ₂ HPO ₄ , pH 7.5 on an Agilent HPLC 1100 system or to a Superdex 200 column (GE Healthcare) in 2 x PBS on a Dionex HPLC-System. The eluted protein was quantified by UV absorbance and integration of peak areas. BioRad Gel Filtration Standard 151-1901 served as a standard.

Example 1 Generation of OX40 antibodies

1.1 Preparation, purification and characterization of antigens and screening tools for the generation of novel OX40 binders by Phage Display

DNA sequences encoding the ectodomains of human, mouse or cynomolgus OX40 (Table 1) were subcloned in frame with the human IgGl heavy chain CH2 and CH3 domains on the knob (Merchant et al, Nat Biotechnol (1998) 16, 677-681). An AcTEV protease cleavage site was introduced between an antigen ectodomain and the Fc of human IgGl . An Avi tag for directed biotinylation was introduced at the C-terminus of the antigen-Fc knob. Combination of the antigen-Fc knob chain containing the S354C/T366W mutations, with a Fc hole chain containing the Y349C/T366S/L368A/Y407V mutations allows generation of a heterodimer which includes a single copy of the OX40 ectodomain containing chain, thus creating a monomeric form of Fc-linked antigen (Figure 1). Table 1 shows the amino acid sequences of the various OX40 ectodomains. Table 2 the cDNA and amino acid sequences of monomeric antigen Fc(kih) fusion molecules as depicted in Figure 1.

Table 1. Amino acid numbering of antigen ectodomains (ECD) and their

SEQ ID NO: Construct Origin ECD

Synthetized according to

1 human OX40 ECD aa 29-214

P43489

Isolated from cynomolgus

3 cynomolgus OX40 ECD aa 29-214 blood

Synthetized according to

2 murine OX40 ECD aa 10-211

P47741 Table 2. cDNA and amino acid sequences of monomeric antigen Fc(kih) fusion molecules (produced by combination of one Fc hole chain with one antigen Fc knob chain)

SEQ ID NO: Antigen Sequence

91 Nucleotide GACAAAACTCACACATGCCCACCGTGCCCAGCACCTG

AACTCCTGGGGGGACCGTCAGTCTTCCTCTTCCCCCCA

sequence AAACCCAAGGACACCCTCATGATCTCCCGGACCCCTGA Fc hole chain GGTCACATGCGTGGTGGTGGACGTGAGCCACGAAGAC

CCTGAGGTCAAGTTCAACTGGTACGTGGACGGCGTGG

AGGTGCATAATGCCAAGACAAAGCCGCGGGAGGAGCA

GTACAACAGCACGTACCGTGTGGTCAGCGTCCTCACCG

TCCTGCACCAGGACTGGCTGAATGGCAAGGAGTACAA

GTGCAAGGTCTCCAACAAAGCCCTCCCAGCCCCCATCG

AGAAAACCATCTCCAAAGCCAAAGGGCAGCCCCGAGA

ACCACAGGTGTGCACCCTGCCCCCATCCCGGGATGAGC

TGACCAAGAACCAGGTCAGCCTCTCGTGCGCAGTCAA

AGGCTTCTATCCCAGCGACATCGCCGTGGAGTGGGAG

AGCAATGGGCAGCCGGAGAACAACTACAAGACCACGC

CTCCCGTGCTGGACTCCGACGGCTCCTTCTTCCTCGTGA

GCAAGCTCACCGTGGACAAGAGCAGGTGGCAGCAGGG

GAACGTCTTCTCATGCTCCGTGATGCATGAGGCTCTGC

ACAACCACTACACGCAGAAGAGCCTCTCCCTGTCTCCG

GGTAAA

92 Nucleotide CTGCACTGCGTGGGCGACACCTACCCCAGCAACGACC

GGTGCTGCCACGAGTGCAGACCCGGCAACGGCATGGT

sequence GTCCCGGTGCAGCCGGTCCCAGAACACCGTGTGCAGA human OX40 CCTTGCGGCCCTGGCTTCTACAACGACGTGGTGTCCAG

CAAGCCCTGCAAGCCTTGTACCTGGTGCAACCTGCGGA

antigen Fc GCGGCAGCGAGCGGAAGCAGCTGTGTACCGCCACCCA knob chain GGATACCGTGTGCCGGTGTAGAGCCGGCACCCAGCCC

CTGGACAGCTACAAACCCGGCGTGGACTGCGCCCCTTG

CCCTCCTGGCCACTTCAGCCCTGGCGACAACCAGGCCT

GCAAGCCTTGGACCAACTGCACCCTGGCCGGCAAGCA

CACCCTGCAGCCCGCCAGCAATAGCAGCGACGCCATCT

GCGAGGACCGGGATCCTCCTGCCACCCAGCCTCAGGA

AACCCAGGGCCCTCCCGCCAGACCCATCACCGTGCAGC

CTACAGAGGCCTGGCCCAGAACCAGCCAGGGGCCTAG

CACCAGACCCGTGGAAGTGCCTGGCGGCAGAGCCGTC

GACGAACAGTTATATTTTCAGGGCGGCTCACCCAAATC

TGCAGACAAAACTCACACATGCCCACCGTGCCCAGCA

CCTGAACTCCTGGGGGGACCGTCAGTCTTCCTCTTCCC

CCCAAAACCCAAGGACACCCTCATGATCTCCCGGACCC

CTGAGGTCACATGCGTGGTGGTGGACGTGAGCCACGA

AGACCCTGAGGTCAAGTTCAACTGGTACGTGGACGGC

GTGGAGGTGCATAATGCCAAGACAAAGCCGCGGGAGG

AGCAGTACAACAGCACGTACCGTGTGGTCAGCGTCCTC

ACCGTCCTGCACCAGGACTGGCTGAATGGCAAGGAGT

ACAAGTGCAAGGTCTCCAACAAAGCCCTCCCAGCCCCC

ATCGAGAAAACCATCTCCAAAGCCAAAGGGCAGCCCC

GAGAACCACAGGTGTACACCCTGCCCCCATGCCGGGA

TGAGCTGACCAAGAACCAGGTCAGCCTGTGGTGCCTG GTCAAAGGCTTCTATCCCAGCGACATCGCCGTGGAGTG

GGAGAGCAATGGGCAGCCGGAGAACAACTACAAGACC

ACGCCTCCCGTGCTGGACTCCGACGGCTCCTTCTTCCTC

TACAGCAAGCTCACCGTGGACAAGAGCAGGTGGCAGC

AGGGGAACGTCTTCTCATGCTCCGTGATGCATGAGGCT

CTGCACAACCACTACACGCAGAAGAGCCTCTCCCTGTC

TCCGGGTAAATCCGGAGGCCTGAACGACATCTTCGAG

GCCCAGAAGATTGAATGGCACGAG

CTCCACTGTGTCGGGGACACCTACCCCAGCAACGACCG

93 Nucleotide

GTGCTGTCAGGAGTGCAGGCCAGGCAACGGGATGGTG

sequence AGCCGCTGCAACCGCTCCCAGAACACGGTGTGCCGTCC cynomolgus GTGCGGGCCCGGCTTCTACAACGACGTGGTCAGCGCCA

AGCCCTGCAAGGCCTGCACATGGTGCAACCTCAGAAG OX40 antigen TGGGAGTGAGCGGAAACAGCCGTGCACGGCCACACAG Fc knob chain GACACAGTCTGCCGCTGCCGGGCGGGCACCCAGCCCCT

GGACAGCTACAAGCCTGGAGTTGACTGTGCCCCCTGCC

CTCCAGGGCACTTCTCCCCGGGCGACAACCAGGCCTGC

AAGCCCTGGACCAACTGCACCTTGGCCGGGAAGCACA

CCCTGCAGCCAGCCAGCAATAGCTCGGACGCCATCTGT

GAGGACAGGGACCCCCCACCCACACAGCCCCAGGAGA

CCCAGGGCCCCCCGGCCAGGCCCACCACTGTCCAGCCC

ACTGAAGCCTGGCCCAGAACCTCACAGAGACCCTCCA

CCCGGCCCGTGGAGGTCCCCAGGGGCCCTGCGGTCGA

CGAACAGTTATATTTTCAGGGCGGCTCACCCAAATCTG

CAGACAAAACTCACACATGCCCACCGTGCCCAGCACCT

GAACTCCTGGGGGGACCGTCAGTCTTCCTCTTCCCCCC

AAAACCCAAGGACACCCTCATGATCTCCCGGACCCCTG

AGGTCACATGCGTGGTGGTGGACGTGAGCCACGAAGA

CCCTGAGGTCAAGTTCAACTGGTACGTGGACGGCGTGG

AGGTGCATAATGCCAAGACAAAGCCGCGGGAGGAGCA

GTACAACAGCACGTACCGTGTGGTCAGCGTCCTCACCG

TCCTGCACCAGGACTGGCTGAATGGCAAGGAGTACAA

GTGCAAGGTCTCCAACAAAGCCCTCCCAGCCCCCATCG

AGAAAACCATCTCCAAAGCCAAAGGGCAGCCCCGAGA

ACCACAGGTGTACACCCTGCCCCCATGCCGGGATGAGC

TGACCAAGAACCAGGTCAGCCTGTGGTGCCTGGTCAA

AGGCTTCTATCCCAGCGACATCGCCGTGGAGTGGGAG

AGCAATGGGCAGCCGGAGAACAACTACAAGACCACGC

CTCCCGTGCTGGACTCCGACGGCTCCTTCTTCCTCTACA

GCAAGCTCACCGTGGACAAGAGCAGGTGGCAGCAGGG

GAACGTCTTCTCATGCTCCGTGATGCATGAGGCTCTGC

ACAACCACTACACGCAGAAGAGCCTCTCCCTGTCTCCG

GGTAAATCCGGAGGCCTGAACGACATCTTCGAGGCCC

AGAAGATTGAATGGCACGAG

GTGACCGCCAGACGGCTGAACTGCGTGAAGCACACCT

94 Nucleotide

ACCCCAGCGGCCACAAGTGCTGCAGAGAGTGCCAGCC

sequence CGGCCACGGCATGGTGTCCAGATGCGACCACACACGG murine OX40 GACACCCTGTGCCACCCTTGCGAGACAGGCTTCTACAA

CGAGGCCGTGAACTACGATACCTGCAAGCAGTGCACC

antigen Fc CAGTGCAACCACAGAAGCGGCAGCGAGCTGAAGCAGA knob chain ACTGCACCCCCACCCAGGATACCGTGTGCAGATGCAG

ACCCGGCACCCAGCCCAGACAGGACAGCGGCTACAAG CTGGGCGTGGACTGCGTGCCCTGCCCTCCTGGCCACTT

CAGCCCCGGCAACAACCAGGCCTGCAAGCCCTGGACC

AACTGCACCCTGAGCGGCAAGCAGACCAGACACCCCG

CCAGCGACAGCCTGGATGCCGTGTGCGAGGACAGAAG

CCTGCTGGCCACCCTGCTGTGGGAGACACAGCGGCCCA

CCTTCAGACCCACCACCGTGCAGAGCACCACCGTGTGG

CCCAGAACCAGCGAGCTGCCCAGTCCTCCTACCCTCGT

GACACCTGAGGGCCCCGTCGACGAACAGTTATATTTTC

AGGGCGGCTCACCCAAATCTGCAGACAAAACTCACAC

ATGCCCACCGTGCCCAGCACCTGAACTCCTGGGGGGAC

CGTCAGTCTTCCTCTTCCCCCCAAAACCCAAGGACACC

CTCATGATCTCCCGGACCCCTGAGGTCACATGCGTGGT

GGTGGACGTGAGCCACGAAGACCCTGAGGTCAAGTTC

AACTGGTACGTGGACGGCGTGGAGGTGCATAATGCCA

AGACAAAGCCGCGGGAGGAGCAGTACAACAGCACGTA

CCGTGTGGTCAGCGTCCTCACCGTCCTGCACCAGGACT

GGCTGAATGGCAAGGAGTACAAGTGCAAGGTCTCCAA

CAAAGCCCTCCCAGCCCCCATCGAGAAAACCATCTCCA

AAGCCAAAGGGCAGCCCCGAGAACCACAGGTGTACAC

CCTGCCCCCATGCCGGGATGAGCTGACCAAGAACCAG

GTCAGCCTGTGGTGCCTGGTCAAAGGCTTCTATCCCAG

CGACATCGCCGTGGAGTGGGAGAGCAATGGGCAGCCG

GAGAACAACTACAAGACCACGCCTCCCGTGCTGGACT

CCGACGGCTCCTTCTTCCTCTACAGCAAGCTCACCGTG

GACAAGAGCAGGTGGCAGCAGGGGAACGTCTTCTCAT

GCTCCGTGATGCATGAGGCTCTGCACAACCACTACACG

CAGAAGAGCCTCTCCCTGTCTCCGGGTAAATCCGGAGG

CCTGAACGACATCTTCGAGGCCCAGAAGATTGAATGG

CACGAG

DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTC

95 Fc hole chain

VWDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNST YRWSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISK AKGQPREPQVCTLPPSRDELTK QVSLSCAVKGFYPSDIA VEWESNGQPEN YKTTPPVLDSDGSFFLVSKLTVDKSRW QQGNVFSCSVMHEALHNHYTQKSLSLSPGK human OX40 LHCVGDTYPSNDRCCHECRPGNGMVSRCSRSQNTVCRPC

96

GPGFYNDWSSKPCKPCTWCNLRSGSERKQLCTATQDTV

antigen Fc CRCRAGTQPLDSYKPGVDCAPCPPGHFSPGDNQACKPWE knob chain pCAMTLAGKHTLQPASNSSDAICEDRDPPATQPQETQGPP

ARPITVQPTEAWPRTSQGPSTRPVEVPGGRAVDEQLYFQ

GGSPKSADKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMIS

RTPEVTCVWDVSHEDPEVKFNWYVDGVEVHNAKTKPR

EEQYNSTYRWSVLTVLHQDWLNGKEYKCKVSNKALPA

PIEKTISKAKGQPREPQVYTLPPCRDELTK QVSLWCLVK

GFYPSDIAVEWESNGQPEN YKTTPPVLDSDGSFFLYSKL

TVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKS

GGLNDIFEAQKIEWHE

LHCVGDTYPSNDRCCQECRPGNGMVSRCNRSQNTVCRP

97 cynomolgus

CGPGFYNDWSAKPCKACTWCNLRSGSERKQPCTATQD OX40 antigen TVCRCRAGTQPLDSYKPGVDCAPCPPGHFSPGDNQACKP

WEpCAMTLAGKHTLQPASNSSDAICEDRDPPPTQPQETQ GPPARPTTVQPTEAWPRTSQRPSTRPVEVPRGPAVDEQLY

Fc knob chain

FQGGSPKSADKTHTCPPCPAPELLGGPSVFLFPPKPKDTL

MISRTPEVTCVWDVSHEDPEVKFNWYVDGVEVHNAKT

KPREEQYNSTYRWSVLTVLHQDWLNGKEYKCKVSNKA

LPAPIEKTISKAKGQPREPQVYTLPPCRDELTK QVSLWC

LVKGFYPSDIAVEWESNGQPEN YKTTPPVLDSDGSFFLY

SKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSP

GKS GGLNDIFEAQKIE WHE

VTARRLNCVKHTYPSGHKCCRECQPGHGMVSRCDHTRD

98 murine OX40

TLCHPCETGFYNEAVNYDTCKQCTQCNHRSGSELKQNCT

antigen Fc PTQDTVCRCRPGTQPRQDSGYKLGVDCVPCPPGHFSPGN knob chain NQACKPWEpCAMTLSGKQTRHPASDSLDAVCEDRSLLAT

LLWETQRPTFRPTTVQSTTVWPRTSELPSPPTLVTPEGPV

DEQLYFQGGSPKSADKTHTCPPCPAPELLGGPSVFLFPPK

PKDTLMISRTPEVTCVWDVSHEDPEVKFNWYVDGVEV

HNAKTKPREEQYNSTYRWSVLTVLHQDWLNGKEYKCK

VSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTK Q

VSLWCLVKGFYPSDIAVEWESNGQPEN YKTTPPVLDSD

GSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQK

SLSLSPGKSGGLNDIFEAQKIEWHE

All OX40-Fc-fusion encoding sequences were cloned into a plasmid vector driving expression of the insert from an MPSV promoter and containing a synthetic polyA signal sequence located at the 3 ' end of the CDS. In addition, the vector contained an EBV OriP sequence for episomal maintenance of the plasmid.

For preparation of the biotinylated monomeric antigen/Fc fusion molecules, exponentially growing suspension HEK293 EBNA cells were co-transfected with three vectors encoding the two components of fusion protein (knob and hole chains) as well as BirA, an enzyme necessary for the biotinylation reaction. The corresponding vectors were used at a 2 : 1 : 0.05 ratio

("antigen ECD-AcTEV- Fc knob" : "Fc hole" : "BirA").

For protein production in 500 ml shake flasks, 400 million HEK293 EBNA cells were seeded 24 hours before transfection. For transfection cells were centrifuged for 5 minutes at 210 g, and supernatant was replaced by pre-warmed CD CHO medium. Expression vectors were resuspended in 20 mL of CD CHO medium containing 200 μg of vector DNA. After addition of 540 of polyethylenimine (PEI), the solution was vortexed for 15 seconds and incubated for 10 minutes at room temperature. Afterwards, cells were mixed with the DNA/PEI solution, transferred to a 500 mL shake flask and incubated for 3 hours at 37°C in an incubator with a 5% C0 ₂ atmosphere. After the incubation, 160 mL of F17 medium was added and cells were cultured for 24 hours. One day after transfection, 1 mM valproic acid and 7% Feed were added to the culture. After 7 days of culturing, the cell supernatant was collected by spinning down cells for 15 min at 210 g. The solution was sterile filtered (0.22 μηι filter), supplemented with sodium azide to a final concentration of 0.01 % (w/v), and kept at 4°C.

Secreted proteins were purified from cell culture supernatants by affinity chromatography using Protein A, followed by size exclusion chromatography. For affinity chromatography, the supernatant was loaded on a HiTrap ProteinA HP column (CV = 5 mL, GE Healthcare) equilibrated with 40 mL 20 mM sodium phosphate, 20 mM sodium citrate pH 7.5. Unbound protein was removed by washing with at least 10 column volumes of a buffer containing 20 mM sodium phosphate, 20 mM sodium citrate and 0.5 M sodium chloride (pH 7.5). The bound protein was eluted using a linear pH-gradient of sodium chloride (from 0 to 500 mM) created over 20 column volumes of 20 mM sodium citrate, 0.01% (v/v) Tween-20, pH 3.0 . The column was then washed with 10 column volumes of a solution containing 20 mM sodium citrate, 500 mM sodium chloride and 0.01% (v/v) Tween-20, pH 3.0.

The pH of the collected fractions was adjusted by adding 1/40 (v/v) of 2M Tris, pH8.0. The protein was concentrated and filtered prior to loading on a HiLoad Superdex 200 column (GE Healthcare) equilibrated with 2 mM MOPS, 150 mM sodium chloride, 0.02% (w/v) sodium azide solution of pH 7.4.

1.2 Selection of OX40-specific 8H9, 20B7, 49B4, 1G4, CLC-563, CLC-564 and 17A9 antibodies from generic Fab and common light chain libraries

Anti-OX40 antibodies were selected from three different generic phage display libraries: DP88-4 (clones 20B7, 8H9 1G4 and 49B4), the common light chain library Vk3_20/VH3_23 (clones CLC-563 and CLC-564) and lambda-DP47 (clone 17A9).

The DP88-4 library was constructed on the basis of human germline genes using the V- domain pairing Vkl_5 (kappa light chain) and VH1 69 (heavy chain) comprising randomized sequence space in CDR3 of the light chain (L3, 3 different lengths) and CDR3 of the heavy chain (H3, 3 different lengths). Library generation was performed by assembly of 3 PCR- amplified fragments applying splicing by overlapping extension (SOE) PCR. Fragment 1 comprises the 5' end of the antibody gene including randomized L3, fragment 2 is a central constant fragment spanning from L3 to H3 whereas fragment 3 comprises randomized H3 and the 3' portion of the antibody gene. The following primer combinations were used to generate these library fragments for DP88-4 library: fragment 1 (forward primer LMB3 combined with reverse primers Vkl_5_L3r_S or Vkl_5_L3r_SY or Vkl_5_L3r_SPY), fragment 2 (forward primer RJH31 combined with reverse primer RJH32) and fragment 3 (forward primers DP88-v4- 4 or DP88-v4-6 or DP88-v4-8 combined with reverse primer fdseqlong), respectively. PCR parameters for production of library fragments were 5 min initial denaturation at 94°C, 25 cycles of 1 min 94°C, 1 min 58°C, 1 min 72°C and terminal elongation for 10 min at 72°C. For assembly PCR, using equimolar ratios of the gel-purified single fragments as template, parameters were 3 min initial denaturation at 94°C and 5 cycles of 30 s 94°C, 1 min 58°C, 2 min 72°C. At this stage, outer primers (LMB3 and fdseqlong) were added and additional 20 cycles were performed prior to a terminal elongation for 10 min at 72°C. After assembly of sufficient amounts of full length randomized Fab constructs, they were digested Ncol / Nhel and ligated into similarly treated acceptor phagemid vector. Purified ligations were used for ~60

transformations into electrocompetent E. coli TGI . Phagemid particles displaying the Fab library were rescued and purified by PEG/NaCl purification to be used for selections. These library construction steps were repeated three times to obtain a final library size of 4.4 x 109.

Percentages of functional clones, as determined by C-terminal tag detection in dot blot, were 92.6% for the light chain and 93.7% for the heavy chain, respectively.

The common light chain library Vk3_20/VH3_23 was constructed on the basis of human germline genes using the V-domain pairing Vk3_20 (kappa light chain) and VH3 23 (heavy chain) comprising a constant non-randomized common light chain Vk3_20 and randomized sequence space in CDR3 of the heavy chain (H3, 3 different lengths). Library generation was performed by assembly of 2 PCR-amplified fragments applying splicing by overlapping extension (SOE) PCR. Fragment 1 is a constant fragment spanning from L3 to H3 whereas fragment 2 comprises randomized H3 and the 3' portion of the antibody gene. The following primer combinations were used to generate these library fragments for the Vk3_20/VH3_23 common light chain library: fragment 1 (forward primer MS64 combined with reverse primer DP47CDR3_ba (mod.)) and fragment 2 (forward primers DP47-v4-4, DP47-v4-6, DP47-v4-8 combined with reverse primer fdseqlong), respectively. PCR parameters for production of library fragments were 5 min initial denaturation at 94°C, 25 cycles of 1 min 94°C, 1 min 58°C, 1 min 72°C and terminal elongation for 10 min at 72°C. For assembly PCR, using equimolar ratios of the gel-purified single fragments as template, parameters were 3 min initial denaturation at 94°C and 5 cycles of 30 s 94°C, 1 min 58°C, 2 min 72°C. At this stage, outer primers (MS64 and fdseqlong) were added and additional 18 cycles were performed prior to a terminal elongation for 10 min at 72°C. After assembly of sufficient amounts of full length randomized VH constructs, they were digested Muni / Notl and ligated into similarly treated acceptor phagemid vector. Purified ligations were used for ~60 transformations into electrocompetent E. coli TGI . Phagemid particles displaying the Fab library were rescued and purified by PEG/NaCl purification to be used for selections. A final library size of 3.75 x 109 was obtained.

Percentages of functional clones, as determined by C-terminal tag detection in dot blot, were 98.9% for the light chain and 89.5% for the heavy chain, respectively. The lambda-DP47 library was constructed on the basis of human germline genes using the following V-domain pairings: V13 19 lambda light chain with VH3 23 heavy chain. The library was randomized in CDR3 of the light chain (L3) and CDR3 of the heavy chain (H3) and was assembled from 3 fragments by "splicing by overlapping extension" (SOE) PCR. Fragment 1 comprises the 5' end of the antibody gene including randomized L3, fragment 2 is a central constant fragment spanning from the end of L3 to the beginning of H3 whereas fragment 3 comprises randomized H3 and the 3 ' portion of the Fab fragment. The following primer combinations were used to generate library fragments for library: fragment 1 (LMB3 - Vl_3_19_L3r_V / Vl_3_19_L3r_HV / Vl_3_19_L3r_HLV), fragment 2 (RJH80 - DP47CDR3_ba (mod)) and fragment 3 (DP47-v4-4 / DP47-v4-6 / DP47-v4-8 - fdseqlong). PCR parameters for production of library fragments were 5 min initial denaturation at 94°C, 25 cycles of 60 sec at 94°C, 60 sec at 55°C, 60 sec at 72°C and terminal elongation for 10 min at 72°C. For assembly PCR, using equimolar ratios of the 3 fragments as template, parameters were 3 min initial denaturation at 94°C and 5 cycles of 60 sec at 94°C, 60 sec at 55°C, 120 sec at 72°C. At this stage, outer primers were added and additional 20 cycles were performed prior to a terminal elongation for 10 min at 72°C. After assembly of sufficient amounts of full length randomized Fab fragments, they were digested with Ncol / Nhel alongside with similarly treated acceptor phagemid vector. 15ug of Fab library insert were ligated with 13.3ug of phagemid vector.

Purified ligations were used for 60 transformations resulting in 1.5 x 10 ⁹ transformants.

Phagemid particles displaying the Fab library were rescued and purified by PEG/NaCl purification to be used for selections.

Human OX40 (CD 134) as antigen for the phage display selections was transiently expressed as N-terminal monomeric Fc-fusion in HEK EBNA cells and in vivo site-specifically biotinylated via co-expression of BirA biotin ligase at the avi-tag recognition sequence located a the C-terminus of the Fc portion carrying the receptor chain (Fc knob chain).

Selection rounds (biopanning) were performed in solution according to the following pattern:

1. Pre-clearing of - 1012 phagemid particles on maxisorp plates coated with lOug/ml of an unrelated human IgG to deplete the libraries of antibodies recognizing the Fc-portion of the antigen,

2. incubation of the non-binding phagemid particles with ΙΟΟηΜ biotinylated human OX40 for 0.5 h in the presence of ΙΟΟηΜ unrelated non-biotinylated Fc knob-into-hole construct for further depletion of Fc-binders in a total volume of 1 ml,

3. capture of biotinylated hu OX40 and attached specifically binding phage by transfer to 4 wells of a neutravidin pre-coated microtiter plate for 10 min (in rounds 1 & 3),

4. washing of respective wells using 5x PBS/Tween20 and 5x PBS,

5. elution of phage particles by addition of 250ul lOOmM TEA (triethylamine) per well for 10 min and neutralization by addition of 500ul 1M Tris/HCl pH 7.4 to the pooled eluates from 4 wells,

6. post-clearing of neutralized eluates by incubation on neutravidin pre-coated microtiter plate with ΙΟΟηΜ biotin-captured Fc knob-into-hole construct for final removal of Fc-binders, 7. re-infection of log-phase E. coli TGI cells with the supernatant of eluted phage particles, infection with helperphage VCSM13, incubation on a shaker at 30°C over night and subsequent PEG/NaCl precipitation of phagemid particles to be used in the next selection round. Selections were carried out over 3 or 4 rounds using constant antigen concentrations of 100 nM. In order to increase the likelihood for binders that are cross-reactive not only to cynomolgus OX40 but also murine OX40, in some selection rounds the murine target was used instead of the human OX40. In rounds 2 and 4, in order to avoid enrichment of binders to neutravidin, capture of antigen : phage complexes was performed by addition of 5.4 x 10 ⁷ streptavidin-coated magnetic beads. Specific binders were identified by ELISA as follows: lOOul of 25nM biotinylated human OX40 and lOug/ml of human IgG were coated on neutravidin plates and maxisorp plates, respectively. Fab-containing bacterial supernatants were added and binding Fabs were detected via their Flag-tags using an anti-Flag/HRP secondary antibody. Clones exhibiting signals on human OX40 and being negative on human IgG were short-listed for further analyses and were also tested in a similar fashion against cynomolgus and murine OX40. They were bacterially expressed in a 0.5 liter culture volume, affinity purified and further characterized by SPR-analysis using BioRad's ProteOn XPR36 biosensor.

Table 3 shows the sequence of generic phage-displayed antibody library (DP88-4), Table 4 provides cDNA and amino acid sequences of library DP88-4 germline template and Table 5 shows the Primer sequences used for generation of DP88-4 germline template.

Table 3. Sequence of generic phage-displayed antibody library (DP88-4)

SEQ ID Description Sequence

NO:

TGAAATACCTATTGCCTACGGCAGCCGCTGGATTGTTATTACTC

nucleotide GCGGCCCAGCCGGCCATGGCCGACATCCAGATGACCCAGTCTC sequence CTTCCACCCTGTCTGCATCTGTAGGAGACCGTGTCACCATCACT of TGCCGTGCCAGTCAGAGTATTAGTAGCTGGTTGGCCTGGTATC

AGCAGAAACCAGGGAAAGCCCCTAAGCTCCTGATCTATGATGC

CTCCAGTTTGGAAAGTGGGGTCCCATCACGTTTCAGCGGCAGT

GGATCCGGGACAGAATTCACTCTCACCATCAGCAGCTTGCAGC

pRJH33

CTGATGATTTTGCAACTTATTACTGCCAACAGTATAATAGTTAT

library

TCTACGTTTGGCCAGGGCACCAAAGTCGAGATCAAGCGTACGG

template TGGCTGCACCATCTGTCTTCATCTTCCCGCCATCTGATGAGCAG

DP88-4 TTGAAATCTGGAACTGCCTCTGTTGTGTGCCTGCTGAATAACTT library; CTATCCCAGAGAGGCCAAAGTACAGTGGAAGGTGGATAACGC complete CCTCCAATCGGGTAACTCCCAGGAGAGTGTCACAGAGCAGGA

Fab coding CAGCAAGGACAGCACCTACAGCCTCAGCAGCACCCTGACGCT region GAGCAAAGCAGACTACGAGAAACACAAAGTCTACGCCTGCGA comprising AGTCACCCATCAGGGCCTGAGCTCGCCCGTCACAAAGAGCTTC

PelB leader AACAGGGGAGAGTGTGGAGCCGCAGAACAAAAACTCATCTCA sequence + GAAGAGGATCTGAATGGAGCCGCAGACTACAAGGACGACGAC

GACAAGGGTGCCGCATAATAAGGCGCGCCAATTCTATTTCAAG

99 Vkl_5

GAGACAGTCATATGAAATACCTGCTGCCGACCGCTGCTGCTGG

kappa V-

TCTGCTGCTCCTCGCTGCCCAGCCGGCGATGGCCCAGGTGCAA

domain + TTGGTGCAGTCTGGGGCTGAGGTGAAGAAGCCTGGGTCCTCGG

CL TGAAGGTCTCCTGCAAGGCCTCCGGAGGCACATTCAGCAGCTA

constant CGCTATAAGCTGGGTGCGACAGGCCCCTGGACAAGGGCTCGA domain for GTGGATGGGAGGGATCATCCCTATCTTTGGTACAGCAAACTAC light chain GCACAGAAGTTCCAGGGCAGGGTCACCATTACTGCAGACAAA and PelB + TCCACGAGCACAGCCTACATGGAGCTGAGCAGCCTGAGATCTG VH1 69 AGGACACCGCCGTGTATTACTGTGCGAGACTATCCCCAGGCGG V-domain TTACTATGTTATGGATGCCTGGGGCCAAGGGACCACCGTGACC + CH1 GTCTCCTCAGCTAGCACCAAAGGCCCATCGGTCTTCCCCCTGG constant CACCCTCCTCCAAGAGCACCTCTGGGGGCACAGCGGCCCTGGG

CTGCCTGGTCAAGGACTACTTCCCCGAACCGGTGACGGTGTCG

domain for

TGGAACTCAGGCGCCCTGACCAGCGGCGTGCACACCTTCCCGG

heavy CTGTCCTACAGTCCTCAGGACTCTACTCCCTCAGCAGCGTGGT chain GACCGTGCCCTCCAGCAGCTTGGGCACCCAGACCTACATCTGC including AACGTGAATCACAAGCCCAGCAACACCAAAGTGGACAAGAAA tags GTTGAGCCCAAATCTTGTGACGCGGCCGCAAGCACTAGTGCCC

ATCACCATCACCATCACGCCGCGGCA

Table 4. cDNA and amino acid sequences of library DP88-4 germline template

SEQ ID Description Sequence

NO: GACATCCAGATGACCCAGTCTCCTTCCACCCTGTCTG

100 nucleotide

CATCTGTAGGAGACCGTGTCACCATCACTTGCCGTGC

sequence of CAGTCAGAGTATTAGTAGCTGGTTGGCCTGGTATCAG Fab light chain CAGAAACCAGGGAAAGCCCCTAAGCTCCTGATCTAT

GATGCCTCCAGTTTGGAAAGTGGGGTCCCATCACGTT

Vkl_5 TCAGCGGCAGTGGATCCGGGACAGAATTCACTCTCAC

CATCAGCAGCTTGCAGCCTGATGATTTTGCAACTTAT

TACTGCCAACAGTATAATAGTTATTCTACGTTTGGCC

AGGGCACCAAAGTCGAGATCAAGCGTACGGTGGCTG

CACCATCTGTCTTCATCTTCCCGCCATCTGATGAGCA

GTTGAAATCTGGAACTGCCTCTGTTGTGTGCCTGCTG

AATAACTTCTATCCCAGAGAGGCCAAAGTACAGTGG

AAGGTGGATAACGCCCTCCAATCGGGTAACTCCCAG

GAGAGTGTCACAGAGCAGGACAGCAAGGACAGCACC

TACAGCCTCAGCAGCACCCTGACGCTGAGCAAAGCA

GACTACGAGAAACACAAAGTCTACGCCTGCGAAGTC

ACCCATCAGGGCCTGAGCTCGCCCGTCACAAAGAGCT

TCAACAGGGGAGAGTGTGGAGCCGCAGAACAAAAAC

TCATCTCAGAAGAGGATCTGAATGGAGCCGCAGACT

ACAAGGACGACGACGACAAGGGTGCCGCA

DIQMTQSPSTLSASVGDRVTITCRASQSISSWLAWYQQK

101 Fab light chain

PGKAPKLLIYDASSLESGVPSRFSGSGSGTEFTLTISSLQP

Vkl_5 DDFATYYCQQYNSYSTFGQGTKVEIKRTVAAPSVFIFPP

SDEQLKSGTASWCLLN FYPREAKVQWKVDNALQSG

NSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACE

VTHQGLSSPVTKSFNRGECGAAEQKLISEEDLNGAADY

KDDDDKGAA

102 CAGGTGCAATTGGTGCAGTCTGGGGCTGAGGTGAAG nucleotide

AAGCCTGGGTCCTCGGTGAAGGTCTCCTGCAAGGCCT

sequence of CCGGAGGCACATTCAGCAGCTACGCTATAAGCTGGGT Fab heavy chain GCGACAGGCCCCTGGACAAGGGCTCGAGTGGATGGG

AGGGATCATCCCTATCTTTGGTACAGCAAACTACGCA VH1 69 CAGAAGTTCCAGGGCAGGGTCACCATTACTGCAGAC

AAATCCACGAGCACAGCCTACATGGAGCTGAGCAGC

CTGAGATCTGAGGACACCGCCGTGTATTACTGTGCGA

GACTATCCCCAGGCGGTTACTATGTTATGGATGCCTG

GGGCCAAGGGACCACCGTGACCGTCTCCTCAGCTAGC

ACCAAAGGCCCATCGGTCTTCCCCCTGGCACCCTCCT

CCAAGAGCACCTCTGGGGGCACAGCGGCCCTGGGCT

GCCTGGTCAAGGACTACTTCCCCGAACCGGTGACGGT

GTCGTGGAACTCAGGCGCCCTGACCAGCGGCGTGCA

CACCTTCCCGGCTGTCCTACAGTCCTCAGGACTCTAC

TCCCTCAGCAGCGTGGTGACCGTGCCCTCCAGCAGCT

TGGGCACCCAGACCTACATCTGCAACGTGAATCACAA

GCCCAGCAACACCAAAGTGGACAAGAAAGTTGAGCC

CAAATCTTGTGACGCGGCCGCAAGCACTAGTGCCCAT

CACCATCACCATCACGCCGCGGCA Fab heavy chain Q VQLVQ S GAEVKKPGS S VKVSCKASGGTF S S YAIS WVR

QAPGQGLEWMGGIIPIFGTANYAQKFQGRVTITADKSTS VH1 69 TAYMELSSLRSEDTAVYYCARLSPGGYYVMDAWGQGT

T VT VS S ASTKGPS VFPLAP S SKSTS GGTAALGCLVKD YF

PEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSWTVP

SSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDAAASTS

AHHHHHHAAA

Table 5. Primer sequences used for generation of DP88-4 library

SEQ Primer name Primer sequence 5' - 3'

ID NO:

104 LMB3 CAGGAAACAGCTATGACCATGATTAC

105 Vkl_5_L3r_S CTCGACTTTGGTGCCCTGGCCAAACGTS2L4A7

CGL4ArrAr^CTGTTGGCAGTAATAAGTTGCAAA

ATCAT

underlined: 60% original base and 40% randomization as M.

bolded and italic: 60% original base and 40%

randomization as N

106 Vkl_5_L3r_SY CTCGACTTTGGTGCCCTGGCCAAACGTMHRSGR

Ar^CG^ArrAr^CTGTTGGCAGTAATAAGTTGCA

AAATCAT

underlined: 60% original base and 40% randomization as M.

bolded and italic: 60% original base and 40%

randomization as N

107 Vkl_5_L3r_SPY CTCGACTTTGGTGCCCTGGCCAAACGTMHHMSS

S GRATACGAATTATA CTGTTGGC AGTAATAAGTT GCAAAATCAT

underlined: 60% original base and 40% randomization as M.

bolded and italic: 60% original base and 40%

randomization as N

108 RJH31 ACGTTTGGCCAGGGCACCAAAGTCGAG SEQ Primer name Primer sequence 5' - 3'

ID NO:

109 RJH32 TCTCGCACAGTAATACACGGCGGTGTCC

110 DP88-v4-4 GGACACCGCCGTGTATTACTGTGCGAGA- 1 -2-2-3- 4-GAC-TAC-

TGGGGCCAAGGGACCACCGTGACCGTCTCC

1 : G/D = 20%, E/V/S = 10%, A/P/R/L/T/Y=5%; 2: G/Y/S=15%, A/D/T/R P/L/V/N/W/F/I/E = 4,6%; 3: G/A/Y = 20%, P/W/S/D/T = 8%; 4: F = 46%, L/M = 15%, G/I/Y = 8%.

111 DP88-v4-6 GGACACCGCCGTGTATTACTGTGCGAGA- 1 -2-2-2- 2-3-4-GAC-TAC-

TGGGGCCAAGGGACCACCGTGACCGTCTCC

1 : G/D = 20%, E/V/S = 10%, A/P/R/L/T/Y=5%; 2: G/Y/S=15%, A/D/T/R P/L/V/N/W/F/I/E = 4,6%; 3: G/A/Y = 20%, P/W/S/D/T = 8%; 4: F = 46%, L/M = 15%, G/I/Y = 8%.

112 DP88-v4-8 GGACACCGCCGTGTATTACTGTGCGAGA- 1 -2-2-2- 2-2-2-3-4-GAC-TAC-

TGGGGCCAAGGGACCACCGTGACCGTCTCC

1 : G/D = 20%, E/V/S = 10%, A/P/R/L/T/Y=5%; 2: G/Y/S=15%, A/D/T/R/P/L/V/N/W/F/I/E = 4,6%; 3: G/A/Y = 20%, P/W/S/D/T = 8%; 4: F = 46%, L/M = 15%, G/I/Y = 8%.

113 fdseqlong GACGTTAGTAAATGAATTTTCTGTATGAGG

Table 6 shows the sequence of generic phage-displayed antibody common light chain library (Vk3_20/VH3_23). Table 7 provides cDNA and amino acid sequences of common light chain library (Vk3_20/VH3_23) germline template and Table 8 shows the Primer sequences used for generation of common light chain library (Vk3_20/VH3_23). Table 6. Sequence of generic phage- displayed antibody common light chain library (Vk3_20/VH3_23) template used for PCR

SEQ ID Description Sequence

NO:

ATGAAATACCTATTGCCTACGGCAGCCGCTGGATTGTTATTACTC

GCGGCCCAGCCGGCCATGGCCGAAATCGTGTTAACGCAGTCTCC

pRJHl lO AGGCACCCTGTCTTTGTCTCCAGGGGAAAGAGCCACCCTCTCTT library GCAGGGCCAGTCAGAGTGTTAGCAGCAGCTACTTAGCCTGGTAC template of CAGCAGAAACCTGGCCAGGCTCCCAGGCTCCTCATCTATGGAGC common ATCCAGCAGGGCCACTGGCATCCCAGACAGGTTCAGTGGCAGTG light chain GATCCGGGACAGACTTCACTCTCACCATCAGCAGACTGGAGCCT library GAAGATTTTGCAGTGTATTACTGTCAGCAGTATGGTAGCTCACC Vk3_20/V GCTGACGTTCGGCCAGGGGACCAAAGTGGAAATCAAACGTACG H3 23; GTGGCTGCACCATCTGTCTTCATCTTCCCGCCATCTGATGAGCAG complete TTGAAATCTGGAACTGCCTCTGTTGTGTGCCTGCTGAATAACTTC

TATCCCAGAGAGGCCAAAGTACAGTGGAAGGTGGATAACGCCC

Fab coding

TCCAATCGGGTAACTCCCAGGAGAGTGTCACAGAGCAGGACAG

region CAAGGACAGCACCTACAGCCTCAGCAGCACCCTGACGCTGAGC comprising AAAGCAGACTACGAGAAACACAAAGTCTACGCCTGCGAAGTCA PelB leader CCCATCAGGGCCTGAGCTCGCCCGTCACAAAGAGCTTCAACAGG sequence + GGAGAGTGTGGAGCCGCACATCACCATCACCATCACGGAGCCG Vk3_20 CAGACTACAAGGACGACGACGACAAGGGTGCCGCATAATAAGG

114 kappa V- CGCGCCAATTCTATTTCAAGGAGACAGTCATATGAAATACCTGC domain + TGCCGACCGCTGCTGCTGGTCTGCTGCTCCTCGCTGCCCAGCCGG CL CGATGGCCGAGGTGCAATTGCTGGAGTCTGGGGGAGGCTTGGTA

constant CAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCCGGATT domain for CACCTTTAGCAGTTATGCCATGAGCTGGGTCCGCCAGGCTCCAG

GGAAGGGGCTGGAGTGGGTCTCAGCTATTAGTGGTAGTGGTGGT

light chain

AGCACATACTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTC

and PelB + CAGAGACAATTCCAAGAACACGCTGTATCTGCAGATGAACAGCC VH3 23 TGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAACCGTTT V-domain CCGTATTTTGACTACTGGGGCCAAGGAACCCTGGTCACCGTCTC + CH1 GAGTGCTAGCACCAAAGGCCCATCGGTCTTCCCCCTGGCACCCT constant CCTCCAAGAGCACCTCTGGGGGCACAGCGGCCCTGGGCTGCCTG domain for GTCAAGGACTACTTCCCCGAACCGGTGACGGTGTCGTGGAACTC heavy AGGCGCCCTGACCAGCGGCGTGCACACCTTCCCGGCTGTCCTAC chain AGTCCTCAGGACTCTACTCCCTCAGCAGCGTGGTGACCGTGCCC including TCCAGCAGCTTGGGCACCCAGACCTACATCTGCAACGTGAATCA tags CAAGCCCAGCAACACCAAAGTGGACAAGAAAGTTGAGCCCAAA

TCTTGTGACGCGGCCGCAGAACAAAAACTCATCTCAGAAGAGGA

TCTGAATGCCGCGGCA Table 7. cDNA and amino acid sequences of common light chain library (Vk3_20/VH3_23) germline template

SEQ ID Description Sequence

NO:

115 nucleotide GAAATCGTGTTAACGCAGTCTCCAGGCACCCTGTCTTT

GTCTCCAGGGGAAAGAGCCACCCTCTCTTGCAGGGCCA

sequence of GTCAGAGTGTTAGCAGCAGCTACTTAGCCTGGTACCAG Fab light chain CAGAAACCTGGCCAGGCTCCCAGGCTCCTCATCTATGG

AGCATCCAGCAGGGCCACTGGCATCCCAGACAGGTTC

Vk3_20 AGTGGCAGTGGATCCGGGACAGACTTCACTCTCACCAT

CAGCAGACTGGAGCCTGAAGATTTTGCAGTGTATTACT

GTCAGCAGTATGGTAGCTCACCGCTGACGTTCGGCCAG

GGGACCAAAGTGGAAATCAAACGTACGGTGGCTGCAC

CATCTGTCTTCATCTTCCCGCCATCTGATGAGCAGTTGA

AATCTGGAACTGCCTCTGTTGTGTGCCTGCTGAATAAC

TTCTATCCCAGAGAGGCCAAAGTACAGTGGAAGGTGG

ATAACGCCCTCCAATCGGGTAACTCCCAGGAGAGTGTC

ACAGAGCAGGACAGCAAGGACAGCACCTACAGCCTCA

GCAGCACCCTGACGCTGAGCAAAGCAGACTACGAGAA

ACACAAAGTCTACGCCTGCGAAGTCACCCATCAGGGC

CTGAGCTCGCCCGTCACAAAGAGCTTCAACAGGGGAG

AGTGTGGAGCCGCACATCACCATCACCATCACGGAGC

CGCAGACTACAAGGACGACGACGACAAGGGTGCCGCA

116 Fab light chain EIVLTQSPGTLSLSPGERATLSCRASQSVSSSYLAWYQQK

Vk3_20 PGQAPRLLIYGASSRATGIPDRFSGSGSGTDFTLTISRLEPE

DFAVYYCQQYGSSPLTFGQGTKVEIKRTVAAPSVFIFPPS

DEQLKS GTAS VVCLLN F YPREAKVQ WKVDNALQ S GNS

QESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTH

QGLSSPVTKSFNRGECGAAHHHHHHGAADYKDDDDKG

AA

117 nucleotide GAGGTGCAATTGCTGGAGTCTGGGGGAGGCTTGGTAC

AGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCC

sequence of GGATTCACCTTTAGCAGTTATGCCATGAGCTGGGTCCG Fab heavy chain CCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCAGCT

ATTAGTGGTAGTGGTGGTAGCACATACTACGCAGACTC VH3 23 CGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCA

AGAACACGCTGTATCTGCAGATGAACAGCCTGAGAGC

CGAGGACACGGCCGTATATTACTGTGCGAAACCGTTTC

CGTATTTTGACTACTGGGGCCAAGGAACCCTGGTCACC

GTCTCGAGTGCTAGCACCAAAGGCCCATCGGTCTTCCC

CCTGGCACCCTCCTCCAAGAGCACCTCTGGGGGCACAG

CGGCCCTGGGCTGCCTGGTCAAGGACTACTTCCCCGAA

CCGGTGACGGTGTCGTGGAACTCAGGCGCCCTGACCA

GCGGCGTGCACACCTTCCCGGCTGTCCTACAGTCCTCA

GGACTCTACTCCCTCAGCAGCGTGGTGACCGTGCCCTC

CAGCAGCTTGGGCACCCAGACCTACATCTGCAACGTGA

ATCACAAGCCCAGCAACACCAAAGTGGACAAGAAAGT

TGAGCCCAAATCTTGTGACGCGGCCGCAGAACAAAAA CTCATCTCAGAAGAGGATCTGAATGCCGCGGCA

1 18 Fab heavy chain EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQ

VH3 23 (DP47) APGKGLEWVSAISGSGGSTYYADSVKGRFTISRDNSK TL

YLQMNSLRAEDTAVYYCAKPFPYFDYWGQGTLVTVSSA

STKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSW

NSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYI

CNVNHKPSNTKVDKKVEPKSCDAAAEQKLISEEDLNAAA

Table 8. Primer sequences used for generation of common light chain library (Vk3_20/VH3_23)

1 : G/D = 20%, E/V/S = 10%, A/P/R/L/T/Y=5%; 2: G/Y/S=15%, A/D/T/R/P/L/V/N/W/F/I/E = 4,6%; 3 : G/A/Y = 20%, P/W/S/D/T = 8%; 4: F = 46%, L/M = 15%, G/I/Y = 8%; 5 : K=70%, R =30%.

Table 9 shows the sequence of generic phage-displayed lambda-DP47 library

(VB_19/VH3_23) template used for PCRs. Table 10 provides cDNA and amino acid sequences of lambda-DP47 library (V13_19/VH3_23) germline template and Table 11 shows the Primer sequences used for generation of lambda-DP47 library (V13_19/VH3_23). Table 9: Sequence of generic phage- displayed lambda-DP47 library (V13_19/VH3_23) template used for PCRs

SEQ ID Description Sequence

NO:

ATGAAATACCTATTGCCTACGGCAGCCGCTGGATTGTTATTACTC

GCGGCCCAGCCGGCCATGGCCTCGTCTGAGCTGACTCAGGACCC

pRJH53 TGCTGTGTCTGTGGCCTTGGGACAGACAGTCAGGATCACATGCC library AAGGAGACAGCCTCAGAAGTTATTATGCAAGCTGGTACCAGCAG template of AAGCCAGGACAGGCCCCTGTACTTGTCATCTATGGTAAAAACAA lambda- CCGGCCCTCAGGGATCCCAGACCGATTCTCTGGCTCCAGCTCAG

DP47 GAAACACAGCTTCCTTGACCATCACTGGGGCTCAGGCGGAAGAT library GAGGCTGACTATTACTGTAACTCCCGTGATAGTAGCGGTAATCA

V13_19/V TGTGGTATTCGGCGGAGGGACCAAGCTGACCGTCCTAGGACAAC

H3 23; CCAAGGCTGCCCCCAGCGTGACCCTGTTCCCCCCCAGCAGCGAG complete GAATTGCAGGCCAACAAGGCCACCCTGGTCTGCCTGATCAGCGA

CTTCTACCCAGGCGCCGTGACCGTGGCCTGGAAGGCCGACAGCA

Fab coding

GCCCCGTGAAGGCCGGCGTGGAGACCACCACCCCCAGCAAGCA

region GAGCAACAACAAGTACGCCGCCAGCAGCTACCTGAGCCTGACC comprising CCCGAGCAGTGGAAGAGCCACAGGTCCTACAGCTGCCAGGTGA

PelB leader CCCACGAGGGCAGCACCGTGGAGAAAACCGTGGCCCCCACCGA sequence + GTGCAGCGGAGCCGCAGAACAAAAACTCATCTCAGAAGAGGAT

V13 19 CTGAATGGAGCCGCAGACTACAAGGACGACGACGACAAGGGTG

125 lambda V- CCGCATAATAAGGCGCGCCAATTCTATTTCAAGGAGACAGTCAT domain + ATGAAATACCTGCTGCCGACCGCTGCTGCTGGTCTGCTGCTCCTC

CL GCTGCCCAGCCGGCGATGGCCGAGGTGCAATTGCTGGAGTCTGG

constant GGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTG domain for CAGCCTCCGGATTCACCTTTAGCAGTTATGCCATGAGCTGGGTCC

GCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCAGCTATTAGT

light chain

GGTAGTGGTGGTAGCACATACTACGCAGACTCCGTGAAGGGCCG

and PelB + GTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGC VH3 23 AGATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGT V-domain GCGAAACCGTTTCCGTATTTTGACTACTGGGGCCAAGGAACCCT + CHI GGTCACCGTCTCGAGTGCTAGCACCAAAGGCCCATCGGTCTTCC constant CCCTGGCACCCTCCTCCAAGAGCACCTCTGGGGGCACAGCGGCC domain for CTGGGCTGCCTGGTCAAGGACTACTTCCCCGAACCGGTGACGGT heavy GTCGTGGAACTCAGGCGCCCTGACCAGCGGCGTGCACACCTTCC chain CGGCTGTCCTACAGTCCTCAGGACTCTACTCCCTCAGCAGCGTG including GTGACCGTGCCCTCCAGCAGCTTGGGCACCCAGACCTACATCTG tags CAACGTGAATCACAAGCCCAGCAACACCAAAGTGGACAAGAAA

GTTGAGCCCAAATCTTGTGACGCGGCCGCAAGCACTAGTGCCCA

TCACCATCACCATCACGCCGCGGCA Table 10. cDNA and amino acid sequences of lambda-DP47 library (V13_19/VH3_23) germline template

SEQ ID Description Sequence

NO:

126 nucleotide TCGTCTGAGCTGACTCAGGACCCTGCTGTGTCTGTGGCCT

TGGGACAGACAGTCAGGATCACATGCCAAGGAGACAGCC

sequence of TCAGAAGTTATTATGCAAGCTGGTACCAGCAGAAGCCAG Fab light chain GACAGGCCCCTGTACTTGTCATCTATGGTAAAAACAACCG

GCCCTCAGGGATCCCAGACCGATTCTCTGGCTCCAGCTCA

V13 19 GGAAACACAGCTTCCTTGACCATCACTGGGGCTCAGGCG

GAAGATGAGGCTGACTATTACTGTAACTCCCGTGATAGTA

GCGGTAATCATGTGGTATTCGGCGGAGGGACCAAGCTGA

CCGTCCTAGGACAACCCAAGGCTGCCCCCAGCGTGACCCT

GTTCCCCCCCAGCAGCGAGGAATTGCAGGCCAACAAGGC

CACCCTGGTCTGCCTGATCAGCGACTTCTACCCAGGCGCC

GTGACCGTGGCCTGGAAGGCCGACAGCAGCCCCGTGAAG

GCCGGCGTGGAGACCACCACCCCCAGCAAGCAGAGCAAC

AACAAGTACGCCGCCAGCAGCTACCTGAGCCTGACCCCC

GAGCAGTGGAAGAGCCACAGGTCCTACAGCTGCCAGGTG

ACCCACGAGGGCAGCACCGTGGAGAAAACCGTGGCCCCC

ACCGAGTGCAGCGGAGCCGCAGAACAAAAACTCATCTCA

GAAGAGGATCTGAATGGAGCCGCAGACTACAAGGACGAC

GACGACAAGGGTGCCGCA

127 Fab light chain SSELTQDPAVSVALGQTVRITCQGDSLRSYYASWYQQKPGQ

V13 19 AP VL VIYGK RP SGIPDRF SGS S S GNTASLTITGAQ AEDEAD

YYCNSRD S S GNH WFGGGTKLTVLGQPKAAP S VTLFPP S SEE LQ ANKATLVCLI SDF YPGAVTVAWKAD S SP VKAGVETTTPS KQSN KYAASSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTV APTECSGAAEQKLISEEDLNGAADYKDDDDKGAA

117 nucleotide see Table 7

sequence of

Fab heavy chain

VH3 23

118 Fab heavy chain see Table 7

VH3 23 (DP47) Table 11. Primer sequences used for generation of lambda-DP47 library (V13_19/VH3_23)

Additional primers used for construction of the lambda-DP47 library, i.e. DP47CDR3_ba (mod.), DP47-v4-4, DP47-v4-6, DP47-v4-8 and fdseqlong, are identical to the primers used for the construction of the common light chain library (Vk3_20/VH3_23) and have already been listed in Table 8.

Clones 8H9, 20B7, 49B4, 1G4, CLC-563, CLC-564 and 17A9 were identified as human OX40-specific binders through the procedure described above. The cDNA sequences of their variable regions are shown in Table 12 below, the corresponding amino acid sequences can be found in Table C. Table 12. Variable region base pair sequences for phage-derived anti-OX40 antibodies. Underlined are the complementarity determining regions (CDRs).

SEQ ID

Clone Sequence

NO:

134 (VL) TCGTCTGAGCTGACTCAGGACCCTGCTGTGTCTGTGGCCTTGG

GACAGACAGTCAGGATCACATGCCAAGGAGACAGCCTCAGAA

GTTATTATGCAAGCTGGTACCAGCAGAAGCCAGGACAGGCCC

CTGTACTTGTCATCTATGGTAAAAACAACCGGCCCTCAGGGAT

CCCAGACCGATTCTCTGGCTCCAGCTCAGGAAACACAGCTTCC

TTGACCATCACTGGGGCTCAGGCGGAAGATGAGGCTGACTATT

ACTGTAACTCCCGTGTTATGCCTCATAATCGCGTATTCGGCGG

AGGGACCAAGCTGACCGTC

8H9

135 (VH) GAGGTGCAATTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCT

GGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCCGGATTCACCT

TTAGCAGTTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAA

GGGGCTGGAGTGGGTCTCAGCTATTAGTGGTAGTGGTGGTAGC

ACATACTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCA

GAGACAATTCCAAGAACACGCTGTATCTGCAGATGAACAGCC

TGAGAGCCGAGGACACGGCCGTATATTACTGTGCGCGTGTTTT

CTACCGTGGTGGTGTTTCTATGGACTACTGGGGCCAAGGAACC

CTGGTCACCGTCTCGAGT

GACATCCAGATGACCCAGTCTCCTTCCACCCTGTCTGCATCTG

TAGGAGACCGTGTCACCATCACTTGCCGTGCCAGTCAGAGTAT

TAGTAGCTGGTTGGCCTGGTATCAGCAGAAACCAGGGAAAGC

CCCTAAGCTCCTGATCTATGATGCCTCCAGTTTGGAAAGTGGG

136 (VL)

GTCCCATCACGTTTCAGCGGCAGTGGATCCGGGACAGAATTCA

CTCTCACCATCAGCAGCTTGCAGCCTGATGATTTTGCAACTTA

TTACTGCCAACAGTATAGTTCGCAGCCGTATACGTTTGGCCAG

GGCACCAAAGTCGAGATCAAG

49B4

CAGGTGCAATTGGTGCAGTCTGGGGCTGAGGTGAAGAAGCCT

GGGTCCTCGGTGAAGGTCTCCTGCAAGGCCTCCGGAGGCACAT

TCAGCAGCTACGCTATAAGCTGGGTGCGACAGGCCCCTGGAC

AAGGGCTCGAGTGGATGGGAGGGATCATCCCTATCTTTGGTAC

137 (VH) AGCAAACTACGCACAGAAGTTCCAGGGCAGGGTCACCATTAC

TGCAGACAAATCCACGAGCACAGCCTACATGGAGCTGAGCAG

CCTGAGATCTGAGGACACCGCCGTGTATTACTGTGCGAGAGA

ATACTACCGTGGTCCGTACGACTACTGGGGCCAAGGGACCAC

CGTGACCGTCTCCTCA

GACATCCAGATGACCCAGTCTCCTTCCACCCTGTCTGCATCTG

TAGGAGACCGTGTCACCATCACTTGCCGTGCCAGTCAGAGTAT

TAGTAGCTGGTTGGCCTGGTATCAGCAGAAACCAGGGAAAGC

CCCTAAGCTCCTGATCTATGATGCCTCCAGTTTGGAAAGTGGG

1G4 138 (VL)

GTCCCATCACGTTTCAGCGGCAGTGGATCCGGGACAGAATTCA

CTCTCACCATCAGCAGCTTGCAGCCTGATGATTTTGCAACTTA

TTACTGCCAACAGTATATTTCGTATTCCATGTTGACGTTTGGCC

AGGGCACCAAAGTCGAGATCAAG CAGGTGCAATTGGTGCAGTCTGGGGCTGAGGTGAAGAAGCCT

GGGTCCTCGGTGAAGGTCTCCTGCAAGGCCTCCGGAGGCACAT

TCAGCAGCTACGCTATAAGCTGGGTGCGACAGGCCCCTGGAC

AAGGGCTCGAGTGGATGGGAGGGATCATCCCTATCTTTGGTAC

139 (VH) AGCAAACTACGCACAGAAGTTCCAGGGCAGGGTCACCATTAC

TGCAGACAAATCCACGAGCACAGCCTACATGGAGCTGAGCAG

CCTGAGATCTGAGGACACCGCCGTGTATTACTGTGCGAGAGA

ATACGGTTCTATGGACTACTGGGGCCAAGGGACCACCGTGAC

CGTCTCCTCA

GACATCCAGATGACCCAGTCTCCTTCCACCCTGTCTGCATCTG

TAGGAGACCGTGTCACCATCACTTGCCGTGCCAGTCAGAGTAT

TAGTAGCTGGTTGGCCTGGTATCAGCAGAAACCAGGGAAAGC

CCCTAAGCTCCTGATCTATGATGCCTCCAGTTTGGAAAGTGGG

140 (VL)

GTCCCATCACGTTTCAGCGGCAGTGGATCCGGGACAGAATTCA

CTCTCACCATCAGCAGCTTGCAGCCTGATGATTTTGCAACTTA

GGCACCAAAGTCGAGATCAAG

20B7

CAGGTGCAATTGGTGCAGTCTGGGGCTGAGGTGAAGAAGCCT

GGGTCCTCGGTGAAGGTCTCCTGCAAGGCCTCCGGAGGCACAT

TCAGCAGCTACGCTATAAGCTGGGTGCGACAGGCCCCTGGAC

AAGGGCTCGAGTGGATGGGAGGGATCATCCCTATCTTTGGTAC

141 (VH) AGCAAACTACGCACAGAAGTTCCAGGGCAGGGTCACCATTAC

TGCAGACAAATCCACGAGCACAGCCTACATGGAGCTGAGCAG

CCTGAGATCTGAGGACACCGCCGTGTATTACTGTGCGAGAGTT

AACTACCCGTACTCTTACTGGGGTGACTTCGACTACTGGGGCC

AAGGGACCACCGTGACCGTCTCCTCA

142 (VL) GAGATCGTGCTGACCCAGAGCCCCGGCACACTCTCCCTGTCTC

CTGGGGAAAGGGCCACCCTTTCATGCAGAGCCAGCCAGTCCG

TCTCTAGTAGCTACCTGGCATGGTATCAGCAGAAGCCAGGACA

AGCCCCCCGCCTCCTGATTTACGGCGCTTCCTCTCGGGCAACT

GGTATCCCTGACAGGTTCTCAGGGAGCGGAAGCGGAACAGAT

TTTACCTTGACTATTTCTAGACTGGAGCCAGAGGACTTCGCCG

TGTATTACTGTCAGCAGTACGGTAGTAGCCCCCTCACCTTTGG

CCAGGGGACAAAAGTCGAAATCAAG

CLC-

563 143 (VH) GAGGTGCAATTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCT

GGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCCGGATTCACCT

TTAGCAGTTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAA

GGGGCTGGAGTGGGTCTCAGCTATTAGTGGTAGTGGTGGTAGC

ACATACTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCA

GAGACAATTCCAAGAACACGCTGTATCTGCAGATGAACAGCC

TGAGAGCCGAGGACACGGCCGTATATTACTGTGCGCTTGACGT

TGGTGCTTTCGACTACTGGGGCCAAGGAGCCCTGGTCACCGTC

TCGAGT 144 (VL) GAGATCGTGCTGACCCAGAGCCCCGGCACACTCTCCCTGTCTC

CTGGGGAAAGGGCCACCCTTTCATGCAGAGCCAGCCAGTCCG

TCTCTAGTAGCTACCTGGCATGGTATCAGCAGAAGCCAGGACA

AGCCCCCCGCCTCCTGATTTACGGCGCTTCCTCTCGGGCAACT

GGTATCCCTGACAGGTTCTCAGGGAGCGGAAGCGGAACAGAT

TTTACCTTGACTATTTCTAGACTGGAGCCAGAGGACTTCGCCG

TGTATTACTGTCAGCAGTACGGTAGTAGCCCCCTCACCTTTGG

CCAGGGGACAAAAGTCGAAATCAAG

CLC- 564 145 (VH) GAGGTGCAATTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCT

GGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCCGGATTCACCT TTAGCAGTTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAA GGGGCTGGAGTGGGTCTCAGCTATTAGTGGTAGTGGTGGTAGC

ACATACTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCA

GAGACAATTCCAAGAACACGCTGTATCTGCAGATGAACAGCC TGAGAGCCGAGGACACGGCCGTATATTACTGTGCGTTCGACGT TGGTCCGTTCGACTACTGGGGCCAAGGAACCCTGGTCACCGTC TCGAGT

146 (VL) TCGTCTGAGCTGACTCAGGACCCTGCTGTGTCTGTGGCCTTGG

GACAGACAGTCAGGATCACATGCCAAGGAGACAGCCTCAGAA

GTTATTATGCAAGCTGGTACCAGCAGAAGCCAGGACAGGCCC

CTGTACTTGTCATCTATGGTAAAAACAACCGGCCCTCAGGGAT

CCCAGACCGATTCTCTGGCTCCAGCTCAGGAAACACAGCTTCC

TTGACCATCACTGGGGCTCAGGCGGAAGATGAGGCTGACTATT

ACTGTAACTCCCGTGTTATGCCTCATAATCGCGTATTCGGCGG

AGGGACCAAGCTGACCGTC

17A9

147 (VH) GAGGTGCAATTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCT

GGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCCGGATTCACCT TTAGCAGTTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAA GGGGCTGGAGTGGGTCTCAGCTATTAGTGGTAGTGGTGGTAGC

ACATACTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCA

GAGACAATTCCAAGAACACGCTGTATCTGCAGATGAACAGCC

TGAGAGCCGAGGACACGGCCGTATATTACTGTGCGCGTGTTTT

CTACCGTGGTGGTGTTTCTATGGACTACTGGGGCCAAGGAACC

CTGGTCACCGTCTCGAGT

1.3 Preparation, purification and characterization of anti-OX40 IgGl P329G LALA antibodies

The variable regions of heavy and light chain DNA sequences of selected anti-OX40 binders were subcloned in frame with either the constant heavy chain or the constant light chain of human IgGl . The Pro329Gly, Leu234Ala and Leu235Ala mutations have been introduced in the constant region of the knob and hole heavy chains to abrogate binding to Fc gamma receptors according to the method described in International Patent Appl. Publ. No. WO 2012/130831 Al . The cDNA and amino acid sequences of the anti-OX40 clones are shown in Table 13. All anti-OX40-Fc-fusion encoding sequences were cloned into a plasmid vector, which drives expression of the insert from an MPSV promoter and contains a synthetic polyA signal sequence located at the 3' end of the CDS. In addition, the vector contains an EBV OriP sequence for episomal maintenance of the plasmid.

Table 13. Sequences of anti-OX40 clones in P329GLALA human IgGl format

Clone SEQ ID No. Sequence

GACATCCAGATGACCCAGTCTCCTTCCACCCTGTCTGCATC

TGTAGGAGACCGTGTCACCATCACTTGCCGTGCCAGTCAG

AGTATTAGTAGCTGGTTGGCCTGGTATCAGCAGAAACCAG

GGAAAGCCCCTAAGCTCCTGATCTATGATGCCTCCAGTTTG

GAAAGTGGGGTCCCATCACGTTTCAGCGGCAGTGGATCCG

GGACAGAATTCACTCTCACCATCAGCAGCTTGCAGCCTGAT

148 GATTTTGCAACTTATTACTGCCAACAGTATTTGACGTATTC (nucleotide GCGGTTTACGTTTGGCCAGGGCACCAAAGTCGAGATCAAG sequence light CGTACGGTGGCTGCACCATCTGTCTTCATCTTCCCGCCATC chain) TGATGAGCAGTTGAAATCTGGAACTGCCTCTGTTGTGTGCC

TGCTGAATAACTTCTATCCCAGAGAGGCCAAAGTACAGTG

GAAGGTGGATAACGCCCTCCAATCGGGTAACTCCCAGGAG

AGTGTCACAGAGCAGGACAGCAAGGACAGCACCTACAGCC

TCAGCAGCACCCTGACGCTGAGCAAAGCAGACTACGAGAA

ACACAAAGTCTACGCCTGCGAAGTCACCCATCAGGGCCTG

AGCTCGCCCGTCACAAAGAGCTTCAACAGGGGAGAGTGT

CAGGTGCAATTGGTGCAGTCTGGGGCTGAGGTGAAGAAGC

CTGGGTCCTCGGTGAAGGTCTCCTGCAAGGCCTCCGGAGG

CACATTCAGCAGCTACGCTATAAGCTGGGTGCGACAGGCC

CCTGGACAAGGGCTCGAGTGGATGGGAGGGATCATCCCTA

TCTTTGGTACAGCAAACTACGCACAGAAGTTCCAGGGCAG

8B9 GGTCACCATTACTGCAGACAAATCCACGAGCACAGCCTAC

ATGGAGCTGAGCAGCCTGAGATCTGAGGACACCGCCGTGT

ATTACTGTGCGAGAGAATACGGTTGGATGGACTACTGGGG

CCAAGGGACCACCGTGACCGTCTCCTCAGCTAGCACCAAG

GGCCCATCGGTCTTCCCCCTGGCACCCTCCTCCAAGAGCAC

CTCTGGGGGCACAGCGGCCCTGGGCTGCCTGGTCAAGGAC

149 TACTTCCCCGAACCGGTGACGGTGTCGTGGAACTCAGGCG

CCCTGACCAGCGGCGTGCACACCTTCCCGGCTGTCCTACAG

(nucleotide

TCCTCAGGACTCTACTCCCTCAGCAGCGTGGTGACCGTGCC

sequence heavy CTCCAGCAGCTTGGGCACCCAGACCTACATCTGCAACGTG chain) AATCACAAGCCCAGCAACACCAAGGTGGACAAGAAAGTTG

AGCCCAAATCTTGTGACAAAACTCACACATGCCCACCGTG

CCCAGCACCTGAAGCTGCAGGGGGACCGTCAGTCTTCCTCT

TCCCCCCAAAACCCAAGGACACCCTCATGATCTCCCGGAC

CCCTGAGGTCACATGCGTGGTGGTGGACGTGAGCCACGAA

GACCCTGAGGTCAAGTTCAACTGGTACGTGGACGGCGTGG

AGGTGCATAATGCCAAGACAAAGCCGCGGGAGGAGCAGT

ACAACAGCACGTACCGTGTGGTCAGCGTCCTCACCGTCCTG

CACCAGGACTGGCTGAATGGCAAGGAGTACAAGTGCAAGG

TCTCCAACAAAGCCCTCGGCGCCCCCATCGAGAAAACCAT

CTCCAAAGCCAAAGGGCAGCCCCGAGAACCACAGGTGTAC

ACCCTGCCCCCATCCCGGGATGAGCTGACCAAGAACCAGG TCAGCCTGACCTGCCTGGTCAAAGGCTTCTATCCCAGCGAC

ATCGCCGTGGAGTGGGAGAGCAATGGGCAGCCGGAGAAC

AACTACAAGACCACGCCTCCCGTGCTGGACTCCGACGGCT

CCTTCTTCCTCTACAGCAAGCTCACCGTGGACAAGAGCAG

GTGGCAGCAGGGGAACGTCTTCTCATGCTCCGTGATGCAT

GAGGCTCTGCACAACCACTACACGCAGAAGAGCCTCTCCC

TGTCTCCGGGTAAA

DIQMTQSPSTLSASVGDRVTITCRASQSISSWLAWYQQKPGK

APKLLIYDASSLESGVPSRFSGSGSGTEFTLTISSLQPDDFATY

150 YCQQYLTYSRFTFGQGTKVEIKRTVAAPSVFIFPPSDEQLKSG (Light chain) TASVVCLLN FYPREAKVQWKVDNALQSGNSQESVTEQDSK

DSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNR

GEC

Q VQLVQ S GAEVKKPGS S VKVS CKAS GGTF S S YAIS WVRQ APG

QGLEWMGGIIPIFGTANYAQKFQGRVTITADKSTSTAYMELSS

LRSEDTAVYYCAREYGWMDYWGQGTTVTVSSASTKGPSVFP

LAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHT

FPAVLQSSGLYSLSSWTVPSSSLGTQTYICNVNHKPSNTKVD

151

KKVEPKS CDKTHTCPPCPAPEAAGGP S VFLFPPKPKDTLMI SR

(Heavy chain) TPEVTCWVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQY

NSTYRWSVLTVLHQDWLNGKEYKCKVSNKALGAPIEKTISK

AKGQPREPQVYTLPPSRDELTK QVSLTCLVKGFYPSDIAVE

WESNGQPEN YKTTPPVLDSDGSFFLYSKLTVDKSRWQQGN

VFSCSVMHEALHNHYTQKSLSLSPGK

GACATCCAGATGACCCAGTCTCCTTCCACCCTGTCTGCATC

TGTAGGAGACCGTGTCACCATCACTTGCCGTGCCAGTCAG

AGTATTAGTAGCTGGTTGGCCTGGTATCAGCAGAAACCAG

GGAAAGCCCCTAAGCTCCTGATCTATGATGCCTCCAGTTTG

GAAAGTGGGGTCCCATCACGTTTCAGCGGCAGTGGATCCG

GGACAGAATTCACTCTCACCATCAGCAGCTTGCAGCCTGAT

152 GATTTTGCAACTTATTACTGCCAACAGTATAGTTCGCAGCC (nucleotide GTATACGTTTGGCCAGGGCACCAAAGTCGAGATCAAGCGT sequence light ACGGTGGCTGCACCATCTGTCTTCATCTTCCCGCCATCTGA chain) TGAGCAGTTGAAATCTGGAACTGCCTCTGTTGTGTGCCTGC

TGAATAACTTCTATCCCAGAGAGGCCAAAGTACAGTGGAA

GGTGGATAACGCCCTCCAATCGGGTAACTCCCAGGAGAGT

GTCACAGAGCAGGACAGCAAGGACAGCACCTACAGCCTCA

GCAGCACCCTGACGCTGAGCAAAGCAGACTACGAGAAACA

CAAAGTCTACGCCTGCGAAGTCACCCATCAGGGCCTGAGC

TCGCCCGTCACAAAGAGCTTCAACAGGGGAGAGTGT

CAGGTGCAATTGGTGCAGTCTGGGGCTGAGGTGAAGAAGC

CTGGGTCCTCGGTGAAGGTCTCCTGCAAGGCCTCCGGAGG

CACATTCAGCAGCTACGCTATAAGCTGGGTGCGACAGGCC

CCTGGACAAGGGCTCGAGTGGATGGGAGGGATCATCCCTA

TCTTTGGTACAGCAAACTACGCACAGAAGTTCCAGGGCAG

153 GGTCACCATTACTGCAGACAAATCCACGAGCACAGCCTAC (nucleotide ATGGAGCTGAGCAGCCTGAGATCTGAGGACACCGCCGTGT sequence heavy ATTACTGTGCGAGAGAATACTACCGTGGTCCGTACGACTA chain) CTGGGGCCAAGGGACCACCGTGACCGTCTCCTCAGCTAGC

ACCAAGGGCCCATCGGTCTTCCCCCTGGCACCCTCCTCCAA

GAGCACCTCTGGGGGCACAGCGGCCCTGGGCTGCCTGGTC

AAGGACTACTTCCCCGAACCGGTGACGGTGTCGTGGAACT

CAGGCGCCCTGACCAGCGGCGTGCACACCTTCCCGGCTGT

CCTACAGTCCTCAGGACTCTACTCCCTCAGCAGCGTGGTGA CCGTGCCCTCCAGCAGCTTGGGCACCCAGACCTACATCTGC

AACGTGAATCACAAGCCCAGCAACACCAAGGTGGACAAG

AAAGTTGAGCCCAAATCTTGTGACAAAACTCACACATGCC

CACCGTGCCCAGCACCTGAAGCTGCAGGGGGACCGTCAGT

CTTCCTCTTCCCCCCAAAACCCAAGGACACCCTCATGATCT

CCCGGACCCCTGAGGTCACATGCGTGGTGGTGGACGTGAG

CCACGAAGACCCTGAGGTCAAGTTCAACTGGTACGTGGAC

GGCGTGGAGGTGCATAATGCCAAGACAAAGCCGCGGGAG

GAGCAGTACAACAGCACGTACCGTGTGGTCAGCGTCCTCA

CCGTCCTGCACCAGGACTGGCTGAATGGCAAGGAGTACAA

GTGCAAGGTCTCCAACAAAGCCCTCGGCGCCCCCATCGAG

AAAACCATCTCCAAAGCCAAAGGGCAGCCCCGAGAACCAC

AGGTGTACACCCTGCCCCCATCCCGGGATGAGCTGACCAA

GAACCAGGTCAGCCTGACCTGCCTGGTCAAAGGCTTCTATC

CCAGCGACATCGCCGTGGAGTGGGAGAGCAATGGGCAGCC

GGAGAACAACTACAAGACCACGCCTCCCGTGCTGGACTCC

GACGGCTCCTTCTTCCTCTACAGCAAGCTCACCGTGGACAA

GAGCAGGTGGCAGCAGGGGAACGTCTTCTCATGCTCCGTG

ATGCATGAGGCTCTGCACAACCACTACACGCAGAAGAGCC

TCTCCCTGTCTCCGGGTAAA

DIQMTQ SP STLS AS VGDRVTITCRAS Q SI S S WLAWYQQKPGK

APKLLIYDASSLESGVPSRFSGSGSGTEFTLTISSLQPDDFATY

154 YCQQYSSQPYTFGQGTKVEIKRTVAAPSVFIFPPSDEQLKSGT (Light chain) ASWCLLN FYPREAKVQWKVDNALQSGNSQESVTEQDSKD

STYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRG

EC

QVQLVQ SGAEVKKPGS SVKVSCKASGGTFS SYAISWVRQAPG

QGLEWMGGIIPIFGTANYAQKFQGRVTITADKSTSTAYMELSS

LRSEDTAVYYCAREYYRGPYDYWGQGTTVTVSSASTKGPSV

FPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGV

HTFPAVLQSSGLYSLSSWTVPSSSLGTQTYICNVNHKPSNTK

155

VDKKVEPKS CDKTHTCPPCPAPEAAGGP S VFLFPPKPKDTLMI

(Heavy chain) SRTPEVTCVWDVSHEDPEVKFNWYVDGVEVHNAKTKPREE

QYNSTYRWSVLTVLHQDWLNGKEYKCKVSNKALGAPIEKT

ISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIA

VEWESNGQPEN YKTTPPVLDSDGSFFLYSKLTVDKSRWQQ

GNVFSCSVMHEALHNHYTQKSLSLSPGK

GACATCCAGATGACCCAGTCTCCTTCCACCCTGTCTGCATC

TGTAGGAGACCGTGTCACCATCACTTGCCGTGCCAGTCAG

AGTATTAGTAGCTGGTTGGCCTGGTATCAGCAGAAACCAG

GGAAAGCCCCTAAGCTCCTGATCTATGATGCCTCCAGTTTG

GAAAGTGGGGTCCCATCACGTTTCAGCGGCAGTGGATCCG

GGACAGAATTCACTCTCACCATCAGCAGCTTGCAGCCTGAT

156 GATTTTGCAACTTATTACTGCCAACAGTATATTTCGTATTC (nucleotide CATGTTGACGTTTGGCCAGGGCACCAAAGTCGAGATCAAG sequence light CGTACGGTGGCTGCACCATCTGTCTTCATCTTCCCGCCATC chain) TGATGAGCAGTTGAAATCTGGAACTGCCTCTGTTGTGTGCC

TGCTGAATAACTTCTATCCCAGAGAGGCCAAAGTACAGTG

GAAGGTGGATAACGCCCTCCAATCGGGTAACTCCCAGGAG

AGTGTCACAGAGCAGGACAGCAAGGACAGCACCTACAGCC

TCAGCAGCACCCTGACGCTGAGCAAAGCAGACTACGAGAA

ACACAAAGTCTACGCCTGCGAAGTCACCCATCAGGGCCTG

AGCTCGCCCGTCACAAAGAGCTTCAACAGGGGAGAGTGT

157 CAGGTGCAATTGGTGCAGTCTGGGGCTGAGGTGAAGAAGC (nucleotide CTGGGTCCTCGGTGAAGGTCTCCTGCAAGGCCTCCGGAGG sequence heavy CACATTCAGCAGCTACGCTATAAGCTGGGTGCGACAGGCC chain) CCTGGACAAGGGCTCGAGTGGATGGGAGGGATCATCCCTA

TCTTTGGTACAGCAAACTACGCACAGAAGTTCCAGGGCAG

GGTCACCATTACTGCAGACAAATCCACGAGCACAGCCTAC

ATGGAGCTGAGCAGCCTGAGATCTGAGGACACCGCCGTGT

ATTACTGTGCGAGAGAATACGGTTCTATGGACTACTGGGG

CCAAGGGACCACCGTGACCGTCTCCTCAGCTAGCACCAAG

GGCCCATCGGTCTTCCCCCTGGCACCCTCCTCCAAGAGCAC

CTCTGGGGGCACAGCGGCCCTGGGCTGCCTGGTCAAGGAC

TACTTCCCCGAACCGGTGACGGTGTCGTGGAACTCAGGCG

CCCTGACCAGCGGCGTGCACACCTTCCCGGCTGTCCTACAG

TCCTCAGGACTCTACTCCCTCAGCAGCGTGGTGACCGTGCC

CTCCAGCAGCTTGGGCACCCAGACCTACATCTGCAACGTG

AATCACAAGCCCAGCAACACCAAGGTGGACAAGAAAGTTG

AGCCCAAATCTTGTGACAAAACTCACACATGCCCACCGTG

CCCAGCACCTGAAGCTGCAGGGGGACCGTCAGTCTTCCTCT

TCCCCCCAAAACCCAAGGACACCCTCATGATCTCCCGGAC

CCCTGAGGTCACATGCGTGGTGGTGGACGTGAGCCACGAA

GACCCTGAGGTCAAGTTCAACTGGTACGTGGACGGCGTGG

AGGTGCATAATGCCAAGACAAAGCCGCGGGAGGAGCAGT

ACAACAGCACGTACCGTGTGGTCAGCGTCCTCACCGTCCTG

CACCAGGACTGGCTGAATGGCAAGGAGTACAAGTGCAAGG

TCTCCAACAAAGCCCTCGGCGCCCCCATCGAGAAAACCAT

CTCCAAAGCCAAAGGGCAGCCCCGAGAACCACAGGTGTAC

ACCCTGCCCCCATCCCGGGATGAGCTGACCAAGAACCAGG

TCAGCCTGACCTGCCTGGTCAAAGGCTTCTATCCCAGCGAC

ATCGCCGTGGAGTGGGAGAGCAATGGGCAGCCGGAGAAC

AACTACAAGACCACGCCTCCCGTGCTGGACTCCGACGGCT

CCTTCTTCCTCTACAGCAAGCTCACCGTGGACAAGAGCAG

GTGGCAGCAGGGGAACGTCTTCTCATGCTCCGTGATGCAT

GAGGCTCTGCACAACCACTACACGCAGAAGAGCCTCTCCC

TGTCTCCGGGTAAA

DIQMTQSPSTLSASVGDRVTITCRASQSISSWLAWYQQKPGK

APKLLIYDASSLESGVPSRFSGSGSGTEFTLTISSLQPDDFATY

158 YCQQYISYSMLTFGQGTKVEIKRTVAAPSVFIFPPSDEQLKSG (Light chain) TASVVCLLN FYPREAKVQWKVDNALQSGNSQESVTEQDSK

DSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNR

GEC

Q VQLVQ S GAEVKKPGS S VKVS CKAS GGTF S S YAIS WVRQ APG

QGLEWMGGIIPIFGTANYAQKFQGRVTITADKSTSTAYMELSS

LRSEDTAVYYCAREYGSMDYWGQGTTVTVSSASTKGPSVFP

LAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHT

FPAVLQSSGLYSLSSWTVPSSSLGTQTYICNVNHKPSNTKVD

159

KKVEPKSCDKTHTCPPCPAPEAAGGPSVFLFPPKPKDTLMISR

(Heavy chain)

TPEVTCWVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQY

NSTYRWSVLTVLHQDWLNGKEYKCKVSNKALGAPIEKTISK

AKGQPREPQVYTLPPSRDELTK QVSLTCLVKGFYPSDIAVE

WESNGQPEN YKTTPPVLDSDGSFFLYSKLTVDKSRWQQGN

VFSCSVMHEALHNHYTQKSLSLSPGK

160 GACATCCAGATGACCCAGTCTCCTTCCACCCTGTCTGCATC (nucleotide TGTAGGAGACCGTGTCACCATCACTTGCCGTGCCAGTCAGB7

sequence light AGTATTAGTAGCTGGTTGGCCTGGTATCAGCAGAAACCAG chain) GGAAAGCCCCTAAGCTCCTGATCTATGATGCCTCCAGTTTG GAAAGTGGGGTCCCATCACGTTTCAGCGGCAGTGGATCCG

GGACAGAATTCACTCTCACCATCAGCAGCTTGCAGCCTGAT

GATTTTGCAACTTATTACTGCCAACAGTATCAGGCTTTTTC

GCTTACGTTTGGCCAGGGCACCAAAGTCGAGATCAAGCGT

ACGGTGGCTGCACCATCTGTCTTCATCTTCCCGCCATCTGA

TGAGCAGTTGAAATCTGGAACTGCCTCTGTTGTGTGCCTGC

TGAATAACTTCTATCCCAGAGAGGCCAAAGTACAGTGGAA

GGTGGATAACGCCCTCCAATCGGGTAACTCCCAGGAGAGT

GTCACAGAGCAGGACAGCAAGGACAGCACCTACAGCCTCA

GCAGCACCCTGACGCTGAGCAAAGCAGACTACGAGAAACA

CAAAGTCTACGCCTGCGAAGTCACCCATCAGGGCCTGAGC

TCGCCCGTCACAAAGAGCTTCAACAGGGGAGAGTGT

CAGGTGCAATTGGTGCAGTCTGGGGCTGAGGTGAAGAAGC

CTGGGTCCTCGGTGAAGGTCTCCTGCAAGGCCTCCGGAGG

CACATTCAGCAGCTACGCTATAAGCTGGGTGCGACAGGCC

CCTGGACAAGGGCTCGAGTGGATGGGAGGGATCATCCCTA

TCTTTGGTACAGCAAACTACGCACAGAAGTTCCAGGGCAG

GGTCACCATTACTGCAGACAAATCCACGAGCACAGCCTAC

ATGGAGCTGAGCAGCCTGAGATCTGAGGACACCGCCGTGT

ATTACTGTGCGAGAGTTAACTACCCGTACTCTTACTGGGGT

GACTTCGACTACTGGGGCCAAGGGACCACCGTGACCGTCT

CCTCAGCTAGCACCAAGGGCCCATCGGTCTTCCCCCTGGCA

CCCTCCTCCAAGAGCACCTCTGGGGGCACAGCGGCCCTGG

GCTGCCTGGTCAAGGACTACTTCCCCGAACCGGTGACGGT

GTCGTGGAACTCAGGCGCCCTGACCAGCGGCGTGCACACC

TTCCCGGCTGTCCTACAGTCCTCAGGACTCTACTCCCTCAG

CAGCGTGGTGACCGTGCCCTCCAGCAGCTTGGGCACCCAG

161 ACCTACATCTGCAACGTGAATCACAAGCCCAGCAACACCA (nucleotide AGGTGGACAAGAAAGTTGAGCCCAAATCTTGTGACAAAAC sequence heavy TCACACATGCCCACCGTGCCCAGCACCTGAAGCTGCAGGG chain) GGACCGTCAGTCTTCCTCTTCCCCCCAAAACCCAAGGACAC

CCTCATGATCTCCCGGACCCCTGAGGTCACATGCGTGGTGG

TGGACGTGAGCCACGAAGACCCTGAGGTCAAGTTCAACTG

GTACGTGGACGGCGTGGAGGTGCATAATGCCAAGACAAAG

CCGCGGGAGGAGCAGTACAACAGCACGTACCGTGTGGTCA

GCGTCCTCACCGTCCTGCACCAGGACTGGCTGAATGGCAA

GGAGTACAAGTGCAAGGTCTCCAACAAAGCCCTCGGCGCC

CCCATCGAGAAAACCATCTCCAAAGCCAAAGGGCAGCCCC

GAGAACCACAGGTGTACACCCTGCCCCCATCCCGGGATGA

GCTGACCAAGAACCAGGTCAGCCTGACCTGCCTGGTCAAA

GGCTTCTATCCCAGCGACATCGCCGTGGAGTGGGAGAGCA

ATGGGCAGCCGGAGAACAACTACAAGACCACGCCTCCCGT

GCTGGACTCCGACGGCTCCTTCTTCCTCTACAGCAAGCTCA

CCGTGGACAAGAGCAGGTGGCAGCAGGGGAACGTCTTCTC

ATGCTCCGTGATGCATGAGGCTCTGCACAACCACTACACG

CAGAAGAGCCTCTCCCTGTCTCCGGGTAAA

DIQMTQSPSTLSASVGDRVTITCRASQSISSWLAWYQQKPGK

APKLLIYDASSLESGVPSRFSGSGSGTEFTLTISSLQPDDFATY

162 YCQQYQAFSLTFGQGTKVEIKRTVAAPSVFIFPPSDEQLKSGT (Light chain) ASWCLLN FYPREAKVQWKVDNALQSGNSQESVTEQDSKD

STYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRG

EC

163 Q VQLVQ S GAEVKKPGS S VKVS CKAS GGTF S S YAIS WVRQ APG

(Heavy chain) QGLEWMGGIIPIFGTANYAQKFQGRVTITADKSTSTAYMELSS LRSEDTAVYYCARVNYPYSYWGDFDYWGQGTTVTVSSAST

KGP S VFPLAP S SKST SGGTAALGCLVKD YFPEPVTVSWNS GA

LTSGVHTFPA VLQ S S GLYSLS S WTVP S S SLGTQTYICNVNHK

PSNTKVDKKVEPKSCDKTHTCPPCPAPEAAGGPSVFLFPPKPK

DTLMISRTPEVTCVWDVSHEDPEVKFNWYVDGVEVHNAKT

KPREEQYNSTYRWSVLTVLHQDWLNGKEYKCKVSNKALG

APIEKTISKAKGQPREPQVYTLPPSRDELTK QVSLTCLVKGF

YPSDIAVEWESNGQPEN YKTTPPVLDSDGSFFLYSKLTVDKS

RWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK

GAGATCGTGCTGACCCAGAGCCCCGGCACACTCTCCCTGTC

TCCTGGGGAAAGGGCCACCCTTTCATGCAGAGCCAGCCAG

TCCGTCTCTAGTAGCTACCTGGCATGGTATCAGCAGAAGCC

AGGACAAGCCCCCCGCCTCCTGATTTACGGCGCTTCCTCTC

GGGCAACTGGTATCCCTGACAGGTTCTCAGGGAGCGGAAG

CGGAACAGATTTTACCTTGACTATTTCTAGACTGGAGCCAG

164 AGGACTTCGCCGTGTATTACTGTCAGCAGTACGGTAGTAGC (nucleotide CCCCTCACCTTTGGCCAGGGGACAAAAGTCGAAATCAAGC sequence light GTACGGTGGCTGCACCATCTGTCTTCATCTTCCCGCCATCT chain) GATGAGCAGTTGAAATCTGGAACTGCCTCTGTTGTGTGCCT

GCTGAATAACTTCTATCCCAGAGAGGCCAAAGTACAGTGG

AAGGTGGATAACGCCCTCCAATCGGGTAACTCCCAGGAGA

GTGTCACAGAGCAGGACAGCAAGGACAGCACCTACAGCCT

CAGCAGCACCCTGACGCTGAGCAAAGCAGACTACGAGAAA

CACAAAGTCTACGCCTGCGAAGTCACCCATCAGGGCCTGA

GCTCGCCCGTCACAAAGAGCTTCAACAGGGGAGAGTGT

GAGGTGCAATTGTTGGAGTCTGGGGGAGGCTTGGTACAGC

CTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCCGGATTC

ACCTTTAGCAGTTATGCCATGAGCTGGGTCCGCCAGGCTCC

AGGGAAGGGGCTGGAGTGGGTCTCAGCTATTAGTGGTAGT

GGTGGTAGCACATACTACGCAGACTCCGTGAAGGGCCGGT

TCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTG

CLC-

CAGATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATT

563 ACTGTGCGCTTGACGTTGGTGCTTTCGACTACTGGGGCCAA

GGAGCCCTGGTCACCGTCTCGAGTGCTAGCACCAAGGGCC

CATCGGTCTTCCCCCTGGCACCCTCCTCCAAGAGCACCTCT

GGGGGCACAGCGGCCCTGGGCTGCCTGGTCAAGGACTACT

TCCCCGAACCGGTGACGGTGTCGTGGAACTCAGGCGCCCT

165 GACCAGCGGCGTGCACACCTTCCCGGCTGTCCTACAGTCCT

CAGGACTCTACTCCCTCAGCAGCGTGGTGACCGTGCCCTCC

(nucleotide

AGCAGCTTGGGCACCCAGACCTACATCTGCAACGTGAATC

sequence heavy ACAAGCCCAGCAACACCAAGGTGGACAAGAAAGTTGAGC chain) CCAAATCTTGTGACAAAACTCACACATGCCCACCGTGCCC

AGCACCTGAAGCTGCAGGGGGACCGTCAGTCTTCCTCTTCC

CCCCAAAACCCAAGGACACCCTCATGATCTCCCGGACCCC

TGAGGTCACATGCGTGGTGGTGGACGTGAGCCACGAAGAC

CCTGAGGTCAAGTTCAACTGGTACGTGGACGGCGTGGAGG

TGCATAATGCCAAGACAAAGCCGCGGGAGGAGCAGTACA

ACAGCACGTACCGTGTGGTCAGCGTCCTCACCGTCCTGCAC

CAGGACTGGCTGAATGGCAAGGAGTACAAGTGCAAGGTCT

CCAACAAAGCCCTCGGCGCCCCCATCGAGAAAACCATCTC

CAAAGCCAAAGGGCAGCCCCGAGAACCACAGGTGTACACC

CTGCCCCCATCCCGGGATGAGCTGACCAAGAACCAGGTCA

GCCTGACCTGCCTGGTCAAAGGCTTCTATCCCAGCGACATC

GCCGTGGAGTGGGAGAGCAATGGGCAGCCGGAGAACAAC TACAAGACCACGCCTCCCGTGCTGGACTCCGACGGCTCCTT

CTTCCTCTACAGCAAGCTCACCGTGGACAAGAGCAGGTGG

CAGCAGGGGAACGTCTTCTCATGCTCCGTGATGCATGAGG

CTCTGCACAACCACTACACGCAGAAGAGCCTCTCCCTGTCT

CCGGGTAAA

EIVLTQSPGTLSLSPGERATLSCRASQSVSSSYLAWYQQKPGQ

APRLLIYGASSRATGIPDRFSGSGSGTDFTLTISRLEPEDFAVY

166 YCQQYGSSPLTFGQGTKVEIKRTVAAPSVFIFPPSDEQLKSGT (Light chain) ASWCLLN FYPREAKVQWKVDNALQSGNSQESVTEQDSKD

STYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRG

EC

EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPG

KGLEWVSAISGSGGSTYYADSVKGRFTISRDNSK TLYLQMN

SLRAEDTAVYYCALDVGAFDYWGQGALVTVSSASTKGPSVF

PLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVH

TFPAVLQSSGLYSLSSWTVPSSSLGTQTYICNVNHKPSNTKV

167

DKKVEPKSCDKTHTCPPCPAPEAAGGPSVFLFPPKPKDTLMIS

(Heavy chain) RTPEVTCVWDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQ

YNSTYRWSVLTVLHQDWLNGKEYKCKVSNKALGAPIEKTIS

KAKGQPREPQVYTLPPSRDELTK QVSLTCLVKGFYPSDIAVE

WESNGQPEN YKTTPPVLDSDGSFFLYSKLTVDKSRWQQGN

VFSCSVMHEALHNHYTQKSLSLSPGK

GAGATCGTGCTGACCCAGAGCCCCGGCACACTCTCCCTGTC

TCCTGGGGAAAGGGCCACCCTTTCATGCAGAGCCAGCCAG

TCCGTCTCTAGTAGCTACCTGGCATGGTATCAGCAGAAGCC

AGGACAAGCCCCCCGCCTCCTGATTTACGGCGCTTCCTCTC

GGGCAACTGGTATCCCTGACAGGTTCTCAGGGAGCGGAAG

CGGAACAGATTTTACCTTGACTATTTCTAGACTGGAGCCAG

168 AGGACTTCGCCGTGTATTACTGTCAGCAGTACGGTAGTAGC (nucleotide CCCCTCACCTTTGGCCAGGGGACAAAAGTCGAAATCAAGC sequence light GTACGGTGGCTGCACCATCTGTCTTCATCTTCCCGCCATCT chain) GATGAGCAGTTGAAATCTGGAACTGCCTCTGTTGTGTGCCT

GCTGAATAACTTCTATCCCAGAGAGGCCAAAGTACAGTGG

AAGGTGGATAACGCCCTCCAATCGGGTAACTCCCAGGAGA

GTGTCACAGAGCAGGACAGCAAGGACAGCACCTACAGCCT

CAGCAGCACCCTGACGCTGAGCAAAGCAGACTACGAGAAA

CACAAAGTCTACGCCTGCGAAGTCACCCATCAGGGCCTGA

CLC- GCTCGCCCGTCACAAAGAGCTTCAACAGGGGAGAGTGT 564 GAGGTGCAATTGTTGGAGTCTGGGGGAGGCTTGGTACAGC

CTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCCGGATTC

ACCTTTAGCAGTTATGCCATGAGCTGGGTCCGCCAGGCTCC

AGGGAAGGGGCTGGAGTGGGTCTCAGCTATTAGTGGTAGT

GGTGGTAGCACATACTACGCAGACTCCGTGAAGGGCCGGT

TCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTG

169 CAGATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATT (nucleotide ACTGTGCGTTCGACGTTGGTCCGTTCGACTACTGGGGCCAA sequence heavy GGAACCCTGGTCACCGTCTCGAGTGCTAGCACCAAGGGCC chain) CATCGGTCTTCCCCCTGGCACCCTCCTCCAAGAGCACCTCT

GGGGGCACAGCGGCCCTGGGCTGCCTGGTCAAGGACTACT

TCCCCGAACCGGTGACGGTGTCGTGGAACTCAGGCGCCCT

GACCAGCGGCGTGCACACCTTCCCGGCTGTCCTACAGTCCT

CAGGACTCTACTCCCTCAGCAGCGTGGTGACCGTGCCCTCC

AGCAGCTTGGGCACCCAGACCTACATCTGCAACGTGAATC

ACAAGCCCAGCAACACCAAGGTGGACAAGAAAGTTGAGC CCAAATCTTGTGACAAAACTCACACATGCCCACCGTGCCC

AGCACCTGAAGCTGCAGGGGGACCGTCAGTCTTCCTCTTCC

CCCCAAAACCCAAGGACACCCTCATGATCTCCCGGACCCC

TGAGGTCACATGCGTGGTGGTGGACGTGAGCCACGAAGAC

CCTGAGGTCAAGTTCAACTGGTACGTGGACGGCGTGGAGG

TGCATAATGCCAAGACAAAGCCGCGGGAGGAGCAGTACA

ACAGCACGTACCGTGTGGTCAGCGTCCTCACCGTCCTGCAC

CAGGACTGGCTGAATGGCAAGGAGTACAAGTGCAAGGTCT

CCAACAAAGCCCTCGGCGCCCCCATCGAGAAAACCATCTC

CAAAGCCAAAGGGCAGCCCCGAGAACCACAGGTGTACACC

CTGCCCCCATCCCGGGATGAGCTGACCAAGAACCAGGTCA

GCCTGACCTGCCTGGTCAAAGGCTTCTATCCCAGCGACATC

GCCGTGGAGTGGGAGAGCAATGGGCAGCCGGAGAACAAC

TACAAGACCACGCCTCCCGTGCTGGACTCCGACGGCTCCTT

CTTCCTCTACAGCAAGCTCACCGTGGACAAGAGCAGGTGG

CAGCAGGGGAACGTCTTCTCATGCTCCGTGATGCATGAGG

CTCTGCACAACCACTACACGCAGAAGAGCCTCTCCCTGTCT

CCGGGTAAA

EIVLTQSPGTLSLSPGERATLSCRASQSVSSSYLAWYQQKPGQ

APRLLIYGASSRATGIPDRFSGSGSGTDFTLTISRLEPEDFAVY

170 YCQQYGSSPLTFGQGTKVEIKRTVAAPSVFIFPPSDEQLKSGT (Light chain) ASWCLLN FYPREAKVQWKVDNALQSGNSQESVTEQDSKD

STYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRG

EC

EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPG

KGLEWVSAISGSGGSTYYADSVKGRFTISRDNSK TLYLQMN

SLRAEDTAVYYCAFDVGPFDYWGQGTLVTVSSASTKGPSVFP

LAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHT

FP AVLQ S SGLYSLS S WTVP S S SLGTQTYICNVNHKP SNTKVD

171

KKVEPKSCDKTHTCPPCPAPEAAGGPSVFLFPPKPKDTLMISR

(Heavy chain) TPEVTCWVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQY

NSTYRWSVLTVLHQDWLNGKEYKCKVSNKALGAPIEKTISK

AKGQPREPQVYTLPPSRDELTK QVSLTCLVKGFYPSDIAVE

WESNGQPEN YKTTPPVLDSDGSFFLYSKLTVDKSRWQQGN

VFSCSVMHEALHNHYTQKSLSLSPGK

TCGTCTGAGCTGACTCAGGACCCTGCTGTGTCTGTGGCCTT

GGGACAGACAGTCAGGATCACATGCCAAGGAGACAGCCTC

AGAAGTTATTATGCAAGCTGGTACCAGCAGAAGCCAGGAC

AGGCCCCTGTACTTGTCATCTATGGTAAAAACAACCGGCCC

TCAGGGATCCCAGACCGATTCTCTGGCTCCAGCTCAGGAA

ACACAGCTTCCTTGACCATCACTGGGGCTCAGGCGGAAGA

172 TGAGGCTGACTATTACTGTAACTCCCGTGTTATGCCTCATA (nucleotide ATCGCGTATTCGGCGGAGGGACCAAGCTGACCGTCCTAGG sequence light TCAACCCAAGGCTGCCCCCAGCGTGACCCTGTTCCCCCCCA chain) GCAGCGAGGAACTGCAGGCCAACAAGGCCACCCTGGTCTG

CCTGATCAGCGACTTCTACCCAGGCGCCGTGACCGTGGCCT

GGAAGGCCGACAGCAGCCCCGTGAAGGCCGGCGTGGAGA

CCACCACCCCCAGCAAGCAGAGCAACAACAAGTACGCCGC

CAGCAGCTACCTGAGCCTGACCCCCGAGCAGTGGAAGAGC

CACAGGTCCTACAGCTGCCAGGTGACCCACGAGGGCAGCA

CCGTGGAGAAAACCGTGGCCCCCACCGAGTGCAGC

173 GAGGTGCAATTGTTGGAGTCTGGGGGAGGCTTGGTACAGC (nucleotide CTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCCGGATTC sequence heavy ACCTTTAGCAGTTATGCCATGAGCTGGGTCCGCCAGGCTCC chain) AGGGAAGGGGCTGGAGTGGGTCTCAGCTATTAGTGGTAGT

GGTGGTAGCACATACTACGCAGACTCCGTGAAGGGCCGGT

TCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTG

CAGATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATT

ACTGTGCGCGTGTTTTCTACCGTGGTGGTGTTTCTATGGAC

TACTGGGGCCAAGGAACCCTGGTCACCGTCTCGAGTGCTA

GCACCAAGGGCCCATCGGTCTTCCCCCTGGCACCCTCCTCC

AAGAGCACCTCTGGGGGCACAGCGGCCCTGGGCTGCCTGG

TCAAGGACTACTTCCCCGAACCGGTGACGGTGTCGTGGAA

CTCAGGCGCCCTGACCAGCGGCGTGCACACCTTCCCGGCT

GTCCTACAGTCCTCAGGACTCTACTCCCTCAGCAGCGTGGT

GACCGTGCCCTCCAGCAGCTTGGGCACCCAGACCTACATCT

GCAACGTGAATCACAAGCCCAGCAACACCAAGGTGGACAA

GAAAGTTGAGCCCAAATCTTGTGACAAAACTCACACATGC

CCACCGTGCCCAGCACCTGAAGCTGCAGGGGGACCGTCAG

TCTTCCTCTTCCCCCCAAAACCCAAGGACACCCTCATGATC

TCCCGGACCCCTGAGGTCACATGCGTGGTGGTGGACGTGA

GCCACGAAGACCCTGAGGTCAAGTTCAACTGGTACGTGGA

CGGCGTGGAGGTGCATAATGCCAAGACAAAGCCGCGGGA

GGAGCAGTACAACAGCACGTACCGTGTGGTCAGCGTCCTC

ACCGTCCTGCACCAGGACTGGCTGAATGGCAAGGAGTACA

AGTGCAAGGTCTCCAACAAAGCCCTCGGCGCCCCCATCGA

GAAAACCATCTCCAAAGCCAAAGGGCAGCCCCGAGAACCA

CAGGTGTACACCCTGCCCCCATCCCGGGATGAGCTGACCA

AGAACCAGGTCAGCCTGACCTGCCTGGTCAAAGGCTTCTA

TCCCAGCGACATCGCCGTGGAGTGGGAGAGCAATGGGCAG

CCGGAGAACAACTACAAGACCACGCCTCCCGTGCTGGACT

CCGACGGCTCCTTCTTCCTCTACAGCAAGCTCACCGTGGAC

AAGAGCAGGTGGCAGCAGGGGAACGTCTTCTCATGCTCCG

TGATGCATGAGGCTCTGCACAACCACTACACGCAGAAGAG

CCTCTCCCTGTCTCCGGGTAAA

SSELTQDPAVSVALGQTVRITCQGDSLRSYYASWYQQKPGQA

PVLVIYGK RPS GIPDRF SGS S S GNTASLTITGAQ AEDEAD Y

174 YCNSRVMPHNRVFGGGTKLTVLGQPKAAPSVTLFPPSSEELQ (Light chain) ANKATLVCLISDFYPGAVTVAWKADSSPVKAGVETTTPSKQS

N KYAASSYLSLTPEQWKSHRSYSCQVTHEGSTVEKTVAPTE

CS

EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPG

KGLEWVSAISGSGGSTYYADSVKGRFTISRDNSK TLYLQMN

SLRAEDTAVYYCARVFYRGGVSMDYWGQGTLVTVSSASTK

GP S VFPLAP S SKSTS GGTAALGCLVKD YFPEPVTVS WNS GALT

SGVHTFP AVLQ S S GLYSLS S WTVP S S SLGTQTYICNVNHKP S

175

NTKVDKKVEPKSCDKTHTCPPCPAPEAAGGPSVFLFPPKPKD

(Heavy chain) TLMISRTPEVTCVWDVSHEDPEVKFNWYVDGVEVHNAKTK

PREEQYNSTYRWSVLTVLHQDWLNGKEYKCKVSNKALGAP

IEKTISKAKGQPREPQVYTLPPSRDELTK QVSLTCLVKGFYP

SDIAVEWESNGQPEN YKTTPPVLDSDGSFFLYSKLTVDKSR

WQQGNVFSCSVMHEALHNHYTQKSLSLSPGK

The anti-OX40 antibodies were produced by co-transfecting HEK293-EBNA cells with the mammalian expression vectors using polyethylenimine. The cells were transfected with the corresponding expression vectors in a 1 : 1 ratio ("vector heavy chain" : "vector light chain" ). For production in 500 mL shake flasks, 400 million HEK293 EBNA cells were seeded 24 hours before transfection. For transfection cells were centrifuged for 5 minutes at 210 x g, and the supernatant was replaced by pre-warmed CD CHO medium. Expression vectors (200 μg of total DNA) were mixed in 20 mL CD CHO medium. After addition of 540 PEI, the solution was vortexed for 15 seconds and incubated for 10 minutes at room temperature. Afterwards, cells were mixed with the DNA/PEI solution, transferred to a 500 mL shake flask and incubated for 3 hours at 37°C in an incubator with a 5% C0 ₂ atmosphere. After the incubation, 160 mL of F17 medium was added and cells were cultured for 24 hours. One day after transfection 1 mM valproic acid and 7% Feed with supplements were added. After culturing for 7 days, the supernatant was collected by centrifugation for 15 minutes at 210 x g. The solution was sterile filtered (0.22 μιη filter), supplemented with sodium azide to a final concentration of 0.01 % (w/v), and kept at 4°C.

Purification of antibody molecules from cell culture supernatants was carried out by affinity chromatography using Protein A as described above for purification of antigen Fc fusions.

The protein was concentrated and filtered prior to loading on a HiLoad Superdex 200 column (GE Healthcare) equilibrated with 20mM Histidine, 140mM NaCl solution of pH 6.0.

The protein concentration of purified antibodies was determined by measuring the OD at 280 nm, using the molar extinction coefficient calculated on the basis of the amino acid sequence. Purity and molecular weight of the antibodies were analyzed by CE-SDS in the presence and absence of a reducing agent (Invitrogen, USA) using a LabChipGXII (Caliper). The aggregate content of antibody samples was analyzed using a TSKgel G3000 SW XL analytical size- exclusion column (Tosoh) equilibrated in a 25 mM K ₂ HP0 ₄ , 125 mM NaCl, 200mM L-Arginine Monohydrocloride, 0.02 % (w/v) NaN ₃ , pH 6.7 running buffer at 25°C. Table 14 summarizes the yield and final content of the anti-OX40 P329G LALA IgGl antibodies.

Table 14: Biochemical analysis of anti-OX40 P329G LALA IgGl clones

Example 2

Generation of bispecific antibodies targeting OX40 and epithelial cell adhesion molecule

(EpCAM) 2.1 Generation of bispecific antibodies targeting human OX40 and human epithelial cell adhesion molecule (EpCAM)

Bispecific agonistic OX40 constructs with tetravalent binding for OX40, and monovalent binding for EpCAM (i.e. '4+1 'constructs) were prepared.

In this example, the antigen binding molecule comprised a first heavy chain (HCl) comprising VHCH1 VHCH1 of anti-OX40 49B4 Fc knob (P329G/LALA), followed by a (G4S)4 linker and VL of anti-EpCAM antibody clone 3-171; and a second heavy chain (HC2) comprising VHCH1 VHCH1 of anti-OX40 49B4 Fc hole (P329G/LALA), followed by a (G4S)4 linker and VH of anti-EpCam 3-171.

The generation of anti-EpCAM antibody 3-171 is described e.g. in WO 2010142990 Al . Nucleotide and amino acid sequences for 3-171 in scFv and IgGl format (and VH and VL sequences thereof) are disclosed e.g. at Table 1 and Figure 1 of WO 2010142990 Al .

The knob into hole technology is described in e.g. in US 5,731,168 and US 7,695,936 and allows the assembly of the HCl and HC2. The Pro329Gly, Leu234Ala and Leu235Ala mutations have been introduced in the constant region of the heavy chains to abrogate binding to Fc gamma receptors according to the method described in International Patent Appl. Publ. No. WO

2012/130831 Al . The heavy chain fusion polypeptides HC1 and HC2 were co-expressed with the light chain of the anti-OX40 clone 49B4 (CLVL), to produce a molecule having tetravalent binding for OX40 and monovalent binding for EpCAM (i.e. '4+1 'constructs) - see Figure 2A. The nucleotide and amino acid sequences are shown in Table 15 and Table 16, respectively. Bispecific agonistic OX40 constructs with tetravalent binding for OX40, and bivalent binding for EpCAM (i.e. '4+2 'constructs) were also prepared.

For the 4+2 constuct, the heavy chains comprise VHCH1 VHCH1 of anti-OX40 49B4_Fc (P329G/LALA) followed by a (G4S)4 linker and a crossed Fab unit (VLCH1) of EpCAM- binding antibody 3-171 fused to the C-terminus of the Fc. The heavy chain fusion polypeptides were co-expressed with the light chain (LCI) of the anti-OX40 clone 49B4 (CLVL). The CH and CL of the anti-OX40 Fabs contained charged residues to prevent the generation of Bence Jones proteins and to further stabilize the correct pairing of LCI to the HCs. Specifically, the substiutions E123R and Q124K (residues according to EU numbering) were made in the CL domain of the OX40(49B4) VLCL light chain, resulting in the light chain sequence SEQ ID NO : 185 ; and the substiutions Kl 47E and K213E (residues according to EU numbering) were made in the CHI domain of OX40(49B4), resulting in the heavy chain sequence SEQ ID NO: 186.

In this case the introduction of a knob into hole was not necessary as both HCs contain the same domains. The heavy chain fusion polypeptides and LCI polypeptides were co-expressed with polypeptide ecoding the VH and CL of the anti-EpCAM binding clone 3-171.

The resulting molecule having tetravalent binding for OX40 and bivalent binding for EpCAM (i.e. '4+2' constructs) is shown in Figure 2B. The nucleotide and amino acid sequences are shown in Table 15 and Table 16, respectively.

Table 15. Base pair sequences of mature bispecific, tetravalent anti-OX40, monovalent and bivalent anti-EpCAM hulgGI P329GLALA molecules

Clone SEQ Base pair sequence

ID NO:

176 GACATCCAGATGACCCAGTCTCCTTCCACC

CTGTCTGCATCTGTAGGAGACCGTGTCACC

ATCACTTGCCGTGCCAGTCAGAGTATTAGT

49B4/ EpCAM LC

AGCTGGTTGGCCTGGTATCAGCAGAAACC

3-171 AGGGAAAGCCCCTAAGCTCCTGATCTATG

49B4 VLCL ATGCCTCCAGTTTGGAAAGTGGGGTCCCA P329GLALA

TCACGTTTCAGCGGCAGTGGATCCGGGAC

4+1 AGAATTCACTCTCACCATCAGCAGCTTGC

AGCCTGATGATTTTGCAACTTATTACTGCC

AACAGTATAGTTCGCAGCCGTATACGTTT

GGCCAGGGCACCAAAGTCGAGATCAAGCG TACGGTGGCTGCACCATCTGTCTTCATCTT

CCCGCCATCTGATGAGCAGTTGAAATCTG

GAACTGCCTCTGTTGTGTGCCTGCTGAATA

ACTTCTATCCCAGAGAGGCCAAAGTACAG

TGGAAGGTGGATAACGCCCTCCAATCGGG

TAACTCCCAGGAGAGTGTCACAGAGCAGG

ACAGCAAGGACAGCACCTACAGCCTCAGC

AGCACCCTGACGCTGAGCAAAGCAGACTA

CGAGAAACACAAAGTCTACGCCTGCGAAG

TCACCCATCAGGGCCTGAGCTCGCCCGTC

ACAAAGAGCTTCAACAGGGGAGAGTGT

177 CAGGTGCAATTGGTGCAGTCTGGGGCTGA

GGTGAAGAAGCCTGGGTCCTCGGTGAAGG

TCTCCTGCAAGGCCTCCGGAGGCACATTC

AGCAGCTACGCTATAAGCTGGGTGCGACA

GGCCCCTGGACAAGGGCTCGAGTGGATGG

GAGGGATCATCCCTATCTTTGGTACAGCA

AACTACGCACAGAAGTTCCAGGGCAGGGT

CACCATTACTGCAGACAAATCCACGAGCA

CAGCCTACATGGAGCTGAGCAGCCTGAGA

TCTGAGGACACCGCCGTGTATTACTGTGC

GAGAGAATACTACCGTGGTCCGTACGACT

ACTGGGGCCAAGGGACCACCGTGACCGTC

TCCTCAGCTAGCACAAAGGGACCTAGCGT

GTTCCCCCTGGCCCCCAGCAGCAAGTCTA

CATCTGGCGGAACAGCCGCCCTGGGCTGC

CTCGTGAAGGACTACTTTCCCGAGCCCGT

GACCGTGTCCTGGAACTCTGGCGCTCTGA

HCl CAAGCGGCGTGCACACCTTTCCAGCCGTG

CTGCAGAGCAGCGGCCTGTACTCTCTGAG

CAGCGTCGTGACAGTGCCCAGCAGCTCTC

49B4VHCH1_ TGGGCACCCAGACCTACATCTGCAACGTG VHCHl Fc k AACCACAAGCCCAGCAACACCAAGGTGGA

CAAGAAGGTGGAACCCAAGAGCTGCGAC

nob_PG/LAL GGCGGAGGGGGATCTGGCGGCGGAGGAT A_3-171 VL CCCAGGTGCAATTGGTGCAGTCTGGGGCT

GAGGTGAAGAAGCCTGGGTCCTCGGTGAA

GGTCTCCTGCAAGGCCTCCGGAGGCACAT

TCAGCAGCTACGCTATAAGCTGGGTGCGA

CAGGCCCCTGGACAAGGGCTCGAGTGGAT

GGGAGGGATCATCCCTATCTTTGGTACAG

CAAACTACGCACAGAAGTTCCAGGGCAGG

GTCACCATTACTGCAGACAAATCCACGAG

CACAGCCTACATGGAGCTGAGCAGCCTGA

GATCTGAGGACACCGCCGTGTATTACTGT

GCGAGAGAATACTACCGTGGTCCGTACGA

CTACTGGGGCCAAGGGACCACCGTGACCG

TCTCCTCAGCTAGCACCAAGGGCCCATCG

GTCTTCCCCCTGGCACCCTCCTCCAAGAGC

ACCTCTGGGGGCACAGCGGCCCTGGGCTG

CCTGGTCAAGGACTACTTCCCCGAACCGG

TGACGGTGTCGTGGAACTCAGGCGCCCTG

ACCAGCGGCGTGCACACCTTCCCGGCTGT

CCTACAGTCCTCAGGACTCTACTCCCTCAG CAGCGTGGTGACCGTGCCCTCCAGCAGCT

TGGGCACCCAGACCTACATCTGCAACGTG

AATCACAAGCCCAGCAACACCAAGGTGGA

CAAGAAAGTTGAGCCCAAATCTTGTGACA

AAACTCACACATGCCCACCGTGCCCAGCA

CCTGAAGCTGCAGGGGGACCGTCAGTCTT

CCTCTTCCCCCCAAAACCCAAGGACACCC

TCATGATCTCCCGGACCCCTGAGGTCACAT

GCGTGGTGGTGGACGTGAGCCACGAAGAC

CCTGAGGTCAAGTTCAACTGGTACGTGGA

CGGCGTGGAGGTGCATAATGCCAAGACAA

AGCCGCGGGAGGAGCAGTACAACAGCAC

GTACCGTGTGGTCAGCGTCCTCACCGTCCT

GCACCAGGACTGGCTGAATGGCAAGGAGT

ACAAGTGCAAGGTCTCCAACAAAGCCCTC

GGCGCCCCCATCGAGAAAACCATCTCCAA

AGCCAAAGGGCAGCCCCGAGAACCACAG

GTGTACACCCTGCCCCCCTGCAGAGATGA

GCTGACCAAGAACCAGGTGTCCCTGTGGT

GTCTGGTCAAGGGCTTCTACCCCAGCGAT

ATCGCCGTGGAGTGGGAGAGCAACGGCCA

GCCTGAGAACAACTACAAGACCACCCCCC

CTGTGCTGGACAGCGACGGCAGCTTCTTC

CTGTACTCCAAACTGACCGTGGACAAGAG

CCGGTGGCAGCAGGGCAACGTGTTCAGCT

GCAGCGTGATGCACGAGGCCCTGCACAAC

CACTACACCCAGAAGTCCCTGAGCCTGAG

CCCCGGCGGAGGCGGCGGAAGCGGAGGA

GGAGGATCCGGCGGAGGCGGATCTGGCGG

GGGAGGTTCGGAGATCGTGATGACCCAGA

GCCCCGCCACCCTGAGTGTGTCTCCAGGC

GAAAGAGCCACCCTGTCCTGCAGAGCCAG

CCAGAGCGTGTCCAGCAACCTGGCCTGGT

ATCAGCAGAAGCCCGGCCAGGCCCCCAGA

CTGATTATCTACGGCGCCAGCACAACCGC

CAGCGGCATCCCTGCCAGATTTTCCGCCTC

TGGCAGCGGCACCGACTTCACCCTGACAA

TCAGCAGCCTGCAGTCCGAGGACTTCGCC

GTGTACTACTGCCAGCAGTACAACAACTG

GCCCCCTGCCTACACCTTCGGCCAGGGCA

CCAAGCTGGAAATCAAG

178 CAGGTGCAATTGGTGCAGTCTGGGGCTGA

GGTGAAGAAGCCTGGGTCCTCGGTGAAGG

HC2 TCTCCTGCAAGGCCTCCGGAGGCACATTC

AGCAGCTACGCTATAAGCTGGGTGCGACA

GGCCCCTGGACAAGGGCTCGAGTGGATGG

49B4VHCH1_ GAGGGATCATCCCTATCTTTGGTACAGCA VHCHl Fc h AACTACGCACAGAAGTTCCAGGGCAGGGT

CACCATTACTGCAGACAAATCCACGAGCA

ole_PG/LALA CAGCCTACATGGAGCTGAGCAGCCTGAGA 3-171 VH TCTGAGGACACCGCCGTGTATTACTGTGC

GAGAGAATACTACCGTGGTCCGTACGACT

ACTGGGGCCAAGGGACCACCGTGACCGTC

TCCTCAGCTAGCACAAAGGGACCTAGCGT GTTCCCCCTGGCCCCCAGCAGCAAGTCTA

CATCTGGCGGAACAGCCGCCCTGGGCTGC

CTCGTGAAGGACTACTTTCCCGAGCCCGT

GACCGTGTCCTGGAACTCTGGCGCTCTGA

CAAGCGGCGTGCACACCTTTCCAGCCGTG

CTGCAGAGCAGCGGCCTGTACTCTCTGAG

CAGCGTCGTGACAGTGCCCAGCAGCTCTC

TGGGCACCCAGACCTACATCTGCAACGTG

AACCACAAGCCCAGCAACACCAAGGTGGA

CAAGAAGGTGGAACCCAAGAGCTGCGAC

GGCGGAGGGGGATCTGGCGGCGGAGGAT

CCCAGGTGCAATTGGTGCAGTCTGGGGCT

GAGGTGAAGAAGCCTGGGTCCTCGGTGAA

GGTCTCCTGCAAGGCCTCCGGAGGCACAT

TCAGCAGCTACGCTATAAGCTGGGTGCGA

CAGGCCCCTGGACAAGGGCTCGAGTGGAT

GGGAGGGATCATCCCTATCTTTGGTACAG

CAAACTACGCACAGAAGTTCCAGGGCAGG

GTCACCATTACTGCAGACAAATCCACGAG

CACAGCCTACATGGAGCTGAGCAGCCTGA

GATCTGAGGACACCGCCGTGTATTACTGT

GCGAGAGAATACTACCGTGGTCCGTACGA

CTACTGGGGCCAAGGGACCACCGTGACCG

TCTCCTCAGCTAGCACCAAGGGCCCATCG

GTCTTCCCCCTGGCACCCTCCTCCAAGAGC

ACCTCTGGGGGCACAGCGGCCCTGGGCTG

CCTGGTCAAGGACTACTTCCCCGAACCGG

TGACGGTGTCGTGGAACTCAGGCGCCCTG

ACCAGCGGCGTGCACACCTTCCCGGCTGT

CCTACAGTCCTCAGGACTCTACTCCCTCAG

CAGCGTGGTGACCGTGCCCTCCAGCAGCT

TGGGCACCCAGACCTACATCTGCAACGTG

AATCACAAGCCCAGCAACACCAAGGTGGA

CAAGAAAGTTGAGCCCAAATCTTGTGACA

AAACTCACACATGCCCACCGTGCCCAGCA

CCTGAAGCTGCAGGGGGACCGTCAGTCTT

CCTCTTCCCCCCAAAACCCAAGGACACCC

TCATGATCTCCCGGACCCCTGAGGTCACAT

GCGTGGTGGTGGACGTGAGCCACGAAGAC

CCTGAGGTCAAGTTCAACTGGTACGTGGA

CGGCGTGGAGGTGCATAATGCCAAGACAA

AGCCGCGGGAGGAGCAGTACAACAGCAC

GTACCGTGTGGTCAGCGTCCTCACCGTCCT

GCACCAGGACTGGCTGAATGGCAAGGAGT

ACAAGTGCAAGGTCTCCAACAAAGCCCTC

GGCGCCCCCATCGAGAAAACCATCTCCAA

AGCCAAAGGGCAGCCCCGAGAACCACAG

GTGTGCACCCTGCCCCCATCCCGGGATGA

GCTGACCAAGAACCAGGTCAGCCTCTCGT

GCGCAGTCAAAGGCTTCTATCCCAGCGAC

ATCGCCGTGGAGTGGGAGAGCAATGGGCA

GCCGGAGAACAACTACAAGACCACGCCTC

CCGTGCTGGACTCCGACGGCTCCTTCTTCC

TCGTGAGCAAGCTCACCGTGGACAAGAGC AGGTGGCAGCAGGGGAACGTCTTCTCATG

CTCCGTGATGCATGAGGCTCTGCACAACC

ACTACACGCAGAAGAGCCTCTCCCTGTCT

CCGGGTGGAGGCGGCGGAAGCGGAGGAG

GAGGATCCGGCGGAGGCGGAAGTGGCGG

CGGAGGTTCGCAGGTGCAGCTGGTGCAGT

CTGGCGCCGAAGTGAAGAAACCCGGCAGC

AGCGTGAAGGTGTCCTGCAAGGCTTCCGG

CGGCACCTTCAGCAGCTACGCCATTTCTTG

GGTGCGCCAGGCCCCTGGACAGGGCCTGG

AATGGATGGGCGGCATCATCCCCATCTTC

GGCACCGCCAACTACGCCCAGAAATTCCA

GGGCAGAGTGACCATCACCGCCGACGAGA

GCACCAGCACCGCCTACATGGAACTGAGC

AGCCTGCGGAGCGAGGACACCGCCGTGTA

CTATTGTGCCAGAGGCCTGCTGTGGAACT

ACTGGGGCCAGGGCACACTCGTGACCGTG

TCCTCT

179 GACATCCAGATGACCCAGTCTCCTTCCACC

CTGTCTGCATCTGTAGGAGACCGTGTCACC

ATCACTTGCCGTGCCAGTCAGAGTATTAGT

AGCTGGTTGGCCTGGTATCAGCAGAAACC

AGGGAAAGCCCCTAAGCTCCTGATCTATG

ATGCCTCCAGTTTGGAAAGTGGGGTCCCA

TCACGTTTCAGCGGCAGTGGATCCGGGAC

AGAATTCACTCTCACCATCAGCAGCTTGC

LCI AGCCTGATGATTTTGCAACTTATTACTGCC

AACAGTATAGTTCGCAGCCGTATACGTTT

49B4 VLCL GGCCAGGGCACCAAAGTCGAGATCAAGCG

TACGGTGGCTGCACCATCTGTCTTCATCTT

CCCGCCATCTGATCGGAAGTTGAAATCTG

+ charges GAACTGCCTCTGTTGTGTGCCTGCTGAATA

ACTTCTATCCCAGAGAGGCCAAAGTACAG

OX40 49B4/ TGGAAGGTGGATAACGCCCTCCAATCGGG

TAACTCCCAGGAGAGTGTCACAGAGCAGG

EpCAM 3-171

ACAGCAAGGACAGCACCTACAGCCTCAGC

P329GLALA AGCACCCTGACGCTGAGCAAAGCAGACTA

4+2 CGAGAAACACAAAGTCTACGCCTGCGAAG

TCACCCATCAGGGCCTGAGCTCGCCCGTC

ACAAAGAGCTTCAACAGGGGAGAGTGT

180 CAGGTGCAGCTGGTGCAGTCTGGCGCCGA

HC AGTGAAGAAACCCGGCAGCAGCGTGAAG

GTGTCCTGCAAGGCTTCCGGCGGCACCTTC

49B4VHCH1_ AGCAGCTACGCCATTTCTTGGGTGCGCCA

GGCCCCTGGACAGGGCCTGGAATGGATGG

49B4VHCH1_ GCGGCATCATCCCCATCTTCGGCACCGCC Fc AACTACGCCCAGAAATTCCAGGGCAGAGT

GACCATCACCGCCGACAAGAGCACCAGCA

CCGCCTACATGGAACTGAGCAGCCTGCGG

PG/LALA 3- AGCGAGGACACCGCCGTGTACTACTGCGC 171 VLCH1 CAGAGAGTACTACAGAGGCCCCTACGACT

ACTGGGGCCAGGGCACAACCGTGACCGTG

TCTAGCGCCAGCACAAAGGGCCCCAGCGT

49B4 Fab +

GTTCCCTCTGGCCCCTAGCAGCAAGAGCA CATCTGGCGGAACAGCCGCCCTGGGCTGC

CTGGTGGAAGATTACTTCCCCGAGCCCGT

GACAGTGTCCTGGAACTCTGGCGCCCTGA

CAAGCGGCGTGCACACCTTTCCAGCCGTG

CTGCAGAGCAGCGGCCTGTACTCACTGTC

CAGCGTCGTGACTGTGCCCAGCAGCAGCC

TGGGAACCCAGACCTACATCTGCAACGTG

AACCACAAGCCCAGCAACACCAAGGTGGA

CGAGAAGGTGGAACCCAAGAGCTGCGAC

GGCGGAGGCGGATCTGGCGGCGGAGGATC

CCAGGTGCAGCTGGTGCAGAGCGGAGCTG

AAGTGAAAAAGCCTGGCTCCTCCGTGAAA

GTGTCTTGTAAAGCCAGCGGCGGCACATT

CTCATCCTACGCCATCAGCTGGGTGCGGC

AGGCTCCAGGCCAGGGACTGGAATGGATG

CAATTATGCTCAGAAATTTCAGGGGCGCG

TGACAATTACAGCCGACAAGTCCACCTCT

ACAGCTTATATGGAACTGTCCTCCCTGCGC

TCCGAGGATACAGCTGTGTATTATTGTGCC

CGCGAGTACTACCGGGGACCTTACGATTA

TTGGGGACAGGGAACCACAGTGACTGTGT

CCTCCGCTAGCACCAAGGGACCTTCCGTG

TTTCCCCTGGCTCCCAGCTCCAAGTCTACC

TCTGGGGGCACAGCTGCTCTGGGATGTCT

GGTGGAAGATTATTTTCCTGAACCTGTGAC

CGTGTCATGGAACAGCGGAGCCCTGACCT

CCGGGGTGCACACATTCCCTGCTGTGCTGC

AGTCCTCCGGCCTGTATAGCCTGAGCAGC

GTCGTGACCGTGCCTTCCAGCTCTCTGGGC

ACACAGACATATATCTGTAATGTGAATCA

CAAACCCTCTAATACCAAAGTGGATGAGA

AAGTGGAACCTAAGTCCTGCGACAAGACC

CACACCTGTCCCCCTTGTCCTGCCCCTGAA

GCTGCTGGCGGCCCATCTGTGTTTCTGTTC

CCCCCAAAGCCCAAGGACACCCTGATGAT

CAGCCGGACCCCCGAAGTGACCTGCGTGG

TGGTGGATGTGTCCCACGAGGACCCAGAA

GTGAAGTTCAATTGGTACGTGGACGGCGT

GGAAGTGCACAACGCCAAGACCAAGCCGC

GGGAAGAACAGTACAACAGCACCTACCGG

GTGGTGTCCGTGCTGACAGTGCTGCACCA

GGACTGGCTGAACGGCAAAGAGTACAAGT

GCAAGGTGTCCAACAAGGCCCTGGGAGCC

CCCATCGAGAAAACCATCAGCAAGGCCAA

GGGCCAGCCCCGCGAACCTCAGGTGTACA

CCCTGCCCCCAAGCAGGGACGAGCTGACC

AAGAACCAGGTGTCCCTGACCTGTCTCGT

GAAGGGCTTCTACCCCTCCGATATCGCCGT

GGAATGGGAGAGCAACGGCCAGCCCGAG

AACAACTACAAGACCACCCCCCCTGTGCT

GGACAGCGACGGCTCATTCTTCCTGTACTC

CAAGCTGACCGTGGACAAGAGCCGGTGGC

AGCAGGGCAACGTGTTCAGCTGCAGCGTG ATGCACGAGGCCCTGCACAACCACTACAC

ACAGAAGTCTCTGAGCCTGAGCCCTGGCG

GAGGGGGAGGATCTGGGGGAGGCGGAAG

TGGGGGAGGGGGTTCCGGAGGCGGTGGTT

CGGAGATCGTGATGACCCAGAGCCCCGCC

ACCCTGAGTGTGTCTCCAGGCGAAAGAGC

CACCCTGTCCTGCAGAGCCAGCCAGAGCG

TGTCCAGCAACCTGGCCTGGTATCAGCAG

AAGCCCGGCCAGGCCCCCAGACTGATTAT

CTACGGCGCCAGCACAACCGCCAGCGGCA

TCCCTGCCAGATTTTCCGCCTCTGGCAGCG

GCACCGACTTCACCCTGACAATCAGCAGC

CTGCAGTCCGAGGACTTCGCCGTGTACTA

CTGCCAGCAGTACAACAACTGGCCCCCTG

CCTACACCTTCGGCCAGGGCACCAAGCTG

GAAATCAAGAGCAGCGCTTCCACCAAGGG

CCCCTCAGTGTTCCCACTGGCACCATCCAG

CAAGTCCACAAGCGGAGGAACCGCCGCTC

TGGGCTGTCTCGTGAAAGACTACTTTCCAG

AGCCAGTGACCGTGTCCTGGAATAGTGGC

GCTCTGACTTCTGGCGTGCACACTTTCCCC

GCAGTGCTGCAGAGTTCTGGCCTGTACTCC

CTGAGTAGCGTCGTGACAGTGCCCTCCTCT

AGCCTGGGCACTCAGACTTACATCTGCAA

TGTGAATCATAAGCCTTCCAACACAAAAG

TGGACAAAAAAGTGGAACCCAAATCTTGC

181 CAGGTGCAGCTGGTGCAGTCTGGCGCCGA

AGTGAAGAAACCCGGCAGCAGCGTGAAG

GTGTCCTGCAAGGCTTCCGGCGGCACCTTC

AGCAGCTACGCCATTTCTTGGGTGCGCCA

GGCCCCTGGACAGGGCCTGGAATGGATGG

GCGGCATCATCCCCATCTTCGGCACCGCC

AACTACGCCCAGAAATTCCAGGGCAGAGT

GACCATCACCGCCGACGAGAGCACCAGCA

LC2 CCGCCTACATGGAACTGAGCAGCCTGCGG

AGCGAGGACACCGCCGTGTACTATTGTGC

EpCAM 3-171 CAGAGGCCTGCTGTGGAACTACTGGGGCC

AGGGCACACTCGTGACCGTGTCCTCTGCT VHCL

AGCGTGGCCGCTCCCTCCGTGTTCATCTTC

CCACCTTCCGACGAGCAGCTGAAGTCCGG

CACCGCTTCTGTCGTGTGCCTGCTGAACAA

CTTCTACCCCCGCGAGGCCAAGGTGCAGT

GGAAGGTGGACAACGCCCTGCAGTCCGGC

AACAGCCAGGAATCCGTGACCGAGCAGGA

CTCCAAGGACAGCACCTACTCCCTGTCCTC

CACCCTGACCCTGTCCAAGGCCGACTACG

AGAAGCACAAGGTGTACGCCTGCGAAGTG

ACCCACCAGGGCCTGTCTAGCCCCGTGAC

CAAGTCTTTCAACCGGGGCGAGTGC Table 16. Amino acid sequences of mature bispecific, tetravalent anti-OX40, monovalent and bivalent anti-EpCAM hulgGI P329GLALA molecules

Clone SEQ ID Amino acid sequence

NO:

182 DIQMTQSPSTLSASVGDRVTITCRASQSISSW

LAWYQQKPGKAPKLLIYDASSLESGVPSRFS

LC

GSGSGTEFTLTISSLQPDDFATYYCQQYSSQP

YTFGQGTKVEIKRTVAAPSVFIFPPSDEQLKS

49B4 VLCL GTASWCLLN FYPREAKVQWKVDNALQS

GNSQESVTEQDSKDSTYSLSSTLTLSKADYE

KHKVYACEVTHQGLSSPVTKSFNRGEC

183 QVQLVQSGAEVKKPGSSVKVSCKASGGTFS

SYAISWVRQAPGQGLEWMGGIIPIFGTANYA

QKFQGRVTITADKSTSTAYMELSSLRSEDTA

VYYCAREYYRGPYDYWGQGTTVTVSSAST

KGPSVFPLAPSSKSTSGGTAALGCLVKDYFP

EPVTVSWNSGALTSGVHTFPAVLQSSGLYSL

S S WTVP S S SLGTQTYICNVNHKPSNTKVDK

KVEPKSCDGGGGS GGGGS Q VQLVQ S GAEV

KKPGSSVKVSCKASGGTFSSYAISWVRQAP

HCl GQGLEWMGGIIPIFGTANYAQKFQGRVTITA

DKSTSTAYMELSSLRSEDTAVYYCAREYYR

49B4 GPYDYWGQGTTVTVSSASTKGPSVFPLAPSS

KSTSGGTAALGCLVKDYFPEPVTVSWNSGA VHCH1 VHC

LTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLG HI Fc knob TQTYICNVNHKPSNTKVDKKVEPKSCDKTH

OX40 49B4/

PG/LALA 3- TCPPCPAPEAAGGPSVFLFPPKPKDTLMISRT EpCam 3-171 PEVTCVWDVSHEDPEVKFNWYVDGVEVH

171 VL NAKTKPREEQYNSTYRWSVLTVLHQDWL P329GLALA

NGKEYKCKVSNKALGAPIEKTISKAKGQPR

4+1 EPQVYTLPPCRDELTK QVSLWCLVKGFYP

SDIAVEWESNGQPEN YKTTPPVLDSDGSFF

LYSKLTVDKSRWQQGNVFSCSVMHEALHN

HYTQKSLSLSPGGGGGSGGGGSGGGGSGGG

GSEIVMTQSPATLSVSPGERATLSCRASQSV

SSNLAWYQQKPGQAPRLIIYGASTTASGIPA

RFSASGSGTDFTLTISSLQSEDFAVYYCQQY

N WPP AYTFGQ GTKLEIK

184 QVQLVQSGAEVKKPGSSVKVSCKASGGTFS

SYAISWVRQAPGQGLEWMGGIIPIFGTANYA

QKFQGRVTITADKSTSTAYMELSSLRSEDTA

HC2 VYYCAREYYRGPYDYWGQGTTVTVSSAST

KGPSVFPLAPSSKSTSGGTAALGCLVKDYFP

49B4 EPVTVSW SGALTSGVHTFPAVLQSSGLYSL

S S WTVP S S SLGTQTYICN VNHKP SNTKVDK VHCH1 VHC

KVEPKSCDGGGGS GGGGS Q VQLVQ S GAEV

Hl Fc hole P KKPGSSVKVSCKASGGTFSSYAISWVRQAP G/LALA 3- GQGLEWMGGIIPIFGTANYAQKFQGRVTITA

DKSTSTAYMELSSLRSEDTAVYYCAREYYR

171 VH GPYDYWGQGTTVTVSSASTKGPSVFPLAPSS

KSTSGGTAALGCLVKDYFPEPVTVSWNSGA

LTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLG

TQTYICNVNHKPSNTKVDKKVEPKSCDKTH TCPPCPAPEAAGGPSVFLFPPKPKDTLMISRT

PEVTCVWDVSHEDPEVKFNWYVDGVEVH

NAKTKPREEQYNSTYRWSVLTVLHQDWL

NGKEYKCKVSNKALGAPIEKTISKAKGQPR

EPQVCTLPPSRDELTK QVSLSCAVKGFYPS

DIAVEWESNGQPEN YKTTPPVLD SDGSFFL

VSKLTVDKSRWQQGNVFSCSVMHEALHNH

YTQKSLSLSPGGGGGSGGGGSGGGGSGGGG

SQ VQLVQ SGAEVKKPGS S VKVS CKAS GGTF

SSYAISWVRQAPGQGLEWMGGIIPIFGTANY

AQKFQGRVTITADESTSTAYMELSSLRSEDT

AVYYCARGLLWNYWGQGTLVTVSS

185 DIQMTQSPSTLSASVGDRVTITCRASQSISSW

LCI

LAWYQQKPGKAPKLLIYDASSLESGVPSRFS

GSGSGTEFTLTISSLQPDDFATYYCQQYSSQP

49B4 VLCL YTFGQGTKVEIKRTVAAP S VFIFPP SDRKLKS

GTASWCLLN FYPREAKVQWKVDNALQS

+ charges GNSQESVTEQDSKDSTYSLSSTLTLSKADYE

KHKVYACEVTHQGLSSPVTKSFNRGEC

186 QVQLVQ SGAEVKKPGS SVKVSCKASGGTFS

SYAISWVRQAPGQGLEWMGGIIPIFGTANYA

QKFQGRVTITADKSTSTAYMELSSLRSEDTA

VYYCAREYYRGPYDYWGQGTTVTVSSAST

KGP S VFPLAP S SKSTSGGTAALGCLVED YFP

EPVTVSWNSGALTSGVHTFPAVLQSSGLYSL

S S WTVP S S SLGTQTYICNVNHKPSNTKVDE

KVEPKSCDGGGGS GGGGS QVQLVQ S GAEV

HC KKPGSSVKVSCKASGGTFSSYAISWVRQAP

GQGLEWMGGIIPIFGTANYAQKFQGRVTITA

49B4VHCH1_ DKSTSTAYMELS SLRSEDTAVYYCAREYYR

OX40 49B4/ GPYDYWGQGTTVTVSSASTKGPSVFPLAPSS

49B4VHCH1_ KSTSGGTAALGCLVEDYFPEPVTVSWNSGA EpCAM 3-171

Fc LTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLG P329GLALA TQTYICNVNHKPSNTKVDEKVEPKSCDKTH

4+2 TCPPCPAPEAAGGPSVFLFPPKPKDTLMISRT

PG/LALA 3-

PEVTCVWDVSHEDPEVKFNWYVDGVEVH

171 VLCH1 NAKTKPREEQYNSTYRWSVLTVLHQDWL

NGKEYKCKVSNKALGAPIEKTISKAKGQPR

49B4 Fab + EPQVYTLPPSRDELTKNQVSLTCLVKGFYPS

DIAVEWESNGQPENNYKTTPPVLD SDGSFFL

charges YSKLTVDKSRWQQGNVFSCSVMHEALHNH

YTQKSLSLSPGGGGGSGGGGSGGGGSGGGG

SEIVMTQSPATLSVSPGERATLSCRASQSVSS

NLAWYQQKPGQAPRLIIYGASTTASGIPARF

SASGSGTDFTLTISSLQSEDFAVYYCQQYNN

WPPAYTFGQGTKLEIKS SASTKGPS VFPLAP

SSKSTSGGTAALGCLVKDYFPEPVTVSWNS

GALTSGVHTFPAVLQSSGLYSLSSWTVPSS

SLGTQTYICNVNHKPSNTKVDKKVEPKSC

187 QVQLVQ SGAEVKKPGS SVKVSCKASGGTFS

LC2 SYAISWVRQAPGQGLEWMGGIIPIFGTANYA

QKFQGRVTITADESTSTAYMELSSLRSEDTA

EpCAM 3-171 VYYCARGLLWNYWGQGTLVTVSSASVAAP

SVFIFPPSDEQLKSGTASWCLLNNFYPREA KVQWKVDNALQSGNSQESVTEQDSKDSTY

VHCL

SLSSTLTLSKADYEKHKVYACEVTHQGLSSP

VTKSFNRGEC

2.2 Generation of bispecific antibodies targeting murine OX40 and murine epithelial cell adhesion molecule (EpCAM)

Bispecific constructs with tetravalent binding for murine OX40, and monovalent binding for murine EpCAM (i.e. '4+1 'constructs) were also prepared.

In this example, the antigen binding molecule comprised a first heavy chain (HC 1) comprising VHCH1 VHCH1 of anti-mouse OX40 antibody clone 0X86 Fc knob (DAPG), followed by a (G4S)4 linker and VL of anti-mouse EpCAM antibody clone G8.8; and a second heavy chain (HC2) comprising VHCH1 VHCH1 of anti-mouse OX40 0X86 Fc hole (DAPG), followed by a (G4S)4 linker and VH of anti-mouse EpCAM G8.8.

The generation of rat anti-mouse OX40 antibody clone 0X86 is described e.g. in Al- Shamkhani et al. Eur J Chem (1996) 26: 1695-1699 or in WO 2016/057667.

The generation of rat anti-mouse EpCAM antibody G8.8 is described e.g. in Farr et al, J Histochem Cytochem. (1991) 39(5):645-53, and is available from the Developmental Studies Hybridoma Bank, University of Iowa, Iowa City, I A. The antibody is also described in WO 2013/1 13615.

The 'DDK ' knob-into-hole technology is described in e.g. in WO 2014/131694 Al , and allows the assembly of the HC1 and HC2. Briefly, aspartic acid residues (D) are provided in the Fc region subunit of one of the heavy chains (HC 1) at positions corresponding to positions 392 and 409 (numbering according to Kabat EU index; i.e. K392D and K409D), and lysine (K) residues are provided in the Fc region subunit of the other of the heavy chains (HC2) at positions corresponding to positions 356 and 399 (numbering according to Kabat EU index; i.e. E356K and D399K).

DAPG mutations were introduced in the constant regions of the heavy chains to abrogate binding to murine Fc gamma receptors according to the method described e.g. in Baudino et al. J. Immunol. (2008), 181 , 6664-6669, or in WO 2016/030350 Al . Briefly, alanine (A) is provided in the Fc region at the position corresponding to position 265, and glycine (G) is provided in the Fc region at the position corresponding to position 329 (numbering according to Kabat EU index; i.e. D265A, P329G). The heavy chain fusion polypeptides HC1 and HC2 were co-expressed with the light chain of the anti-OX40 clone 0X86 (CLVL), to produce a molecule having tetravalent binding for mouse OX40 and monovalent binding for mouse EpCAM (i.e. '4+1 'constructs). The nucleotide and amino acid sequences are shown respectively in Table 17 and Table 18.

Table 17. Base pair sequences of mature bispecific, tetravalent anti-muOX40, monovalent anti-muEpCAM hulgGI DAPG kin 4+1 molecules

Clone SEQ ID Base pair sequence

NO:

188 GATATTGTGATGACCCAGGGTGCACTCCCC

AATCCTGTCCCTTCTGGAGAGTCAGCTTCCA

TCACCTGCAGGTCTAGTCAGAGTCTGGTAT

ACAAAGACGGCCAGACATACTTGAATTGGT

TTCTGCAGAGGCCAGGACAGTCTCCTCAGC

TTCTGACCTATTGGATGTCTACCCGTGCATC

AGGAGTCTCAGACAGGTTCAGTGGCAGTGG

LC GTCAGGAACATATTTCACACTGAAAATCAG

TAGAGTGAGGGCTGAGGATGCGGGTGTGTA

OX40 0X86 TTACTGTCAGCAAGTTCGAGAGTATCCTTTC

ACTTTCGGCTCAGGGACGAAGTTGGAAATA VLCL AAACGTGCCGATGCTGCACCAACTGTATCG

ATTTTCCCACCATCCAGTGAGCAGTTAACAT

CTGGAGGTGCCTCAGTCGTGTGCTTCTTGAA

CAACTTCTACCCCAAAGACATCAATGTCAA

GTGGAAGATTGATGGCAGTGAACGACAAA

ATGGCGTCCTGAACAGTTGGACTGATCAGG

ACAGCAAAGACAGCACCTACAGCATGAGC

AGCACCCTCACGTTGACCAAGGACGAGTAT

muOX40 GAACGACATAACAGCTATACCTGTGAGGCC OX86/ ACTCACAAGACATCAACTTCACCCATTGTC

AAGAGCTTCAACAGGAATGAGTGT

muEpCAM 189 CAGGTGCAGCTGAAGGAGTCTGGACCTGGT G8.8 DAPG CTGGTGCAGCCCTCACAGACCCTGTCCCTC

ACCTGCACTGTCTCTGGGTTCTCACTAACCG

4+1

GTTACAATTTACACTGGGTTCGCCAGCCTCC

AGGAAAGGGTCTGGAGTGGATGGGAAGAA

TGAGGTATGATGGAGACACATATTATAATT

CAGTTCTCAAATCCCGACTGAGCATCAGCA

HCl GGGACACCTCCAAGAACCAAGTTTTCTTGA

AAATGAACAGTCTGCAAACGGATGACACAG

0X86 CCATTTACTATTGTACCAGAGACGGGCGTG

GTGACTCCTTTGATTACTGGGGCCAAGGAG VHCH1 VHC

TCATGGTCACAGTCTCCAGCGCTAAGACCA

Hl Fc hole D CCCCCCCCTCCGTGTATCCTCTGGCTCCTGG APG DD G8.8 ATCTGCCGCCCAGACCAACAGCATGGTCAC

CCTGGGCTGCCTCGTGAAGGGCTACTTCCCT VL GAGCCTGTGACCGTGACCTGGAACTCCGGC

TCTCTGTCCTCTGGCGTGCACACCTTCCCTG

CCGTGCTGCAGTCCGACCTGTACACCCTGTC

CTCCAGCGTGACCGTGCCTTCCTCCACCTGG

CCTTCCCAGACCGTGACATGCAACGTGGCC

CACCCTGCCAGCTCCACCAAGGTGGACAAG

AAAATCGTGCCCCGGGACTGCGGAGGGGGC

GGTTCCGGCGGAGGAGGATCCCAGGTGCAG CTGAAGGAGTCTGGACCTGGTCTGGTGCAG

CCCTCACAGACCCTGTCCCTCACCTGCACTG

TCTCTGGGTTCTCACTAACCGGTTACAATTT

ACACTGGGTTCGCCAGCCTCCAGGAAAGGG

TCTGGAGTGGATGGGAAGAATGAGGTATGA

TGGAGACACATATTATAATTCAGTTCTCAA

ATCCCGACTGAGCATCAGCAGGGACACCTC

CAAGAACCAAGTTTTCTTGAAAATGAACAG

TCTGCAAACGGATGACACAGCCATTTACTA

TTGTACCAGAGACGGGCGTGGTGACTCCTT

TGATTACTGGGGCCAAGGAGTCATGGTCAC

AGTCTCCAGCGCTAAGACCACCCCCCCTAG

CGTGTACCCTCTGGCCCCTGGATCTGCCGCC

CAGACCAACAGCATGGTGACCCTGGGCTGC

CTGGTGAAGGGCTACTTCCCCGAGCCTGTG

ACCGTGACCTGGAACAGCGGCAGCCTGAGC

AGCGGCGTGCACACCTTTCCAGCCGTGCTG

CAGAGCGACCTGTACACCCTGAGCAGCTCC

GTGACCGTGCCTAGCAGCACCTGGCCCAGC

CAGACAGTGACCTGCAACGTGGCCCACCCT

GCCAGCAGCACCAAGGTGGACAAGAAAAT

CGTGCCCCGGGACTGCGGCTGCAAGCCCTG

CATCTGCACCGTGCCCGAGGTGTCCAGCGT

GTTCATCTTCCCACCCAAGCCCAAGGACGT

GCTGACCATCACCCTGACCCCCAAAGTGAC

CTGCGTGGTGGTGGCCATCAGCAAGGACGA

CCCCGAGGTGCAGTTCTCTTGGTTTGTGGAC

GACGTGGAGGTGCACACAGCCCAGACAAA

GCCCCGGGAGGAACAGATCAACAGCACCTT

CAGAAGCGTGTCCGAGCTGCCCATCATGCA

CCAGGACTGGCTGAACGGCAAAGAATTCAA

GTGCAGAGTGAACAGCGCCGCCTTCGGCGC

CCCCATCGAGAAAACCATCAGCAAGACCAA

GGGCAGACCCAAGGCCCCCCAGGTGTACAC

CATCCCCCCACCCAAAGAACAGATGGCCAA

GGACAAGGTGTCCCTGACCTGCATGATCAC

CAACTTTTTCCCCGAGGACATCACCGTGGA

GTGGCAGTGGAATGGCCAGCCCGCCGAGAA

CTACGACAACACCCAGCCCATCATGGACAC

CGACGGCAGCTACTTCGTGTACAGCGACCT

GAACGTGCAGAAGTCCAACTGGGAGGCCG

GCAACACCTTCACCTGTAGCGTGCTGCACG

AGGGCCTGCACAACCACCACACCGAGAAGT

CCCTGAGCCACAGCCCAGGCGGCGGAGGCG

GATCTGGCGGAGGAGGTTCCGGTGGCGGAG

GTTCCGGAGGCGGTGGATCCGACATCCAGA

TGACACAGAGCCCCGCCAGCCTGAGCGCCT

CTCTGGGCGAGACAGTGTCCATCGAGTGCC

TGGCCAGCGAGGGCATCAGCAACGACCTGG

CCTGGTATCAGCAGAAGTCCGGCAAGAGCC

CCCAGCTGCTGATCTACGCCACCAGCAGAC

TGCAGGACGGCGTGCCCAGCAGATTCAGCG

GCAGCGGCTCCGGCACCCGGTACAGCCTGA

AGATCAGCGGCATGCAGCCCGAGGACGAG GCCGACTACTTCTGCCAGCAGAGCTACAAG TACCCCTGGACCTTCGGCGGCGGCACCAAG CTGGAACTGAAG

190 CAGGTGCAGCTGAAGGAGTCTGGACCTGGT

CTGGTGCAGCCCTCACAGACCCTGTCCCTC

ACCTGCACTGTCTCTGGGTTCTCACTAACCG

GTTACAATTTACACTGGGTTCGCCAGCCTCC

AGGAAAGGGTCTGGAGTGGATGGGAAGAA

TGAGGTATGATGGAGACACATATTATAATT

CAGTTCTCAAATCCCGACTGAGCATCAGCA

GGGACACCTCCAAGAACCAAGTTTTCTTGA

AAATGAACAGTCTGCAAACGGATGACACAG

CCATTTACTATTGTACCAGAGACGGGCGTG

GTGACTCCTTTGATTACTGGGGCCAAGGAG

TCATGGTCACAGTCTCCAGCGCTAAGACCA

CCCCCCCCTCCGTGTATCCTCTGGCTCCTGG

ATCTGCCGCCCAGACCAACAGCATGGTCAC

CCTGGGCTGCCTCGTGAAGGGCTACTTCCCT

GAGCCTGTGACCGTGACCTGGAACTCCGGC

TCTCTGTCCTCTGGCGTGCACACCTTCCCTG

CCGTGCTGCAGTCCGACCTGTACACCCTGTC

CTCCAGCGTGACCGTGCCTTCCTCCACCTGG

CCTTCCCAGACCGTGACATGCAACGTGGCC

CACCCTGCCAGCTCCACCAAGGTGGACAAG

HC2 AAAATCGTGCCCCGGGACTGCGGAGGGGGC

GGTTCCGGCGGAGGAGGATCCCAGGTGCAG

0X86 CTGAAGGAGTCTGGACCTGGTCTGGTGCAG

CCCTCACAGACCCTGTCCCTCACCTGCACTG VHCH1 VHC

TCTCTGGGTTCTCACTAACCGGTTACAATTT HI Fc knob ACACTGGGTTCGCCAGCCTCCAGGAAAGGG DAPG K G TCTGGAGTGGATGGGAAGAATGAGGTATGA

TGGAGACACATATTATAATTCAGTTCTCAA

8.8 VH ATCCCGACTGAGCATCAGCAGGGACACCTC

CAAGAACCAAGTTTTCTTGAAAATGAACAG

TCTGCAAACGGATGACACAGCCATTTACTA

TTGTACCAGAGACGGGCGTGGTGACTCCTT

TGATTACTGGGGCCAAGGAGTCATGGTCAC

AGTCTCCAGCGCTAAGACCACCCCCCCTAG

CGTGTACCCTCTGGCCCCTGGATCTGCCGCC

CAGACCAACAGCATGGTGACCCTGGGCTGC

CTGGTGAAGGGCTACTTCCCCGAGCCTGTG

ACCGTGACCTGGAACAGCGGCAGCCTGAGC

AGCGGCGTGCACACCTTTCCAGCCGTGCTG

CAGAGCGACCTGTACACCCTGAGCAGCTCC

GTGACCGTGCCTAGCAGCACCTGGCCCAGC

CAGACAGTGACCTGCAACGTGGCCCACCCT

GCCAGCAGCACCAAGGTGGACAAGAAAAT

CGTGCCCCGGGACTGCGGCTGCAAGCCCTG

CATCTGCACCGTGCCCGAGGTGTCCAGCGT

GTTCATCTTCCCACCCAAGCCCAAGGACGT

GCTGACCATCACCCTGACCCCCAAAGTGAC

CTGCGTGGTGGTGGCCATCAGCAAGGACGA

CCCCGAGGTGCAGTTCTCTTGGTTTGTGGAC

GACGTGGAGGTGCACACAGCCCAGACAAA GCCCCGGGAGGAACAGATCAACAGCACCTT

CAGAAGCGTGTCCGAGCTGCCCATCATGCA

CCAGGACTGGCTGAACGGCAAAGAATTCAA

GTGCAGAGTGAACTCCGCCGCCTTTGGCGC

CCCTATCGAAAAGACCATCTCCAAGACCAA

GGGCAGACCCAAGGCCCCCCAGGTGTACAC

AATCCCCCCACCCAAGAAACAGATGGCCAA

GGACAAGGTGTCCCTGACCTGCATGATCAC

ATGGCAGTGGAACGGCCAGCCCGCCGAGA

ACTACAAGAACACCCAGCCCATCATGAAGA

CCGACGGCTCCTACTTCGTGTACTCCAAGCT

GAACGTGCAGAAGTCCAACTGGGAGGCCG

GCAACACCTTCACCTGTTCCGTGCTGCACG

AGGGCCTGCACAACCACCACACCGAGAAGT

CCCTGTCCCACTCTCCTGGCGGAGGCGGAG

GATCTGGTGGCGGTGGTTCTGGCGGTGGCG

GTTCCGGAGGCGGTGGTTCCGAAGTGCAGC

TGGCCGAGAGCGGCGGAGGCCTGGTGCAGC

CTGGCAGATCCATGAAGCTGAGCTGCGCCG

CCAGCGGCTTCACCTTCAGCAACTTCCCCAT

GGCCTGGGTCCGACAGGCCCCCACCAAGGG

CCTGGAATGGGTGGCCACCATCAGCACCAG

CGGCGGCAGCACCTACTACCGGGACAGCGT

GAAGGGCCGGTTCACCATCAGCCGGGACAA

CGCCAAGAGCACCCTGTACCTGCAGATGAA

CAGCCTGCGGAGCGAGGACACCGCCACCTA

CTACTGCACCCGGACCCTGTATATCCTGCG

GGTGTTCTACTTCGACTACTGGGGCCAGGG

CGTGATGGTCACCGTGTCTAGC

Table 18. Amino acid sequences of mature bispecific, tetravalent anti-muOX40, monovalent anti-muEpCAM mulgGI DAPG kih 4+1 molecules

Clone SEQ ID Amino acid sequence

NO:

LC 191 DIVMTQGALPNPVPSGESASITCRSSQSLVYK

DGQTYLNWFLQPvPGQSPQLLTYWMSTRASG

VSDPvFSGSGSGTYFTLKISRVRAEDAGVYYCQ

OX40 0X86 Q VREYPFTFGS GTKLEIKRAD AAPTVSIFPP S S

EQLTSGGASWCFLN FYPKDINVKWKIDGS VLCL ERQNGVLNSWTDQDSKDSTYSMSSTLTLTKD

muOX40 EYERHNSYTCEATHKTSTSPIVKSFNRNEC OX86/muEpC

AM G8.8

DAPG 4+1 HCl 192 QVQLKESGPGLVQPSQTLSLTCTVSGFSLTGY

NLHWVRQPPGKGLEWMGRMRYDGDTYYNS VLKSRLSISRDTSK QVFLKMNSLQTDDTAIY

0X86 YCTRDGRGD SFD YWGQGVMVTVS SAKTTPP VHCH1 VHC SVYPLAPGSAAQTNSMVTLGCLVKGYFPEPV

T VT WNS GSLS SGVHTFP AVLQ SDLYTLS S S VT

Hl Fc hole D VPSSTWPSQTVTCNVAHPASSTKVDKKIVPRD APG DD G8.8 CGGGGSGGGGSQVQLKESGPGLVQPSQTLSL VL TCTVSGFSLTGYNLHWVRQPPGKGLEWMGR

MRYDGDTYYNSVLKSRLSISRDTSK QVFLK

MNSLQTDDTAIYYCTRDGRGDSFDYWGQGV

MVTVSSAKTTPPSVYPLAPGSAAQTNSMVTL

GCLVKGYFPEPVTVTWNSGSLSSGVHTFPAV

LQSDLYTLSSSVTVPSSTWPSQTVTCNVAHPA

SSTKVDKKIVPRDCGCKPCICTVPEVSSVFIFP

PKPKDVLTITLTPKVTCVWAISKDDPEVQFS

WFVDDVEVHTAQTKPREEQINSTFRSVSELPI

MHQDWLNGKEFKCRVNSAAFGAPIEKTISKT

KGRPKAPQVYTIPPPKEQMAKDKVSLTCMIT

NFFPEDITVEWQWNGQPAENYDNTQPIMDTD

GSYFVYSDLNVQKSNWEAGNTFTCSVLHEGL

HNHHTEKSLSHSPGGGGGSGGGGSGGGGSGG

GGSDIQMTQSPASLSASLGETVSIECLASEGIS

NDLAWYQQKSGKSPQLLIYATSRLQDGVPSR

FSGSGSGTRYSLKISGMQPEDEADYFCQQSYK

YPWTFGGGTKLELK

193 QVQLKESGPGLVQPSQTLSLTCTVSGFSLTGY

NLHWVRQPPGKGLEWMGRMRYDGDTYYNS

VLKSRLSISRDTSK QVFLKMNSLQTDDTAIY

YCTRDGRGDSFDYWGQGVMVTVSSAKTTPP

SVYPLAPGSAAQTNSMVTLGCLVKGYFPEPV

T VT WNS GSLS SGVHTFP AVLQ SDLYTLS S S VT

VPSSTWPSQTVTCNVAHPASSTKVDKKIVPRD

CGGGGSGGGGSQVQLKESGPGLVQPSQTLSL

HC2 TCTVSGFSLTGYNLHWVRQPPGKGLEWMGR

MRYDGDTYYNSVLKSRLSISRDTSKNQVFLK

MNSLQTDDTAIYYCTRDGRGDSFDYWGQGV

0X86 MVTVS SAKTTPPS VYPLAPGS AAQTNSMVTL VHCH1 VHC GCLVKGYFPEPVTVTWNSGSLSSGVHTFPAV HI Fc knob LQSDLYTLSSSVTVPSSTWPSQTVTCNVAHPA

SSTKVDKKIVPRDCGCKPCICTVPEVSSVFIFP DAPG KK G PKPKDVLTITLTPKVTCVWAISKDDPEVQFS

8.8 VH WFVDDVEVHTAQTKPREEQINSTFRSVSELPI

MHQDWLNGKEFKCRVNSAAFGAPIEKTISKT

KGRPKAPQVYTIPPPKKQMAKDKVSLTCMIT

NFFPEDITVEWQWNGQPAENYKNTQPIMKTD

GSYFVYSKLNVQKSNWEAGNTFTCSVLHEGL

HNHHTEKSLSHSPGGGGGSGGGGSGGGGSGG

GGSEVQLAESGGGLVQPGRSMKLSCAASGFT

FSNFPMAWVRQAPTKGLEWVATISTSGGSTY

YRDSVKGRFTISRDNAKSTLYLQMNSLRSEDT

ATYYCTRTLYILRVFYFDYWGQGVMVTVSS

For production of the different bispecific anti-OX40, anti-EpCAM antigen binding molecules, all genes were transiently expressed under control of a chimeric MPSV promoter consisting of the MPSV core promoter combined with the CMV promoter enhancer fragment. The expression vector also contains the oriP region for episomal replication in EBNA (Epstein Barr Virus Nuclear Antigen) containing host cells. The bispecific anti-OX40, anti-EpCam molecules were produced by co-transfecting

HEK293-EBNA cells with the mammalian expression vectors using polyethylenimine. The cells were transfected with the corresponding expression vectors in a 1 : 1 :4 ratio ("vector heavy chain" : "vector light chainl" : "vector light chain2" for 4+2 molecules) and 1 : 1 :4 ("vector heavy chainl" : "vector heavy chain2" : "vector light chain" for 4+1 molecules).

For a 200 mL production in 500 mL shake flasks, 250 million HEK293 EBNA cells were seeded 24 hours before transfection in Excell media with supplements. For transfection, the cells were centrifuged for 5 minutes at 210 x g, and supernatant was replaced by pre-warmed CD- CHO medium. Expression vectors were mixed in 20 mL CD-CHO medium to a final amount of 200 μg DNA. After addition of 540 PEI (1 mg/mL), the solution was vortexed for 15 seconds and incubated for 10 minutes at room temperature. Afterwards, cells were mixed with the

DNA/PEI solution, transferred to a 500 mL shake flask and incubated for 3 hours at 37°C in an incubator with a 5% C0 ₂ atmosphere and shaking at 165 rpm. After the incubation, 160 mL Excell medium with supplements was added and cells were cultured for 24 hours. At this point the valproic acid concentration is 1 mM (in the media there's as well 5 g/L PepSoy and 6 mM L- Glutamine). 24h after transfection the cells are supplement with Feed 7 at 12% final volume (24 mL) and 3 g/L glucose (1.2 mL from 500 g/L stock). After culturing for 7 days, the cell supernatant was collected by centrifugation for 45 minutes at 2000-3000 x g. The solution was sterile filtered (0.22 μιη filter), supplemented with sodium azide to a final concentration of 0.01 % (w/v), and kept at 4°C.

For affinity chromatography of the anti-human OX40, anti-human EpCAM molecules, the supernatant was loaded on a ProtA MabSelect Sure column (CV = 5 mL, GE Healthcare) equilibrated with 30 mL 20 mM Sodium Citrate, 20 mM Sodium Phosphate, pH 7.5. Unbound protein was removed by washing with 6-10 column volumes of a buffer containing 20 mM sodium phosphate, 20 mM sodium citrate, pH 7.5. The bound protein was eluted using a step elution with 8 CV of 20 mM Sodium Citrate, lOOmM Sodium Chloride, 100 mM Glycine, pH 3.0.

For affinity chromatography of the anti-mouse OX40, anti-mouse EpCAM molecules, the supernatant was loaded on a ProtA MabSelect Sure column (CV = 5 mL, GE Healthcare) equilibrated with 30 mL 1 M Glycine, 0.3 M Sodium Chloride, pH 8.6. Unbound protein was removed by washing with 6-10 column volumes of equilibration buffer. The bound protein was eluted with 15 CV using a gradient elution from 20-100% of 20 mM Sodium Citrate, 0.3 M NaCl, 0.01% Tween pH 2.5.

For both of the anti-human OX40, anti-human EpCAM and anti-mouse OX40, anti-mouse EpCAM molecules, the pH of the collected fractions was adjusted by adding 1/10 (v/v) of 0.5 M Na ₂ HP0 ₄ , pH8.0. The protein was concentrated and filtered prior to loading on a HiLoad Superdex 200 column (GE Healthcare) equilibrated with 20 mM Histidine, 140 mM NaCl, 0.01% Tween20, pH 6.0.

The protein concentration of purified bispecific tetravalent 4+1 and 4+2 constructs was determined by measuring the OD at 280 nm, using the molar extinction coefficient calculated on the basis of the amino acid sequence. Purity and molecular weight of the bispecific constructs were analyzed by CE-SDS in the presence and absence of a reducing agent (Invitrogen, USA) using a LabChipGXII (Caliper). The aggregate content of bispecific constructs was analyzed using a TSKgel G3000 SW XL analytical size-exclusion column (Tosoh) equilibrated in a 25 mM K2HP04, 125 mM NaCl, 200mM L-Arginine Monohydrocloride, 0.02 % (w/v) NaN3, pH 6.7 running buffer at 25°C.

Table 19. Biochemical analysis of bispecific, tetravalent anti-OX40, anti-EpCAM IgGl 4+1 and 4+2 constructs.

2.3 Determination of the aggregation temperature of anti-OX40, anti-EpCAM 4+1 and 4+2 constructs

For direct comparison of all formats the thermal stability was monitored by Static Light Scattering (SLS) and by measuring the intrinsic protein fluorescence in response to applied temperature stress. 30 μg of filtered protein sample with a protein concentration of 1 mg/ml was applied in duplicate to an Optim 2 instrument (Avacta Analytical Ltd). The temperature was ramped from 25 to 85 °C at 0.1 °C/min, with the radius and total scattering intensity being collected. For determination of intrinsic protein fluorescence the sample was excited at 266 nm and emission was collected between 275 nm and 460 nm. Table 20. Aggregation temperatures for the bispecific, anti-OX40, anti-EpCAM 4+1 and

4+2 constructs

Example 3

Binding of bispecific antibodies targeting murine OX40 and murine epithelial cell adhesion molecule (EpCAM)

3.1 Analysis of binding to murine OX40 expressing cells: naive and activated splenocytes

Murine spleens were obtained from C57B1/6 female mice and collected in 3 mL DPBS.

Single cell suspension was generated by mashing the spleens onto a 70 μιη cell strainer using the back of a syringe. The filter was washed with 10 ml of T cell medium consisting of RPMI 1640 medium (Gibco by Life Technology, Cat. No. 42401-042) supplemented with 10% heat- inactivated Fetal Bovine Serum (Gibco Cat No. 16140-071, Lot No. 1797306A), 1% (v/v) GlutaMAX I (GIBCO by Life Technologies, Cat. No. 35050 038), 1 mM Sodium-Pyruvate (SIGMA, Cat. No. S8636), 1% (v/v) non-essential amino acids (SIGMA, Cat. No. M7145) and 50 μΜ β-Mercaptoethanol (SIGMA, M3148) and cells were centrifuged for 7 min at 350 x g at 4°C. After centrifugation, the cell pellet was re-suspended in 6 ml IX lysis buffer (BD Pharm LyseTM: concentrated (10X) ammonium chloride-based lysing reagent, BD Biosciences, Cat No. 555899) and incubated for 3 min at room temperature. Erythrolysis was stopped by addition of 10 ml T cell medium. Cells were washed once with X-Vivo 15 medium (Lonza, Cat No. 04- 744Q), re-suspended in 10 ml X-Vivo 15 medium and filtered through a 70 μιη cell strainer to remove debris.

Splenocytes were activated to upregulate murine OX40 in X-Vivo 15 medium containing anti-CD3 [Clone 145-2C11, BD Bioscence, Cat. No. 553057 at 1 μg/mL] and anti-CD28 [Clone 37.51, Biolegend, Cat. No. 102102 at 1 μg/mL] antibodies at a density of 1 * 10 ⁶ cells/mL in 6 well plates and incubated at 37°C, 5% C0 ₂ for two days. For detection of OX40, naive splenocytes and activated splenocytes were mixed. To enable distinction of naive from activated splenocytes, naive cells were labeled prior to the binding assay using the eFluor670 cell proliferation dye (eBioscience, Cat.-No.65-0840-85).

For labeling cells were harvested, washed with pre-warmed (37°C) DPBS and adjusted to a cell density of 1 x 10 ⁷ cells/mL in DPBS. eFluor670 cell proliferation dye (eBioscience, Cat.- No.65-0840-85 ) was added to the suspension of na ^' ive splenocytes at a final concentration of 2.5 μΜ and a final cell density of 0.5 x 10 ⁷ cells/mL in DPBS. Cells were then incubated for 10 min at room temperature in the dark. To stop labeling reaction, 4 mL heat inactivated FBS were added and cells were washed three times with T cell medium. A mixture of 1 x 10 ⁵ resting eFluor670 labeled splenocytes and 1 x 10 ⁵ unlabeled activated splenocytes were then added to wells of round-bottomed suspension 96-well plates (Greiner bio-one, cellstar, Cat. No. 650185).

For discrimination between live and dead cells, samples were stained with Zombie Aqua Viability Dye (Bio legend, Cat. No. 423102) in DPBS for 10 minutes at room temperature. Cells were then washed once with FACS buffer and subsequently stained for 90 minutes at 4°C in the dark in 50 μίΛνεΙΙ 4°C FACS buffer containing titrated anti-OX40 antigen binding molecules. After washing three times with excess FACS buffer, cells were stained for 30 minutes at 4°C in the dark in 25 μίΛνεΙΙ 4°C FACS buffer containing a mixture of fluorescently labeled anti- mouse CD4 (clone GK1.5, Rat IgG2b, κ, BioLegend, Cat. No. 100438), anti-mouse CD 8 (clone 53-6.7, Rat IgG2a, κ, BioLegend, Cat.-No. 100748) and PE-conjugated AffiniPure anti-mouse IgG Fcy-fragment-specific goat IgG F(ab")2 fragment (Jackson ImmunoResearch, Cat. No. 115- 116-71).

Plates were finally resuspended in 85 μΙ,ΛνεΙΙ FACS buffer and acquired the same day using 4-laser LSR-II cytometer (BD Bioscience with DIVA software).

As shown in Figure 3 A to 3D, none of the OX40-specific antigen binding molecules displayed binding to resting murine CD4+ T-cells or CD8+ T-cells, which are negative for OX40. By contrast, all of the OX40-specific antigen binding molecules displayed binding to activated CD 8+ or CD4+ T-cells, which express OX40. The different bispecific anti-murine OX40 molecules having tetravalent binding for murine OX40 showed comparable binding strength for OX40 (EC50 values Table 21). The presence of a muEpCAM binding moiety had minimal impact on OX40 binding for the 4+1 OX40 molecules (compare triangle vs open circle). 3.2 Binding to murine EpCAM-expressing and EpCAM-negative tumor cells

The binding to cell surface murine EpCAM was analysed using mouse EpCAM-positive CT26muEpCAM cl25 cells, which stably expresses murine EpCAM. The specificity of binding was analysed by determination of binding to muEpCAM-negative cell line CT26muFAP, which stably expresses murine FAP. For analysis of binding of the antigen binding mo lecules, 0.5 x 10 ⁵ CT26muEpCAM or 0.5 x 10 ⁵ CT26muFAP cells were added to wells of round-bottomed suspension cell 96-well plates (greiner bio-one, cellstar, Cat. No. 650185). For discrimination of live and dead cells, samples were stained with Zombie Aqua Viability Dye (Biolegend, Cat. No 423102) in PBS for 10 minutes at room temperature. Cells were then washed once with FACS buffer and subsequently stained for 90 minutes at 4°C in the dark in 50 μΕ/well 4°C FACS buffer (DPBS (Gibco by Life Technologies, Cat. No. 14190 326) w/ BSA (0.1 % v/w, Sigma-Aldrich, Cat. No. A9418) containing titrated anti-OX40 antigen binding molecules. After washing three times with excess FACS buffer, cells were stained for 30 minutes at 4°C in the dark in 25 μΕ/well 4 ^° C FACS buffer containing Fluorescein isothiocyanate (FITC)-conjugated AffiniPure anti-mouse IgG Fcy- fragment-specific goat IgG F(ab")2 fragment (Jackson ImmunoResearch, Cat. No. 115-096-071).

Plates were finally resuspended in 85 μίΛνεΙΙ FACS-buffer and acquired the same day using 4-laser LSR-II cytometer (BD Bioscience with DIVA software).

As shown in Figures 4A and 4B, the murine EpCAM-targeted antigen binding molecuels did not display binding to muEpCAM-negative CT26muFAP cells, whereas the molecules comprising a murine EpCAM binding domain displayed binding to CT26muEpCAM cells. The parental bivalent anti-muEpCAM antibody (muEpCAM IgG; open triangle) showed strong binding to muEpCAM on CT26muEpCAM cells, and the 4+1 molecule with monovalent binding for murine EpCAM (filled triangle) showed comparatively reduced binding capacity as compared to the bivalent IgG. However, the VH/VL fusion did not hinder the binding.

EC50 values of binding to activated murine CD4 T and CD8 T cells as well as to muEpCAM positive tumor cells are summarized in Table 21.

Table 21. EC50 values for binding of anti-murine OX40, anti-murine EpCAM antigen binding molecules to cells expressing murine OX40 or murine EpCAM.

n.a. = not applicable (EC50 not calculated). Example 4

Biological activity of bispecific antigen binding molecules targeting murine OX40 and murine EpCAM

4.1 OX40 mediated costimulation of suboptimally TCR triggered murine

splenocytes and hypercrosslinking by cell surface murine EpCAM

The ability of the murine EpCAM targeted tetravalent anti-OX40 antigen binding molecule to rescue suboptimal TCR stimulation of resting murine splenocytes was analysed.

CT26muEpCAM cl25 cells were used in assays to cross-link the antibody.

Freshly isolated murine splenocytes contain (1) resting OX40 negative CD4 ⁺ and CD8 ⁺ T cells and (2) antigen presenting cells with various Fc-γ receptor molecules on their cell surface e.g. B cells and monocytes. Anti-mouse CD3 antibody (clone 145-2C11, BD Bioscience, Cat. No. 553057) can bind with its Fc part to the present Fc-γ receptor molecules and mediate a prolonged TCR activation on resting OX40-negative CD4 ⁺ and CD8 ⁺ T cells. These cells then start to express OX40 within several hours. Functional agonistic compounds against OX40 can signal via the OX40 receptor present on activated CD8 ⁺ and CD4 ⁺ T cells and support TCR-mediated stimulation.

Resting CFSE-labeled murine splenocytes were stimulated for three days with a

suboptimal concentration of anti-CD3 antibody in the presence of irradiated CT26muEpCAM cl25 cells, and titrated OX40 antigen binding molecules. The effects on T-cell survival and proliferation were analyzed by monitoring FSC-area, total cell counts and CFSE dilution in living cells by flow cytometry. Additionally, cells were co-stained with fluorescently-labeled antibodies against the T-cell activation marker CD25.

CT26muEpCAM cl25 cells were harvested using cell dissociation buffer (Invitrogen, Cat.- No. 13151-014) for 10 minutes at 37°C. Cells were washed once with DPBS and irradiated in an xRay irradiator at a dose of 4,500 RAD to prevent later overgrowth of splenocytes by the tumor cell line. Irradiated cells were cultured at a density of 0.2* 10 ⁵ cells per well in X-Vivo 15 medium in wells of a sterile 96-well round bottomed adhesion tissue culture plate (TPP, Cat. No. 92097) overnight at 37°C and 5% C0 ₂ in an incubator (SteriCycleil60).

Murine splenocytes were isolated as described above and labeled with CFSE as follows. Freshly isolated PBMCs were washed with pre-warmed (37°C) DPBS and adjusted to a cell density of 2 x 10 ⁶ cells/mL in DPBS. Cell Trace CFSE proliferation dye (ThermoFisher, Cat. No. C34554) was added to the suspension of splenocytes at a final concentration of 0.2 μΜ and a final cell density of 1 x 10 ⁶ cells/mL in DPBS. Cells were then incubated for 10 min at 37°C/5%C0 ₂ in the dark. To stop the labeling reaction, 20 mL heat inactivated FBS was added, cells were washed three times with T cell medium and finally re-suspended in X-Vivo 15 medium. All antibody dilutions were performed in X-Vivo 15 medium because it was selected as optimal assay medium for splenocytes proliferation and maintaining their viability. CFSE-labeled splenocytes were then added to wells at a density of 1 * 10 ⁵ cells per well.

Anti-mouse CD3 antibody (clone 145-2C11) was added at a final concentration of 0^g/ml, and anti-OX40 molecules were added at the indicated concentrations. Cells were activated for three days at 37°C in a 5% C0 ₂ atmosphere in an incubator (SteriCycleil60).

For discrimination between live and dead cells, samples were stained with Zombie Aqua Viability Dye (Bio legend, Cat. No 423102) in PBS for 10 minutes at room temperature. Cells were then washed once with FACS buffer and subsequently surface- stained with fluorescent dye-conjugated antibodies anti-mouse CD4 (clone GK1.5, Rat IgG2b, κ, BioLegend, Cat. No. 100438), anti-mouse CD8 (clone 53-6.7, Rat IgG2a, κ, BioLegend, Cat.-No. 100748) and anti- mouse CD25 (clone 3C7, Rat IgG2b, κ Biolegend, Cat. No 101912) for 20 min at 4°C. Cell pellets were washed once with FACS buffer, re-suspended in 85 μΙ,ΛνεΙΙ FACS-buffer and acquired the same day using 4-laser LSR-II cytometer (BD Bioscience with DIVA software).

The results are shown in Figures 5 A to 5D and Figures 6 A to 6D. Hyper-crosslinking of the antigen binding molecules bound to OX40 by culture in the presence of CT26muEpCAM cells strongly promoted maturation (as evidenced by an increase in the size of CD4 ⁺ and CD8 ⁺ cells) (Figures 5A and 5B), and cell proliferation (Figures 5C and 5D), and induced an enhanced activated (CD25 ) phenotype (Figures 6A to 6D) in murine CD4 ⁺ and CD8 ⁺ T cells. The non-targeted 4+1 control molecule only showed minimal activity, demonstrating the importance of cross-linking. Control muEpCAM IgG showed no additional activity as compared to anti-CD3 stimulus only. The results suggest that cell surface immobilization of OX40 receptor oligomers is important for obtaining optimal agonist activity of tetravalent anti-mouse OX40 antigen binding molecules. Example 5

Binding of bispecific antibodies targeting human OX40 and human epithelial cell adhesion molecule (EpCAM)

5.1 Analysis of binding to human OX40 expressing cells: naive and activated PBMCs Buffy coats were obtained from the Zurich blood donation center. To isolate fresh peripheral blood mononuclear cells (PBMCs) buffy coats were diluted with an equal volume of DPBS (Gibco by Life Technologies, Cat. No. 14190 326). 50 mL polypropylene centrifuge tubes (TPP, Cat. No. 91050) were supplied with 15 mL Histopaque 1077 (SIGMA Life Science, Cat. No. 10771, polysucrose and sodium diatrizoate, adjusted to a density of 1.077 g/mL) and the buffy coat solution was layered above the Histopaque 1077. The tubes were centrifuged for 30 min at 400 x g, at room temperature, with low acceleration and no break. Subsequently the PBMCs were collected from the interphase, washed three times with DPBS and resuspended in T cell medium consisting of RPMI 1640 medium (Gibco by Life Technology, Cat. No. 42401-042) supplemented with 10 % Fetal Bovine Serum (FBS, Gibco by Life Technology, Cat. No. 16000- 044, Lot 941273, gamma-irradiated, mycoplasma-free and heat inactivated at 56°C for 35 min), 1 % (v/v) GlutaMAX I (GIBCO by Life Technologies, Cat. No. 35050 038), 1 mM Sodium- Pyruvat (SIGMA, Cat. No. S8636), 1 % (v/v) MEM non-essential amino acids (SIGMA, Cat- No. M7145) and 50 μΜ β-Mercaptoethanol (SIGMA, M3148).

PBMCs were used in experiments either directly after isolation (for analysis of binding to resting human PBMCs) or following stimulation to provide for high expression of human OX40 expression on the cell surface of T cells (for analysis of binding to activated human PBMCs). For stimulations, naive PBMCs were cultured for two days in T cell medium supplied with 400 U/mL Proleukin (Novartis) and 2 μg/mL PHA-L (Sigma- Aldrich, L2769-10) in wells of a 6-well tissue culture plate at 37°C and 5% C0 ₂ . For detection of OX40, naive human PBMCs and activated human PBMCs were mixed.

To enable discrimination of naive from activated human PBMCs, naive cells were labeled prior to the binding assay using the eFluor670 cell proliferation dye (eBioscience, Cat.-No.65-0840- 85).

For labelling, cells were harvested, washed with pre-warmed (37°C) DPBS and adjusted to a cell density of 1 x 10 ⁷ cells/mL in DPBS. eFluor670 cell proliferation dye (eBioscience, Cat.- No.65-0840-85 ) was added to the suspension of naive human PBMCs at a final concentration of 2.5 μΜ, and a final cell density of 0.5 x 10 ⁷ cells/mL in DPBS. Cells were then incubated for 10 min at room temperature in the dark. To stop labeling reaction, 4 mL heat-inactivated FBS was added and cells were washed three times with T cell medium. A mixture of 1 x 10 ⁵ resting eFluor670 labeled human PBMCs and 1 x 10 ⁵ unlabeled activated human PBMCs was then added to each well of a round-bottom suspension 96-well plates (greiner bio-one, cellstar, Cat. No. 650185).

For discrimination of live and dead cells, samples were stained with Zombie Aqua Viability Dye (Bio legend, Cat. No. 423102) in DPBS for 10 minutes at room temperature. Cells were then washed once with FACS buffer and subsequently stained for 90 minutes at 4°C in the dark in 50 μίΛνεΙΙ 4°C cold FACS buffer containing titrated anti-OX40 antigen binding molecules. After three washes with excess FACS buffer, cells were stained for 30 minutes at 4°C in the dark in 25 μίΛνεΙΙ 4°C FACS buffer containing a mixture of fluorescently labeled anti- human CD4 (clone RPA-T4, mouse IgGl k, BioLegend, Cat. No. 300532), anti-human CD8 (clone RPa-T8, mouse IgGlk, BioLegend, Cat.-No. 3010441) and Fluorescein isothiocyanate (FITC)-conjugated AffiniPure anti- human IgG Fcy-fragment-specific goat IgG F(ab ^" )2 fragment (Jackson ImmunoResearch, Cat. No. 109 096 098).

Cells were then resuspended in 85 μΙ,ΛνεΙΙ FACS-buffer and acquired the same day using 4-laser LSR-II cytometer (BD Bioscience with DIVA software).

As shown in Figures 7A to 7D, none of the antigen binding molecules specific for OX40 bound to resting human CD4 ⁺ T-cells or CD8 ⁺ T-cells, which do not express OX40 at the cell surface. By contrast, all of the bispecific anti-OX40, anti-EpCAM molecules displayed binding to activated CD8 ⁺ or CD4 ⁺ T-cells, which express OX40. Binding to CD4 ⁺ T-cells was much stronger than that to CD8+ T cells. Activated human CD8 ⁺ T cells express OX40 at a much lower level than the level of expression by activated CD4 ⁺ T cells. Expression levels for OX40 are depended on the kinetics and strength of stimulation and conditions were here optimized for OX40 expression on CD4 ⁺ T cells but not for CD8 ⁺ T cells. The tetravalent, bispecific anti- OX40 antigen binding molecules in 4+1 and 4+2 formats displayed comparable binding strength to OX40-expressing cells (as shown by their EC50 values, see Table 22). The presence of a huEpCAM binding moiety had no impact on OX40 binding for the 4+1 OX40 binders (as compared to the monospecific, tetravalent, anti-OX40 untargeted control).

5.2 Binding to human EpCAM-expressing and EpCAM-negative tumor cells

The ability of the bispecific anti-human OX40, anti-human EpCAM antigen binding molecules to bind to human EpCAM expressed at the cell surface was analysed using huEpCAM positive KATO-III cells (ATCC HTB-103). The specificity of binding was determined by analysing binding to the human EpCAM-negative cell line A549 NucLight Red (Essen

Bioscience Cat. No. 4491). A549 cells express a red protein which allowed the KATO-III and A549 NLR cells to be distinguished. Expression of huEpCAM on tumor cells was analysed using an anti-human EpCAM antibody (clone EBA-1, BD Cat. No. 347198). Human EpCAM was expressed at a high level on KATO-III cells, to lesser extent on NIH/3T3 huEpCAM clone 44 cells (which stably express human EpCAM at the cell surface), but not on HeLa_huOX40_NFkB_Lucl cells (Figure 8). To determine binding of the antigen binding molecules to the human EpCAM-positive and human EpCAM-negative cells, 0.5 x 10 ⁵ KATO-III and 0.5 x 10 ⁵ A549 NLR cells were added to wells of round-bottomed suspension cell 96-well plates (greiner bio-one, cellstar, Cat. No.

650185). For discrimination of live and dead cells, samples were stained with Zombie Aqua Viability Dye (Bio legend, Cat. No 423102) in PBS for 10 minutes at room temperature. Cells were then washed once with FACS buffer and subsequently stained for 90 minutes at 4 °C in the dark in 50 uL/well 4 °C FACS buffer (DPBS (Gibco by Life Technologies, Cat. No. 14190 326) w/ BSA (0.1 % v/w, Sigma- Aldrich, Cat. No. A9418) containing titrated anti-OX40 antigen binding molecules. After three washes with excess FACS buffer, cells were stained for 30 minutes at 4°C in the dark in 25 μΕΛνεΙΙ 4 °C FACS buffer containing Fluorescein

isothiocyanate (FITC)-conjugated AffiniPure anti-human IgG Fey- fragment-specific goat IgG F(ab")2 fragment (Jackson ImmunoResearch, Cat. No. 109 096 098).

Cells were then resuspended in 85 μΕ/well FACS-buffer and acquired the same day using 4-laser LSR-II cytometer (BD Bioscience with DIVA software).

The results are shown in Figures 9 A and 9B. No binding of the human EpCAM-targeted molecules to huEpCAM-negative A549 NLR cells was observed (Figure 9B). The parental bivalent anti- human EpCAM antibody (clone 3-171, Affitech) displayed strong binding to human EpCAM expressed on KATO-III cells (Figure 9 A; open triangle). Bispecific tetravalent anti- human OX40, bivalent anti-human EpCAM 4+2 molecule showed a reduced level of binding to KATO-III cells as compared to the parental bivalent anti-human EpCAM antibody (Figure 9A; compare closed triangle with open triangle). No binding of the bispecific tetravalent anti- human OX40, monovalent anti-human EpCAM 4+1 molecule to KATO-III cells was observed, suggesting a format restriction of the VH/VL fusion for this target.

EC50 values of binding to activated human CD4 T and CD8 T cells as well as to huEpCAM positive tumor cells are summarized in Table 22. Table 22. EC50 values for binding of anti-human OX40, anti-human EpCAM antigen binding molecules to cells expressing human OX40 or human EpCAM.

n.a. = not applicable (EC50 not calculated).

n.c. = curve was not to fit, no EC50 calculation possible

Example 6

Biological activity of bispecific antigen binding molecules targeting human OX40 and human EpCAM

6.1 HeLa cells expressing human OX40 and reporter gene NF- B-luciferase

Agonstic binding of Ox40 to its ligand induces downstream signaling via activation of nuclear factor kappa B (NFKB) (A. D. Weinberg et al, J. Leukoc. Biol. 2004, 75(6), 962-972). The recombinant reporter cell line HeLa_huOX40_NFKB_Lucl expressing human OX40 on its surface was generated. This cell line harbors a reporter plasmid containing the luciferase gene under the control of an NFKB-sensitive enhancer segment. Binding and activation of OX40 induces dose-dependent activation of NFKB, which then translocates to the nucleus, where it binds to the NFKB-sensitive enhancer of the reporter plasmid to increase expression of the luciferase protein. Luciferase catalyzes luciferin-oxidation resulting in oxyluciferin, which emits light. This can be detected and quantified using a luminometer. Thus, the

HeLa_huOX40_NFkB_Lucl reporter cells can be used to analyse the ability of anti-OX40 molecules to induce NFKB activation as a measure for bioactivity.

Adherent HeLa_huOX40_NFkB_Lucl cells were harvested using cell dissociation buffer (Invitrogen, Cat.-No. 13151-014) for 10 minutes at 37°C. Cells were washed once with DPBS and were adjusted to a cell density of 2 x 10 ⁵ in assay media comprising of MEM (Invitrogen, Cat.-No. 22561-021), 10 % (v/v) heat-inactivated FBS, 1 mM Sodium-Pyruvate and 1% (v/v) non-essential amino acids. Cells were seeded at a density of 0.3 x 10 ⁵ cells per well in a sterile, white 96-well flat-bottomed tissue culture plate with lid (greiner bio-one, Cat. No. 655083) and incubated overnight at 37°C in a 5% C0 ₂ atmosphere, in an incubator (Hera Cell 150).

The next day, HeLa_huOX40_NFkB_Lucl cells were stimulated for 5 hours by adding assay medium containing various titrated bispecific antigen binding molecules targeting OX40. To analyse the effect of hyper-crosslinking on bioactivity, 25 μίΛνεΙΙ of medium containing secondary antibody anti-human IgG Fcy-fragment-specific goat IgG F(ab ^" ) ₂ fragment (Jackson ImmunoResearch, 109-006-098) was added in a or 1 :2 ratio (2 times more secondary antibody than the primary anti-OX40 antigen binding molecule). Hyper-crosslinking of the constructs by cell surface human EpCAM ⁺ cells was tested by adding 25 μΙ,ΛνεΙΙ of medium containing NIH/3T3huEpCAM cl44 cells in a 3: 1 ratio (three times as many EpCAM ⁺ tumor cells as reporter cells, per well).

After incubation, assay supernatant was aspirated and plates washed two times with DPBS. Quantification of light emission was performed using the luciferase 100 assay system and the reporter lysis buffer (both Promega, Cat.-No. E4550 and Cat-No: E3971) according to manufacturer's instructions. Briefly, cells were lysed for 10 minutes at -20 °C by addition of 30 uL per well lx lysis buffer. Cells were thawed for 20 minutes at 37°C before 90 uL luciferase assay reagent was added per well. Light emission was quantified immediately with a TECAN SPARK 10M Plate reader using 500 ms integration time, without any filter to collect all wavelengths. Emitted relative light units (RLU) were corrected by basal luminescence of HeLa_huOX40_NFkB_Lucl cells and were plotted against the logarithmic primary antibody concentration using Prism6 (GraphPad Software, USA). Curves were fitted to the data using the inbuilt sigmoidal dose response. For a better comparison of all formats the area under the curve (AUC) of the respective dose-response curves was quantified as a marker for the agonistic capacity of each construct (Figure 10D). As shown in Figure 10, all of the anti-OX40 antigen binding molecules induced limited

NFkB activation (Figure 10A). Crosslinking by anti-human Fc specific secondary antibody strongly enhanced bioactivity independently of the targeting moiety (Figure 10B). Human EpCAM-expressing tumor cells increased induction of NFKB-mediated luciferase-activation only when the bispecific, tetravalent anti-human OX40, bivalent anti-human EpCAM 4+2 molecules were used, and not when the bispecific, tetravalent anti-human OX40, monovalent anti-human EpCAM 4+1 molecules were used (see Figures IOC and 10D); this is consistent with the finding that the bispecific, tetravalent anti-human OX40, monovalent anti-human EpCAM 4+1 molecules do not display binding to human EpCAM-expressing cells (see Figure 9A). The results indicate that hypercrosslinking by EpCAM and high valency for OX40 are important determinants for OX40 agonist activity.

6.2 OX40 mediated costimulation of suboptimally TCR triggered resting human PBMCs and hypercrosslinking by cell surface human EpCAM

As shown in Example 6.1 and Figure 10, addition of huEpCAM+ tumor cells can strongly increase the NFKB activation in human OX40 positive reporter cell lines by huEpCAM-targeted tetravalent anti-OX40 antigen binding molecules, by providing for strong oligomerization of OX40 receptors. The EpCAM-targeted tetravalent anti-OX40 antigen binding molecules were analysed for their ability to rescue suboptimal TCR stimulation of resting human PBMCs, in the presence of human EpCAM-expressing KATO-III or NIH/3T3huEpCAM clone 44 cells.

Human PBMC preparations contain (1) resting, OX40-negative CD4 ⁺ and CD8 ⁺ T cells and (2) antigen presenting cells with various Fc-receptor molecules on their cell surface e.g. B cells and monocytes. Anti- human CD3 antibody of human IgGl isotype binds through its Fc to the Fc-γ receptor molecules and trigger a prolonged TCR activation on resting OX40-negative CD4 and CD8 T cells. These cells then start to express OX40 within several hours. Functional agonistic compounds against OX40 can signal via the OX40 receptor present on activated CD8+ and CD4 ⁺ T cells and support TCR-mediated stimulation.

Resting CFSE-labelled human PBMCs were stimulated for five days with a suboptimal concentration of anti-CD3 antibody in the presence of irradiated KATO-III or

NIH/3T3huEpCAM cl44 cells and titrated anti-OX40 antigen binding molecules. The effects on T-cell survival and proliferation were analysed by monitoring total cell counts and CFSE dilution in living cells by flow cytometry. Additionally, cells were co-stained with fluorescently-labeled antibodies against T-cell activation marker CD25. KATO-III and NIH/3T3huEpCAM cl44 cells were harvested using cell dissociation buffer

(Invitrogen, Cat.-No. 13151-014) for 10 minutes at 37°C. Cells were washed once with DPBS. KATO-III and NIH/3T3huEpCAM cl44 cells were irradiated in an xRay irradiator using a dose of 4,500 RAD, to prevent later overgrowth of human PBMCs by the tumor cell line. Irradiated cells were cultured at a density of 0.2* 10 ⁵ cells per well in T cell media, in sterile 96-well round- bottomed adhesion tissue culture plates (TPP, Cat. No. 92097) overnight at 37 °C and 5% C0 ₂ in an incubator (SteriCycleil60).

Human PBMCs were isolated by ficoll density centrifugation and were labeled with CFSE as follows. Freshly isolated PBMCs were washed with pre-warmed (37 °C) DPBS and adjusted to a cell density of 2 x 10 ⁶ cells/mL in DPBS. Cell Trace CFSE proliferation dye (ThermoFisher, Cat.-No. C34554) was added to the suspension of resting human PBMCs at a final concentration of 0.2 μΜ, and a final cell density of 1 x 10 ⁶ cells/mL in DPBS. Cells were then incubated for 10 min at 37 °C and 5% C0 ₂ in the dark. To stop labeling reaction 20 mL heat inactivated FBS were added and cells were washed three times with T cell medium. The cells were then added to each well at a density of 0.6* 10 ⁵ cells per well. Anti-human CD3 antibody (clone V9, human IgGl) at a final concentration of 10 nM, and the indicated anti-OX40 antigen binding molecules were added at the indicated concentrations. Cells were activated for five days at 37°C and 5% C0 ₂ in an incubator (SteriCycleil60). For discrimination between live and dead cells, samples were stained with Zombie Aqua Viability Dye (Biolegend, Cat. No 423102) in PBS for 10 minutes at room temperature. Cells were then washed once with FACS buffer and subsequently surface-stained with fluorescent dye-conjugated antibodies anti-human CD4 (clone RPA-T4, BioLegend, Cat.-No. 300532), anti-CD8 (clone RPA-T8, BioLegend, Cat.-No. 3010441) and anti-CD25 for 20 min at 4°C. Cells were subsequently washed once with FACS buffer, re- suspended in 85 μΕ/well FACS-buffer, and acquired the same day using 4-laser LSR-II cytometer (BD Bioscience with DIVA software).

The results of the experiments are shown in Figures 11 to 14.

Hyper-crosslinking by KATO-III cells of the bispecific, tetravalent anti-human OX40, bivalent anti-human EpCAM (4+2) molecules strongly promoted proliferation and maturation of human CD4 ⁺ and CD8 ⁺ T cells (Figure 11; filled triangle), and induced an enhanced the activated (CD25 ⁺ ) phenotype (Figure 12; filled triangle). On the other hand, bispecific, tetravalent anti-human OX40, monovalent anti-human EpCAM (4+1) molecules showed similar activity to that of the monospecific, tetravalent anti-human OX40, non-targeted (4+1) control molecules (Figures 11 and 12; filled circles compared with open circles). This finding was consistent with the finding that the bispecific, tetravalent anti-human OX40, monovalent anti- human EpCAM 4+1 molecules do not display binding to human EpCAM-expressing cells (see Figure 9A).

Similar findings were obtained when the bispecific, tetravalent anti-human OX40, bivalent anti-human EpCAM (4+2) molecules were cross-linked using the NIH/3T3huEpCAM cl44 cells. The bispecific, tetravalent anti-human OX40, bivalent anti-human EpCAM (4+2) molecules strongly promoted proliferation and maturation of human CD4 ⁺ and CD8 ⁺ T cells (Figure 13; filled triangle) and induced an enhanced the activated (CD25 ) phenotype (Figure 14; filled triangle). In these experiments, the CD4 ⁺ and CD8 ⁺ T cells had proliferated more rapidly after five days, which made it more difficult to see robust additional effects due to the antigen binding molecules. The results suggest that for optimal OX40 agonism in T cells, not only sufficient oligomerization of the OX40 is required, but additionally, cell surface immobilization of OX40 oligomers is necessary.