COMBINATION THERAPIES USING TLR7/8 AGONIST

FIELD

The present disclosure relates to combination therapies useful for the treatment of cancers. Certain embodiments relate to a combination therapy which comprises a PD-1 axis binding antagonist, in combination with a Toll-like receptor 7/8 (TLR7/8) agonist or a pharmaceutically acceptable salt thereof, or a pharmaceutical composition comprising such compounds or salts. The disclosure also relates to associated methods of treatment, pharmaceutical combinations, and pharmaceutical uses. The methods and combinations are useful for any indication for which the therapeutic is itself useful in the detection, treatment and/or prevention of a disease, disorder, or other condition of a subject.

BACKGROUND

Bladder cancer accounts for approximately 6.6% of all cancer cases and 70-75% are Non-muscle invasive bladder cancer (NMIBC). There is an increasing need for alternative therapies targeting NMIBC.

Currently, balder cancer patients generally undergo transurethral resection of the bladder tumor (TURBT) and Intravesical (IVe) adjuvant chemotherapy (mitomycin) or immunotherapy with Bacillus Calmette-Guerin (BCG) to prevent recurrence. While BCG is well-entrenched, there is a need for options that delay progression to muscle invasive disease and prevent recurrence. In addition, a worldwide BCG shortage has increased the need for BCG alternatives.

There remains a need for new therapies for the treatment of cancers such as bladder cancers. Preferred combination therapies of the present invention show greater efficacy than treatment with either therapeutic agent alone.

SUMMARY

This disclosure relates to therapeutic methods, combinations, and combinations for use in the treatment of cancer. Also provided are combination therapies comprising the compounds of the disclosure, in combination with other therapeutic agents or therapies. The present disclosure also provides kits comprising one or more of the combinations of the disclosure. In one embodiment, the disclosure provides a method for treating cancer comprising administering to a subject in need thereof a therapeutically effective amount of a Programmed Death 1 protein (PD-1 ) axis binding antagonist, in combination with a compound of Formula I: or a pharmaceutically acceptable salt thereof, wherein

R ¹ and R ² are independently Ci 3 alkyl; or

R ¹ and R ² are joined to form a 5- to 7-membered carbocyclic ring, wherein said carbocyclic ring may be saturated or unsaturated;

R ³ is

R ⁴ is C1-6 alkyl, or (CH2)nO(CH2)mCH3, wherein said C1 -6 alkyl or any carbon of the (CH2)nO(CH2)mCH3 group is substituted with 0 to 3 F as valency allows;

R ⁵ is 0-3 alkyl, or OC1 -3 alkyl, wherein the C1-3 alkyl is substituted by 0 to 3 F;

R ⁶ is H, or C1-3 alkyl, wherein the C1-3 alkyl is substituted with 0 to 3 F; m is 0 to 2; and n is 1 to 3.

In some embodiments of the methods as described herein, the compound is of Formula I, wherein:

R ¹ and R ² are independently Ci 2 alkyl; or

R ¹ and R ² are joined to form a 5- to 7-membered carbocyclic ring, wherein said carbocyclic ring may be saturated or unsaturated;

R ⁴ is C3-5 alkyl, or (CH2)nO(CH2)mCH ₃ ;

R ⁵ is C1-2 alkyl;

R6 is H; m is 1 ; and n is 1 .

In some embodiments of the methods as described herein, the compound of Formula I is selected from:

2-((4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1 -yl)methyl)- 2-methylpropane-1 ,3-diol,

2-((4-amino-2-(ethoxymethyl)-1 /7-imidazo[4,5-c]qu inolin- 1-yl)methyl)-2- methylpropane-1 ,3-diol,

2-((4-amino-2-(ethoxymethyl)-7,8-dihydrocyclopenta[b]imid azo[4,5-d]pyridin-

1 (6H)-yl)methyl)-2-methylpropane-1 ,3-diol,

2-((4-amino-2-(ethoxymethyl)-6,7,8,9-tetrahydro-1 H-imidazo[4,5-c]quinolin-1 - yl)methyl)-2-methylpropane-1 ,3-diol,

3-(4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1 -yl)-2-

(methoxymethyl)-2-methylpropan-1 -ol,

(R)-3-(4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin- 1 -y l)-2- (methoxymethyl)-2-methylpropan-1 -ol,

(S)-3-(4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1 -yl)-2- (methoxymethyl)-2-methylpropan-1 -ol,

2-((4-amino-6,7-dimethyl-2-(2,2,2-trifluoroethyl)-1 H-imidazo[4,5-c]pyridin- 1 - yl)methyl)-2-methylpropane-1 ,3-diol,

2-((4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1 -yl)methyl)- 2-ethylpropane-1 ,3-diol,

2-((4-amino-2-butyl-1 H-imidazo[4,5-c]quinolin-1-yl)methyl)-2-methylpropane-1 ,3- diol,

2-((4-amino-2-butyl-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1-yl)methyl)-2- methylpropane-1 ,3-diol, and

2-((4-amino-2-pentyl-1 H-imidazo[4, 5-c]quinolin-1 -yl)methyl)-2-methylpropane-

1 ,3-diol; or a pharmaceutically acceptable salt thereof.

In one preferred embodiment of the methods as described herein, the compound of Formula I is preferably 2-((4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5- c]pyridin-1-yl)methyl)-2-methylpropane-1 ,3-diol, or a pharmaceutically acceptable salt thereof. The preferred compound is also known as PF- 07225570 and has the following structure A:

A

In some embodiments of the methods as described herein, the PD-1 axis binding antagonist comprises a PD-1 binding antagonist, or a PD-L1 binding antagonist.

In some embodiments, the PD-1 binding antagonist is an anti-PD-1 antibody. In a more specific embodiment, the anti-PD-1 antibody is sasanlimab, nivolumab, pembrolizumab, pidilizumab, cemiplimab, tislelizumab, spartalizumab, sintilimab, MEDI- 0680, BGB-108, AGEN2034, genolimzumab, CBT-502, camrelizumab, or any combination thereof.

In one preferred embodiment of the methods as described herein, the preferred anti-PD-1 antibody is sasanlimab.

In some embodiments, the PD-L1 binding antagonist is an anti-PD-L1 antibody. In a more specific embodiment, the anti-PD-L1 antibody is BMS-936559, KN035, atezolizumab, durvalumab, avelumab, or any combination thereof.

In one preferred embodiment of the methods as described herein, the cancer being treated is bladder cancer. In one more preferred embodiment, the cancer being treated is non-muscle invasive bladder cancer. In one even more preferred aspect, the non-muscle invasive bladder cancer is Bacillus Calmette-Guerin (BCG) un-responsive non-muscle invasive bladder cancer.

In some embodiments, the PD-1 axis binding antagonist is administered by intravenous infusion or subcutaneous delivery, and the compound of Formula I, or a pharmaceutically acceptable salt thereof, is administered by intravesical delivery to bladder epithelium of the subject.

In one embodiment of the methods as described herein, wherein a therapeutically effective amount of BCG immunotherapy may be further administered. BCG immunotherapy in this disclosure refers to a weakened, live bacterium, bacillus Calmette-Guerin (BCG), which is FDA-approved immunotherapy and helps reduce the risk of bladder cancer recurrence by stimulating an immune response that targets the bacteria as well as any nearby bladder cancer cells.

In one embodiment of the methods as described herein, the compound 2-((4- amino-2-(ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1 -yl)methyl)-2- methylpropane-1 ,3-diol, or a pharmaceutically acceptable salt thereof, is administered with an interval of at least about 7 days (7± 2 days).

In one aspect, the disclosure provides a combination therapy comprising a PD-1 axis binding antagonist and a TLR7/8 agonist, as provided in this disclosure, for use in the treatment of cancer in a subject in need thereof.

In one aspect, the disclosure provides a combination of a PD-1 axis binding antagonist and a TLR7/8 agonist, for use in the treatment of cancer in a subject. Such combination can be used, for example, in the methods of the present disclosure.

In one aspect, the disclosure provides a medicament comprising a TLR7/8 agonist for use, in combination with a PD-1 axis binding antagonist, for treating a cancer.

In one aspect, the disclosure provides a medicament comprising a PD-1 axis binding antagonist for use, in combination with a TLR7/8 agonist in the treatment of a cancer.

In one aspect, the disclosure provides the use of a combination comprising a PD-1 axis binding antagonist and a TLR7/8 agonist for the treatment of cancer in a subject in need thereof.

In one aspect, the disclosure provides a kit that comprises a PD-1 axis binding antagonist, a TLR7/8 agonist, and a package insert, and the package insert comprises instructions for treating a subject for cancer using the medicaments. Such kit can be used, for example, in the methods of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows tumor growth inhibition in MB49 subcutaneous tumor model with various combinatorial strategies of PF-07225570 and Anti-PD-1 compared to Vehicle + Isotype control. Data and p-values for FIG. 1 are presented in Table 1. Number of animals per group = 10. The statistical significance of differences between experimental groups was assessed by ANCOVA using Pfizer-internal TGI analyzer software. **, p<0.01 ; *“*, p<0.0001 Data is depicted as mean ± SEM. FIG. 2 shows tumor growth inhibition in MB49 subcutaneous tumor model with various combinatorial strategies of PF-07225570 and Anti-PD-1 compared to Single Agent Anti-PD-1 or Single Agent PF-07225570. Data and p-values for FIG. 2 are presented in Table 2 and Table 3. Number of animals per group = 10. The statistical significance of differences between experimental groups was assessed by ANCOVA using Pfizer-internal TGI analyzer software. # p=0.0592; *, p<0.05. Data is depicted as mean ± SEM.

FIG. 3 shows survival in MB49 subcutaneous tumor model with various combinatorial strategies of PF-07225570 and Anti-PD-1. Data and p-values for FIG. 3 are presented in Table 5. Number of animals per group = 10. Statistical significance in survival determined using Logrank Mantel-cox test compared to Vehicle + Isotype using GraphPad Prism. *,p<0.05, **, p<0.01 ; ****, p<0.0001.

DETAILED DESCRIPTION

Each of the embodiments described below can be combined with any other embodiment described herein not inconsistent with the embodiment with which it is combined.

I. Definitions

As used herein, the singular form "a," "an," and "the" include plural references unless indicated otherwise. For example, "a" substituent includes one or more substituents. Where the plural form is used for compounds, salts, and the like, this is taken to mean also a single compound, salt, or the like.

The term “about” when used to modify a numerically defined parameter means that the parameter may vary by as much as 10% above or below the stated numerical value for that parameter.

The term "alkyl" refers to a saturated, monovalent aliphatic hydrocarbon radical including straight chain and branched chain groups having the specified number of carbon atoms. The alkyl substituents disclosed herein may be specified as 1 to 6 carbon atoms (“Ci -6 alkyl”), or 1 to 3 carbon atoms (“Ci -3 alkyl”), and so forth. Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, iso-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, n-heptyl, n-octyl and the like.

The term “alkoxy” refers to a monovalent -O-alkyl group, wherein the alkyl portion has the specified number of carbon atoms. Alkoxy groups typically contain 1 to 8 carbon atoms (“Ci -8 alkoxy”), or 1 to 6 carbon atoms (“Ci -6 alkoxy”), or 1 to 4 carbon atoms (“Ci -4 alkoxy”). For example, C1-4 alkoxy includes methoxy, ethoxy, isopropoxy, tert-butyloxy (i.e., -OCH3, -OCH2CH3, -OCH(CH3)2, -OC(CH3)3), and the like.

As used herein, terms, including, but not limited to, “drug,” “agent,” “component,” “composition," “compound," “substance," “targeted agent," “targeted therapeutic agent," “therapeutic agent,” and “medicament” may be used interchangeably to refer to the small molecule compounds of the present disclosure, e.g., a TLR7/8 agonist, an anti- PD-L1 antibody, an anti-PD-1 antibody, or combinations thereof.

As used herein, terms “therapeutic antibody” and “antibody” may be used interchangeable to refer to an antibody that is used in the treatment of a disease or a disorder. A therapeutic antibody may have various mechanisms of action. A therapeutic antibody may bind and neutralize the normal function of a target associated with an antigen. For example, a monoclonal antibody that blocks the activity of the protein needed for the survival of a cancer cell causes the cell's death. Another therapeutic antibody may bind and activate the normal function of a target associated with an antigen. For example, a monoclonal antibody can bind to a protein on a cell and trigger an apoptosis signal. Yet another monoclonal antibody may bind to a target antigen expressed only on diseased tissue; conjugation of a toxic payload (effective agent), such as a chemotherapeutic or radioactive agent, to the monoclonal antibody can create an agent for specific delivery of the toxic payload to the diseased tissue, reducing harm to healthy tissue. A “biologically functional fragment” of a therapeutic antibody will exhibit at least one if not some or all of the biological functions attributed to the intact antibody, the function comprising at least specific binding to the target antigen.

The therapeutic antibody may bind to any protein, including, without limitation, a PD-L1 , a PD-1. Accordingly, therapeutic antibodies include, without limitation, anti-PD- L1 antibodies, anti-PD-1 antibodies, or combinations thereof.

The terms “synergy” or “synergistic” are used to mean that the result of the combination of two or more compounds, components or targeted agents is greater than the sum of each agent together. The terms “synergy” or “synergistic” also means that there is an improvement in the disease condition or disorder being treated, over the use of the two or more compounds, components or targeted agents while each compound, component or targeted agent individually. This improvement in the disease condition or disorder being treated is a “synergistic effect”. A “synergistic amount” is an amount of the combination of the two compounds, components or targeted agents that results in a synergistic effect, as “synergistic” is defined herein. Determining a synergistic interaction between one or two components, the optimum range for the effect and absolute dose ranges of each component for the effect may be definitively measured by administration of the components over different w/w (weight per weight) ratio ranges and doses to patients in need of treatment. However, the observation of synergy in in vitro models or in vivo models can be predictive of the effect in humans and other species and in vitro models or in v/vomodels exist, as described herein, to measure a synergistic effect and the results of such studies can also be used to predict effective dose and plasma concentration ratio ranges and the absolute doses and plasma concentrations required in humans and other species by the application of pharmacokinetic/pharmacodynamic methods.

A "chemotherapeutic agent" is a chemical compound useful in the treatment of cancer.

The term "immunotherapy" refers to the treatment of a subject by a method comprising inducing, enhancing, suppressing, or otherwise modifying an immune response.

The terms “abnormal cell growth” as used herein, unless otherwise indicated, refers to cell growth that is independent of normal regulatory mechanisms (e.g., loss of contact inhibition). Abnormal cell growth may be benign (not cancerous), or malignant (cancerous).

A “disorder” is any condition that would benefit from treatment with the compounds of the present invention. This includes chronic and acute disorders or diseases including those pathological conditions which predispose the subject to the disorder in question.

The term “antibody,” as used herein, refers to an immunoglobulin molecule capable of specific binding to a target, such as a carbohydrate, polynucleotide, lipid, polypeptide, etc., through at least one antigen recognition site, located in the variable region of the immunoglobulin molecule. As used herein, the term encompasses a polyclonal antibody, a monoclonal antibody, a chimeric antibody, a bispecific antibody, a dual-specific antibody, bifunctional antibody, a trispecific antibody, a multispecific antibody, a bispecific heterodimeric diabody, a bispecific heterodimeric IgG, a labeled antibody, a humanized antibody, a human antibody, and fragments thereof (such as Fab, Fab’, F(ab’)2, Fv), single chain (ScFv) and domain antibodies (including, for example, shark and camelid antibodies), fusion proteins comprising an antibody, any other modified configuration of the immunoglobulin molecule that comprises an antigen recognition site, and antibody like binding peptidomimetics (ABiPs). An antibody includes an antibody of any class, such as IgG, IgA, or IgM (or sub-class thereof), and the antibody need not be of any particular class. Depending on the antibody amino acid sequence of the constant region of its heavy chains, immunoglobulins can be assigned to different classes. There are five major classes of immunoglobulins: IgA, IgD, IgE, IgG, and IgM, and several of these may be further divided into subclasses (isotypes), e.g., IgG - 1 , lgG-2, lgG-3, IgG -4, Ig A1 and lgA2. The heavy-chain constant regions that correspond to the different classes of immunoglobulins are called alpha, delta, epsilon, gamma, and mu, respectively. The subunit structures and three-dimensional configurations of different classes of immunoglobulins are well known.

The term "immunoglobulin" (Ig) is used interchangeably with "antibody" herein. The basic 4-chain antibody unit is a heterotetrameric glycoprotein composed of two identical light (L) chains and two identical heavy (H) chains. An IgM antibody consists of 5 of the basic heterotetramer units along with an additional polypeptide called a J chain, and contains 10 antigen binding sites, while IgA antibodies comprise from 2-5 of the basic 4-chain units which can polymerize to form polyvalent assemblages in combination with the J chain. In the case of IgGs, the 4-chain unit is generally about 150,000 Daltons. Each L chain is linked to an H chain by one covalent disulfide bond, while the two H chains are linked to each other by one or more disulfide bonds depending on the H chain isotype. Each H and L chain also has regularly spaced intrachain disulfide bridges. Each H chain has at the N-terminus, a variable domain (VH) followed by three constant domains (CH) for each of the a and y chains and four CH domains for p and £ isotypes. Each L chain has at the N-terminus, a variable domain (VL) followed by a constant domain at its other end. The VL is aligned with the VH and the CL is aligned with the first constant domain of the heavy chain (CHI). Particular amino acid residues are believed to form an interface between the light chain and heavy chain variable domains. The pairing of a VH and VL together forms a single antigen-binding site. For the structure and properties of the different classes of antibodies, e.g., Daniel P. Sties, Abba I. Terr and Tristram G. Parsolw (eds), Basic and Clinical Immunology, 8th Edition, 1994, page 71 and Chapter 6. The L chain from any vertebrate species can be assigned to one of two clearly distinct types, called kappa and lambda, based on the amino acid sequences of their constant domains. Depending on the amino acid sequence of the constant domain of their heavy chains (CH), immunoglobulins can be assigned to different classes or isotypes.

"Monoclonal antibody" or “mAb” or “Mab,” as used herein, refers to a population of substantially homogeneous antibodies, i.e., the antibody molecules comprising the population are identical in amino acid sequence except for possible naturally occurring mutations that may be present in minor amounts. In contrast, conventional (polyclonal) antibody preparations typically include a multitude of different antibodies having different amino acid sequences in their variable domains, particularly their CDRs, which are often specific for different epitopes. The modifier "monoclonal" indicates the character of the antibody as being obtained from a substantially homogeneous population of antibodies and is not to be construed as requiring production of the antibody by any particular method. For example, the monoclonal antibodies to be used in accordance with the present invention may be made by the hybridoma method first described by Kohler et al., Continuous cultures of fused cells secreting antibody of predefined specificity, Nature 1975, 256: 495; or may be made by recombinant DNA methods (e.g., U.S. Patent No. 4,816,567). The "monoclonal antibodies" may also be isolated from phage antibody libraries using the techniques described in Clackson et al., Making antibody fragments using phage display libraries, Nature 1991 , 352: 624-628 and Marks et al., By-passing immunization: human antibodies from V-gene libraries displayed on phage, J. Mol. Biol. 1991 , 222: 581-597, for example. See also Presta, Selection, design, and engineering of therapeutic antibodies, J. Allergy Clin. Immunol. 2005,116:731.

"Chimeric antibody" refers to an antibody in which a portion of the heavy and/or light chain is identical with or homologous to corresponding sequences in an antibody derived from a particular species (e.g., human) or belonging to a particular antibody class or subclass, while the remainder of the chain(s) is identical with or homologous to corresponding sequences in an antibody derived from another species (e.g., mouse) or belonging to another antibody class or subclass, as well as fragments of such antibodies, so long as they exhibit the desired biological activity.

“Human antibody” refers to an antibody that comprises human immunoglobulin protein sequences only. A human antibody may contain murine carbohydrate chains if produced in a mouse, in a mouse cell, or in a hybridoma derived from a mouse cell. Similarly, “mouse antibody” or “rat antibody” refer to an antibody that comprises only mouse or rat immunoglobulin sequences, respectively.

"Humanized antibody" refers to forms of antibodies that contain sequences from non-human (e.g., murine) antibodies as well as human antibodies. Such antibodies contain minimal sequence derived from non-human immunoglobulin. In general, the humanized antibody will comprise substantially all of at least one, and typically two, variable domains, in which all or substantially all of the hypervariable loops correspond to those of a non-human immunoglobulin and all or substantially all of the FR regions are those of a human immunoglobulin sequence. The humanized antibody optionally also will comprise at least a portion of an immunoglobulin constant region (Fc), typically that of a human immunoglobulin. The prefix “hum,” “hu” or “h” is added to antibody clone designations when necessary to distinguish humanized antibodies from parental rodent antibodies. The humanized forms of rodent antibodies will generally comprise the same CDR sequences of the parental rodent antibodies, although certain amino acid substitutions may be included to increase affinity, increase stability of the humanized antibody, or for other reasons.

The phrase "substantially reduced," "substantially different," or “substantially inhibit,” as used herein, denotes a sufficiently high degree of difference between two numeric values (generally one associated with a molecule and the other associated with a reference/comparator molecule) such that one of skill in the art would consider the difference between the two values to be of statistical significance within the context of the biological characteristic measured by said values (e.g., Kd values). The difference between said two values is, for example, greater than about 10%, greater than about 20%, greater than about 30%, greater than about 40%, and/or greater than about 50% as a function of the value for the reference/comparator molecule.

As use herein, the term "specifically binds to" or is "specific for" refers to measurable and reproducible interactions such as binding between a target and an antibody, which is determinative of the presence of the target in the presence of a heterogeneous population of molecules including biological molecules. For example, an antibody that specifically binds to a target (which can be an epitope) is an antibody that binds this target with greater affinity, avidity, more readily, and/or with greater duration than it binds to other targets. In one embodiment, the extent of binding of an antibody to an unrelated target is less than about 10 percent of the binding of the antibody to the target as measured, e.g., by a radioimmunoassay (RIA). In certain embodiments, an antibody that specifically binds to a target has a dissociation constant (Kd) of < 1 pM, < 100 nM, < 10 nM, < 1 nM, or < 0.1 nM. In certain embodiments, an antibody specifically binds to an epitope on a protein that is conserved among the protein from different species. In another embodiment, specific binding can include, but does not require exclusive binding.

As used herein, the term "immunoadhesin" designates antibody-like molecules which combine the binding specificity of a heterologous protein (an "adhesin") with the effector functions of immunoglobulin constant domains. Structurally, the immunoadhesins comprise a fusion of an amino acid sequence with the desired binding specificity which is other than the antigen recognition and binding site of an antibody (/.e., is "heterologous"), and an immunoglobulin constant domain sequence. The adhesin part of an immunoadhesin molecule typically is a contiguous amino acid sequence comprising at least the binding site of a receptor or a ligand. The immunoglobulin constant domain sequence in the immunoadhesin may be obtained from any immunoglobulin, such as lgG-1 , lgG-2 (including lgG2A and lgG2B), lgG-3, or lgG-4 subtypes, IgA (including IgA-1 and IgA-2), IgE, IgD or IgM. The Ig fusions preferably include the substitution of a domain of a polypeptide or antibody described herein in the place of at least one variable region within an Ig molecule. In a particularly preferred embodiment, the immunoglobulin fusion includes the hinge, CH2 and CH3, or the hinge, CHI, CH2 and CH3 regions of an lgG-1 molecule. For the production of immunoglobulin fusions, see also US Patent No. 5,428,130 issued June 27, 1995. Immunoadhesin combinations of Ig Fc and ECD of cell surface receptors are sometimes termed soluble receptors.

A "fusion protein" and a "fusion polypeptide" refer to a polypeptide having two portions covalently linked together, where each of the portions is a polypeptide having a different property. The property may be a biological property, such as activity in vitro or in vivo. The property may also be simple chemical or physical property, such as binding to a target molecule, catalysis of a reaction, etc. The two portions may be linked directly by a single peptide bond or through a peptide linker but are in reading frame with each other.

An "antagonist” antibody or a "blocking" antibody is one that inhibits or reduces a biological activity of the antigen it binds. In some embodiments, blocking antibodies or antagonist antibodies substantially or completely inhibit the biological activity of the antigen. The anti-PD-L1 antibodies of the invention block the signaling through PD-1 so as to restore a functional response by T-cells (e.g., proliferation, cytokine production, target cell killing) from a dysfunctional state to antigen stimulation.

An "agonist antibody" or “activating antibody” is one that enhances or initiates signaling by the antigen to which it binds. In some embodiments, agonist antibodies cause or activate signaling without the presence of the natural ligand.

An small molecule “agonist” such as a TLR7/8 agonist of the present disclosure is a small molecule chemical that binds to a receptor and activates the receptor to produce a biological response. The term "dysfunction" in the context of immune dysfunction, refers to a state of reduced immune responsiveness to antigenic stimulation. The term includes the common elements of both exhaustion and/or anergy in which antigen recognition may occur, but the ensuing immune response is ineffective to control infection or tumor growth.

The term "dysfunctional", as used herein, also includes refractory or unresponsive to antigen recognition, specifically, impaired capacity to translate antigen recognition into down-stream T-cell effector functions, such as proliferation, cytokine production and/or target cell killing.

The term "anergy" refers to the state of unresponsiveness to antigen stimulation resulting from incomplete or insufficient signals delivered through the T-cell receptor (e.g., increase in intracellular Ca+2 in the absence of ras- activation). T cell anergy can also result upon stimulation with antigen in the absence of co- stimulation, resulting in the cell becoming refractory to subsequent activation by the antigen even in the context of co stimulation. The unresponsive state can often be overridden by the presence of lnterleukin-2. Anergic T-cells do not undergo clonal expansion and/or acquire effector functions.

The term "exhaustion" refers to T cell exhaustion as a state of T cell dysfunction that arises from sustained TCR signaling that occurs during many chronic infections and cancer. It is distinguished from anergy in that it arises not through incomplete or deficient signaling, but from sustained signaling. It is defined by poor effector function, sustained expression of inhibitory receptors and a transcriptional state distinct from that of functional effector or memory T cells. Exhaustion prevents optimal control of infection and tumors. Exhaustion can result from both extrinsic negative regulatory pathways (e.g., immunoregulatory cytokines) as well as cell intrinsic negative regulatory (co stimulatory) pathways.

"Enhancing T-cell function" means to induce, cause or stimulate a T-cell to have a sustained or amplified biological function, or renew or reactivate exhausted or dysfunctional T-cells. Examples of enhancing T-cell function include: increased secretion of y-interferon from CD4+ or CD8+ T-cells, increased proliferation, increased survival, increased differentiation, increased antigen responsiveness (e.g., viral, pathogen, or tumor clearance) relative to such levels before the intervention. In some embodiments, the level of enhancement is as least 50%, alternatively 60%, 70%, 80%, 90%, 100%, 120%, 150%, 200%. The manner of measuring this enhancement is known to one of ordinary skill in the art. As used herein, "metastasis" or “metastatic” is meant the spread of cancer from its primary site to other places in the body. Cancer cells can break away from a primary tumor, penetrate into lymphatic and blood vessels, circulate through the bloodstream, and grow in a distant focus (metastasize) in normal tissues elsewhere in the body. Metastasis can be local or distant. Metastasis is a sequential process, contingent on tumor cells breaking off from the primary tumor, traveling through the bloodstream, and stopping at a distant site. At the new site, the cells establish a blood supply and can grow to form a life-threatening mass. Both stimulatory and inhibitory molecular pathways within the tumor cell regulate this behavior, and interactions between the tumor cell and host cells in the distant site are also significant.

The term “cancer,” “cancerous,” or “malignant” refers to or describe the physiological condition in subjects that is typically characterized by unregulated cell growth. The term “cancer” includes but is not limited to a primary cancer that originates at a specific site in the body, a metastatic cancer that has spread from the place in which it started to other parts of the body, a recurrence from the original primary cancer after remission, and a second primary cancer that is a new primary cancer in a person with a history of previous cancer of a different type from the latter one.

The term “subject” or “a subject in need thereof” refers to a human or non-human subject including veterinary subjects such as, cows, sheep, cats, dogs, horses, primates, rabbits, and rodents (e.g., mice and rats) for which therapy is desired. In one preferred embodiment, the subject is a human and may be referred to as a patient or individual, e.g., a human suffering from, at risk of suffering from, or potentially capable of suffering from cancer. Those skilled in the medical art are readily able to identify individual patients who are afflicted with cancer.

The term “treat” or “treating” a cancer, as used herein means to administer a combination therapy according to the present disclosure to a subject having cancer, or diagnosed with cancer, to achieve at least one positive therapeutic effect, such as, for example, reduced number of cancer cells, reduced tumor size, reduced rate of cancer cell infiltration into peripheral tissues, or reduced rate of tumor metastases or tumor growth, reversing, stopping, controlling, slowing, interrupting, arresting, alleviating, and/or inhibiting the progression or severity of a sign, symptom, disorder, condition, or disease, but does not necessarily involve a total elimination of all disease-related signs, symptoms, conditions, or disorders. Within the meaning of the present disclosure, the term “treat” or “treating” also denotes, to arrest, delay the onset (i.e., the period prior to clinical manifestation of a disease or symptom of a disease) and/or reduce the risk of developing or worsening a symptom of a disease.

As used herein, “in combination with,” “combined administration,” or “coadministration” refers to the administration of one agent and in addition to at least one other agent, wherein said agents are part of the same or separate dosage formsand are administered via the same or different routes of administration and on the same or different administration schedule. In some embodiments, the co-administration of two or more agents can be useful for treating individuals suffering from cancer who have primary or acquired resistance to ongoing therapies. The combination therapy provided herein may be useful for improving the efficacy and/or reducing the side effects of cancer therapies for individuals who do respond to such therapies.

As used herein, the term “simultaneously,” "simultaneous administration,” "administered simultaneously,” “concurrently,” or "concurrent administration,” means that the agents are administered at the same point in time or immediately following one another, but that the agents can be administered in any order. For example, in the latter case, the two or more agents are administered at times sufficiently close that the results observed are indistinguishable from those achieved when the agents are administered at the same point in time. The term simultaneous includes the administration of each agent of the combination therapy of the disclosure in the same medicament.

The agents of the present disclosure can be administered completely separately or in the form of one or more separate compositions. For example, the agents may be given separately at different times during the course of therapy (in a chronologically staggered manner, especially a sequence-specific manner) in such time intervals that the combination therapy is effective in treating cancer.

As used herein, the term “sequential,” “sequentially,” “administered sequentially,” or “sequential administration” refers to the administration of each agent of the combination therapy of the invention, either alone or in a medicament, one after the other, wherein each agent can be administered in any order. Sequential administration may be particularly useful when the therapeutic agents in the combination therapy are in different dosage forms, for example, one agent is a tablet and another agent is a sterile liquid, and/or the agents are administered according to different dosing schedules, for example, one agent is administered daily, and the second agent is administered less frequently such as weekly. The term “advanced,” as used herein, as it relates to breast cancer, includes locally advanced (non-metastatic) disease and metastatic disease.

The term “pharmaceutical composition” refers to a preparation which is in such form as to permit the biological activity of the active ingredient to be effective, and which contains no additional components which are unacceptably toxic to a subject to which the formulation would be administered. Such formulations are sterile. “Pharmaceutically acceptable” carriers or excipients are those which can reasonably be administered to a subject to provide an effective dose of the active ingredient employed.

The combinations provided herein may be formulated by a variety of methods apparent to those of skill in the art of pharmaceutical formulation. The various release properties described above may be achieved in a variety of different ways. Suitable formulations include, for example, tablets, capsules, press coat formulations, and other easily administered formulations.

A "package insert" refers to instructions customarily included in commercial packages of medicaments that contain information about the indications customarily included in commercial packages of medicaments that contain information about the indications, usage, dosage, administration, contraindications, other medicaments to be combined with the packaged product, and/or warnings concerning the use of such medicaments, etc.

In reference to the treatment of cancer, a therapeutically effective amount refers to that amount of a drug, agent, component, composition, compound, substance, targeted agent, targeted therapeutic agent, therapeutic antibody, therapeutic agent, medicament or pharmaceutical composition which is effective to achieve one or more of the following results following the administration of one or more therapies: (1) reducing the size of the tumor, (2) reducing the number of cancer cells, (3) inhibiting (/.e., slowing to some extent, preferably stopping) cancer cell infiltration into peripheral organs, (4) inhibiting (/.e., slowing to some extent, preferably stopping) tumor metastasis, (5) inhibiting (i.e., slowing to some extent, preferably stopping) tumor growth or tumor invasiveness, (6) relieving (i.e., to some extent, preferably eliminating) one or more signs or symptoms associated with the cancer, (7) decreasing the dose of other medications required to treat the disease, (8) enhancing the effect of another medication, (9) delaying the progression of the disease, (10) improving or increasing the disease-free, relapse-free, progression-free, and/or overall survival, duration, or rate, (11) increasing the response rate, the durability of response, or number of patients who respond or are in remission, (12) decreasing the hospitalization rate, (13) decreasing the hospitalization lengths, (14) the size of the tumor is maintained and does not increase or increases by less than 10%, preferably less than 5%, preferably less than 4%, preferably less than 2%; (15) an increase in the number of patients in remission, (16) increasing the length or duration of remission, (17) decreasing the recurrence rate of cancer; (18) decreasing the time to recurrence of cancer, and (19) an amelioration of cancer related symptoms and/or quality of life.

An effective amount can be administered in one or more administrations. For purposes of this disclosure, an effective amount of drug, compound, and/or pharmaceutical composition is an amount sufficient to accomplish prophylactic or therapeutic treatment either directly or indirectly.

As is understood in the clinical context, an effective amount of a drug, compound, or pharmaceutical composition may or may not be achieved in conjunction with another drug, compound, or pharmaceutical composition. Thus, an “effective amount” may be considered in the context of administering one or more therapeutic agents, and a single agent may be considered to be given in an effective amount if, in conjunction with one or more other agents, a desirable result may be or is achieved.

A therapeutic amount may also refer to a dosage of a drug that has been approved for use by a regulatory agency. A "subtherapeutic amount," as used herein, refers to a dosage of a drug that is significantly lower than the approved dosage, such as 10%, 20%, 30%, 40%, or 50% lower than the approved dosage.

The terms “treatment regimen,” “dosing protocol” and “dosing regimen” are used interchangeably to refer to the dose and timing of administration of each therapeutic agent in a combination of the invention.

“Tumor” as it applies to a subject diagnosed with, or suspected of having, a cancer refers to a malignant or potentially malignant neoplasm or tissue mass of any size and includes primary tumors and secondary neoplasms. A solid tumor is an abnormal growth or mass of tissue that usually does not contain cysts or liquid areas. Examples of solid tumors are sarcomas, carcinomas, and lymphomas.

Determining a synergistic interaction between two or more agents, the optimum range for the effect and absolute dose ranges of each agent for the effect may be definitively measured by administration of the agents over different dose ranges, and/or dose ratios to subjects in need of treatment. However, the observation of synergy in in vitro models or in vivo models can be predictive of the effect in humans and other species and in vitro models or in vivo models exist, as described herein, to measure a synergistic effect. The results of such studies can also be used to predict effective dose and plasma concentration ratio ranges and the absolute doses and plasma concentrations required in humans and other species such as by the application of pharmacokinetic and / or pharmacodynamics methods.

The term "pharmaceutically acceptable salt," as used herein, refers to pharmaceutically acceptable organic or inorganic salts of a compound of the invention. Some embodiments also relate to the pharmaceutically acceptable acid addition salts of the compounds described herein. Suitable acid addition salts are formed from acids which form non-toxic salts. Non-limiting examples of suitable acid addition salts, i.e., salts containing pharmacologically acceptable anions, include, but are not limited to, the acetate, acid citrate, adipate, aspartate, benzoate, besylate, bicarbonate/carbonate, bisulphate/sulphate, bitartrate, borate, camsylate, citrate, cyclamate, edisylate, esylate, ethanesulfonate, formate, fumarate, gluceptate, gluconate, glucuronate, hexafluorophosphate, hibenzate, hydrochloride/chloride, hydrobrom ide/brom ide, hydroiodide/iodide, isethionate, lactate, malate, maleate, malonate, methanesulfonate, methylsulphate, naphthylate, 2-napsylate, nicotinate, nitrate, orotate, oxalate, palmitate, pamoate, phosphate/hydrogen phosphate/dihydrogen phosphate, pyroglutamate, saccharate, stearate, succinate, tannate, tartrate, p-toluenesulfonate, trifluoroacetate and xinofoate salts.

For a review on suitable salts, see Handbook of Pharmaceutical Salts: Properties, Selection, and Use by Stahl and Wermuth (Wiley-VCH, 2002). Methods for making pharmaceutically acceptable salts of compounds described herein are known to one of skill in the art.

"Carriers," as used herein, include pharmaceutically acceptable carriers, excipients, or stabilizers that are nontoxic to the cell or subject being exposed thereto at the dosages and concentrations employed. Often the physiologically acceptable carrier is an aqueous pH buffered solution. Examples of physiologically acceptable carriers include buffers such as phosphate, citrate, and other organic acids; antioxidants including ascorbic acid; low molecular weight (less than about 10 residues) polypeptide; proteins, such as serum albumin, gelatin, or immunoglobulins; hydrophilic polymers such as polyvinylpyrrolidone; amino acids such as glycine, glutamine, asparagine, arginine or lysine; monosaccharides, disaccharides, and other carbohydrates including glucose, mannose, or dextrins; chelating agents such as EDTA; sugar alcohols such as mannitol or sorbitol; salt-forming counterions such as sodium; and/or nonionic surfactants such as TWEEN™, polyethylene glycol (PEG), and PLURONICS™. The compounds described herein may also exist in unsolvated and solvated forms. Accordingly, some embodiments relate to the hydrates and solvates of the compounds described herein. The term “solvate,” as used herein, describes a molecular complex comprising a compound described herein and one or more pharmaceutically acceptable solvent molecules, for example, water (hydrate) and ethanol.

Compounds described herein containing one or more asymmetric carbon atoms can exist as two or more stereoisomers. Where structural isomers are interconvertible via a low energy barrier, tautomeric isomerism (‘tautomerism’) can occur. This can take the form of proton tautomerism in compounds described herein containing, for example, an imino, keto, or oxime group, or so-called valence tautomerism in compounds which contain an aromatic moiety. A single compound may exhibit more than one type of isomerism.

The compounds of the embodiments described herein include all stereoisomers (e.g., cis and trans isomers) and all optical isomers of compounds described herein (e.g., R and S enantiomers), as well as racemic, diastereomeric and other mixtures of such isomers. While all stereoisomers are encompassed within the scope of our claims, one skilled in the art will recognize that particular stereoisomers may be preferred.

Exemplary methods and materials are described herein, although methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the invention. The materials, methods, and examples are illustrative only and not intended to be limiting.

II. TLR7/8 Agonists

Toll-like receptors (TLRs) are a family of transmembrane proteins that recognize structurally conserved molecules that are derived from and unique to pathogens, referred to as pathogen-associated molecular patterns (PAMPS). As such, TLRs function in the mammalian immune system as front-line sensors of pathogen- associated molecular patterns, detecting the presence of invading pathogens.

The human genome contains 10 known TLRs, of these TLRS, TLR7, TLR8, and TLR9 recognize nucleic acids and their degradation products. The distribution of TLR3, TLR7, TLR8, and TLR9 is restricted to the endosomal compartments of cells and they are preferentially expressed in cells of the immune system. In the activated dimeric receptor configuration TLR7 and TLR8 recognize single strand RNA at one ligand binding site and the ribonucleoside degradation products guanosine and uridine, respectively, (as well as small molecule ligands with related structural motifs) at a second ligand binding site.

Some small-molecule TLR7 or TLR8 agonists have been identified. Those agonists can be grouped into purine-like molecules, such as 7-thia-8-oxoguanosine (TOG, isatoribine) or the imidazoquinoline-based compounds such as imiquimod. Imiquimod is so far the only approved TLR7 agonist, marketed as a 5% cream (Aldara). It generates approximately 80% 5-year clearance of superficial basal cell carcinomas, which is the most common cancer worldwide, thus demonstrating the importance of TLR7 agonists in cancer immunotherapy.

A TLR7/TLR8 (TLR7/8) small molecule agonist with dual bioactivity could provide further benefit over a more selective TLR7 agonist and would cause innate immune responses in a wider range of antigen presenting cells and other key immune cell types, including plasmacytoid and myeloid dendritic cells, monocytes, and B cells. Such potent dual TLR7/8 agonists may also be effective in stimulating effective anti-tumor responses in cancer.

Methods of preparing the TLR7/8 agonists that are required for the combination therapy purposes of the present disclosure have been disclosed in PCT Publication No. WO 2021/009676 A1 , which is hereby incorporated for all purposes.

Embodiments of the present invention comprise a TLR7/8 agonist of Formula I: or a pharmaceutically acceptable salt thereof, wherein

R ¹ and R ² are independently Ci 3 alkyl; or

R ¹ and R ² are joined to form a 5- to 7-membered carbocyclic ring, wherein said carbocyclic ring may be saturated or unsaturated;

R ³ is

R ⁴ is Ci -6 alkyl, or (CH2)nO(CH2)mCH3, wherein said Ci -6 alkyl or any carbon of the (CH2)nO(CH2)mCH3 group is substituted with 0 to 3 F as valency allows;

R ⁵ is Ci-3 alkyl, or OC1 -3 alkyl, wherein the C1-3 alkyl is substituted by 0 to 3 F;

R ⁶ is H, or C1-3 alkyl, wherein the C1-3 alkyl is substituted with 0 to 3 F; m is 0 to 2; and n is 1 to 3.

In some preferred embodiments, the TLR7/8 agonist is of Formula I, wherein:

R ¹ and R ² are independently Ci 2 alkyl; or

R ¹ and R ² are joined to form a 5- to 7-membered carbocyclic ring, wherein said carbocyclic ring may be saturated or unsaturated;

R ⁴ is C3-5 alkyl, or (CH2)nO(CH2)mCH3;

R ⁵ is C1-2 alkyl;

R ⁶ is H; m is 1 ; and n is 1 .

In some preferred embodiments of the methods as described herein, the TLR7/8 agonist may be selected from:

2-((4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1 -yl)methyl)- 2-m ethylpropane- 1 ,3-diol,

2-((4-amino-2-(ethoxymethyl)-1 H-imidazo[4,5-c]qu inolin- 1 -yl)methyl)-2- methylpropane-1 ,3-diol,

2-((4-amino-2-(ethoxymethyl)-7,8-dihydrocyclopenta[b]imid azo[4,5-d]pyridin-

1 (6H)-yl)methyl)-2-methylpropane-1 ,3-diol, 2-((4-amino-2-(ethoxymethyl)-6,7,8,9-tetrahydro-1 H-imidazo[4,5-c]quinolin-1 - yl)methyl)-2-methylpropane-1 ,3-diol,

3-(4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1 -yl)-2-

(methoxymethyl)-2-methylpropan-1 -ol,

(R)-3-(4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1-yl)-2-

(methoxymethyl)-2-methylpropan-1 -ol,

(S)-3-(4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1 -yl)-2- (methoxymethyl)-2-methylpropan-1 -ol,

2-((4-amino-6,7-dimethyl-2-(2,2,2-trifluoroethyl)-1 H-imidazo[4,5-c]pyridin- 1 - yl)methyl)-2-methylpropane-1 ,3-diol,

2-((4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1 -yl)methyl)- 2-ethylpropane-1 ,3-diol,

2-((4-amino-2-butyl-1 H-imidazo[4,5-c]quinolin-1-yl)methyl)-2-methylpropane-1 ,3- diol,

2-((4-amino-2-butyl-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1-yl)methyl)-2- methylpropane-1 ,3-diol, and

2-((4-amino-2-pentyl-1 H-imidazo[4,5-c]quinolin-1 -yl)methyl)-2-methylpropane- 1 ,3-diol; or any pharmaceutically acceptable salt thereof.

In some preferred embodiments of the methods as described herein, the preferred TLR7/8 agonist is 2-((4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5- c]pyridin-1-yl)methyl)-2-methylpropane-1 ,3-diol, or a pharmaceutically acceptable salt thereof. The preferred TLR7/8 agonist is also referred as PF- 07225570 in this disclosure (or PF-5570 as referred in FIG.1-FIG.3) and has the following structure A:

In some preferred embodiments, the TLR7/8 agonist, especially the preferred PF- 07225570 or a pharmaceutically acceptable salt thereof, may be administered with an interval of at least 2 days, at least 3 days, at least 4 days, at least 5 days, at least 6 days, at least 7 days, at least 10 days, at least 14 days, or at least 21 days. In some aspects, the dose interval for the TLR7/8 agonist, especially the preferred PF- 07225570 or a pharmaceutically acceptable salt thereof, may be about 2-21 days, 2-14 days, 2-10 days, 2-7 days, 3-21 days, 3-14 days, 3-10 days, 3-7 days, 5-21 days, 5-14 days, 5-10 days, or 5-7 days. In one aspect, the dose interval for the TLR7/8 agonist, especially the preferred PF- 07225570 or a pharmaceutically acceptable salt thereof, is at least about 7 days (7 ± 2 days), at least about 14 days (14 ± 2 days), or at least about 21 days (21 ± 2 days).

III. PD-1 Axis Binding Antagonists

Embodiments of the present disclosure comprise a PD-1 axis binding antagonist. As used herein, the term “PD-1 axis binding antagonist” or “PD-1 axis antagonist” refers to a molecule that inhibits the interaction of a PD-1 axis binding partner (e.g., PD-1 , PD-L1 , PD-L2) with either one or more of its binding partners, for example so as to overcome or partially overcome T-cell dysfunction resulting from signaling on the PD-1 signaling axis — with a result being to restore, partially restore or enhance T-cell function (e.g., proliferation, cytokine production, target cell killing, survival). As used herein, a PD-1 axis binding antagonist includes one or more of (i) a PD-1 antagonist, (ii) a PD-L1 antagonist, and/or (iii) a PD-L2 antagonist. i) PD-1 antagonist

The term “PD-1 antagonist,” as used herein, refers to a molecule that decreases, blocks, inhibits, abrogates or interferes with signal transduction resulting from the interaction of PD-1 with one or more of its binding partners, such as PD-L1 , PD-L2. In some embodiments, the PD-1 antagonist is a molecule that inhibits the binding of PD-1 to its binding partners. In a specific aspect, the PD-1 antagonist inhibits the binding of PD-1 to PD-L1 and/or PD-L2. In specific embodiments, the PD-1 antagonist inhibits the binding of PD-1 to PD-LI. In another embodiment, the PD-1 antagonist inhibits the binding of PD-1 to PD-L2. In a further embodiment, the PD-1 antagonist inhibits the binding of PD-1 to both PD-L1 and PD-L2. For example, PD-1 antagonists include anti- PD-1 antibodies, antigen binding fragments thereof, immunoadhesins, fusion proteins, and other molecules that decrease, block, inhibit, abrogate or interfere with signal transduction resulting from the interaction of PD-1 with PD-L1 and/or PD-L2. In some embodiments, a PD-1 antagonist reduces the negative co-stimulatory signal mediated by or through cell surface proteins expressed on T lymphocytes mediated signaling through PD-1 so as to render a dysfunctional T-cell less non-dysfunctional. In some embodiments, the PD-1 antagonist is an anti-PD-1 antibody (aPD-1 ). In some embodiments, the PD-1 antagonist blocks binding of PD-L1 expressed on a cancer cell to PD-1 expressed on an immune cell (T cell, B cell or NKT cell) and preferably also blocks binding of PD-L2 expressed on a cancer cell to the immune-cell expressed PD-1. Alternative names or synonyms for PD-1 and its ligands include: PDCD1 , PD1 , CD279 and SLEB2 for PD-1 ; PDCD1 L1 , PDL1 , B7H1 , B7-4, CD274 and B7-H for PD-L1 ; and PDCD1 L2, PDL2, B7-DC, Btdc and CD273 for PD-L2. In any of the treatment method, medicaments and uses of the present invention in which a human individual is being treated, the PD-1 antagonist may block binding of human PD- L1 to human PD-1 , and block binding of both human PD-L1 and PD-L2 to human PD-1.

PD-1 antagonists useful in any of the treatment methods, medicaments and uses of the present disclosure include a monoclonal antibody (mAb), or antigen binding fragment thereof, which specifically binds to PD-1 or PD-L1 , and preferably specifically binds to human PD-1 or human PD-L1. The mAb may be a human antibody, a humanized antibody or a chimeric antibody, and may include a human constant region. In some embodiments, the human constant region is selected from the group consisting of lgG1 , lgG2, lgG3 and lgG4 constant regions, and in some embodiments, the human constant region is an IgG 1 or lgG4 constant region. In some embodiments, the antigen binding fragment is selected from the group consisting of Fab, Fab'-SH, F(ab')2, scFv and Fv fragments.

Examples of mAbs that bind to human PD-1 , and useful in the treatment method, medicaments and uses of the present disclosure, are described in U.S. Patent Nos. 7,488,802, 7,521 ,051 , 8,008,449, 8,354,509, 8,168,757, PCT Patent Publication Nos. WO 2004/004771 , WO 2004/072286, WO 2004/056875, and US Patent Publication No. 2011/0271358. Specific anti-human PD-1 mAbs useful as the PD-1 antagonist in the treatment method, medicaments and uses of the present disclosure include: sasanlimab (RN888, PF-06801591 , Pfizer Inc.), nivolumab (OPDIVO®, ONO-4538, BMS-936558, MDX1106, Bristol-Myers Squibb Company), pembrolizumab (KEYTRUDA®, MK-3475, lambrolizumab, Merck & Co., Inc.), pidilizumab (CT-011), cemiplimab (LIBTAYO®, REGN2810, Regeneron Pharmaceuticals, Inc.), tislelizumab (BGB-A317, BeiGene Ltd./Celgene Corporation), spartalizumab (PDR001 , Novartis AG), sintilimab (IBI308, Innovent Biologies, Inc.), MEDI-0680 (AMP-514, AstraZeneca PLC, CAS No.: 1642374-69-3, PCT Publication No. WO2014204856A1), BGB-108 (CAS No.: 1859072-61-9, PCT Publication No. W02016007235A1 ), or AGEN2034 (Agenus Inc. CAS No.: 2230167-06-1 , PCT Publication No. WO2018106864A1 ), genolimzumab (CBT Pharmaceuticals, CAS No. 2135810-45-4, PCT Publication No. WO2017176965 A1 ), CBT-502 (CBT Pharmaceuticals, CAS No.: 2303884-58-2, PCT Publication No. WO2019176965 A1), camrelizumab (SHR-1210, Incyte Corporation), or any combination thereof.

In certain embodiments, the PD-1 antagonist is an anti-PD-1 antibody.

In some embodiments, the anti-PD-1 antibody is nivolumab. In some embodiments, the anti-PD-1 antibody is pembrolizumab. In some embodiments, the anti-PD-1 antibody is sasanlimab. Sasanlimab is a humanized, immunoglobulin G4 (lgG4) monoclonal antibody (mAb) that binds to the PD-1 receptor. By blocking its interaction with PD-L1 and PD-L2, PD-1 pathway-mediated inhibition of the immune response is released, leading to an anti-tumor immune response. Clinical anti-tumor activity with sasanlimab has been seen in a panel of anti-PD1 sensitive solid tumor types including non-small cell lung cancer and urothelial carcinoma. Sasanlimab is described, for example, in US Patent No. US 10,155,037, which is hereby incorporated for all purposes.

Additional exemplary PD-1 antagonists include those described in U.S. Patent Application Publication 20130280265, U.S. Patent Application Publication 20130237580, U.S. Patent Application Publication 20130230514, U.S. Patent Application Publication 20130109843, U.S. Patent Application Publication 20130108651 , U.S. Patent Application Publication 20130017199, U.S. Patent Application Publication 20120251537, U.S. Patent Application Publication 20110271358, European Patent EP2170959B1 , in PCT Publication No. WO 2011/066342, PCT Publication No. WO 2015/035606, PCT Publication No. WO

2015/085847, PCT Publication No. WO 2015/112800, PCT Publication No. WO

2015/112900, PCT Publication No. WO 2016/092419, PCT Publication No. WO

2017/017623, PCT Publication No. WO 2017/024465, PCT Publication No. WO

2017/054646, PCT Publication No. WO 2017/071625, PCT Publication No. WO

2017/019846, PCT Publication No. WO 2017/132827, PCT Publication No. WO

2017/214092, PCT Publication No. WO 2018/013017, PCT Publication No. WO

2018/053106, PCT Publication No. WO 2018/055503, PCT Publication No. WO

2018/053709, PCT Publication No. WO 2018/068336, and PCT Publication No. WO

2018/072743, the entire disclosures of which are incorporated herein by reference.

Other exemplary PD-1 antagonists are described in Curran et al., PD-1 and CTLA-4 combination blockade expands infiltrating T cells and reduces regulatory T and myeloid cells within B16 melanoma tumors, PNAS, 2010, 107, 4275; Topalian etal., Safety, activity, and immune correlates of anti-PD-1 antibody in cancer, New Engl. J. Med. 2012, 366, 2443; Brahmer et al., Safety and activity of anti-PD-L1 antibody in patients with advanced cancer, New Engl. J. Med. 2012, 366, 2455; Dolan et al., PD-1 pathway inhibitors: changing the landscape of cancer immunotherapy, Cancer Control 2014, 21 , 3; and Sunshine et al., Pd-1/Pd-L1 Inhibitors, Curr. Opin. in Pharmacol. 2015, 23. ii) PD-L1 antagonist

The term “PD-L1 antagonist,” as used herein, refers to a molecule that decreases, blocks, inhibits, abrogates or interferes with signal transduction resulting from the interaction of PD-L1 with either one or more of its binding partners, such as PD-1 , B7-1. In some embodiments, the PD-1 axis antagonist comprises a PD-L1 antagonist. In some embodiments, the PD-L1 antagonist inhibits the binding of PD-L1 to its binding partners. In a specific aspect, the PD-L1 antagonist inhibits the binding of PD-L1 to PD-1 . In another specific aspect, the PD-L1 antagonist inhibits the binding of PD-L1 to PD-1 and/or B7-1. In another specific aspect, the PD-L1 antagonist inhibits the binding of PD-L1 to both PD-1 and B7-1.

In some embodiments, the PD-L1 antagonists include anti-PD-L1 antibodies, antigen binding fragments thereof, immunoadhesins, fusion proteins, and other molecules that decrease, block, inhibit, abrogate or interfere with signal transduction resulting from the interaction of PD-L1 with one or more of its binding partners, such as PD-1 , and/or B7-1. In some embodiments, a PD-L1 antagonist reduces the negative costimulatory signal mediated by or through cell surface proteins expressed on T lymphocytes mediated signaling through PD-L1 so as render a dysfunctional T-cell less non-dysfunctional. In some embodiments, a PD-L1 antagonist is an anti-PD-L1 antibody (OPD-L1).

In some embodiments, the PD-1 antagonist is an anti-PD-1 antibody.

In some embodiments, the anti-PD-1 antibody useful for this disclosure include BMS-936559 (Bristol-Myers Squibb Company, CAS No. 1422185-22-5, PCT Publication No. WO2013019906 A1), KN035 (envafolimab, Jiangsu Alphamab biopharmaceuticals Co., Ltd., CAS No. 2102192-68-5, Zhang F, Wei H, Wang X, Bai Y, Wang P, Wu J, et al. Structural basis of a novel PD-L1 nanobody for immune checkpoint blockade. Cell Discov. 2017;3:1700), atezolizumab (TECENTRIQ®, MPDL3280A, Roche Holding AG), durvalumab (IMFINZI®, AstraZeneca PLC), and/or avelumab (BAVENCIO®, Merck & Co., Inc. and Pfizer, Inc.).

Additional exemplary PD-L1 antagonists include those described in U.S. Patent Application Publication 20090055944, U.S. Patent Application Publication 20100203056, U.S. Patent Application Publication 20120039906, U.S. Patent Application Publication 20130045202, U.S. Patent Application Publication

20130309250, U.S. Patent Application Publication US20130034559, U.S. Patent

Application Publication US20150282460, U.S. Patent Application Publication

20160108123, PCT Publication No. WO 2011/066389, PCT Publication No. WO

2016/000619, PCT Publication No. WO 2016/094273, PCT Publication No. WO

2016/061142, PCT Publication No. WO 2016/149201 , PCT Publication No. WO

2016/149350, PCT Publication No. WO 2016/179576, PCT Publication No. WO

2017/020801 , PCT Publication No. WO 2017/103147, PCT Publication No. WO

2017/112741 , PCT Publication No. WO 2017/205213, PCT Publication No. WO

2017/054646, PCT Publication No. WO 2017/084495, PCT Publication No. WO

2017/161976, PCT Publication No. WO 2018/005682, PCT Publication No. WO

2018/053106, PCT Publication No. WO 2018/085469, PCT Publication No. WO

2018/111890, and PCT Publication No. WO 2018/106529, the entire disclosures of which are incorporated herein by reference. Other exemplary PD-L1 binding antagonists are described in Sunshine etal., 2015. iii) PD-L2 antagonist

The term “PD-L2 antagonist,” as used herein, refers to a molecule that decreases, blocks, inhibits, abrogates or interferes with signal transduction resulting from the interaction of PD-L2 with either one or more of its binding partners, such as PD-1. In some embodiments, a PD-L2 antagonist is a molecule that inhibits the binding of PD-L2 to its binding partners. In a specific aspect, the PD-L2 antagonist inhibits binding of PD-L2 to PD-1. In some embodiments, the PD-L2 antagonists include anti- PD-L2 antibodies, antigen binding fragments thereof, immunoadhesins, fusion proteins, and other molecules that decrease, block, inhibit, abrogate or interfere with signal transduction resulting from the interaction of PD-L2 with either one or more of its binding partners, such as PD-1. In some embodiments, a PD-L2 antagonist reduces the negative co-stimulatory signal mediated by or through cell surface proteins expressed on T lymphocytes mediated signaling through PD-L2 so as render a dysfunctional T-cell less non-dysfunctional. In some embodiments, a PD-L2 antagonist is a PD-L2 immunoadhesin.

IV. METHODS, USES AND MEDICAMENTS

General Methods Standard methods in molecular biology are described in Sambrook, Fritsch and Maniatis (1982 & 1989 2nd Edition, 2001 3rd Edition) Molecular Cloning, A Laboratory Manual; Sambrook and Russell Molecular Cloning, 3rd ed., 2001 ; Wu, Recombinant DNA, Vol. 217. Standard methods also appear in Ausbel, et al., Current Protocols in Molecular Biology, Vols.1-4, 2001 , which describes cloning in bacterial cells and DNA mutagenesis (Vol. 1), cloning in mammalian cells and yeast (Vol. 2), glycoconjugates and protein expression (Vol. 3), and bioinformatics (Vol. 4).

Methods for protein purification including immunoprecipitation, chromatography, electrophoresis, centrifugation, and crystallization are described (Coligan, et al., Current Protocols in Protein Science, Vol. 1 , 2000, John Wiley and Sons, Inc., New York). Chemical analysis, chemical modification, post-translational modification, production of fusion proteins, and glycosylation of proteins are described (e.g., Coligan, et al., Current Protocols in Protein Science, Vol. 2, 2000; Ausubel, et al., Current Protocols in Molecular Biology, Vol. 3, 2001 , pp. 16.0.5-16.22.17; Sigma-Aldrich, Co. Products for Life Science Research, 2001 , pp. 45-89; Amersham Pharmacia Biotech (2001) BioDirectory, pp. 384-391). Production, purification, and fragmentation of polyclonal and monoclonal antibodies are described (Coligan, etal., Current Protocols in Immunology, Vol. 1 , 2001 ; Harlow and Lane, Using Antibodies, 1999). Standard techniques for characterizing ligand/receptor interactions are available (e.g., Coligan, etal., Current Protocols in Immunology, Vol. 4, 2001).

Monoclonal, polyclonal, and humanized antibodies can be prepared (e.g., Sheperd and Dean (eds.) Monoclonal Antibodies, 2000; Kontermann and Dubel (eds.) Antibody Engineering, 2001 ; Harlow and Lane, Antibodies A Laboratory Manual, 1988, pp. 139-243; Carpenter, et al., Non-Fc receptor-binding humanized anti-CD3 antibodies induce apoptosis of activated human T cells, J. Immunol. 2000, 165:6205; He, et al., Humanization and pharmacokinetics of a monoclonal antibody with specificity for both E-and P-selectin,J. Immunol. 1998, 160:1029; Tang et al., Use of a peptide mimotope to guide the humanization of MRK-16, an anti-P-glycoprotein monoclonal antibody , J. Biol. Chem. 1999, 274:27371-27378; Baca et al., Antibody humanization using monovalent phage display, J. Biol. Chem. 1997, 272:10678-10684; Chothia et al., Conformations of immunoglobulin hypervariable regions, Nature 1989, 342:877-883; Foote and Winter Antibody framework residues affecting the conformation of the hypervariable loops, J. Mol. Biol. 1992, 224:487-499; U.S. Patent No. 6,329,511 ).

An alternative to humanization is to use human antibody libraries displayed on phage or human antibody libraries in transgenic mice (Vaughan et al., Human antibodies with sub-nanomolar affinities isolated from a large non-immunized phage display library, Nature Biotechnol. 1996, 14:309-314; Barbas , Synthetic human antibodies, Nature Medicine 1995, 1 :837-839; Mendez et al., Functional transplant of megabase human immunoglobulin loci recapitulates human antibody response in mice, Nature Genetics 1997, 15:146-156; Hoogenboom and Chames, Natural and designer binding sites made by phage display technology, Immunol. Today 2000, 21 :371-377; Barbas etal., Phage Display: A Laboratory Manual, 2001 ; Kay et al., Phage Display of Peptides and Proteins: A Laboratory Manual, 1996; de Bruin et al., Selection of high- affinity phage antibodies from phage display libraries, Nature Biotechnol. 1999, 17:397- 399).

Purification of antigen is not necessary for the generation of antibodies. Animals can be immunized with cells bearing the antigen of interest. Splenocytes can then be isolated from the immunized animals, and the splenocytes can be fused with a myeloma cell line to produce a hybridoma (e.g., Meyaard, L., et. al., LAIR-1 , a novel inhibitory receptor expressed on human mononuclear leukocytes, Immunity 1997, 7:283-290; Wright etal., Inhibition of chicken adipocyte differentiation by in vitro exposure to monoclonal antibodies against embryonic chicken adipocyte plasma membranes, Immunity 2000, 13:233-242; Preston, et al., The leukocyte/neuron cell surface antigen OX2 binds to a ligand on macrophages,) Ear. J. Immunol. 1997, 27:1911 -1918, Kaithamana et al., Induction of experimental autoimmune Graves' disease in BALB/c mice, J. Immunol. 1999, 163:5157-5164).

Antibodies can be conjugated, e.g., to small drug molecules, enzymes, liposomes, polyethylene glycol (PEG). Antibodies are useful for therapeutic, diagnostic, kit or other purposes, and include antibodies coupled, e.g., to dyes, radioisotopes, enzymes, or metals, e.g., colloidal gold (e.g., Le Doussal et al., Enhanced in vivo targeting of an asymmetric bivalent hapten to double-antigen-positive mouse B cells with monoclonal antibody conjugate cocktails, J. Immunol. 1991 , 146:169-175; Gibellini et al., Extracellular HIV-1 Tat protein induces the rapid Ser133 phosphorylation and activation of CREB transcription factor in both Jurkat lymphoblastoid T cells and primary peripheral blood mononuclear cells, J. Immunol. 1998160:3891-3898; Hsing and Bishop, Requirement for nuclear factor-KB activation by a distinct subset of CD40- mediated effector functions in B lymphocytes, J. Immunol. 1999, 162:2804-2811 ; Everts et al., Selective intracellular delivery of dexamethasone into activated endothelial cells using an E-selectin-directed immunoconjugate, J. Immunol. 2002, 168:883-889). Methods for flow cytometry, including fluorescence activated cell sorting (FACS), are available (e.g., Owens, etal., Flow Cytometry Principles for Clinical Laboratory Practice, 1994; Givan Flow Cytometry, 2nd ed.; 2001 ; Shapiro, Practical Flow Cytometry, 2003). Fluorescent reagents suitable for modifying nucleic acids, including nucleic acid primers and probes, polypeptides, and antibodies, for use, e.g., as diagnostic reagents, are available (Molecular Probes, Catalogue, 2003; Sigma-Aldrich, Catalogue, 2003.

Standard methods of histology of the immune system are described (e.g., Muller- Harmelink (ed.), Human Thymus: Histopathology and Pathology, 1986; Hiatt, etal., Color Atlas of Histology, 2000; Louis, et al., Basic Histology: Text and Atlas, 2002.

Software packages and databases for determining, e.g., antigenic fragments, leader sequences, protein folding, functional domains, glycosylation sites, and sequence alignments, are available (e.g., GenBank, Vector NTI® Suite (Informax, Inc, Bethesda, MD); GCG Wisconsin Package (Accelrys, Inc., San Diego, CA); DeCypher® (TimeLogic Corp., Crystal Bay, Nevada); Menne, etal., A comparison of signal sequence prediction methods using a test set of signal peptides, Bioinformatics 2000, 16: 741-742; Menne, K.M.L., et. al. A comparisonof signal sequence prediction methods using a test set of signal peptides, Bioinformatics 2000, 16, 741-742; Wren, et al., SIGNAL-sequence information and GeNomic AnaLy sis Comput. Methods Programs Biomed. 2002, 68:177-181 ; von Heijne, Patterns of amino acids near signal-sequence cleavage sites, Ear. J. Biochem. 1983, 133:17-21 ; von Heijne, A new method for predicting signal sequence cleavage sites, Nucleic Acids Res. 1986, 14:4683-4690).

Therapeutic Methods and Uses

The disclosure provides therapeutic methods and uses comprising administering to the subject the combinations as described herein, optionally in further combination with other therapeutic agents.

In one aspect, the disclosure provides a method for treating a cancer in a subject comprising administering to the subject a combination therapy of the disclosure. In one aspect, the disclosure provides a method for treating a cancer comprising administering to a subject in need thereof an amount of a PD-1 axis binding antagonist and an amount of a TLR7/8 agonist, wherein the amounts together are effective in treating cancer, and wherein the TLR7/8 agonist is a compound of Formula I, or a pharmaceutically acceptable salt thereof, disclosed herein. In some such embodiments, the subject is a human. In some embodiments, the method involves the use of an anti-PD-L1 antibody in combination with a TLR7/8 agonist described herein.

In some preferred embodiments, the method involves the use of an anti-PD-1 antibody selected from sasanlimab, nivolumab, pembrolizumab, pidilizumab, cemiplimab, tislelizumab, spartalizumab, sintilimab, MEDI-0680, BGB-108, AGEN2034 genolimzumab, CBT-502, camrelizumab, or any combination thereof, in combination with 2-((4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1-yl)methyl)-2- methylpropane-1 ,3-diol, or a pharmaceutically acceptable salt thereof.

In some more preferred embodiments, the method involves the use of sasanlimab, in combination with 2-((4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H- imidazo[4,5-c]pyridin-1 -yl)methyl)-2-methylpropane- 1 ,3-diol, or a pharmaceutically acceptable salt thereof.

In some embodiments, the treatment results in sustained response in the individual after cessation of the treatment. The methods of this disclosure may find use in treating conditions where enhanced immunogenicity is desired such as increasing tumor immunogenicity for the treatment of cancer. As such, a variety of cancers may be treated, or their progression may be delayed.

In some embodiments, the individual has cancer that is resistant (has been demonstrated to be resistant) to one or more PD-1 axis binding antagonists. In some embodiments, resistance to PD-1 axis binding antagonist includes recurrence of cancer or refractory cancer. Recurrence may refer to the reappearance of cancer, in the original site or a new site, after treatment. In some embodiments, resistance to PD-1 axis binding antagonist includes progression of the cancer during treatment with the PD-1 axis binding antagonist. In some embodiments, resistance to PD-1 axis binding antagonist includes cancer that does not response to treatment. The cancer may be resistant at the beginning of treatment or it may become resistant during treatment. In some embodiments, the cancer is at early stage or at late stage.

In certain embodiments, the subject has received one, two, three, four, five or more prior cancer treatments. In other embodiments, the subject is treatment- naive. In some embodiments, the subject has progressed on other cancer treatments. In certain embodiments, the prior cancer treatment comprised an immunotherapy. In other embodiments, the prior cancer treatment comprised a chemotherapy. In some embodiments, the tumor has reoccurred. In some embodiments, the tumor is metastatic. In other embodiments, the tumor is not metastatic. In some embodiments, the subject has received a prior therapy to treat the tumor and the tumor is relapsed or refractory. In some embodiments, the subject has received a prior immuno-oncology therapy to treat the tumor and the tumor is relapsed or refractory. In some embodiments, the subject has received more than one prior therapy to treat the tumor and the subject is relapsed or refractory.

In some embodiments of the methods as described herein, the cancer is a solid tumor.

In a further embodiment, the disclosure is related to a method for treating cancer, wherein the cancer may be brain cancer, head/neck cancer (including squamous cell carcinoma of the head and neck (SCCHN)), prostate cancer, bladder cancer (including non-muscle invasive bladder cancer (NMIBC), or urothelial carcinoma, also known as transitional cell carcinoma (TCC)), lung cancer (including squamous cell carcinoma, small cell lung cancer (SCLC), and non-small cell lung cancer (NSCLC)), breast cancer, ovarian cancer, bone cancer, colorectal cancer, kidney cancer, liver cancer (including hepatocellular carcinoma (HCC)), pancreatic cancer, esophageal cancer (including sauamous cell carcinoma (SCCGC)), gastric cancer, gastroesophageal junction cancer, thyroid cancer, cervical cancer, uterine cancer, and/or renal cancer. Preferably, the cancer is bladder cancer. In a more preferred aspect, the method of the present disclosure is for treating non-muscle invasive bladder cancer (NMIBC).

In some embodiments, the combination therapy of the disclosure comprises administration of a PD-1 axis binding antagonist in combination with a TLR7/8 agonist. In the methods provided herein, each of the PD-1 axis binding antagonist and the TLR7/8 agonist, may be administered in any suitable manner known in the art. In one embodiment, the PD-1 axis binding antagonist and the TLR7/8 agonist are administered simultaneously or sequentially in either order.

In some embodiments, the disclosure provides a combination comprising: (i) a PD-1 axis binding antagonist described herein; and (ii) a TLR7/8 agonist of Formula I, or a pharmaceutically acceptable salt thereof, for use in the treatment of cancer in a subject. In some embodiments, the PD-1 axis binding antagonist is a PD-1 antagonist. In some embodiments, the PD-1 axis binding antagonist is a PD-L1 antagonist.

In some embodiments, the disclosure provides a combination comprising: (i) an anti-PD-1 antibody; and (ii) 2-((4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5- c]pyridin-1-yl)methyl)-2-methylpropane-1 ,3-diol, or a pharmaceutically acceptable salt thereof, for use in the treatment of cancer in a subject. In one preferred embodiment, the disclosure provides a combination comprising: (i) sasanlimab; and (ii) 2-((4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5- c]pyridin-1-yl)methyl)-2-methylpropane-1 ,3-diol, or a pharmaceutically acceptable salt thereof. In one aspect, the combination is for use in the treatment of cancer in a subject.

V. Dosage Forms and Regimens

Administration of the compounds of the disclosure may be affected by any method that enables delivery of the compounds to the site of action. These methods include oral routes, intraduodenal routes, parenteral injection (including intravenous, subcutaneous (sc), intramuscular, intravesical delivery such as intravesical instillation, intravascular or infusion), topical, and rectal administration.

Those skilled in the art will be able to determine the appropriate amount, dose or dosage of each compound, as used in the combination of the present disclosure, to administer to a patient, taking into account variety of factors, including, though not limited to, the degree of advancement of the disease, age, weight, general health, gender, diet, the compound administered, the time and route of administration, the nature and advancement of cancer, requiring treatment, and other medications the individual is taking.

In some embodiments, the methods of administration of the agents and combinations herein may include oral, intravenous, intramuscular subcutaneous, topical, transdermal, intraperitoneal, by implantation, by inhalation, intrathecal, intraventricular, intravesical delivery such as intravesical instillation, or intranasal administration. In a preferred embodiment, the method of administration for the TLR7/8 agonist is by intravesical instillation.

Dosage regimens may be adjusted to provide the optimum desired response. For example, a single bolus may be administered, several divided doses may be administered over time or the dose may be proportionally reduced or increased as indicated by the exigencies of the therapeutic situation. It is especially advantageous to formulate parenteral compositions in dosage unit form for ease of administration and uniformity of dosage. Dosage unit form, as used herein, refers to physically discrete units suited as unitary dosages for the subjects to be treated; each unit containing a predetermined quantity of active compound calculated to produce the desired therapeutic effect in association with the required pharmaceutical carrier. The specification for the dosage unit forms of the disclosure is dictated by and directly dependent on (a) the unique characteristics of the chemotherapeutic agent and the particular therapeutic or prophylactic effect to be achieved, and (b) the limitations inherent in the art of compounding such an active compound for the treatment of sensitivity in individuals.

Thus, the skilled artisan would appreciate, based upon the disclosure provided herein, that the dose and dosing regimen is adjusted in accordance with methods well- known in the therapeutic arts. That is, the maximum tolerable dose can be readily established, and the effective amount providing a detectable therapeutic benefit to a patient may also be determined, as can the temporal requirements for administering each agent to provide a detectable therapeutic benefit to the patient. Accordingly, while certain dose and administration regimens are exemplified herein, these examples in no way limit the dose and administration regimen that may be provided to a patient in practicing the present disclosure.

For combination therapies as described herein, the agents may be administered at their approved dosages. Treatment is continued as long as clinical benefit is observed or until unacceptable toxicity or disease progression occurs. Nevertheless, in certain embodiments, the combination therapies of the present disclosure may advantageously utilize lower dosages of the administered therapeutic agents, thus avoiding possible toxicities or complications associated with the various monotherapies. For example, the dosages of the agents administered are significantly lower than the approved dosage, e.g., a subtherapeutic dosage of the TLR7/8 agonist is administered in combination with a subtherapeutic dosage of a PD-1 axis binding antagonist. It will be appreciated by the skilled practitioner that when the agents of the disclosure are used as part of a combination therapy, a lower dosage of the agent may be desirable than when the agent alone is administered to a subject, a synergistic therapeutic effect may be achieved through the use of combination therapy which, in turn, permits use of a lower dose of the agent to achieve the desired therapeutic effect.

In one embodiment, the dosages may be lower and may also be applied less frequently, which may diminish the incidence or severity of side-effects. This is in accordance with the desires and requirements of the subjects to be treated.

The amount of the agent of the disclosure administered will be dependent on the subject being treated, the severity of the disorder or condition, the rate of administration, the disposition of the compound and the discretion of the prescribing physician. An effective amount of the PD-1 axis binding antagonist and the TLR7/8 agonist may be administered for prevention or treatment of disease. The appropriate dosage of the TLR7/8 agonist, and PD-1 axis binding antagonist, may be determined based on the type of disease to be treated, the TLR7/8 agonist, the PD-1 axis binding antagonist, the severity and course of the disease, the clinical condition of the subject, the subject's clinical history and response to the treatment, and the discretion of the attending physician. In some embodiments, combination treatment with TLR7/8 agonist, and PD- 1 axis binding antagonist (e.g., anti- PD-1 antibody or anti-PD-L1 antibody), are synergistic, whereby an efficacious dose of the TLR7/8 agonist, PD-1 axis binding antagonist, in the combination is reduced relative to efficacious dose of the each of the TLR7/8 agonist, PD-1 axis binding antagonist, as a single agent.

In some preferred embodiments, the TLR7/8 agonist such as 2-((4-amino-2- (ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1-yl)methyl)-2-methylpropane- 1 ,3-diol, or a pharmaceutically acceptable salt thereof, can be administered with an interval of about at least 7 days (7 ± 2 days), at least 14 days (14± 2 days), or at least 21 days (21 ± 2 days). The efficacy observed (see Table 1 to Table 5, and FIG. 1 to FIG. 3) for a single-dose treatment or with a weekly dose interval for a small molecule compound is very surprising. Such weekly dose interval, or longer interval, may provide more convenience and less toxicity to a patient being treated.

VI. Kits

In some embodiments, the disclosure provides a kit comprising: (i) a pharmaceutical composition comprising a PD-1 axis binding antagonist described herein; and (ii) a pharmaceutical composition comprising a TLR7/8 agonist described herein and a pharmaceutically acceptable carrier.

In some embodiments, the kit further comprises package insert comprising instructions for using the TLR7/8 agonist in conjunction with PD-1 axis binding antagonist (e.g., anti-PD-1 or anti-PD-L1 antibody), treat or delay progression of cancer in a subject or to enhance immune function of a subject having cancer. In further embodiment, any of the PD-1 axis binding antagonists and the TLR7/8 agonists described herein may be included in the kits. In one preferred embodiment, the PD-1 binding antagonist is sasanlimab, and the TLR7/8 agonist is 2-((4-amino-2- (ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1-yl)methyl)-2-methylpropane- 1 ,3-diol, or a pharmaceutically acceptable salt thereof. In some embodiments, the PD-1 axis binding antagonist and the TLR7/8 agonist and are stored in the same container or in separate containers. Suitable containers include, for example, bottles, vials, bags and syringes. The container may be formed from a variety of materials such as glass, plastic (such as polyvinyl chloride or polyolefin), or metal alloy. In some embodiments, the container holds the formulation and the label on, or associated with, the container may indicate directions for use. The kit may further include other materials desirable from a commercial and user standpoint, including other buffers, diluents, filters, needles, syringes, and package inserts with instructions for use. In some embodiments, the kit further includes one or more of another agent (e.g., a chemotherapeutic agent, and anti-neoplastic agent). Suitable containers for the one or more agent include, for example, bottles, vials, bags and syringes.

The specification is sufficient to enable one skilled in the art to practice the disclosure. Various modifications of the disclosure in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description and fall within the scope of the appended claims. All publications, patents, and patent applications cited herein are hereby incorporated by reference in their entirety for all purposes.

VII. Embodiments (EBs)

EB1 : A method for treating cancer comprising administering to a subject in need thereof a therapeutically effective amount of a Programmed Death 1 protein (PD-1) axis binding antagonist in combination with a compound of Formula I: or a pharmaceutically acceptable salt thereof, wherein

R ¹ and R ² are independently Ci -3 alkyl; or

R ¹ and R ² are joined to form a 5- to 7-membered carbocyclic ring, wherein said carbocyclic ring may be saturated or unsaturated;

R ³ is

R ⁴ is C1-6 alkyl, or (CH2)nO(CH2)mCH3, wherein said C1-6 alkyl or any carbon of the (CH2)nO(CH2)mCH3 group is substituted with 0 to 3 F as valency allows;

R ⁵ is C1-3 alkyl, or OC1 -3 alkyl, wherein the C1-3 alkyl is substituted by 0 to 3 F;

R ⁶ is H, or C1-3 alkyl, wherein the C1-3 alkyl is substituted with 0 to 3 F; m is 0 to 2; and n is 1 to 3.

EB2: The method of EB1 , wherein:

R ¹ and R ² are independently Ci 2 alkyl; or

R ¹ and R ² are joined to form a 5- to 7-membered carbocyclic ring, wherein said carbocyclic ring may be saturated or unsaturated;

R ⁴ is C3-5 alkyl, or (CH2)nO(CH2)mCH ₃ ;

R ⁵ is C1-2 alkyl;

R ⁶ is H; m is 1 ; and n is 1 .

EB3: The method of EB1 , wherein the compound of Formula I is:

2-((4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1 -yl)methyl)-

2-m ethylpropane- 1 ,3-diol,

2-((4-amino-2-(ethoxymethyl)-1 H-imidazo[4,5-c]qu inolin- 1-yl)methyl)-2- methylpropane-1 ,3-diol,

2-((4-amino-2-(ethoxymethyl)-7,8-dihydrocyclopenta[b]imid azo[4,5-d]pyridin-

1 (6H)-yl)methyl)-2-methylpropane-1 ,3-diol,

2-((4-amino-2-(ethoxymethyl)-6,7,8,9-tetrahydro-1 H-imidazo[4,5-c]quinolin-1 - yl)methyl)-2-methylpropane-1 ,3-diol,

3-(4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1 -yl)-2-

(methoxymethyl)-2-methylpropan-1 -ol, (R)-3-(4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1-yl)-2- (methoxymethyl)-2-methylpropan-1 -ol,

(S)-3-(4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1 -yl)-2- (methoxymethyl)-2-methylpropan-1 -ol,

2-((4-amino-6,7-dimethyl-2-(2,2,2-trifluoroethyl)-1 H-imidazo[4,5-c]pyridin- 1 - yl)methyl)-2-methylpropane-1 ,3-diol,

2-((4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1 -yl)methyl)- 2-ethylpropane-1 ,3-diol,

2-((4-amino-2-butyl-1 H-imidazo[4,5-c]quinolin-1-yl)methyl)-2-methylpropane-1 ,3- diol,

2-((4-amino-2-butyl-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1-yl)methyl)-2- methylpropane-1 ,3-diol, and

2-((4-amino-2-pentyl-1 H-imidazo[4, 5-c]quinolin-1 -yl)methyl)-2-methylpropane- 1 ,3-diol; or a pharmaceutically acceptable salt thereof.

EB4: The method of any one of EB1 to EB3, wherein the compound of Formula I is 2- ((4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1-yl)methyl)-2- methylpropane-1 ,3-diol, or a pharmaceutically acceptable salt thereof.

EB5: The method of any one of EB1 to EB4, wherein the PD-1 axis binding antagonist is an anti-PD-1 antibody selected from the group consisting of sasanlimab, nivolumab, pembrolizumab, pidilizumab, cemiplimab, tislelizumab, spartalizumab, sintilimab, MEDI- 0680, BGB-108, AGEN2034, genolimzumab, CBT-502, camrelizumab, and any combination thereof.

EB6: The method of EB5, wherein the anti-PD-1 antibody is sasanlimab.

EB7: The method of any one of EB1 to EB4, wherein the PD-1 axis binding antagonist is an anti-PD-L1 antibody selected from the group consisting of BMS-936559, KN035, atezolizumab, durvalumab, avelumab, and any combination thereof.

E8: The method of any one of EB1 to EB7, wherein the cancer is bladder cancer.

E9. The method of EB8, wherein the bladder cancer is non-muscle invasive bladder cancer (NMIBC).

E10: The method of EB9, wherein the NMIBC is Bacillus Calmette-Guerin (BCG) unresponsive NMIBC.

E11 : The method of any one of EB1 to EB10, wherein the PD-1 axis binding antagonist is administered by intravenous infusion or subcutaneous delivery, and the compound of Formula I, or a pharmaceutically acceptable salt thereof, is administered by intravesical delivery to bladder epithelium of the subject.

E12: The method of any one of EB1 to EB11 , wherein a therapeutically effective amount of BCG immunotherapy is further administered.

EB13: The method of any one of EB4 to EB12, wherein 2-((4-amino-2-(ethoxymethyl)- 6,7-dimethyl-1 H-imidazo[4,5-c]pyridin- 1 -yl)methyl)-2-methylpropane- 1 ,3-diol, or a pharmaceutically acceptable salt thereof, is administered with a dosing interval of about at least 7 days (7± 2 days).

EB14: A combination comprising a Programmed Death 1 protein (PD-1 ) axis binding antagonist and a compound of Formula I , or a pharmaceutically acceptable salt thereof, wherein the PD-1 axis binding antagonist comprises an anti-PD-1 antibody selected from the group consisting of sasanlimab, nivolumab, pembrolizumab, pidilizumab, cemiplimab, tislelizumab, spartalizumab, sintilimab, MEDI-0680, BGB-108, AGEN2034, genolimzumab, CBT-502, camrelizumab, and any combination thereof, or an anti-PD-L1 antibody selected from the group consisting of BMS-936559, KN035, atezolizumab, durvalumab, avelumab, and any combination thereof ; and wherein the compound of Formula I is: or a pharmaceutically acceptable salt thereof, wherein

R ¹ and R ² are independently Ci -3 alkyl; or

R ¹ and R ² are joined to form a 5- to 7-membered carbocyclic ring, wherein said carbocyclic ring may be saturated or unsaturated;

R ⁴ is Ci -6 alkyl, or (CH2)nO(CH2)mCH3, wherein said Ci -6 alkyl or any carbon of the (CH2)nO(CH2)mCH3 group is substituted with 0 to 3 F as valency allows;

R ⁵ is C1 -3 alkyl, or OC1 -3 alkyl, wherein the C1 -3 alkyl is substituted by 0 to 3 F; R ⁶ is H, or C1-3 alkyl, wherein the C1-3 alkyl is substituted with 0 to 3 F; m is 0 to 2; and n is 1 to 3.

EB15: The combination of EB14, wherein:

R ¹ and R ² are independently Ci 2 alkyl; or

R ¹ and R ² are joined to form a 5- to 7-membered carbocyclic ring, wherein said carbocyclic ring may be saturated or unsaturated;

R ³ is

R ⁴ is C3-5 alkyl, or (CH2)nO(CH2)mCH ₃ ;

R ⁵ is C1-2 alkyl;

R ⁶ is H; m is 1 ; and n is 1 .

EB16: The combination of EB14 or EB15, wherein the PD-1 axis binding antagonist is sasanlimab, and the compound of Formula I is 2-((4-amino-2-(ethoxymethyl)-6,7- dimethyl-1 H-imidazo[4,5-c]pyridin-1 -yl)methyl)-2-methylpropane- 1 ,3-diol, or a pharmaceutically acceptable salt thereof.

EB17: The combination of any one of EB14 to EB16, for use in the treatment of cancer.

EB18: The combination for use in the treatment of cancer of EB 17, wherein said cancer is bladder cancer

EB19: The combination for use in the treatment of cancer of EB18, wherein the bladder cancer is NMIBC.

EB20: The combination for use in the treatment of cancer of EB19, wherein the NMIBC is BCG un-responsive NMIBC.

EB21 : The combination for use in the treatment of cancer of any one of EB18 to EB20, wherein 2-((4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1- yl)methyl)-2-methylpropane-1 ,3-diol, or a pharmaceutically acceptable salt thereof, is administered with a dosing interval of about at least 7 days).

EB22. The method of any of EB4 to EB13, wherein the compound 2-((4-amino-2- (ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1-yl)methyl)-2-methylpropane- 1 ,3-diol, or a pharmaceutically acceptable salt thereof, is administered with a dosing interval of at least about 14 days.

EB23. The method of any of EB1 to EB13, wherein the compound 2-((4-amino-2- (ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5-c]pyridin-1-yl)methyl)-2-methylpropane- 1 ,3-diol, or a pharmaceutically acceptable salt thereof, is administered with a dosing interval of at least about 21 days.

EB24. The combination for use in the treatment of cancer of any one of EB18 to EB20, wherein the compound 2-((4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H-imidazo[4,5- c]pyridin-1-yl)methyl)-2-methylpropane-1 ,3-diol, or a pharmaceutically acceptable salt thereof, is administered with a dosing interval of at least about 14 days.

EB25. The combination for use in the treatment of cancer of any one of EB18 to EB20, and EB24, wherein the compound 2-((4-amino-2-(ethoxymethyl)-6,7-dimethyl-1 H- imidazo[4,5-c]pyridin-1 -yl)methyl)-2-methylpropane- 1 ,3-diol, or a pharmaceutically acceptable salt thereof, is administered with a dosing interval of at least about 21 days.

VIII. Examples

In order that this invention may be better understood, the following examples are set forth. These examples are for purposes of illustration only and are not to be construed as limiting the scope of the invention in any manner.

Example 1 : In vivo efficacy induced by combinatorial therapy of PF-07225570 and anti-PD-1 in MB49 syngeneic tumor model

The purpose of this study was to evaluate the in vivo efficacy of the combinatorial therapy of PF-07225570 and murine surrogate anti-PD-1 (PF-06937004) in a syngeneic mouse bladder cancer model. MB49 cells were implanted subcutaneously and PF-07225570 was tested through intra-tumor (IT) delivery to mimic local administration while anti-PD-1 was dosed Intra-peritoneally (IP) for systemic exposure. This study addressed two main questions: 1) does combinatorial therapy of PF-07225570 and anti-PD-1 treatment provide significant benefit over single agent therapy in MB-49 tumor bearing mice, and 2) does reducing number of doses or increasing time between doses of PF-07225570 in combination with anti-PD-1 still provide significant benefit in MB-49 tumor bearing mice? Efficacy was assessed comparing combination therapy to control or single agent therapy.

Materials and Methods-Table A

RPMI: Roswell Park Memorial Institute; DMEM: Dulbecco’s Modified Eagle Medium; FBS: Fetal bovine serum; DPBS: Dulbecco’s Phosphate buffer solution; EDTA: Ethylenediaminetetraacetic. Compounds Tested-Table B:

*PF-06937004 is a chimeric mAb (human anti-PD-1 CDR) on mouse lgG1 (mlgG1) frame. It binds to mouse PD-1 with an affinity of about 685 nM. PF-06937004 is an anti-mouse PD-1 mlgG1 having the same heavy chain variable region (VH) and light chain variable region (VL) sequence of the PD1 -F2 clone described in PCT Publication No. WO 2004/056875 A1 , which is hereby incorporated for all purposes. No substantial mutation has been introduced into the mouse fragment crystallizable (Fc) regions.

Animals-Table C

Organ system evaluated: Measurement of subcutaneous tumor growth and mouse body weight

Species/Strain: Mus musculus/C57BI/6J mice

Doses: 14mg/kg of PF-07225570; 10mg/kg of Anti-PD-1

Gender and No. per group/replicates: Female 10 mice/group

Age: 7-8 weeks old

Source: The Jackson Laboratory, Sacramento, CA

Q1 Dx1 : Single dose; Q3Dx2: Dose every 3 days for a total of 2 doses; Q3Dx3: Dose every 3 days for atotal of 3 doses; QWx2: Dose every week foratotal of 2 doses.

Equipment Fowler calipers Ultra Cal VI, Fowler High Precision, Newton Massachusetts, order number: NC1677319, Model number: 54-100-444-1.

Ohaus balance SPX422, Ohaus Corporation, Parsippany, New Jersey, order number: 30253020, model number: (01-922-401).

Software

Studylog 4.0 was used to acquire mouse body weights and tumor volumes. GraphPad Prism 9.0.0 were used for analysis of mouse tumor volumes, body weights and survival. Statistics

The statistical significance of differences between experimental groups was assessed by ANCOVA using Pfizer-internal TGI analyzer software. Data is depicted as mean ±SEM. *p<0.05 **p <0.01 , ***p <0.001 , ****p <0.0001. Statistical significance in survival determination using Logrank Mantel-cox test compared to Vehicle + Isotype using GraphPad Prism *p <0.05 **p <0.01 , ***p<0.001 , ****p<0.0001. Fisher’s exact test for contingency to determine statistically significant differences between proportion of responders vs non- responders using GraphPad Prism.

Methods

MB-49 cells were cultured in DM EM supplemented with 10% FBS. The cells were expanded for SC implantation in mice. Cells were harvested by 5-minute digestion with 0.25% trypsin and resuspended in DPBS. Mice were anaesthetized with 3% vaporized Isoflurane. The lower right flank of 7 to 8-week old female C57BI6/J mice were shaved and implanted with 200,000 MB-49 cells using 27.5-gauge syringe. At day 7 post implantation, tumor volumes for individual mice were measured and assigned to groups by mean tumor volumes at n=10 per group. Length (L) and width (W) of tumors were recorded and tumor volume was calculated using the formula: Volume = 0.5*L*W ^A 2. Mice were treated with isotype or anti-PD-1 (IP) or with vehicle or PF- 07225570 (IT). In brief, anti-PD-1 was dosed on a Q3Dx3 schedule, and PF-07225570 treatment was altered testing Q3Dx3, Q3Dx2, Q1 Dx1 , or QWx2 dose strategy. Body weight and tumor volume were measured twice a week throughout the study. TGI was calculated with the following formula: 1 -(Tend-Tbegin/Cend-Cbegin) where Tend is final average tumor volume of treated group, Tbegin is average starting volume of treated group, Cend is final average volume of control group, and Cbegin is average starting volume of control group. TGI was calculated on the first day an animal was lost in any group due to excessive tumor volume (for Vehicle + Isotype controls, TGI was assessed at day 20 and for single agent controls, TGI was assessed at day 24). In Vivo Efficacy Study Antitumor efficacy was evaluated following different dose regimen strategies of combination therapy with PF-07225570 and anti-PD-1 in the MB49 syngeneic mouse model. Anti-PD-1 treatment remained consistent with Q3Dx3 IP dosing and PF- 07225570 IT treatment was altered to explore how reducing frequency (Q3Dx3, Q3Dx2, Q1 Dx1) or increasing length of time (QWx2) between dosing would affect TGI, number of responders or survival compared to isotype + vehicle controls or single agent treatments.

TGI, calculated at day 20 post tumor cell implant, and p-values are summarized in Table 1 and FIG. 1. No significant body weight loss was observed in any group. Statistically significant TGI was measured in all treatment groups when compared to vehicle + isotype controls. While single agent PF-07225570 (TGI = 87%; p <0.0001 ) and anti-PD-1 (TGI = 75%; p=0.00379) resulted in significant anti-tumor efficacy, the greatest efficacy was achieved with combination therapy (>93% TGI for all combination conditions tested compared to vehicle + isotype controls (p <0.0001 ). PF-07225570 administered Q3Dx3 in the combination regimen also resulted in statistically significant TGI compared to anti-PD-1 single agent therapy (p = 0.0091) but did not reach significance compared to PF-07225570 single agent therapy (p = 0.1676) at day 20 post implant. Significant single agent efficacy of anti-PD-1 and PF-07225570 was observed in this model when using vehicle + isotype as the control using TGI calculated at day 20 post implant. Using single agents as the control group in the TGI formula, we were able to calculate TGI and compare combination groups to single agents at day 24 post implant. TGI and p-values are summarized in Table 2 (anti-PD-1 single agent as the control), Table 3 (PF-07225570 single agent as the control), and FIG. 2. PF- 07225570 Q3Dx3 combination therapy resulted in significant TGI compared to both anti-PD-1 and PF-07225570 single agent controls at day 24 post implant (TGI = 94.1%, p = 0.0382 and TGI = 93.84%, p = 0.0287, respectively).

Table 1 : In Vivo Efficacy Summary for Combinatorial Study of PF-07225570 and

Anti-PD-1 in MB-49 Syngeneic Model Compared to Vehicle + Isotype Control p-values determined by ANCOVA and TGI were determined on day 20 with Vehicle + Isotype as control using Pfizer-internal TGI analyzer software. Number of animals per group = 10.

Table 2: In Vivo Efficacy Summary for Combinatorial Study of PF-07225570 and

Anti-PD-1 in MB-49 Syngeneic Model Compared to Single Agent Anti-PD-1 Control p-values determined by ANCOVA and TGI were determined on day 24 with Vehicle + anti- PD-1 as control using Pfizer-internal TGI analyzer software. Number of animals per group = 10

Table 3: In Vivo Efficacy Summary for Combinatorial Study of PF-07225570 and

Anti-PD-1 in MB-49 Syngeneic Model Compared to Single Agent PF-07225570 Control

Responders were defined as having two consecutive tumor measurements that were lower than previous measurements after randomization and dosing began. The number of responders and p-values are summarized in Table 4. Single agent therapy did not produce a statistically significant number of responders compared to vehicle + isotype control group, whereas combination therapy induced statistically significant increased numbers of responders in all combination regimens tested compared to vehicle + isotype control (Q3Dx3, p = 0.0001 ; Q3Dx2, p = 0.0007; Q1 Dx1 , p = 0.0031 ; QWx2, p = 0.0031). PF-07225570 Q3Dx3 combination therapy also resulted in statistically significant increased number of responders compared to anti-PD-1 single agent therapy (p = 0.0055) and trended towards significance compared to PF- 07225570 single agent therapy (p = 0.0573). Table 4: Number of Responders in Combinatorial Study of PF-07225570 and

Anti-PD-1 in MB-49 Syngeneic Model

Survival and p-values are summarized in Table 5 and FIG. 3. Single agent therapy resulted in significant survival benefit compared to vehicle + isotype treated control (anti-PD-1 alone, p=0.006; PF-07225570 alone, p=0.0021 ) and all combination therapies tested resulted in significant survival benefit (p <0.0001 ) compared to vehicle + isotype treated controls. Additionally, combination group PF-07225570 dosed Q3Dx3 also showed significant survival benefit over single agent anti-PD-1 (p=0.0271 ) and single agent PF-07225570 (p=0.0319). PF-07225570 Q1 Dx1 combination therapy also resulted in statistically significant

TGI at day 20 compared to anti-PD-1 single agent therapy (p = 0.009, Table 1) and at day 24 compared to PF-07225570 single agent therapy (TGI = 67.07%, p = 0.046, Table 3). Q3Dx2 combination therapy resulted in statistically significant increased number of responders compared to anti-PD-1 single agent therapy (p = 0.023, Table 4). Lastly, Q1 Dx1 combination therapy showed significant survival benefit over single agent anti-PD-1 (p = 0.0361 , Table 5) and single agent PF-07225570 (p = 0.0392, Table 5) treatment.

Table 5: Survival Summary for Combinatorial Study of PF-07225570 and Anti-

PD-1 in MB-49 Syngeneic Model group=10

In summary, single agent PF-07225570 and single agent anti-PD-1 provided statistically significant TGI and survival benefit compare to vehicle + isotype controls. While the number of responders was not significantly different comparing single agent therapy to vehicle + isotype controls, all combination therapies, regardless of PF- 07225570 dose regimen tested, resulted in an increased number of responders, significant TGI at day 20 post implant, and significant survival advantage compared to vehicle + isotype treated controls. The combination of anti-PD-1 and PF-07225570 dosed Q3Dx3 provided significant survival and TGI at day 24 post implant over anti-PD- 1 and PF-07225570 single agent therapy. In addition, combination of anti-PD-1 and PF- 07225570 dosed Q3Dx3 provided significant responder benefit over anti-PD-1 and near significant (p = 0.0573) responder benefit over PF-07225570 single agent controls. Reducing PF-07225570 dosing (Q3Dx2 or Q1 Dx1 ) in combination with anti-PD-1 did provided some efficacy over anti-PD-1 and single agent PF-07225570 therapy but did not reach significance with every metric. Taken together, this data supports the therapeutic benefit of PF-07225570 in combination with anti-PD-1 in the MB-49 bladder cancer model.

All references cited herein, including patent applications, patent publications cited in the specification are herein incorporated by reference in their entirety. Although the foregoing disclosure has been described in some detail by way of illustration and example, it will be readily apparent to those of ordinary skill in the art in light of the teachings of this disclosure that certain changes and modifications may be made thereto without departing from the spirit or scope of the appended claims.

The foregoing description and Examples detail certain specific embodiments of the disclosure and describes the best mode contemplated by the inventors. It will be appreciated, however, that no matter how detailed the foregoing may appear in text, the disclosure may be practiced in many ways and the disclosure should be construed in accordance with the appended claims and any equivalents thereof.