COMBINATION THERAPIES USING CDK INHIBITORS Reference to Sequence Listing

This application is being filed electronically via EFSWeb and includes an electronically submitted sequence listing in .txt format. The .txt file contains a sequence listing entitled "PC72482ApctSEQLISTING_ST25.txt" created on April 13, 2020 and having a size of 19 KB. The sequence listing contained in this .txt file is part of the specification and is herein incorporated by reference in its entirety.

Field of the Invention

The present invention relates to combination therapies useful for the treatment of cancers. In particular, the invention relates to combination therapies which comprise administering a CDK inhibitor or a pharmaceutically acceptable salt thereof, or a pharmaceutical composition comprising such compounds or salts, in combination with an 0X40 agonist and/or a 4-1 BB agonist. The invention also relates to associated methods of treatment, pharmaceutical compositions, and pharmaceutical uses. The methods and compositions 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

Cyclin dependent kinases (CDKs) are important cellular enzymes that perform essential functions in regulating eukaryotic cell division and proliferation. The cyclin dependent kinase catalytic units are activated by regulatory subunits known as cyclins. At least sixteen mammalian cyclins have been identified (Johnson DG, Walker CL. Cyclins and Cell Cycle Checkpoints. Annu. Rev. Pharmacol. Toxicol. 1999, 39:295312). Cyclin B/CDK1 , cyclin A/CDK2, cyclin E/CDK2, cyclin D/CDK4, cyclin D/CDK6, and likely other heterodynes are important regulators of cell cycle progression. Additional functions of cyclin/CDK heterodynes include regulation of transcription, DNA repair, differentiation and apoptosis (Morgan DO. Cyclin dependent kinases: engines, clocks, and microprocessors. Annu. Rev. Cell. Dev. Biol. 1997, 13:261291).

Cyclin dependent kinase inhibitors have been demonstrated to be useful in treating cancer. Increased activity or temporally abnormal activation of cyclin dependent kinases has been shown to result in the development of human tumors, and human tumor development is commonly associated with alterations in either the CDK proteins themselves or their regulators (CordonCardo C., Mutations of cell cycle regulators: biological and clinical implications for human neoplasia. Am. J. Pathol. 1995, 147:545560; Karp JE, Broder S. Molecular foundations of cancer: new targets for intervention. Nat. Med. 1995, 1 :309320; Hall M, Peters G. Genetic alterations of cyclins, cyclin dependent kinases, and CDK inhibitors in human cancer. Adv. Cancer Res. 1996, 68:67108). Amplifications of the regulatory subunits of CDKs and cyclins, and mutation, gene deletion, or transcriptional silencing of endogenous CDK inhibitors have also been reported (Smalley et at. Identification of a novel subgroup of melanomas with KIT/cyclin dependent kinase4 overexpression. Cancer Res 2008, 68: 574352).

CDK4/6 inhibitors palbociclib, ribociclib and abemaciclib have been approved for treatment of hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced or metastatic breast cancer in combination with aromatase inhibitors in post-menopausal women, and in combination with fulvestrant after disease progression following endocrine therapy, (O’Leary et at. Treating cancer with selective CDK4/6 inhibitors. Nature Reviews 2016, 13:417-430). While CDK4/6 inhibitors have shown significant clinical efficacy in HR-positive metastatic breast cancer, as with other kinases their effects may be limited over time by the development of primary or acquired resistance.

Overexpression of CDK2 is associated with abnormal regulation of cell-cycle. The cyclin E/CDK2 complex plays and important role in regulation of the G1/S transition, histone biosynthesis and centrosome duplication. Progressive phosphorylation of Rb by cyclin D/Cdk4/6 and cyclin E/Cdk2 releases the G1 transcription factor, E2F, and promotes S-phase entry. Activation of cyclin A/CDK2 during early S-phase promotes phosphorylation of endogenous substrates that permit DNA replication and inactivation of E2F, for S-phase completion. (Asghar et at. The history and future of targeting cyclin- dependent kinases in cancer therapy, Nat. Rev. Drug. Discov. 2015, 14(2): 130-146).

Cyclin E, the regulatory cyclin for CDK2, is frequently overexpressed in cancer. Cyclin E amplification or overexpression has long been associated with poor outcomes in breast cancer. (Keyomarsi et ai, Cyclin E and survival in patients with breast cancer, N Engl J Med. 2002, 347:1566-75). Cyclin E2 (CCNE2) overexpression is associated with endocrine resistance in breast cancer cells and CDK2 inhibition has been reported to restore sensitivity to tamoxifen or CDK4 inhibitors in tamoxifen-resistant and CCNE2 overexpressing cells. (Caldon et ai, Cyclin E2 overexpression is associated with endocrine resistance but not insensitivity to CDK2 inhibition in human breast cancer cells. Mol Cancer Tfter. 2012, 1 1 : 1488-99; Herrera-Abreu et al., Early Adaptation and Acquired Resistance to CDK4/6 Inhibition in Estrogen Receptor-Positive Breast Cancer, Cancer Res. 2016, 76: 2301-2313). Cyclin E amplification also reportedly contributes to trastuzumab resistance in HER2+ breast cancer. (Scaltriti et at. Cyclin E amplification/overexpression is a mechanism of trastuzumab resistance in HER2+ breast cancer patients, Proc Natl Acad Sci. 2011 , 108: 3761-6). Cyclin E overexpression has also been reported to play a role in basal-like and triple negative breast cancer (TNBC), as well as inflammatory breast cancer. (Elsawaf & Sinn, Triple Negative Breast Cancer: Clinical and Histological Correlations, Breast Care 201 1 , 6:273-278; Alexander et ai, Cyclin E overexpression as a biomarker for combination treatment strategies in inflammatory breast cancer, Oncotarget 2017, 8: 14897-1491 1).

Amplification or overexpression of cyclin E1 (CCNE1) is associated with poor outcomes in ovarian, gastric, endometrial and other cancers. (Nakayama et ai, Gene amplification CCNE1 is related to poor survival and potential therapeutic target in ovarian cancer, Cancer 2010, 1 16: 2621-34; Etemadmoghadam et ai, Resistance to CDK2 Inhibitors Is Associated with Selection of Polyploid Cells in CCNE1-Amplified Ovarian Cancer, Clin Cancer Res 2013, 19: 5960-71 ; Au-Yeung et ai, Selective Targeting of Cyclin E1 -Amplified High-Grade Serous Ovarian Cancer by Cyclin-Dependent Kinase 2 and AKT Inhibition, Clin. Cancer Res. 2017, 23: 1862-1874; Ayhan et ai, CCNE1 copy- number gain and overexpression identify ovarian clear cell carcinoma with a poor prognosis, Modern Pathology 2017, 30: 297-303; Ooi et ai, Gene amplification of CCNE1 , CCND1 , and CDK6 in gastric cancers detected by multiplex ligation-dependent probe amplification and fluorescence in situ hybridization, Hum Pathol. 2017, 61 : 58-67; Noske et ai, Detection of CCNE1/URI (19q12) amplification by in situ hybridization is common in high grade and type II endometrial cancer, Noske, et. al. , Detection of CCNE1/URI (19q12) amplification by in situ hybridisation is common in high grade and type II endometrial cancer, Oncotarget 2017, 8: 14794-14805).

Palbociclib, or 6-acetyl-8-cyclopentyl-5-methyl-2-(5-piperazin-1-yl-pyridin- 2- ylamino)-8/-/-pyrido[2,3-c]pyrimidin-7-one (also referred to as“palbo,”“Palbo” or“PD- 0332991”) is a potent and selective inhibitor of CDK4 and CDK6, having the structure: Palbociclib is described in WHO Drug Information, 2013, Vol. 27, No. 2, page 172. Palbociclib and pharmaceutically acceptable salts thereof, are disclosed in International Publication No. WO 2003/062236 and U.S. Patent Nos. 6,936,612, 7,208,489 and 7,456,168; International Publication No. WO 2005/005426 and U.S. Patent Nos. 7,345,171 and 7,863,278; International Publication No. WO 2008/032157 and U.S. Patent No. 7,781 ,583; and International Publication No. WO 2014/128588. The contents of each of the foregoing references are incorporated herein by reference in their entirety.

The compound PF-06873600, or 6-(difluoromethyl)-8-((1 R,2R)-2-hydroxy-2- methylcyclopentyl)-2-(1-(methylsulfonyl)piperidin-4-ylamino) pyrido[2,3-d]pyrimidin- 7(8H)-one, is a potent and selective inhibitor of CDK2, CDK4 and CDK6, having the structure:

PF-06873600 and pharmaceutically acceptable salts thereof, are disclosed in

International Publication No. WO 2018/033815 published February 22, 2018. The contents of that reference are incorporated herein by reference in their entirety. The 0X40 receptor (also known as CD134, TNFRSF4, ACT-4, ACT35, and TXGP1 L) is a member of the TNF receptor superfamily. 0X40 is found to be expressed on activated CD4+ and CD8+ T-cells. High numbers of 0X40+ T cells have been demonstrated within tumors (tumor infiltrating lymphocytes) and in the draining lymph nodes of cancer patients (Weinberg, A. et ai, J. Immunol. 2000, 164: 2160-69; Petty, J. et ai, Am. J. Surg. 2002, 183: 512-518). It was shown in tumor models in mice that engagement of 0X40 in vivo during tumor priming significantly delayed and prevented the appearance of tumors as compared to control treated mice (Weinberg et ai , 2000). Therefore, it has been contemplated to enhance the immune response of a mammal to an antigen by engaging 0X40 through the use of an 0X40 binding agent (WO 1999/042585; Weinberg et ai., 2000).

4-1 BB (also known as CD137 and TNFRSF9), which was first identified as an inducible costimulatory receptor expressed on activated T cells, is a membrane spanning glycoprotein of the Tumor Necrosis Factor (TNF) receptor superfamily. Current understanding of 4-1 BB indicates that expression is generally activation dependent and encompasses a broad subset of immune cells including activated NK and NKT cells; regulatory T cells; dendritic cells (DC) including follicular DC; stimulated mast cells, differentiating myeloid cells, monocytes, neutrophils, eosinophils, and activated B cells. 4-1 BB expression has also been demonstrated on tumor vasculature (19-20) and atherosclerotic endothelium. The ligand that stimulates 4-1 BB (4-1 BBL) is expressed on activated antigen presenting cells (APCs), myeloid progenitor cells and hematopoietic stem cells. 4-1 BB agonist mAbs increase costimulatory molecule expression and markedly enhance cytolytic T lymphocyte responses, resulting in anti-tumor efficacy in various models. 4-1 BB agonist mAbs have demonstrated efficacy in prophylactic and therapeutic settings and both monotherapy and combination therapy tumor models and have established durable anti-tumor protective T cell memory responses.

Improved therapies for treating, stabilizing, preventing, and/or delaying development of various cancers, including cancers resistant to CDK inhibitors, comprise a large unmet medical need and the identification of novel combination regimens are required to improve treatment outcome. Preferred combination therapies of the present invention show greater efficacy than treatment with the individual therapeutic agents alone.

All references cited herein, including patent applications, patent publications, and UniProtKB/Swiss-Prot Accession numbers are herein incorporated by reference in their entirety, as if each individual reference were specifically and individually indicated to be incorporated by reference.

Summary of the Invention

This invention relates to therapeutic methods, combinations, and pharmaceutical compositions for use in the treatment of cancer. Also provided are combination therapies comprising the compounds of the invention, in combination with other therapeutic agents. The present invention also provides kits comprising one or more of the compositions of the invention.

In one aspect, the invention provides a method for treating cancer comprising administering to a subject in need thereof, an amount of a cyclin dependent kinase (CDK) inhibitor in combination with an amount of: a. an OX-40 agonist; b. a 4-1 BB agonist; or c. an OX-40 agonist and a 4-1 BB agonist; wherein the CDK inhibitor is an inhibitor of CDK4 and CDK6 (CDK4/6 inhibitor); or an inhibitor of CDK2, CDK4 and CDK6 (CDK2/4/6 inhibitor); and wherein the amounts together are effective in treating cancer.

In some embodiments of the treatment methods as described herein, the 0X40 agonist is an anti-OX40 antibody, an OX40L agonist fragment, an 0X40 oligomeric receptor, a trimeric OX40L-Fc protein or an 0X40 immunoadhesin, or a combination thereof.

In one embodiment, the 0X40 agonist is an anti-OX40 antibody. In a specific embodiment, the anti-OX40 antibody is MEDI6469, MEDI0562, MEDI6383, MOXR0916, or GSK3174998, or a combination thereof.

In a further embodiment, the anti-OX40 antibody is a full-length human lgG-1 antibody.

In some embodiments, the 0X40 agonist is an OX40L agonist fragment comprising one or more extracellular domains of OX40L.

In some embodiments of the treatment methods as described herein, the 4-1 BB agonist is an anti-4-1 BB antibody.

In some embodiments, the 4-1 BB agonist is utomilumab (PF-05082566), 1 D8, 3Elor, 4B4, H4-1 BB-M127, BBK2, 145501 , antibody produced by cell line deposited as ATCC No. HB-1 1248, 5F4, C65-485, urelumab (BMS-663513), 20H4.9-lgG-1 (BMS- 663031), 4E9, BMS-554271 , BMS-469492, 3H3, BMS- 469497, 3EI, 53A2, or 3B8.

In some embodiments of the methods as described herein, the CDK inhibitor is a

CDK4/6 inhibitor. In a specific embodiment, the CDK4/6 inhibitor is palbociclib, or a pharmaceutically acceptable salt thereof.

In some embodiments of the methods as described herein, the CDK inhibitor is a CDK2/4/6 inhibitor.

In a specific embodiment, the CDK2/4/6 inhibitor is 6-(difluoromethyl)-8-((1 R,2R)- 2-hydroxy-2-methylcyclopentyl)-2-(1-(methylsulfonyl)piperidi n-4-ylamino)pyrido[2,3- d]pyrimidin-7(8H)-one, or a pharmaceutically acceptable salt thereof.

In some embodiments of the methods as described herein, the subject is a human.

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

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

In some embodiments of the methods as described herein, the cancer is selected from the group consisting of brain cancer, head/neck cancer (including squamous cell carcinoma of the head and neck (SCCHN)), prostate cancer, ovarian cancer, bladder cancer (including 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, bone cancer, colorectal cancer, kidney cancer, liver cancer (including hepatocellular carcinoma (HCC)), stomach cancer, pancreatic cancer, esophageal cancer , cervical cancer, sarcoma, skin cancer (including melanoma and Merkel cell carcinoma (MCC)), multiple myeloma, mesothelioma, malignant rhabdoid tumors, neuroblastoma, diffuse intrinsic pontine glioma (DIPG), carcinoma, lymphoma, diffuse large B-cell lymphoma (DLBCL), primary mediastinal B- cell lymphoma (PMBCL), follicular lymphoma, acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), chronic myeloid leukemia (CML), follicular lymphoma, Hodgkin’s lymphoma (HL), classical Hodgkin lymphoma (cHL), mantle cell lymphoma (MCL), multiple myeloma (MM), myeloid cell leukemia-1 protein (Mcl-1), myelodysplastic syndrome (MDS), non-Hodgkin’s lymphoma (NHL), small lymphocytic lymphoma (SLL), and SWI/SNF-mutant cancer.

In certain embodiments, the methods of the present invention further comprise administering chemotherapy, radiotherapy, immunotherapy, or phototherapy, or any combinations thereof, to the subject.

In one aspect, the invention provides a combination comprising: a. (i) palbociclib, or a pharmaceutically acceptable salt thereof; and (ii) an 0X40 agonist;

b. (i) palbociclib, or a pharmaceutically acceptable salt thereof; (ii) a 4-1 BB agonist; or

c. (i) palbociclib, or a pharmaceutically acceptable salt thereof; (ii) an 0X40 agonist; and (iii) a 4-1 BB agonist;

for use in the treatment of cancer in a subject.

In one aspect, the invention provides a combination comprising:

a. (i) 6-(difluoromethyl)-8-((1 R,2R)-2-hydroxy-2-methylcyclopentyl)-2-(1-

(methylsulfonyl)piperidin-4-ylamino)pyrido[2,3-d]pyrimidi n-7(8H)-one, or a pharmaceutically acceptable salt thereof; and (ii) an 0X40 agonist;

b. (i) 6-(difluoromethyl)-8-((1 R,2R)-2-hydroxy-2-methylcyclopentyl)-2-(1-

(methylsulfonyl)piperidin-4-ylamino)pyrido[2,3-d]pyrimidi n-7(8H)-one, or a pharmaceutically acceptable salt thereof; and (ii) a 4-1 BB agonist; or

c. (i) 6-(difluoromethyl)-8-((1 R,2R)-2-hydroxy-2-methylcyclopentyl)-2-(1-

(methylsulfonyl)piperidin-4-ylamino)pyrido[2,3-d]pyrimidi n-7(8H)-one, or a pharmaceutically acceptable salt thereof; (ii) an 0X40 agonist; and (iii) a 4-1 BB agonist; for use in the treatment of cancer in a subject.

In some embodiments of the combinations as described herein, the 0X40 agonist is an anti-OX40 antibody; and/or the 4-1 BB agonist is an anti-4-1 BB antibody.

In specific embodiments of the combinations as described herein, the combination is synergistic. In some embodiments of the combinations as described herein, the subject is a human. In some embodiments of the combinations as described herein, the cancer is a solid tumor. In some embodiments of the combinations as described herein, the cancer is a hematologic cancer.

In some embodiments of the combinations as described herein, the cancer is selected from the group consisting of brain cancer, head/neck cancer (including squamous cell carcinoma of the head and neck (SCCHN)), prostate cancer, ovarian cancer, bladder cancer (including 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, bone cancer, colorectal cancer, kidney cancer, liver cancer (including hepatocellular carcinoma (HCC)), stomach cancer, pancreatic cancer, esophageal cancer , cervical cancer, sarcoma, skin cancer (including melanoma and Merkel cell carcinoma (MCC)), multiple myeloma, mesothelioma, malignant rhabdoid tumors, neuroblastoma, diffuse intrinsic pontine glioma (DIPG), carcinoma, lymphoma, diffuse large B-cell lymphoma (DLBCL), primary mediastinal B-cell lymphoma (PMBCL), follicular lymphoma, acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), chronic myeloid leukemia (CML), follicular lymphoma, Hodgkin’s lymphoma (HL), classical Hodgkin lymphoma (cHL), mantle cell lymphoma (MCL), multiple myeloma (MM), myeloid cell leukemia-1 protein (Mcl-1), myelodysplastic syndrome (MDS), non- Hodgkin’s lymphoma (NHL), small lymphocytic lymphoma (SLL), and SWI/SNF-mutant cancer.

In some embodiments, the cancer is breast cancer. Breast cancer may include luminal A, luminal B, triple negative/basal-like, or HER2-enriched subtypes. Breast cancers may be estrogen receptor (ER)-positive and/or progesterone receptor (PR)- positive, alternatively referred to as hormone receptor (HR)-positive. HR-positive breast cancers may be human epidermal growth factor receptor 2 (HER2)-negative (i.e. , HR+/HER2-) or HER2-positive (i.e., HR+/HER2+). HR-negative breast cancers may be HER2-positive (i.e., HR-/HER2+) or HER-negative (HR-/HER2-), i.e.,“triple negative” breast cancer (TNBC). In some embodiments, the breast cancer demonstrates primary or acquired resistance to endocrine therapy, anti-HER2 agents and/or CDK4/CDK6 inhibitors. In some embodiments, the breast cancer is advanced or metastatic breast cancer. In some embodiments of the foregoing, the breast cancer is characterized by amplification or overexpression of CCNE1 and/or CCNE2.

In one aspect, the invention provides a kit comprising: a. (i) a pharmaceutical composition comprising a CDK inhibitor and a pharmaceutically acceptable carrier; and (ii) a pharmaceutical composition comprising an 0X40 agonist and a pharmaceutically acceptable carrier; b. (i) a pharmaceutical composition comprising a CDK inhibitor and a pharmaceutically acceptable carrier; and (ii) a pharmaceutical composition comprising a 4-1 BB agonist and a pharmaceutically acceptable carrier; or c. (i) a pharmaceutical composition comprising a CDK inhibitor and a pharmaceutically acceptable carrier; (ii) a pharmaceutical composition comprising an 0X40 agonist and a pharmaceutically acceptable carrier; and (iii) a pharmaceutical composition comprising a 4-1 BB agonist and a pharmaceutically acceptable carrier; and instructions for dosing of the pharmaceutical compositions for the treatment of cancer.

In some embodiments of the kits as described herein, the 0X40 agonist is an anti- 0X40 antibody; and/or the 4-1 BB agonist is an anti-4-1 BB antibody. In some embodiments of the kits as described herein, the CDK inhibitor is a CDK4/6 inhibitor. In a particular embodiment, the CDK4/6 inhibitor is palbociclib, or a pharmaceutically acceptable salt thereof.

In some embodiments of the kits as described herein, the CDK inhibitor is a CDK2/4/6 inhibitor. In a particular embodiment, CDK2/4/6 inhibitor is 6-(difluoromethyl)- 8-((1 R,2R)-2-hydroxy-2-methylcyclopentyl)-2-(1-(methylsulfonyl)pi peridin-4- ylamino)pyrido[2,3-d]pyrimidin-7(8H)-one, or a pharmaceutically acceptable salt thereof.

Brief Description of the Drawings

Figure 1 depicts syngeneic MC38 tumor growth inhibition comparing Isotype/Vehicle control with immune checkpoint blockade alone (anti-OX40 antibody (PF- 07201252)/anti-4-1 BB antibody (PF-07218859)), CDK2/4/6 inhibition alone (PF- 06873600) and the combination of checkpoint blockade with CDK2/4/6 inhibition (CDK2/4/6 inhibitor + anti-OX40 antibody (PF-07201252)/anti-4-1 BB antibody (PF- 07218859)) as cohort mean tumor volume (error bars represent standard error of the mean).

Figure 2A depicts syngeneic MC38 tumor growth inhibition response to isotype and vehicle control from Figure 1 as individual tumor growth curves.

Figure 2B depicts syngeneic MC38 tumor growth inhibition response to immune checkpoint blockade alone (anti-OX40 antibody (PF-07201252)/anti-4-1 BB antibody (PF- 07218859)) from Figure 1 as individual tumor growth curves.

Figure 2C depicts syngeneic MC38 tumor growth inhibition response to CDK2/4/6 inhibition alone (PF-06873600) from Figure 1 as individual tumor growth curves.

Figure 2D depicts syngeneic MC38 tumor growth inhibition response to the combination of checkpoint blockade with CDK2/4/6 inhibition (CDK2/4/6 inhibitor + anti- 0X40 antibody (PF-07201252)/anti-4-1 BB antibody (PF-07218859)) from Figure 1 as individual tumor growth curves.

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. Furthermore, each of the embodiments described herein envisions within its scope pharmaceutically acceptable salts of the small molecule compounds described herein. Accordingly, the phrase“or a pharmaceutically acceptable salt thereof” is implicit in the description of all small molecule compounds described herein. I. Abbreviations

Throughout the detailed description and examples of the invention the following abbreviations will be used:

BID One dose twice daily

CDR Complementarity determining region

CHO Chinese hamster ovary

CR Complete Response

DFS Disease free survival

DMSO Dimethylsulphoxide

DTR Dose limiting toxicity

FBS Fetal bovine serum

FFPE Formalin-fixed, paraffin-embedded

FR Framework region

IgG Immunoglobulin G

IHC Immunohistochemistry or immunohistochemical

MPK Milligram Per Kilogram (mg/kg or mg drug per kg body weight of animal)

MTD Maximum tolerated dose

NCBI National Center for Biotechnology Information

NCI National Cancer Institute

OR Overall response

OS Overall survival

PD Progressive disease

PFS Progression free survival

PR Partial response

G2W One dose every two weeks

G3W One dose every three weeks

G4W One dose every four weeks

QD One dose per day

RECIST Response Evaluation Criteria in Solid Tumors

RPMI Roswell Park Memorial Institute

SD Stable disease

TGI Tumor Growth Inhibition

VH Immunoglobulin heavy chain variable region

VK Immunoglobulin kappa light chain variable region

w/w Weight per weight II. Definitions

The present invention may be understood more readily by reference to the following detailed description of the preferred embodiments of the invention and the Examples included herein. It is to be understood that the terminology used herein is for the purpose of describing specific embodiments only and is not intended to be limiting. It is further to be understood that unless specifically defined herein, the terminology used herein is to be given its traditional meaning as known in the relevant art.

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 invention described herein suitably may be practiced in the absence of any element(s) not specifically disclosed herein. Thus, for example, in each instance herein any of the terms "comprising," "consisting essentially of,” and "consisting of" may be replaced with either of the other two terms.

The term“about” when used to modify a numerically defined parameter (e.g., the dose of an CDK inhibitor, the dose of an 0X40 agonist (e.g., anti-OX40 antibody), the dose of a 4-1 BB agonist (e.g., anti-4-1 BB antibody), and the like) means that the parameter may vary by as much as 10% above or below the stated numerical value for that parameter. For example, a dose of about 5 mg/kg should be understood to mean that the dose may vary between 4.5 mg/kg and 5.5 mg/kg.

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 invention, e.g., a CDK inhibitor. As used herein, terms, including, but not limited to, “drug,” “agent," “component," “composition," “compound,"“substance,"“targeted agent,"“targeted therapeutic agent,"“therapeutic agent," therapeutic antibody,” and“medicament” may be used interchangeably to refer to the antibodies of the present invention, e.g., an anti-OX40 antibody, and an anti-4- 1 BB antibody, or combinations thereof.

The term“therapeutic antibody” refers 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 of 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 an 0X40, and/or a 4-1 BB antigen. Accordingly, therapeutic antibodies include, without limitation, anti-OX40 antibodies, and anti-4-1 BB antibodies, or combinations thereof.

"Biotherapeutic agent" means a biological molecule, such as an antibody or fusion protein, that blocks ligand / receptor signaling in any biological pathway that supports tumor maintenance and/or growth or suppresses the anti-tumor immune response.

A "chemotherapeutic agent" is a chemical compound useful in the treatment of cancer. Examples of chemotherapeutic agents include alkylating agents such as thiotepa and cyclophosphamide (CYTOXAN®); alkyl sulfonates such as busulfan, improsulfan, and piposulfan; aziridines such as.benzodopa, carboquone, meturedopa, and uredopa; ethylenimines and methylamelamines including altretamine, triethylenemelamine, trietylenephosphoramide, triethiylenethiophosphoramide and trimethylolomelamine; acetogenins (especially bullatacin and bullatacinone); delta-9-tetrahydrocannabinol (dronabinol, MARINOL®); beta-lapachone; lapachol; colchicines; betulinic acid; a camptothecin (including the synthetic analogue topotecan (HYCAMTIN®), CPT- 11 (irinotecan, CAMPTOSAR®), acetylcamptothecin, scopolectin, and 9- aminocamptothecin); bryostatin; pemetrexed; callystatin; CC- 1065 (including its adozelesin, carzelesin and bizelesin synthetic analogues); podophyllotoxin; podophyllinic acid; teniposide; cryptophycins (particularly cryptophycin 1 and cryptophycin 8); dolastatin; duocarmycin (including the synthetic analogues, KW-2189 and CB 1 -TM 1 ); eleutherobin; pancratistatin; TLK-286; CDP323, an oral alpha-4 integrin inhibitor; a sarcodictyin; spongistatin; nitrogen mustards such as chlorambucil, chlornaphazine, cholophosphamide, estramustine, ifosfamide, mechlorethamine, mechlorethamine oxide hydrochloride, melphalan, novembichin, phenesterine, prednimustine, trofosfamide, uracil mustard; nitrosureas such as carmustine, chlorozotocin, fotemustine, lomustine, nimustine, and ranimnustine; antibiotics such as the enediyne antibiotics (e. g. , calicheamicin, especially calicheamicin gamma and calicheamicin omegal (see, e.g., Nicolaou et ai, Angew. Chem Inti. Ed. Engl., 1994, 33: 183- 186); dynemicin, including dynemicin A; an esperamicin; as well as neocarzi nostatin chromophore and related chromoprotein enediyne antibiotic chromophores), aclacinomysins, actinomycin, authramycin, azaserine, bleomycins, cactinomycin, carabicin, carminomycin, carzinophilin, chromomycinis, dactinomycin, daunorubicin, detorubicin, 6-diazo-5-oxo-L- norleucine, doxorubicin (including ADRIAMYCIN®, morpholino-doxorubicin, cyanomorpholino-doxorubicin, 2-pyrrolino-doxorubicin, doxorubicin HC1 liposome injection (DOXIL®) and deoxydoxorubicin), epirubicin, esorubicin, idarubicin, marcellomycin, mitomycins such as mitomycin C, mycophenolic acid, nogalamycin, olivomycins, peplomycin, potfiromycin, puromycin, quelamycin, rodorubicin, streptonigrin, streptozocin, tubercidin, ubenimex, zinostatin, zorubicin; anti-metabolites such as methotrexate, gemcitabine (GEMZAR®), tegafur (UFTORAL®), capecitabine (XELODA®), an epothilone, and 5-fluorouracil (5-FU); folic acid analogues such as denopterin, methotrexate, pteropterin, trimetrexate; purine analogs such as fludarabine, 6-mercaptopurine, thiamiprine, thioguanine; pyrimidine analogs such as ancitabine, azacitidine, 6-azauridine, carmofur, cytarabine, dideoxyuridine, doxifluridine, enocitabine, floxuridine, and imatinib (a 2-phenylaminopyrimidine derivative), as well as other c- it inhibitors; anti-adrenals such as aminoglutethimide, mitotane, trilostane; folic acid replenisher such as frolinic acid; aceglatone; aldophosphamide glycoside; aminolevulinic acid; eniluracil; amsacrine; bestrabucil; bisantrene; edatraxate; defofamine; demecolcine; diaziquone; elfornithine; elliptinium acetate; etoglucid; gallium nitrate; hydroxyurea; lentinan; lonidainine; maytansinoids such as maytansine and ansamitocins; mitoguazone; mitoxantrone; mopidanmol; nitraerine; pentostatin; phenamet; pirarubicin; losoxantrone; 2-ethylhydrazide; procarbazine; PSK® polysaccharide complex (JHS Natural Products, Eugene, OR); razoxane; rhizoxin; sizofiran; spirogermanium; tenuazonic acid; triaziquone; 2,2',2"-trichlorotriethylamine; trichothecenes (especially T-2 toxin, verracurin A, roridin A and anguidine); urethan; vindesine (ELDIS1 NE®, FILDESIN®); dacarbazine; mannomustine; mitobronitol; mitolactol; pipobroman; gacytosine; arabinoside ("Ara-C"); thiotepa; taxoids, e.g., paclitaxel (TAXOL®), albumin-engineered nanoparticle formulation of paclitaxel (ABRAXANE™), and doxetaxel (TAXOTERE®); chloranbucil; 6-thioguanine; mercaptopurine; methotrexate; platinum analogs such as cisplatin and carboplatin; vinblastine (VELBAN®); platinum; etoposide (VP-16); ifosfamide; mitoxantrone; vincristine (ONCOVIN®); oxaliplatin; leucovovin; vinorelbine (NAVELBINE®); novantrone; edatrexate; daunomycin; aminopterin; ibandronate; topoisomerase inhibitor RFS 2000; difluorometlhylomithine (DMFO); retinoids such as retinoic acid; pharmaceutically acceptable salts, acids or derivatives of any of the above; as well as combinations of two or more of the above such as CHOP, an abbreviation for a combined therapy of cyclophosphamide, doxorubicin, vincristine, and prednisolone, and FOLFOX, an abbreviation for a treatment regimen with oxaliplatin (ELOXATIN™) combined with 5- FU and leucovovin.

Additional examples of chemotherapeutic agents include anti-hormonal agents that act to regulate, reduce, block, or inhibit the effects of hormones that can promote the growth of cancer, and are often in the form of systemic, or whole-body treatment. They may be hormones themselves. Examples include anti-estrogens and selective estrogen receptor modulators (SERMs), including, for example, tamoxifen (including NOLVADEX® tamoxifen), raloxifene (EVISTA®), droloxifene, 4-hydroxytamoxifen, trioxifene, keoxifene, LY 1 1 7018, onapristone, and toremifene (FARESTON®); anti-progesterones; estrogen receptor down-regulators (ERDs); estrogen receptor antagonists such as fulvestrant (FASLODEX®); agents that function to suppress or shut down the ovaries, for example, luteinizing hormone-releasing hormone (LHRFI) agonists such as leuprolide acetate (LUPRON® and ELIGARD®), goserelin acetate, buserelin acetate and tripterelin; anti androgens such as fiutamide, nilutamide and bicalutamide; and aromatase inhibitors that inhibit the enzyme aromatase, which regulates estrogen production in the adrenal glands, such as, for example, 4(5)-imidazoles, aminoglutethimide, megestrol acetate (MEGASE®), exemestane (AROMASIN®), formestanie, fadrozole, vorozole (RJVISOR®), letrozole (FEMARA®), and anastrozole (ARIMIDEX®). In addition, such definition of chemotherapeutic agents includes bisphosphonates such as clodronate (for example, BONEFOS® or OSTAC®), etidronate (DIDROCAL®), NE-58095, zoledronic acid/zoledronate (ZOMETA®), alendronate (FOSAMAX®), pamidronate (AREDIA®), tiludronate (SKELID®), or risedronate (ACTONEL®); as well as troxacitabine (a 1 ,3- dioxolane nucleoside cytosine analog); anti-sense oligonucleotides, particularly those that inhibit expression of genes in signaling pathways implicated in abherant cell proliferation, such as, for example, PKC-alpha, Raf, H-Ras, and epidermal growth factor receptor (EGF-R); vaccines such as THERATOPE® vaccine and gene therapy vaccines, for example, ALLOVECTIN® vaccine, LEUVECTIN® vaccine, and VAXID® vaccine; topoisomerase 1 inhibitor (e.g., LURTOTECAN®); an anti-estrogen such as fulvestrant; a Kit inhibitor such as imatinib or EXEL-0862 (a tyrosine kinase inhibitor); EGFR inhibitor such as erlotinib or cetuximab; an anti-VEGF inhibitor such as bevacizumab; arinotecan; rmRH (e.g., ABARELIX®); lapatinib and lapatinib ditosylate (an ErbB-2 and EGFR dual tyrosine kinase small-molecule inhibitor also known as GW572016); 17AAG (geldanamycin derivative that is a heat shock protein (Hsp) 90 poison), and pharmaceutically acceptable salts, acids or derivatives of any of the above.

As used herein, the term "cytokine" refers generically to proteins released by one cell population that act on another cell as intercellular mediators or have an autocrine effect on the cells producing the proteins. Examples of such cytokines include lymphokines, monokines; interleukins ("ILs") such as IL- 1 , IL- la, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL10, IL-1 1 , IL-12, IL-13, IL-15, IL-17A-F, IL-18 to IL-29 (such as IL-23), IL-31 , including PROLEUKIN ^® rlL-2; a tumor-necrosis factor such as TNF-a or TNF-b, TGF- I -3; and other polypeptide factors including leukemia inhibitory factor ("LIF"), ciliary neurotrophic factor ("CNTF"), CNTF-like cytokine ("CLC"), cardiotrophin ("CT"), and kit ligand (" L").

As used herein, the term "chemokine" refers to soluble factors (e.g., cytokines) that have the ability to selectively induce chemotaxis and activation of leukocytes. They also trigger processes of angiogenesis, inflammation, wound healing, and tumorigenesis. Example chemokines include IL-8, a human homolog of murine keratinocyte chemoattractant (KC).

The terms “abnormal cell growth” and “hyperprol iterative disorder” are used interchangeably in this application. “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., lgG-1 , lgG-2, lgG-3, lgG-4, lgA1 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.

As used herein, a “bispecific antibody,” “dual-specific antibody,” “bifunctional antibody,” "heteromultimer,” "heteromultimeric complex,” “bispecific heterodimeric diabody” or a "heteromultimeric polypeptide” is a molecule comprising at least a first polypeptide and a second polypeptide, wherein the second polypeptide differs in amino acid sequence from the first polypeptide by at least one amino acid residue. In some instances, the bispecific is an artificial hybrid antibody having two different heavy chain region and light chain region. Preferably, the bispecific antibody has binding specificity for at least two different ligands, antigens or binding sites. Accordingly, the bispecific antibodies can bind simultaneously two different antigens. The two antigen binding sites of a bispecific antibody bind to two different epitopes, which may reside on the same or different protein targets, e.g., tumor target.

The bispecific antibody, dual-specific antibody, bifunctional antibody, heteromultimer, heteromultimeric complex, bispecific heterodimeric diabody or the heteromultimeric polypeptide can be prepared by constructing sFv fragments with short linkers (e.g., about 3-10 residues) between the VH and VL regions such that inter-chain but not intra-chain pairing of the V regions is achieved, resulting in a bivalent fragment, i.e., fragment having two antigen-binding sites. Bispecific antibodies can be derived from full length antibodies or antibody fragments (e.g., Ftab^ bispecific antibodies). Diabodies are described more fully in, for example, EP404,097; WO 1993/011 161 ; and Hollinger ef a/., Proc. Natl. Acad. Sci. 1993, 90:6444-6448. Bispecific antibodies are heterodimers of two "crossover" sFv fragments in which the VH and VL regions of the two antibodies are present on different polypeptide chains.

By way of non-limiting example, a bispecific antibody may comprise one antigen binding site that recognizes an epitope on one protein (e.g., 0X40, 4-1 BB) and further comprise a second, different antigen-binding site that recognizes a different epitope on a second protein (e.g. , 0X40, 4-1 BB). Generally, but not necessarily, reference to binding means specific binding.

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 g chains and four CH domains for m and e 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, see e.g., Daniel P. Sties, Abba I. Terr and Tristram G. Parslow (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. The terms "full-length antibody," "intact antibody" or "whole antibody" are used interchangeably to refer to an antibody in its substantially intact form, as opposed to an antibody fragment. Specifically, whole antibodies include those with heavy and light chains including an Fc region. The constant domains may be native sequence constant domains (e.g., human native sequence constant domains) or amino acid sequence variants thereof. In some cases, the intact antibody may have one or more effector functions.

An "antibody fragment" comprises a portion of an intact antibody, preferably the antigen binding and/or the variable region of the intact antibody. Examples of antibody fragments suitable for use in this invention include, without limitation: (i) the Fab fragment, consisting of VL, VH, CL, and CH1 domains; (ii) the“Fd” fragment consisting of the VH and CH1 domains; (iii) the“Fv” fragment consisting of the VL and VH domains of a single antibody; (iv) the“dAb” fragment, which consists of a VH domain; (v) isolated CDR regions; (vi) F(ab')2 fragments, a bivalent fragment comprising two linked Fab fragments; (vii) single chain Fv molecules (“scFv”), wherein a VH domain and a VL domain are linked by a peptide linker that allows the two domains to associate to form a binding domain; (viii) bi-specific single chain Fv dimers (see U.S. Pat. No. 5,091 ,513); and (ix) diabodies, multivalent or multispecific fragments constructed by gene fusion (US Pat. Pub. 20050214860). Fv, scFv, or diabody molecules may be stabilized by the incorporation of disulphide bridges linking the VH and VL domains. Minibodies comprising a scFv joined to a CH3 domain may also be made (Hu et ai, Minibodies are minimized antibody-like proteins comprising a scFv joined to a CH3 domain, Cancer Res. 1996, 56:3055-3061).

Murali et ai, Antibody like peptidomimetics as large scale immunodetection probes, Cell Mol Biol 2003, 49:209-216, describe a methodology for reducing antibodies into smaller peptidomimetics, they term“antibody like binding peptidomimetics” (ABiP) which may also be useful as an alternative to antibodies.

"Isolated antibody" or“isolated antibody fragment” refers to the purification status and in such context means the named molecule is substantially free of other biological molecules such as nucleic acids, proteins, lipids, carbohydrates, or other material such as cellular debris and growth media. Generally, the term "isolated" is not intended to refer to a complete absence of such material or to an absence of water, buffers, or salts, unless they are present in amounts that substantially interfere with experimental or therapeutic use of the binding compound as described herein. "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 ai, 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. Pat. No. 4,816,567). The "monoclonal antibodies" may also be isolated from phage antibody libraries using the techniques described in Clackson et ai, Making antibody fragments using phage display libraries, Nature 1991 , 352: 624-628 and Marks et ai, By-passing immunization: human antibodies from V-gene libraries displayed on phage, J. Mot. 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.

A“variable region” of an antibody refers to the variable region of the antibody light chain or the variable region of the antibody heavy chain, either alone or in combination. As known in the art, the variable regions of the heavy and light chain each consist of four framework regions (FR) connected by three complementarity determining regions (CDRs) also known as hypervariable regions.

The term "hypervariable region," "HVR," or "HV " when used herein refers to the regions of an antibody variable domain which are hypervariable in sequence and/or form structurally defined loops. Generally, antibodies comprise six HVRs; three in the VH (H1 , H2, H3), and three in the VL (L1 , L2, L3). In native antibodies, H3 and L3 display the most diversity of the six HVRs, and H3 in particular is believed to play a unique role in conferring fine specificity to antibodies. See, e.g., Xu et al, Disruption of Early Tumor Necrosis Factor Alpha Signaling Prevents Classical Activation of Dendritic Cells in Lung- Associated Lymph Nodes and Development of Protective Immunity against Cryptococcal Infection, Immunity 2000, J-3:37-45; Johnson and Wu, Antibody Engineering Methods and Protocols Methods in Molecular Biology 2003, 248: 1 -25. Indeed, naturally occurring camelid antibodies consisting of a heavy chain only are functional and stable in the absence of light chain. See, e.g., Hamers-Casterman et al., Naturally occurring antibodies devoid of light chains, Nature 1993, 363:446-448; Sheriff et al., Similarity between C2 domain jaws and immunoglobulin CDRs, Nature Struct. Biol 1996, 3:733- 736.

A number of HVR delineations are in use and are encompassed herein. The Kabat Complementarity Determining Regions (CDRs) are based on sequence variability and are the most commonly used (Kabat et al., Sequences of Proteins of Immunological Interest, 5 ^lh Ed. Public Health Service, National Institutes of Health, 1991). Chothia refers instead to the location of the structural loops ( Chothia and Lesk, Canonical structures for the hypervariable regions of immunoglobulins, J. Mol. Biol. 1987, 196:901 -917). The AbM HVRs represent a compromise between the Kabat HVRs and Chothia structural loops, are used by Oxford Molecular's AbM antibody modeling software. The "contact" HVRs are based on an analysis of the available complex crystal structures.

A“CDR” of a variable domain are amino acid residues within the variable region that are identified in accordance with the definitions of the Kabat, Chothia, the accumulation of both Kabat and Chothia, AbM, contact, and/or conformational definitions or any method of CDR determination well known in the art. Antibody CDRs may be identified as the hypervariable regions originally defined by Kabat et al. See, e.g., Kabat et al. See, e.g., Kabat et ai, Sequences of Proteins of Immunological Interest, 5th ed., Public Health Service, NIH, 1992. The positions of the CDRs may also be identified as the structural loop structures originally described by Chothia and others. See, e.g., Chothia et al., Conformations of immunoglobulin hypervariable regions, Nature 1989, 342:877-883. Other approaches to CDR identification include the“AbM definition,” which is a compromise between Kabat and Chothia and is derived using Oxford Molecular's AbM antibody modeling software (now Accelrys ^® ), or the“contact definition” of CDRs based on observed antigen contacts, set forth in MacCallum et al., Antibody-antigen interactions: contact analysis and binding site topography, J. Mol. Biol., 1996, 262:732- 745. In another approach, referred to herein as the“conformational definition” of CDRs, the positions of the CDRs may be identified as the residues that make enthalpic contributions to antigen binding. See, e.g., Makabe et al., Thermodynamic consequences of mutations in vernier zone residues of a humanized anti-human epidermal growth factor receptor murine antibody, 528, Journal of Biological Chemistry, 2008, 283:1156-1166. Still other CDR boundary definitions may not strictly follow one of the above approaches but will nonetheless overlap with at least a portion of the Kabat CDRs, although they may be shortened or lengthened in light of prediction or experimental findings that particular residues or groups of residues or even entire CDRs do not significantly impact antigen binding. As used herein, a CDR may refer to CDRs defined by any approach known in the art, including combinations of approaches. The methods used herein may utilize CDRs defined according to any of these approaches. For any given embodiment containing more than one CDR, the CDRs may be defined in accordance with any of Kabat, Chothia, extended, AbM, contact, and/or conformational definitions.

The expression "variable-domain residue-numbering as in Kabat" or "amino-acid- position numbering as in Kabat," and variations thereof, refers to the numbering system used for heavy-chain variable domains or light-chain variable domains of the compilation of antibodies in Kabat et ai, supra. Using this numbering system, the actual linear amino acid sequence may contain fewer or additional amino acids corresponding to a shortening of, or insertion into, a FR or HVR of the variable domain. For example, a heavy-chain variable domain may include a single amino acid insert (residue 52a according to Kabat) after residue 52 of H2 and inserted residues (e.g., residues 82a, 82b, and 82c, etc. according to Kabat) after heavy-chain FR residue 82. The Kabat numbering of residues may be determined for a given antibody by alignment at regions of homology of the sequence of the antibody with a "standard" Kabat numbered sequence.

"Framework" or "FR" residues are those variable-domain residues other than the HVR residues as herein defined.

A "human consensus framework” or "acceptor human framework " is a framework that represents the most commonly occurring amino acid residues in a selection of human immunoglobulin VL or VH framework sequences. Generally, the selection of human immunoglobulin VL or VH sequences is from a subgroup of variable domain sequences.

Generally, the subgroup of sequences is a subgroup as in Kabat et ai, Sequences of Proteins of Immunological Interest, 5 ^lh Ed. Public Health Service, National Institutes of Health, 1991. Examples for the VL, the subgroup may be subgroup kappa I, kappa II, kappa III or kappa IV as in Kabat et ai, supra. Additionally, for the VH, the subgroup may be subgroup I, subgroup II, or subgroup III as in Kabat et ai., supra. Alternatively, a human consensus framework can be derived from the above in which particular residues, such as when a human framework residue is selected based on its homology to the donor framework by aligning the donor framework sequence with a collection of various human framework sequences. An acceptor human framework "derived from" a human immunoglobulin framework or a human consensus framework may comprise the same amino acid sequence thereof, or it may contain pre-existing amino acid sequence changes. In some embodiments, the number of pre-existing amino acid changes are 10 or less, 9 or less, 8 or less, 7 or less, 6 or less, 5 or less, 4 or less, 3 or less, or 2 or less.

An "amino-acid modification" at a specified position, e.g., of the Fc region, refers to the substitution or deletion of the specified residue, or the insertion of at least one amino acid residue adjacent the specified residue. Insertion "adjacent" to a specified residue means insertion within one to two residues thereof. The insertion may be N- terminal or C-terminal to the specified residue. The preferred amino acid modification herein is a substitution.

"Conservatively modified variants" or "conservative substitution" refers to substitutions of amino acids in a protein with other amino acids having similar characteristics (e.g., charge, side-chain size, hydrophobicity/hydrophilicity, backbone conformation and rigidity, etc.), such that the changes can frequently be made without altering the biological activity or other desired property of the protein, such as antigen affinity and/or specificity. Those of skill in this art recognize that, in general, single amino acid substitutions in non-essential regions of a polypeptide do not substantially alter biological activity (e.g., Watson et a!., Molecular Biology of the Gene (4th Ed.), 1987, p. 224). In addition, substitutions of structurally or functionally similar amino acids are less likely to disrupt biological activity. Exemplary conservative substitutions are set forth in Table 1 below.

Table 1

An "affinity-matured" antibody is one with one or more alterations in one or more HVRs thereof, that result in an improvement in the affinity of the antibody for antigen, compared to a parent antibody that does not possess those alteration(s). In one embodiment, an affinity-matured antibody has nanomolar or even picomolar affinities for the target antigen. Affinity-matured antibodies are produced by procedures known in the art. For example, Marks et ai, By-passing immunization: Building high affinity human antibodies by chain shuffling, Bio/Technology 1992, 10:779-783, describes affinity maturation by VH- and VL- domain shuffling. Random mutagenesis of HVR and/or framework residues is described by, for example: Barbas et ai, In vitro evolution of a neutralizing human antibody to human immunodeficiency virus type 1 to enhance affinity and broaden strain cross-reactivity, Proc Nat. Acad. Sci. 1994, 91 :3809-3813; Schier ef a/., Identification of functional and structural amino-acid residues by parsimonious mutagenesis, Gene 1995, 169: 147- 155; Yelton et ai, Affinity maturation of the BR96 anti-carcinoma antibody by codon-based mutagenesis, J. Immunol. 1995, 155: 1994- 2004; Jackson et ai, In vitro antibody maturation. Improvement of a high affinity, neutralizing antibody against IL-1 beta, J. Immunol. 1995, 154(7):33 10-9; and Hawkins et ai, Selection of phage antibodies by binding affinity: mimicking affinity maturation, J. Mol. Biol. 1992, 226:889-896.

The term "Fc region" herein is used to define a C-terminal region of an immunoglobulin heavy chain, including native-sequence Fc regions and variant Fc regions. Although the boundaries of the Fc region of an immunoglobulin heavy chain might vary, the human IgG heavy-chain Fc region is usually defined to stretch from an amino acid residue at position Cys226, or from Pro230, to the carboxyl-terminus thereof. The C-terminal lysine (residue 447 according to the EU numbering system) of the Fc region may be removed, for example, during production or purification of the antibody, or by recombinantly engineering the nucleic acid encoding a heavy chain of the antibody. Accordingly, a composition of intact antibodies may comprise antibody populations with all K447 residues removed, antibody populations with no K447 residues removed, and antibody populations having a mixture of antibodies with and without the K447 residue. Suitable native-sequence Fc regions for use in the antibodies of the invention include human lgG-1 , lgG-2 (lgG2A, lgG2B), lgG-3 and lgG-4.

"Fc receptor" or "FcR" describes a receptor that binds to the Fc region of an antibody. The preferred FcR is a native sequence human FcR. Moreover, a preferred FcR is one which binds an IgG antibody (a gamma receptor) and includes receptors of the FcyRI, FcyRII, and FeyRIII subclasses, including allelic variants and alternatively spliced forms of these receptors, FcyRII receptors include FcyRI IA (an "activating receptor") and FcyRIIB (an "inhibiting receptor"), which have similar amino acid sequences that differ primarily in the cytoplasmic domains thereof. Activating receptor FcyRIIA contains an immunoreceptor tyrosine-based activation motif (ITAM) in its cytoplasmic domain. Inhibiting receptor FcyRIIB contains an immunoreceptor tyrosine- based inhibition motif (ITGM) in its cytoplasmic domain, (e.g., M. Daeron, Fc RECEPTOR BIOLOGY, Annu. Rev. Immunol. J 1997, 5 :203-234); FcRs are reviewed in Ravetch and Kinet, Fc Receptors, Annu. Rev. Immunol. 1991 , 9: 457-92; Capel et ai, Heterogeneity of human IgG Fc receptors, Immunomethods 1994, 4: 25-34; and de Haas et ai, Fey receptors of phagocytes, J. Lab. Clin. Med. 1995, 126: 330-41. Other FcRs, including those to be identified in the future, are encompassed by the term "FcR" herein.

The term "Fc receptor" or "FcR" also includes the neonatal receptor, FcRn, which is responsible for the transfer of maternal IgGs to the fetus. Guyer et ai, Immunoglobulin binding by mouse intestinal epithelial cell receptors, J. Immunol. 1976, 1 17: 587, and Tokoyama et ai, How do natural killer cells find self to achieve tolerance? Immunity, 1994, 24, 249-257. Methods of measuring binding to FcRn are known (e.g. , Ghetie and Ward, FcRn: the MHC class l-related receptor that is more than an IgG transporter, Immunol. Today 1997, 1 8: (12): 592-8; Ghetie et al., Increasing the serum persistence of an IgG fragment by random mutagenesis, Nat Biotechnol. Jul. 1997; 15(7):637-40; Hinton et ai, Engineered human IgG antibodies with longer serum half-lives in primates, J. Biol. Chem. 2004, 279 (8): 6213-6; WO 2004/092219 (Hinton et ai). Binding to FcRn in vivo and serum half-life of human FcRn high-affinity binding polypeptides can be assayed, e.g., in transgenic mice or transfected human cell lines expressing human FcRn, or in primates to which the polypeptides having a variant Fc region are administered. WO 2004/042072 (Presta) describes antibody variants which improved or diminished binding to FcRs. See also, e.g., Shields et ai, High Resolution Mapping of the Binding Site on Human lgG1 for FcyRI, FcyRII, FeyRIII, and FcRn and Design of lgG1 Variants with Improved Binding to the FcyR, J. Biol. Chem. 2001 , 9(2): 6591 -6604. 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.

The term "substantially similar" or "substantially the same," as used herein, denotes a sufficiently high degree of similarity between two numeric values (for example, one associated with an antibody of the invention and the other associated with a reference/comparator antibody), such that one of skill in the art would consider the difference between the two values to be of little or no biological and/or 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, less than about 50%, less than about 40%, less than about 30%, less than about 20%, and/or less than about 10% as a function of the reference/comparator value.

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 mM, £ 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.

An "agonist" 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.

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 g-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. Examples of cancer include, but are not limited to, brain cancer, head/neck cancer (including squamous cell carcinoma of the head and neck (SCCHN)), prostate cancer, ovarian cancer, bladder cancer (including 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, bone cancer, colorectal cancer, kidney cancer, liver cancer (including hepatocellular carcinoma (HCC)), stomach cancer, pancreatic cancer, esophageal cancer , cervical cancer, sarcoma, skin cancer (including melanoma and Merkel cell carcinoma (MCC)), multiple myeloma, mesothelioma, malignant rhabdoid tumors, diffuse intrinsic pontine glioma (DIPG), carcinoma, lymphoma, diffuse large B-cell lymphoma (DLBCL), primary mediastinal B-cell lymphoma (PMBCL), follicular lymphoma, acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), chronic myeloid leukemia (CML), follicular lymphoma, Hodgkin’s lymphoma (HL), classical Hodgkin lymphoma (cHL), mantle cell lymphoma (MCL), multiple myeloma (MM), myeloid cell leukemia-1 protein (Mcl-1), myelodysplastic syndrome (MDS), non-Hodgkin’s lymphoma (NHL), small lymphocytic lymphoma (SLL), and SWI/SNF-mutant cancer.

As used herein, “in combination with” or "in conjunction with" refers to administration of one treatment modality in addition to at least one other treatment modality. As such,“in combination with” or "in conjunction with" refers to administration of one treatment modality before, during, or after administration of at least one other treatment modality to the individual. An "objective response" refers to a measurable response, including complete response (CR) or partial response (PR). In some embodiments, the term "objective response rate" (ORR) refers to the sum of complete response (CR) rate and partial response (PR) rate.

"Complete response" or "CR," as used herein means the disappearance of all signs of cancer (e.g., disappearance of all target lesions) in response to treatment. This does not always mean the cancer has been cured.

As used herein, "partial response" or "PR" refers to a decrease in the size of one or more tumors or lesions, or in the extent of cancer in the body, in response to treatment. For example, in some embodiments, PR refers to at least a 30% decrease in the sum of the longest diameters (SLD) of target lesions, taking as reference the baseline SLD.

As used herein, "progressive disease" or "PD" refers to at least a 20% increase in the SLD of target lesions, taking as reference the smallest SLD recorded since the treatment started or the presence of one or more new lesions.

As used herein, "progression free survival" or“PFS” refers to the length of time during and after treatment during which the disease being treated (e.g., cancer) does not get worse. Progression-free survival may include the amount of time patients have experienced a complete response or a partial response, as well as the amount of time patients have experienced stable disease.

As used herein, "overall response rate" (ORR) refers to the sum of complete response (CR) rate and partial response (PR) rate.

As used herein, "overall survival" refers to the percentage of individuals in a group who are likely to be alive after a particular duration of time.

"Sustained response" refers to the sustained effect on reducing tumor growth after cessation of a treatment. For example, the tumor size may be the same size or smaller as compared to the size at the beginning of the medicament administration phase. In some embodiments, the sustained response has a duration of at least the same as the treatment duration, at least 1 5x, 2x, 2.5x, or 3x length of the treatment duration, or longer.

“Duration of Response” for purposes of the present invention means the time from documentation of tumor model growth inhibition due to drug treatment to the time of acquisition of a restored growth rate similar to pretreatment growth rate.

In some embodiments, the anti-cancer effect of the method of treating cancer, including “objective response,” “complete response,” “partial response,” “progressive disease,”“stable disease,”“progression free survival,” “duration of response,” as used herein, are as defined and assessed by the investigators using RECIST v1.1 (Eisenhauer et ai, Eur J of Cancer 2009; 45(2):228-47) in patients with locally advanced or metastatic solid tumors other than metastatic CRPC, and RECIST v1.1 and PCWG3 (Scher et al., Trial Design and Objectives for Castration-Resistant Prostate Cancer: Updated Recommendations From the Prostate Cancer Clinical Trials Working Group 3, J Clin Oncol 2016; 34(12): 1402- 18) in patients with metastatic CRPC. The disclosures of Eisenhauer et al., Eur J of Cancer 2009; 45(2):228-47 and Scher et al., 2016 are herein incorporated by references in their entireties.

The term“patient” or“subject” refers to any subject for which therapy is desired or that is participating in a clinical trial, epidemiological study or used as a control, including humans and non-human animals, including veterinary subjects such as cattle, horses, dogs and cats. In a preferred embodiment, the subject is a human and may be referred to as a patient. Those skilled in the medical art are readily able to identify individual patients who are afflicted with cancer.

In some embodiments, the combination or 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“combination therapy” refers to the administration of each agent of the combination therapy of the invention, either alone or in a medicament, either simultaneously, separately or sequentially, as mixed or individual dosages.

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 invention in the same medicament.

The agents of the present invention 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.

As used herein, “in combination with,” "in conjunction with" or “combined administration” refers to administration of one agent in addition to at least one other agent. As such,“in combination with,” "in conjunction with" or“combined administration” refers to administration of one agent before, during, or after administration of at least one other agent to the individual. The administration of two or more agents are intended to include treatment regimens in which the agents are not necessarily administered by the same route of administration or at the same time.

A“combination” or“pharmaceutical combination” refers to a combination of any two or more agents as described herein, e.g., any CDK inhibitor described herein with any 0X40 agonist as described herein; any 4-1 BB agonist as described herein; or any 0X40 agonist and any 4-1 BB agonist as described herein. These two or more agents may (but do not necessarily) belong to different classes of agents.

In some embodiments, a combination as described herein, e.g., a CDK inhibitor in combination with an 0X40 agonist as described herein; a 4-1 BB agonist as described herein; or an 0X40 agonist and a 4-1 BB agonist as described herein, is administered in a single dose. In some embodiments, a combination as described herein, e.g., a CDK inhibitor in combination an 0X40 agonist as described herein; a 4-1 BB agonist as described herein; or an 0X40 agonist and a 4-1 BB agonist as described herein, is administered in multiple doses. In some embodiments, an amount of a combination as described herein, e.g., a CDK inhibitor in combination an 0X40 agonist as described herein; a 4-1 BB agonist as described herein; or an 0X40 agonist and a 4-1 BB agonist as described herein, may be administered periodically at regular intervals (e.g. , 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10 or more times every 1 , 2, 3, 4, 5, or 6 days, or every 1 , 2, 3, 4, 5, 6, 7, 8, or 9 weeks, or every 1 , 2, 3, 4, 5, 6, 7, 8, 9 months or longer).

In some embodiments, a combination as described herein, e.g., a CDK inhibitor in combination an 0X40 agonist as described herein; a 4-1 BB agonist as described herein; or an 0X40 agonist and a 4-1 BB agonist as described herein, is administered at a predetermined interval (e.g., 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10 or more times every 1 , 2, 3, 4, 5, or 6 days, or every 1 , 2, 3, 4, 5, 6, 7, 8, or 9 weeks, or every 1 , 2, 3, 4, 5, 6, 7, 8, 9 months or longer).

The present invention relates to combinations of two or more agents for simultaneous, separate or sequential administration, in particular for the treatment or prevention of cancer. For example, the individual agents of the combination of the invention can be administered separately at different times in any order during the course of therapy or concurrently in divided or single combination forms.

The terms "concurrent administration,” "administration in combination," "simultaneous administration" or "administered simultaneously," as used herein, means that the agents are administered at the same point in time or immediately following one another. For example, in the latter case, the two 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 agents of the present invention 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.

The term “sequentially,” as used herein, refers to a treatment in which administration of a first treatment, such as administration of first agent, follows administration of a second treatment, such as administration of a second agent.

The dosage of the individual agents of the combination may require more frequent administration of one of the agent(s) as compared to the other agent(s) in the combination. Therefore, to permit appropriate dosing, packaged pharmaceutical products may contain one or more dosage forms that contain the combination of agents, and one or more dosage forms that contain one of the combination of agents, but not the other agent(s) of the combination. The term“single formulation,” as used herein refers to a single carrier or vehicle formulated to deliver effective amounts of both therapeutic agents to a subject. The single vehicle is designed to deliver an effective amount of each of the agents, along with any pharmaceutically acceptable carriers or excipients. In some embodiments, the vehicle is a tablet, capsule, pill, or a patch. In other embodiments, the vehicle is a solution or a suspension.

The term“unit dose” is used herein to mean simultaneous administration of both agents together, in one dosage form, to the subject being treated. In some embodiments, the unit dose is a single formulation. In certain embodiments, the unit dose includes one or more vehicles such that each vehicle includes an effective amount of at least one of the agents along with pharmaceutically acceptable carriers and excipients. In some embodiments, the unit dose is one or more tablets, capsules, pills, or patches administered to the subject at the same time.

An“oral dosage form” includes a unit dosage form prescribed or intended for oral administration.

The term“advanced,” as used herein, as it relates to breast cancer, includes locally advanced (non-metastatic) disease and metastatic disease.

The term“treat” or“treating” a cancer, as used herein, means to administer a combination therapy according to the present invention 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 organize, 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. The term "treatment,” as used herein, unless otherwise indicated, refers to the act of treating as "treating" is defined immediately above. The term “treating” also includes adjuvant and neo-adjuvant treatment of a subject. For the purposes of this invention, beneficial or desired clinical results include, but are not limited to, one or more of the following: reducing the proliferation of (or destroying) neoplastic or cancerous cell; inhibiting metastasis or neoplastic cells; shrinking or decreasing the size of tumor; remission of the cancer; decreasing symptoms resulting from the cancer; increasing the quality of life of those suffering from the cancer; decreasing the dose of other medications required to treat the cancer; delaying the progression the cancer; curing the cancer; overcoming one or more resistance mechanisms of the cancer; and / or prolonging survival of patients the cancer. Positive therapeutic effects in cancer can be measured in a number of ways (see, for example, W. A. Weber, Assesing Tumor Response To Therapy, J. Nucl. Med. 2009, 50: 1 S-10S). In some embodiments, the treatment achieved by a combination of the invention is any of the partial response (PR), complete response (CR), overall response (OR), progression free survival (PFS), disease free survival (DFS) and overall survival (OS). PFS, also referred to as“Time to Tumor Progression” indicates the length of time during and after treatment that the cancer does not grow and includes the amount of time patients have experience a CR or PR, as well as the amount of time patients have experience stable disease (SD). DFS refers to the length of time during and after treatment that the patient remains free of disease. OS refers to a prolongation in life expectancy as compared to naive or untreated subjects or patients. In some embodiments, response to a combination of the invention is any of PR, CR< PFS, DFS, OR or OS that is assessed using Response Evaluation Criteria in Solid T umors (RECIST) 1.1 response criteria. The treatment regimen for a combination of the invention that is effective to treat a cancer patient may vary according to factors such as the disease state, age, and weight of the patient, and the ability of the therapy to elicit an anti-cancer response in the subject. While an embodiment of any of the aspects of the invention may not be effective in achieving a positive therapeutic effect in every subject, it should do so in a statistically significant number of subjects as determined by any statistical test known in the art such as the Student’s t-test, the chi2-test the U-test according to Mann and Whitney, the Kruskal-Wallis test (H-test), Jonckheere-Terpstrat- testy and the Wilcon on- test. The term“treatment” also encompasses in vitro and ex vivo treatment, e.g. , of a cell, by a reagent, diagnostic, binding compound, or by another cell.

The term "diagnosis" is used herein to refer to the identification or classification of a molecular or pathological state, disease or condition (e.g., cancer). For example, "diagnosis" may refer to identification of a particular type of cancer. "Diagnosis" may also refer to the classification of a particular subtype of cancer, e.g., by histopathological criteria, or by molecular features (e.g., a subtype characterized by expression of one or a combination of biomarkers (e.g., particular genes or proteins encoded by said genes)).

The term "aiding diagnosis" is used herein to refer to methods that assist in making a clinical determination regarding the presence, or nature, of a particular type of symptom or condition of a disease or disorder (e.g., cancer). For example, a method of aiding diagnosis of a disease or condition (e.g., cancer) can comprise measuring certain biomarkers in a biological sample from an individual.

The term "sample," as used herein, refers to a composition that is obtained or derived from a subject and/or individual of interest that contains a cellular and/or other molecular entity that is to be characterized and/or identified, for example based on physical, biochemical, chemical and/or physiological characteristics. For example, the phrase "disease sample" and variations thereof refers to any sample obtained from a subject of interest that would be expected or is known to contain the cellular and/or molecular entity that is to be characterized. Samples include, but are not limited to, primary or cultured cells or cell lines, cell supernatants, cell lysates, platelets, serum, plasma, vitreous fluid, lymph fluid, synovial fluid, follicular fluid, seminal fluid, amniotic fluid, milk, whole blood, blood-derived cells, urine, cerebro-spinal fluid, saliva, sputum, tears, perspiration, mucus, tumor lysates, and tissue culture medium, tissue extracts such as homogenized tissue, tumor tissue, cellular extracts, and combinations thereof.

By "tissue sample" or "cell sample" is meant a collection of similar cells obtained from a tissue of a subject or individual. The source of the tissue or cell sample may be solid tissue as from a fresh, frozen and/or preserved organ, tissue sample, biopsy, and/or aspirate; blood or any blood constituents such as plasma; bodily fluids such as cerebral spinal fluid, amniotic fluid, peritoneal fluid, or interstitial fluid; cells from any time in gestation or development of the subject. The tissue sample may also be primary or cultured cells or cell lines. Optionally, the tissue or cell sample is obtained from a disease tissue/organ. The tissue sample may contain compounds which are not naturally intermixed with the tissue in nature such as preservatives, anticoagulants, buffers, fixatives, nutrients, antibiotics, or the like.

A “reference sample,” “reference cell,” “reference tissue,” “control sample,” “control cell,” or“control tissue,” as used herein, refers to a sample, cell, tissue, standard, or level that is used for comparison purposes. In one embodiment, a reference sample, reference cell, reference tissue, control sample, control cell, or control tissue is obtained from a healthy and/or non-diseased part of the body (e.g., tissue or cells) of the same subject or individual. For example, healthy and/or non-diseased cells or tissue adjacent to the diseased cells or tissue (e.g., cells or tissue adjacent to a tumor). In another embodiment, a reference sample is obtained from an untreated tissue and/or cell of the body of the same subject or individual. In yet another embodiment, a reference sample, reference cell, reference tissue, control sample, control cell, or control tissue is obtained from a healthy and/or non-diseased part of the body (e.g., tissues or cells) of an individual who is not the subject or individual. In even another embodiment, a reference sample, reference cell, reference tissue, control sample, control cell, or control tissue is obtained from an untreated tissue and/or cell of the body of an individual who is not the subject or individual.

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” excipients (vehicles, additives) are those which can reasonably be administered to a subject to provide an effective dose of the active ingredient employed.

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.

An “effective amount” is at least the minimum amount required to affect a measurable improvement or prevention of a particular disorder. An effective amount herein may vary according to factors such as the disease state, age, sex, and weight of the patient, and the ability of the antibody to elicit a desired response in the individual. An effective amount is also one in which any toxic or detrimental effects of the treatment are outweighed by the therapeutically beneficial effects. For prophylactic use, beneficial or desired results include results such as eliminating or reducing the risk, lessening the severity, or delaying the onset of the disease, including biochemical, histological and/or behavioral symptoms of the disease, its complications and intermediate pathological phenotypes presenting during development of the disease. For therapeutic use, beneficial or desired results include clinical results such as decreasing one or more symptoms resulting from the disease, increasing the quality of life of those suffering from the disease, decreasing the dose of other medications required to treat the disease, enhancing effect of another medication such as via targeting, delaying the progression of the disease, and/or prolonging survival. In the case of cancer or tumor, an effective amount of the drug may have the effect in reducing the number of cancer cells; reducing the tumor size; inhibiting (/.e., slow to some extent or desirably stop) cancer cell infiltration into peripheral organs; inhibit (/.e. , slow to some extent and desirably stop) tumor metastasis; inhibiting to some extent tumor growth; and/or relieving to some extent one or more of the symptoms associated with the disorder. An effective amount can be administered in one or more administrations. For purposes of this invention, an effective amount of drug, compound, 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.

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.

The term "ameliorating,” with reference to a disease, disorder or condition, refers to any observable beneficial effect of the treatment. Treatment need not be absolute to be beneficial to the subject. For example, ameliorating means a lessening or improvement of one or more symptoms of a disease, disorder or condition as compared to not administering a therapeutic agent of a method or regimen of the invention. Ameliorating also includes shortening or reduction in duration of a symptom.

As used herein, an“effective dosage” or“effective amount” of drug, compound or pharmaceutical composition is an amount sufficient to affect any one or more beneficial or desired, including biochemical, histological and / or behavioral symptoms, of the disease, its complications and intermediate pathological phenotypes presenting during development of the disease. For therapeutic use, a“therapeutically effective amount” refers to that amount of a compound being administered which will relieve to some extent one or more of the symptoms of the disorder being treated. In reference to the treatment of cancer, a therapeutically effective amount refers to that amount which has the effect of (1) reducing the size of the tumor, (2) inhibiting (that is, slowing to some extent, preferably stopping) tumor metastasis, (3) inhibiting to some extent (that is, slowing to some extent, preferably stopping) tumor growth or tumor invasiveness, (4) relieving to some extent (or, preferably, eliminating) one or more signs or symptoms associated with the cancer, (5) decreasing the dose of other medications required to treat the disease, and / or (6) enhancing the effect of another medication, and / or delaying the progression of the disease of patients. An effective dosage can be administered in one or more administrations. For the purposes of this invention, an effective dosage of drug, compound, 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 dosage of drug, compound or pharmaceutical composition may or may not be achieved in conjunction with another drug, compound or pharmaceutical composition.

The term "biosimilar" refers to a biological product that is highly similar to an FDA- approved biological product (reference product) and has no clinically meaningful differences in terms of pharmacokinetics, safety and efficacy from the reference product.

The term "bioequivalent" refers to a biological product that is pharmaceutically 5 equivalent and has a similar bioavailability to an FDA-approved biological product (reference product). For example, according to the FDA the term bioequivalence is defined as "the absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions 10 in an appropriately designed study" (United States Food and Drug Administration, "Guidance for Industry: Bioavailability and Bioequicalence Studies for Orally Administered Drug Products - General Considerations," 2003, Center for Drug Evaluation and Research).

The term "biobetter" refers a biological product that is in the same class as an FDA approved biological product (reference product) but is not identical and is improved in terms of safety, efficacy, stability, etc. over the reference product.

“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. Leukemia’s (cancers of the blood) generally do not form solid tumors (National Cancer Institute, Dictionary of Cancer Terms).

“Tumor burden” also referred to as a“tumor load’, refers to the total amount of tumor material distributed throughout the body. Tumor burden refers to the total number of cancer cells or the total size of tumor(s), throughout the body, including lymph nodes and bone marrow. Tumor burden can be determined by a variety of methods known in the art, such as, e.g., using calipers, or while in the body using imaging techniques, e.g., ultrasound, bone scan, computed tomography (CT), or magnetic resonance imaging (MRI) scans.

The term“tumor size” refers to the total size of the tumor which can be measured as the length and width of a tumor. Tumor size may be determined by a variety of methods known in the art, such as, e.g., by measuring the dimensions of tumor(s) upon removal from the subject, e.g., using calipers, or while in the body using imaging techniques, e.g., bone scan, ultrasound, CR or MRI scans.

The term“additive” is used to mean that the result of the combination of two or more agents is no greater than the sum of each agent individually. In one embodiment, the combination of agents described herein displays a synergistic effect. The term “synergy” or“synergistic” are used to mean that the result of the combination of two or more agents is greater than the sum of each 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 or more agents that results in a synergistic effect, as“synergistic” is defined herein. A“synergistic combination” refers to a combination of agents which produces a synergistic effect in vivo, or alternatively in vitro as measured according to the methods described herein.

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.

A“nonstandard clinical dosing regimen,” as used herein, refers to a regimen for administering a substance, agent, compound or composition, which is different to the amount, dose or schedule typically used for that substance, agent, compound or composition in a clinical setting. A“non-standard clinical dosing regimen,” includes a “non-standard clinical dose” or a“nonstandard dosing schedule”. A“low dose amount regimen,” as used herein refers to a dosing regimen where one or more of the substances, agents, compounds or compositions in the regimen are dosed at a lower amount or dose than typically used in a clinical setting for that agent, for example when that agent is dosed as a singleton therapy.

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, hydrobromide/bromide, 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.

Additional embodiments relate to base addition salts of the compounds described herein. Suitable base addition salts are formed from bases which form non-toxic salts. Non-limiting examples of suitable base salts include the aluminum, arginine, benzathine, calcium, choline, diethylamine, diolamine, glycine, lysine, magnesium, meglumine, olamine, potassium, sodium, tromethamine and zinc salts.

The compounds described herein that are basic in nature are capable of forming a wide variety of salts with various inorganic and organic acids. The acids that may be used to prepare pharmaceutically acceptable acid addition salts of such basic compounds described herein are those that form non-toxic acid addition salts, e.g., salts containing pharmacologically acceptable anions, such as the hydrochloride, hydrobromide, hydroiodide, nitrate, sulfate, bisulfate, phosphate, acid phosphate, isonicotinate, acetate, lactate, salicylate, citrate, acid citrate, tartrate, pantothenate, bitartrate, ascorbate, succinate, maleate, gentisinate, fumarate, gluconate, glucuronate, saccharate, formate, benzoate, glutamate, methanesulfonate, ethanesulfonate, benzenesulfonate, p-toluenesulfonate and pamoate [i.e., 1 , T-methylene-bis-(2-hydroxy- 3-naphthoate)] salts. The compounds described herein that include a basic moiety, such as an amino group, may form pharmaceutically acceptable salts with various amino acids, in addition to the acids mentioned above.

The chemical bases that may be used as reagents to prepare pharmaceutically acceptable base salts of those compounds of the compounds described herein that are acidic in nature are those that form non-toxic base salts with such compounds. Such non-toxic base salts include but are not limited to those derived from such pharmacologically acceptable cations such as alkali metal cations (e.g., potassium and sodium) and alkaline earth metal cations (e.g., calcium and magnesium), ammonium or water-soluble amine addition salts such as N-methylglucamine-(meglumine), and the lower alkanolammonium and other base salts of pharmaceutically acceptable organic amines. Hemisalts of acids and bases may also be formed, for example, hemisulphate and hemicalcium 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 term“solvate” is used herein to describe a molecular complex comprising a compound described herein and one or more pharmaceutically acceptable solvent molecules, for example, water and ethanol. 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.

Compounds described herein containing one or more asymmetric carbon atoms can exist as two or more stereoisomers. Where a compound described herein contains an alkenyl or alkenylene group, geometric cis/trans (or Z/E) isomers are possible. 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.

In some embodiments, the compounds described herein can exist in several tautomeric forms, including the enol and imine form, and the keto and enamine form and geometric isomers and mixtures thereof. All such tautomeric forms are included within the scope of the present embodiments. Tautomers exist as mixtures of a tautomeric set in solution. In solid form, usually one tautomer predominates. Even though one tautomer may be described, the present embodiments include all tautomers of the present compounds.

Included within the scope of the present embodiments are all stereoisomers, geometric isomers and tautomeric forms of the compounds described herein, including compounds exhibiting more than one type of isomerism, and mixtures of one or more thereof. Also included are acid addition or base salts wherein the counterion is optically active, for example, d-lactate or l-lysine, or racemic, for example, dl-tartrate or dl-arginine.

The present embodiments also include atropisomers of the compounds described herein. Atropisomers refer to compounds that can be separated into rotationally restricted isomers.

Cis/trans isomers may be separated by conventional techniques well known to those skilled in the art, for example, chromatography and fractional crystallization. Conventional techniques for the preparation/isolation of individual enantiomers include chiral synthesis from a suitable optically pure precursor or resolution of the racemate (or the racemate of a salt or derivative) using, for example, chiral high-pressure liquid chromatography (HPLC).

Alternatively, the racemate (or a racemic precursor) may be reacted with a suitable optically active compound, for example, an alcohol, or, in the case where a compound described herein contains an acidic or basic moiety, a base or acid such as 1- phenylethylamine or tartaric acid. The resulting diastereomeric mixture may be separated by chromatography and/or fractional crystallization and one or both of the diastereoisomers converted to the corresponding pure enantiomer(s) by means well known to a skilled person.

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.

In accordance with the present invention, an amount of a first compound or component is combined with an amount of a second compound or component, and the amounts together are effective in the treatment of cancer. The amounts, which together are effective, will relieve to some extent one or more of the symptoms of the disorder being treated. In reference to the treatment of cancer, an effective amount refers to that amount which has the effect of (1) reducing the size of the tumor, (2) inhibiting (that is, slowing to some extent, preferably stopping) tumor metastasis emergence, (3) inhibiting to some extent (that is, slowing to some extent, preferably stopping) tumor growth or tumor invasiveness, and/or (4) relieving to some extent (or, preferably, eliminating) one or more signs or symptoms associated with the cancer. Therapeutic or pharmacological effectiveness of the doses and administration regimens may also be characterized as the ability to induce, enhance, maintain or prolong disease control and/or overall survival in patients with these specific tumors, which may be measured as prolongation of the time before disease progression”.

III. CDK Inhibitors

Embodiments of the present invention comprise a CDK inhibitor. CDKs and related serine/threonine kinases are important cellular enzymes that perform essential functions in regulating cell division and proliferation. In an embodiment, the CDK inhibitor is an inhibitor of CDK4/6 (CDK4/6 inhibitor or CDK4/6i) or an inhibitor of CDK2/4/6 (CDK2/4/6 inhibitor or CDK2/4/6i). In one such embodiment, the CDK2/4/6 inhibitor is 6-(difluoromethyl)-8-((1 R,2R)-2-hydroxy-2- methylcyclopentyl)-2-(1-(methylsulfonyl)piperidin-4-ylamino) pyrido[2,3-d]pyrimidin- 7(8H)-one (“PF-06873600”), or a pharmaceutically acceptable salt thereof.

In another embodiment, the CDK4/6 inhibitor is palbociclib. Unless otherwise indicated herein, palbociclib (also referred to herein as“palbo” or“Palbo”) refers to 6- acetyl-8-cyclopentyl-5-methyl-2-(5-piperazin-1-yl-pyridin-2- ylamino)-8/-/-pyrido[2,3- cflpyrimidin-7-one, or a pharmaceutically acceptable salt thereof.

IV. 0X40 Agonists

Certain embodiments of the present invention concern an 0X40 agonist. The term ΌC40 agonist” or ΌC40 binding agonist,” as used herein, means, any chemical compound or biological molecule, as defined herein, which upon binding to 0X40, (1) stimulates or activates 0X40, (2) enhances, increases, promotes, induces, or prolongs an activity, function, or presence of 0X40, or (3) enhances, increases, promotes, or induces the expression of 0X40. 0X40 agonists useful in the any of the treatment method, medicaments and uses of the present invention include a monoclonal antibody (mAb), or antigen binding fragment thereof, which specifically binds to 0X40. In any of the treatment method, medicaments and uses of the present invention in which a human individual is being treated, the 0X40 agonists increase a OX40-mediated response. In some embodiments of the treatment method, medicaments and uses of the present invention, 0X40 agonists markedly enhance cytotoxic T-cell responses, resulting in antitumor activity in several models.

An 0X40 agonist includes, for example, an 0X40 agonist antibody (e.g., an anti human 0X40 agonist antibody), an OX40L agonist fragment, an 0X40 oligomeric receptor, and an 0X40 immunoadhesin.

The term ΌC40 antibody,” ΌC40 agonist antibody,” “anti-OX40 monoclonal antibody,”“aOX40” or“anti-OX40 antibody,” as used herein, means an antibody, as defined herein, capable of binding to 0X40 receptor (e.g., human 0X40 receptor).

The terms "0X40” and“0X40 receptor” are used interchangeably in the present application, and refer to any form of 0X40 receptor, as well as variants, isoforms, and species homologs thereof that retain at least a part of the activity of 0X40 receptor. Accordingly, a binding molecule, as defined and disclosed herein, may also bind 0X40 from species other than human. In other cases, a binding molecule may be completely specific for the human 0X40 and may not exhibit species or other types of cross reactivity. Unless indicated differently, such as by specific reference to human 0X40, 0X40 includes all mammalian species of native sequence 0X40, e.g., human, canine, feline, equine and bovine. One exemplary human 0X40 is a 277 amino acid protein (UniProt Accession No. P43489).

An 0X40 agonist antibody as used herein means, any antibody, as defined herein, which upon binding to 0X40, (1) stimulates or activates 0X40, (2) enhances, increases, promotes, induces, or prolongs an activity, function, or presence of 0X40, or (3) enhances, increases, promotes, or induces the expression of 0X40. 0X40 agonists useful in the any of the treatment method, medicaments and uses of the present invention include a monoclonal antibody (mAb) which specifically binds to 0X40.

In some embodiments, the 0X40 agonist antibody increases CD4+ effector T cell proliferation and/or increases cytokine production by the CD4+ effector T cell as compared to proliferation and/or cytokine production prior to treatment with the 0X40 agonist antibody. In some embodiments, the cytokine is IFN-y.

In some embodiments, the 0X40 agonist antibody increases memory T cell proliferation and/or increasing cytokine production by the memory cell. In some embodiments, the cytokine is IFN-y. [0211] In some embodiments, the 0X40 agonist antibody inhibits Treg suppression of effector T cell function. In some embodiments, effector T cell function is effector T cell proliferation and/or cytokine production. In some embodiments, the effector T cell is a CD4+ effector T cell.

In some embodiments, the 0X40 agonist antibody increases 0X40 signal transduction in a target cell that expresses 0X40. In some embodiments, 0X40 signal transduction is detected by monitoring NFkB downstream signaling.

In some embodiments, the anti-human 0X40 agonist antibody is a depleting anti human 0X40 antibody (e.g., depletes cells that express human 0X40). In some embodiments, the human 0X40 expressing cells are CD4+ effector T cells. In some embodiments, the human 0X40 expressing cells are Treg cells. In some embodiments, depleting is by ADCC and/or phagocytosis. In some embodiments, the antibody mediates ADCC by binding FcyR expressed by a human effector cell and activating the human effector cell function. In some embodiments, the antibody mediates phagocytosis by binding FcyR expressed by a human effector cell and activating the human effector cell function. Exemplary human effector cells include, e.g., macrophage, natural killer (NK) cells, monocytes, neutrophils. In some embodiments, the human effector cell is macrophage.

In some embodiments, the anti-human 0X40 agonist antibody has a functional Fc region. In some embodiments, effector function of a functional Fc region is ADCC. In some embodiments, effector function of a functional Fc region is phagocytosis. In some embodiments, effector function of a functional Fc region is ADCC and phagocytosis. In some embodiments, the Fc region is human lgG-1. In some embodiments, the Fc region is human lgG-4.

In some embodiments, the anti-human 0X40 agonist antibody is a human or humanized antibody.

Examples of 0X40 agonist antibody, and useful in the treatment method, medicaments and uses of the present invention, are described in, for example, U.S. Pat. No. 7,960,515, PCT Pat. Publication Nos. and WO 2013/119202, and U.S. Pat. Publication No. 20150190506.

In some embodiments an anti-OX40 antibody useful in the treatment, method, medicaments and uses disclosed herein is a fully human agonist monoclonal antibody comprising a heavy chain variable region and a light chain variable region comprising the amino acid sequences shown in SEQ ID NO: 7 and SEQ ID NO: 8, respectively. In some embodiments, the anti-OX40 antibody is a fully human lgG-2 or lgG-1 antibody.

Table 2 below provides exemplary anti-OX40 monoclonal antibody sequences for use in the treatment method, medicaments and uses of the present invention.

Table 2

V. 4-1 BB Agonist

Certain embodiments of the present invention concern a 4-1 BB binding agonist. The term “4-1 BB binding agonist” or“4-1 BB agonist,” as used herein, means, any chemical compound or biological molecule, as defined herein, which upon binding to 4- 1 BB, (1) stimulates or activates 4-1 BB, (2) enhances, increases, promotes, induces, or prolongs an activity, function, or presence of 4-1 BB, or (3) enhances, increases, promotes, or induces the expression of 4-1 BB. 4-1 BB agonists useful in the any of the treatment method, medicaments and uses of the present invention include a monoclonal antibody (mAb), or antigen binding fragment thereof, which specifically binds to 4-1 BB. Alternative names or synonyms for 4-1 BB include CD137 and TNFRSF9. In any of the treatment method, medicaments and uses of the present invention in which a human individual is being treated, the 4-1 BB agonists increase a 4-1 BB-mediated response. In some embodiments of the treatment method, medicaments and uses of the present invention, 41 BB agonists markedly enhance cytotoxic T-cell responses, resulting in antitumor activity in several models.

The term“4-1 BB antibody,”“4-1 BB agonist antibody,”“anti-4-1 BB monoclonal antibody,”“a 4-1 BB” or“anti- 4-1 BB antibody,” as used herein, means an antibody, as defined herein, capable of binding to 4-1 BB receptor (e.g., human 4-1 BB receptor).

The terms "4-1 BB” and“4-1 BB receptor” are used interchangeably in the present application and refer to any form of 4-1 BB receptor, as well as variants, isoforms, and species homologs thereof that retain at least a part of the activity of 4-1 BB receptor. Accordingly, a binding molecule, as defined and disclosed herein, may also bind 4-1 BB from species other than human. In other cases, a binding molecule may be completely specific for the human 4-1 BB and may not exhibit species or other types of cross reactivity. Unless indicated differently, such as by specific reference to human4-1 BB,4- 1 BB includes all mammalian species of native sequence4-1 BB, e.g., human, canine, feline, equine and bovine. One exemplary human 4-1 BB is a 255 amino acid protein (Accession No. NM_001561 ; NP_001552).

4-1 BB comprises a signal sequence (amino acid residues 1-17), followed by an extracellular domain (169 amino acids), a transmembrane region (27 amino acids), and an intracellular domain (42 amino acids) (Cheuk ATC et a!., 2004 Cancer Gene Therapy 11 : 215-226). The receptor is expressed on the cell surface in monomer and dimer forms and likely trimerizes with 4-1 BB ligand to signal.

Human 4-1 BB comprises a signal sequence (amino acid residues 1-17), followed by an extracellular domain (169 amino acids), a transmembrane region (27 amino acids), and an intracellular domain (42 amino acids) (Cheuk ATC et a!., Role of 4-1 BB:4-1 BB ligand in cancer immunotherapy, Cancer Gene Therapy 2004, 11 : 215-226). The receptor is expressed on the cell surface in monomer and dimer forms and likely trimerizes with 4-1 BB ligand to signal.

Examples of mAbs that bind to human 4-1 BB, and useful in the treatment method, medicaments and uses of the present invention, are described in US Pat. 8,337,850 and Pub. US20130078240. In some embodiments an anti-4-1 BB antibody useful in the treatment, method, medicaments and uses disclosed herein is a fully humanized lgG-2 agonist monoclonal antibody comprising a heavy chain variable region and a light chain variable region comprising the amino acid sequences shown in SEQ ID NO: 64 and SEQ ID NO: 65, respectively.

Table 3 below provides exemplary anti-4-1 BB antibody sequences for use in the treatment method, medicaments and uses of the present invention.

Table 3

VI. METHODS, USES AND MEDICAMENTS

General Methods

Standard methods in molecular biology are described Sambrook, Fritsch and Maniatis (1982 & 1989 2nd Edition, 2001 3rd Edition) Molecular Cloning, A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY; Sambrook and Russell (2001) Molecular Cloning, 3rd ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY; Wu, Recombinant DNA, Methods in enzymology, 1993, Vol. 217, p754.

Standard methods also appear in Ausbel, et ai, 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 ai, Current Protocols in Protein Science, 2000, Vol. 1). Chemical analysis, chemical modification, post-translational modification, and production of fusion proteins, glycosylation of proteins are described (e.g., Coligan, et ai, Current Protocols in Protein Science, 2000, Vol. 2; Ausubel, et ai, 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 ; Hamilton et. ai , DNA polymerases as engines for biotechnology, BioDirectory 2001 , pp. 384-391). Production, purification, and fragmentation of polyclonal and monoclonal antibodies are described (Coligan, et ai., Current Protocols in Immunology, 2001 , Vol. 1 ; Harlow and Lane, Using Antibodies, A Laboratory Manuarl, Journal of Antimicrobial Chemotherapy, 1999 Vol 45). Standard techniques for characterizing ligand/receptor interactions are available (e.g., Coligan, et ai., Current Protocols in Immunology, 2001 , Vol. 4). Monoclonal, polyclonal, and humanized antibodies can be prepared (see, e.g., Sheperd and Dean (eds.) Monoclonal Antibodies, 2000; Kontermann and Dubel (eds.) Antibody Engineering, 2001 , Springer-Verlag, Antibodies A Laboratory Manual, 1988, pp. 139-243; Carpenter, et ai, Non-Fc receptor-binding humanized anti-CD3 antibodies induce apoptosis of activated human T cells, J. Immunol. 2000, 165:6205; He, et ai, Humanization and pharmacokinetics of a monoclonal antibody with specificity for both E- and P-selectin,J. Immunol. 1998, 160:10299; Tang et ai, 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 ai, Antibody humanization using monovalent phage display, J. Biol. Chem. 1997, 272:10678-10684; Chothia et ai, 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. Pat. 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 ai, Human antibodies with sub-nanomolar affinities isolated from a large non-immunized phage display library, Nature Biotechnol. 1996, 14:309-314; Vaughan et ai, Human antibodies with sub nanomolar affinities isolated from a large non-immunized phage display library, Nature Biotechnol. 1996, 14:309-314 Mendez et ai, 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 et ai, Phage Display: A Laboratory Manual, 2001 ; Kay et ai, Phage Display of Peptides and Proteins: A Laboratory Manual, 1996; de Bruin et ai, 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 fused with a myeloma cell line to produce a hybridoma (see, e.g., Meyaard, L, et. ai, LAIR-1 , a novel inhibitory receptor expressed on human mononuclear leukocytes, Immunity 1997, 7:283-290; Wright et ai, Inhibition of chicken adipocyte differentiation by in vitro exposure to monoclonal antibodies against embryonic chicken adipocyte plasma membranes, Immunity 2000, 13:233-242Kaithamana et ai, Induction of experimental autoimmune Graves' disease in BALB/c mice, J. Immunol. 1999, 163:5157-5164; Preston, et ai., The leukocyte/neuron cell surface antigen 0X2 binds to a ligand on macrophages) Eur. J. Immunol. 1997, 27:1911-1918); Kaithamana et ai, 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 (see, e.g., Le Doussal et ai, 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 ai, Extracellular HIV-1 Tat protein induces the rapid Ser133 phosphorylation and activation of CREB transcription factor in both Jurkat lymphoblastoid T cells and primary ... , 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, 162:2804-281 1 ; Everts et ai, 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 (see, e.g., Owens, et ai, 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 Probesy (2003) Catalogue, Molecular Probes, Inc., Eugene, OR; Sigma-Aldrich (2003) Catalogue, St. Louis, MO).

Standard methods of histology of the immune system are described (see, e.g., Muller-Harmelink (ed.), Human Thymus: Histopathology and Pathology, 1986; Hiatt, et ai, Color Atlas of Histology, 2000; Hiatt, et ai, Color Atlas of Histology, 2000; Louis, et ai, 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 (see, 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, et ai, A comparison of signal sequence prediction methods using a test set of signal peptides, Bioinformatics 2000, 16: 741-742; Wren, et ai, SIGNAL-sequence information and GeNomic AnaLysis Comput. Methods Programs Biomed. 2002, 68: 177-181 ; von Heijne, Patterns of amino acids near signal- sequence cleavage sites, Eur. 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 invention further provides therapeutic methods and uses comprising administering to the subject a therapy that comprises compounds of the present invention alone or in combination with other therapeutic agents. In one aspect of the invention, the invention provides for treating cancer comprising administering to a subject in need thereof an amount of a cyclin dependent kinase (CDK) inhibitor in combination with: a. an OX-40 agonist; b. a 4-1 BB agonist; or c. an OX-40 agonist and a 4-1 BB agonist; wherein the CDK inhibitor is an inhibitor of CDK4 and CDK6 (CDK4/6 inhibitor); or an inhibitor of CDK2, CDK4 and CDK6 (CDK2/4/6 inhibitor); and wherein the amounts together are effective in treating cancer.

In some embodiments, the treatment results in sustained response in the individual after cessation of the treatment. The methods of this invention 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 an aspect of the present invention, the 0X40 agonist is an anti-OX40 antibody, an OX40L agonist fragment, an 0X40 oligomeric receptor, a trimeric OX40L-Fc protein or an 0X40 immunoadhesin, or a combination thereof. In some embodiments, the 0X40 agonist antibody binds human 0X40. In some embodiments, the 0X40 antibody is any one of the anti-human 0X40 antibodies disclosed herein. In a particular embodiment of each of the foregoing, the 0X40 agonist is an anti-OX40 antibody. In some embodiments, the anti-OX40 antibody is a biosimilar, biobetter, or bioequivalent thereof. In one such embodiment, the anti-OX40 antibody is MEDI6469, MEDI0562, MEDI6383, MOXR0916, or GSK3174998, or a combination thereof.

In some embodiments of the each of the foregoing, the anti-OX40 antibody is a full-length human lgG-1 antibody. In a particular embodiment, the 0X40 agonist is an OX40L agonist fragment comprising one or more extracellular domains of OX40L.

In yet another aspect, the 4-1 BB agonist is an anti-4-1 BB antibody. In some embodiments, the anti-4-1 BB antibody is a biosimilar, biobetter, or bioequivalent thereof. In a particular embodiment, the 4-1 BB agonist is utomilumab (PF-05082566), 1 D8, 3Elor, 4B4, H4-1 BB-M127, BBK2, 145501 , antibody produced by cell line deposited as ATCC No. HB-1 1248, 5F4, C65-485, urelumab (BMS-663513), 20H4.9-lgG-1 (BMS-663031), 4E9, BMS-554271 , BMS-469492, 3H3, BMS- 469497, 3EI, 53A2, or 3B8.

In one aspect, the antibody against 0X40, and/or 4-1 BB may incorporated into a multi-specific antibody (e.g., a bispecifc antibody). In some such embodiments, a bispecific antibody comprises a first antibody variable domain and a second antibody variable domain, wherein the first antibody variable domain is capable of recruiting the activity of a human immune effector cell by specifically binding to an effector antigen located on the human immune effector cell, and wherein the second antibody variable domain is capable of specifically binding to a target antigen as provided herein. In some embodiments, the antibody has an lgG1 , lgG2, lgG3, or lgG4 isotype. In some embodiments, the antibody comprises an immunologically inert Fc region. In some embodiments the antibody is a human antibody or humanized antibody.

In some embodiments, the bispecific antibody provided herein binds to two different target antigens on the same target cell (e.g., two different antigens on the same tumor cell). Such antibodies may be advantageous, for example, for having increased specificity for a target cell of interest (e.g., for a tumor cell that expresses two particular tumor associated antigens of interest). For example, in some embodiments, a bispecific antibody provided herein comprises a first antibody variable domain and a second antibody variable domain, wherein the first antibody variable domain is capable of specifically binding to a first target antigen as provided herein and the second antibody variable domain is capable of specifically binding to a second target antigen as provided herein.

Methods for making bispecific antibodies are known in the art (see, e.g., Suresh et a!., Advantages of bispecific hybridomas in one-step immunocytochemistry and immunoassays, Methods in Enzymology 1986, 121 :210). Traditionally, the recombinant production of bispecific antibodies was based on the coexpression of two immunoglobulin heavy chain-light chain pairs, with the two heavy chains having different specificities (Millstein and Cuello, Hybrid hybridomas and their use in immunohistochemistry, Nature 1983, 305, 537-539).

In an aspect of the present invention, the CDK inhibitor is a CDK4/6 inhibitor. In one such embodiment, the CDK4/6 inhibitor is palbociclib, or a pharmaceutically acceptable salt thereof. In another aspect, the CDK inhibitor is a CDK2/4/6 inhibitor. In some such embodiments, the CDK2/4/6 inhibitor is 6-(difluoromethyl)-8-((1 R,2R)-2-hydroxy-2- methylcyclopentyl)-2-(1-(methylsulfonyl)piperidin-4-ylamino) pyrido[2,3-d]pyrimidin- 7(8H)-one, or a pharmaceutically acceptable salt thereof.

In one aspect, the invention provides a method for treating a cancer in a subject comprising administering to the subject a combination therapy of the invention. In one aspect, the invention provides a method for treating a cancer comprising administering to a subject in need thereof an amount of a cyclin dependent kinase (CDK) inhibitor and an amount of a. an OX-40 agonist; b. a 4-1 BB agonist; or c. an OX-40 agonist and a 4- 1 BB agonist; wherein the amounts together are effective in treating cancer, and wherein the CDK inhibitor is an inhibitor of CDK4 and CDK6 (CDK4/6 inhibitor), or an inhibitor of CDK2, CDK4 and CDK6 (CDK2/4/6 inhibitor). In some such embodiments the subject is a human. In some embodiments of the each of the foregoing, the cancer is a solid tumor. In yet another embodiment, the cancer is a hematologic cancer.

In a further embodiment, the invention is related to a method for treating cancer, wherein the cancer is selected from the group consisting of brain cancer, head/neck cancer (including squamous cell carcinoma of the head and neck (SCCHN)), prostate cancer, ovarian cancer, bladder cancer (including 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, bone cancer, colorectal cancer, kidney cancer, liver cancer (including hepatocellular carcinoma (HCC)), stomach cancer, pancreatic cancer, esophageal cancer , cervical cancer, sarcoma, skin cancer (including melanoma and Merkel cell carcinoma (MCC)), multiple myeloma, mesothelioma, malignant rhabdoid tumors, neuroblastoma, diffuse intrinsic pontine glioma (DIPG), carcinoma, lymphoma, diffuse large B-cell lymphoma (DLBCL), primary mediastinal B-cell lymphoma (PMBCL), follicular lymphoma, acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), chronic myeloid leukemia (CML), follicular lymphoma, Hodgkin’s lymphoma (HL), classical Hodgkin lymphoma (cHL), mantle cell lymphoma (MCL), multiple myeloma (MM), myeloid cell leukemia-1 protein (Mcl-1), myelodysplastic syndrome (MDS), non- Hodgkin’s lymphoma (NHL), small lymphocytic lymphoma (SLL), and SWI/SNF-mutant cancer.

In some embodiments, the methods may further comprise an additional therapy. The additional therapy may be radiation therapy, surgery (e.g., lumpectomy and a mastectomy), chemotherapy, gene therapy, DNA therapy, viral therapy, RNA therapy, immunotherapy, bone marrow transplantation, nanotherapy, monoclonal antibody therapy, or phototherapy, or a combination of the foregoing. The additional therapy may be in the form of adjuvant or neoadjuvant therapy. In some embodiments, the additional therapy is the administration of small molecule enzymatic inhibitor or anti-metastatic agent. In some embodiments, the additional therapy is the administration of side effect limiting agents (e.g., agents intended to lessen the occurrence and/or severity of side effects of treatment, such as anti-nausea agents, etc.). In some embodiments, the additional therapy is radiation therapy. In some embodiments, the additional therapy is surgery. In some embodiments, the additional therapy is a combination of radiation therapy and surgery.

The CDK inhibitor, the OX-40 agonist and/or the 4-1 BB agonist may be administered by the same route of administration or by different routes of administration. In some embodiments, the CDK inhibitor is administered intravenously, intramuscularly, subcutaneously, topically, orally, transdermally, intraperitoneally, intraorbitally, by implantation, by inhalation, intrathecally, intraventricularly, or intranasally. In some embodiments, the 0X40 agonist is administered intravenously, intramuscularly, subcutaneously, topically, orally, transdermally, intraperitoneally, intraorbitally, by implantation, by inhalation, intrathecally, intraventricularly, or intranasally. In yet another such embodiments, the 4-1 BB agonist is administered intravenously, intramuscularly, subcutaneously, topically, orally, transdermally, intraperitoneally, intraorbitally, by implantation, by inhalation, intrathecally, intraventricularly, or intranasally. An effective amount of the CDK inhibitor 0X40 agonist and/or 4-1 BB agonist may be administered for prevention or treatment of disease. The appropriate dosage of the CDK inhibitor, 0X40 agonist and/or 4-1 BB agonist may be determined based on the type of disease to be treated, the type of the CDK inhibitor, 0X40 agonist and/or 4-1 BB agonist, 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 of the methods, uses, compositions, and kits described above and herein, the treatment further comprises administering a chemotherapeutic agent for treating or delaying progression of cancer in a subject. In some embodiments, the subject has been treated with a chemotherapeutic agent before the combination treatment with the CDK inhibitor, the 0X40 binding agonist and/or the 4-1 BB agonist. In some embodiments, the subject treated with the combination of the CDK inhibitor, the 0X40 binding agonist and/or the 4-1 BB agonist is refractory to a chemotherapeutic agent treatment. Some embodiments of the methods, uses, compositions, and kits described throughout the application, further comprise administering a chemotherapeutic agent for treating or delaying progression of cancer.

In some embodiments, the combination therapy of the invention comprises administration of a CDK inhibitor, an 0X40 agonist (e.g., anti-human 0X40 agonist antibody) and/or a 4-1 BB agonist (anti- human 4-1 BB antibody). In the methods provided herein, each of the CDK inhibitor, 0X40 agonist and/or 4-1 BB agonist may be administered in any suitable manner known in the art. In one embodiment, the CDK inhibitor and the 0X40 agonist are administered simultaneously or sequentially in any order. In additional embodiments, the CDK inhibitor and the 4-1 BB agonist are administered simultaneously or sequentially in any order. In yet another embodiment, the CDK inhibitor, the 0X40 agonist and the 4-1 BB agonist are administered simultaneously or sequentially in any order.

In some embodiments of the each of the foregoing, the 0X40 agonist and the 4- 1 BB agonist are in the same composition.

VII. Dosage Forms and Regimens

Administration of the compounds of the invention 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, intramuscular, intravascular or infusion), topical, and rectal administration.

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 mammalian mammals 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 invention are 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 invention.

It is to be noted that dosage values may vary with the type and severity of the condition to be alleviated and may include single or multiple doses. It is to be further understood that for any particular subject, specific dosage regimens should be adjusted over time according to the individual need and the professional judgment of the person administering or supervising the administration of the compositions, and that dosage ranges set forth herein are exemplary only and are not intended to limit the scope or practice of the claimed composition. For example, doses may be adjusted based on pharmacokinetic or pharmacodynamic parameters, which may include clinical effects such as toxic effects and/or laboratory values. Thus, the present invention encompasses intra-patient dose-escalation as determined by the skilled artisan. Determining appropriate dosages and regimens for administration of the chemotherapeutic agent are well-known in the relevant art and would be understood to be encompassed by the skilled artisan once provided the teachings disclosed herein.

The amount of the compound of the invention 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 CDK inhibitor, 0X40 agonist and/or 4-BB agonist may be administered for prevention or treatment of disease. The appropriate dosage of the CDK inhibitor, 0X40 agonist and/or 4-BB agonist (e.g., anti-human 0X40 agonist antibody) may be determined based on the type of disease to be treated, the type of the CDK inhibitor, the 0X40 agonist and/or 4-BB agonist, 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 CDK inhibitor, 0X40 agonist (e.g., anti-human 0X40 agonist antibody) and/or 4-BB agonist (e.g., anti-human 4-1 BB agonist antibody) are synergistic, whereby an efficacious dose of the CDK inhibitor, 0X40 agonist and/or 4-BB agonist in the combination is reduced relative to efficacious dose of the each of the CDK inhibitor, 0X40 agonist and/or 4-1 BB agonist as a single agent.

In some embodiments, the patient is treated with a 3-week lead-in period of single-agent CDK inhibitor directly preceding the combination administration of the CDK inhibitor and 0X40 agonist and/or 4-1 BB agonist.

In some embodiments, a treatment cycle begins with the first day of combination treatment and last for 3 weeks. In such embodiments, the combination therapy is preferably administered for at least 18 weeks (6 cycles of treatment), more preferably at least 24 weeks (8 cycles of treatment), and even more preferably at least 2 weeks after the patient achieves a CR.

In some embodiments, the 4-1 BB agonist in the combination therapy comprises an anti-4-1 BB monoclonal antibody comprising heavy chain variable region and a light chain variable region comprising the amino acid sequences shown in SEQ ID NO: 17 and SEQ ID NO: 18, respectively, and is administered in a liquid medicament at a dose selected from the group consisting of 1 mg/kg Q2W, 2 mg/kg Q2W, 3 mg/kg Q2W, 5 mg/kg Q2W, 10 mg Q2W, 1 mg/kg Q3W, 2 mg/kg Q3W, 3 mg/kg Q3W, 5 mg/kg Q3W, and 10 mg Q3W. In some embodiments, the anti-4-1 BB monoclonal antibody is administered as a liquid medicament, and the selected dose of the medicament is administered by IV infusion over a time period of about 60 minutes.

An effective dosage of a CDK inhibitor, or a pharmaceutically acceptable salt thereof, is in the range of from about 0.001 to about 100 mg per kg body weight per day, preferably about 1 to about 35 mg/kg/day, in single or divided doses. For example, for a 70 kg human, this would amount to about 0.01 to about 7 g/day, preferably about 0.02 to about 2.5 g/day. In some instances, dosage levels below the lower limit of the aforesaid range may be more than adequate, while in other cases still larger doses may be employed without causing any harmful side effect, provided that such larger doses are first divided into several small doses for administration throughout the day.

In some embodiments, the dose of CDK inhibitor is increased up to a maximum dose of 250 mg BID if the patient tolerates the combination treatment at a lower total dose of CDK inhibitor. In some embodiments, the CDK inhibitor, or a pharmaceutically acceptable salt thereof, is administered at a daily dosage of from about 50 mg to about 2000 mg per day, about 50 mg per day, about 100 mg per day, about 150 mg per day, about 200 mg per day, about 250 mg per day, about 300 mg per day, about 350 mg per day, about 400 mg per day, about 450 mg per day, about 500 mg per day, about 550 mg per day, about 600 mg per day, about 650 mg per day, about 700 mg per day, about 750 mg per day, about 800 mg per day, about 850 mg per day, about 900 mg per day, about 950 mg per day, about 1000 mg per day, about 1 100 mg per day, about 1200 mg per day, about 1300 mg per day, about 1400 mg per day, or about 1500 mg per day. This dose may optionally be sub-divided into small doses, for example a dosage of 150 mg per day could be dosed as 75 mg dose twice per day.

Dosage units for a CDK inhibitor (e.g., PF-06873600 or palbociclib) may be expressed as a flat dose, i.e., 25 mg, 50 mg, 75 mg, 100 mg, 125 mg, etc. or as a patient- specific dose, i.e., mg/kg (mg therapeutic agent/kg of body weight) or mg/m ² (quantity in milligrams per square meter of body surface area).

Some embodiments may comprise administering the CDK inhibitor in a dose of about: 10 mg, 15 mg, 20 mg, 25 mg, 30 mg, 35 mg, 40 mg, 45 mg, 50 mg, 55 mg, 60 mg, 65 mg, 70 mg, 75 mg, 80 mg, 85 mg, 90 mg, 95 mg, 100 mg, 125 mg, 150 mg, 175 mg, 200 mg, 225 mg, 250 mg, or more than 250 mg, wherein the amounts can be administered once a day (q.d.), twice a day (b.i.d.), three times a day (t.i.d.), four times a day (q.i.d.), or on some other dosing schedule.

Repetition of the administration or dosing regimens, or adjustment of the administration or dosing regimen may be conducted as necessary to achieve the desired treatment. A“continuous dosing schedule,” as used herein, is an administration or dosing regimen without dose interruptions, e.g., without days off treatment. Repetition of 21 or 28 day treatment cycles without dose interruptions between the treatment cycles is an example of a continuous dosing schedule. In an embodiment, the compounds of the combination of the present invention can be administered in a continuous dosing schedule.

In some such embodiments, the CDK inhibitor is a CDK4/6 inhibitor or a pharmaceutically acceptable salt thereof. In one such embodiment, the CDK4/6 inhibitor is palbociclib or a pharmaceutically acceptable salt thereof. In one such embodiment, the CDK4/6 inhibitor is palbociclib. In another embodiment, the CDK inhibitor is a CDK2/4/6 inhibitor or a pharmaceutically acceptable salt thereof. In a specific embodiment, the CDK2/4/6 inhibitor is 6-(difluoromethyl)-8-((1 R,2R)-2-hydroxy-2-methylcyclopentyl)-2-(1- (methylsulfonyl)piperidin-4-ylamino)pyrido[2,3-d]pyrimidin-7 (8H)-one (PF-06873600) or a pharmaceutically acceptable salt thereof. In one such embodiment, the CDK2/4/6 inhibitor is PF-06873600.

Those skilled in the art will be able to determine, according to known methods, the appropriate amount, dose or dosage of each compound, as used in the combination of the present invention, to administer to a patient, taking into account factors such as age, weight, general health, the compound administered, the route of administration, the nature and advancement of breast cancer, requiring treatment, and the presence of other medications.

In an embodiment, palbociclib, or a pharmaceutically acceptable salt thereof, is administered at a daily dosage of about 125 mg once daily, about 100 mg once daily, about 75 mg once daily, or about 50 mg daily. In an embodiment, which is the recommended starting dose or standard clinical dose, palbociclib, or a pharmaceutically acceptable salt thereof, is administered at a daily dosage of about 125 mg once a day. In an embodiment, palbociclib, or a pharmaceutically acceptable salt thereof, is administered at a non-standard clinical dose. In an embodiment, a non-standard clinical dose is a low-dose amount of palbociclib, or a pharmaceutically acceptable salt thereof. For example, palbociclib, or a pharmaceutically acceptable salt thereof, is administered at a dose of about 100 mg once daily, about 75 mg once daily, or about 50 mg once daily. In an embodiment, palbociclib, or a pharmaceutically acceptable salt thereof, is administered at a dose of about 100 mg once daily. In an embodiment, palbociclib, or a pharmaceutically acceptable salt thereof, is administered at a dose of about 75 mg once daily. In an embodiment, palbociclib, or a pharmaceutically acceptable salt thereof, is administered at a dose of about 50 mg once daily. Dosage amounts provided herein refer to the dose of the free base form of palbociclib, or are calculated as the free base equivalent of an administered palbociclib salt form. For example, a dosage or amount of palbociclib, such as 100 mg, 75 mg or 50 mg, refers to the free base equivalent. This dosage regimen may be adjusted to provide the optimal therapeutic response. For example, the dose may be proportionally reduced or increased as indicated by the exigencies of the therapeutic situation. In an embodiment, PF-06873600, or a pharmaceutically acceptable salt thereof, is administered at a daily dosage of about 125 mg once daily, about 100 mg once daily, about 75 mg once daily, or about 50 mg daily. In an embodiment, PF-06873600, or a pharmaceutically acceptable salt thereof, is administered at a daily dosage of about 125 mg once a day. In an embodiment, PF-06873600, or a pharmaceutically acceptable salt thereof, is administered at a non-standard clinical dose. In an embodiment, a non standard clinical dose is a low-dose amount of PF-06873600, or a pharmaceutically acceptable salt thereof. For example, PF-06873600, or a pharmaceutically acceptable salt thereof, is administered at a dose of about 100 mg once daily, about 75 mg once daily, or about 50 mg once daily. In an embodiment, PF-06873600, or a pharmaceutically acceptable salt thereof, is administered at a dose of about 100 mg once daily. In an embodiment, PF-06873600, or a pharmaceutically acceptable salt thereof, is administered at a dose of about 75 mg once daily. In an embodiment, PF-06873600, or a pharmaceutically acceptable salt thereof, is administered at a dose of about 50 mg once daily. Dosage amounts provided herein refer to the dose of the free base form of PF-06873600, or are calculated as the free base equivalent of an administered PF- 06873600 salt form. For example, a dosage or amount of PF-06873600, such as 100 mg, 75 mg or 50 mg, refers to the free base equivalent. This dosage regimen may be adjusted to provide the optimal therapeutic response. For example, the dose may be proportionally reduced or increased as indicated by the exigencies of the therapeutic situation.

The practice of the method of this invention may be accomplished through various administration or dosing regimens. The compounds of the combination of the present invention can be administered intermittently, concurrently or sequentially. In an embodiment, the compounds of the combination of the present invention can be administered in a concurrent dosing regimen.

In one aspect, the invention provides a combination which is synergistic. In one such embodiment, the invention provides a synergistic combination comprising: a. (i) palbociclib, or a pharmaceutically acceptable salt thereof; and (ii) an 0X40 agonist; for use in the treatment of cancer in a subject, wherein component (i) and component (ii) are synergistic; b. (i) palbociclib, or a pharmaceutically acceptable salt thereof; and (ii) a 4-1 BB agonist; for use in the treatment of cancer in a subject, wherein component (i) and component (ii) are synergistic; or c. (i) palbociclib, or a pharmaceutically acceptable salt thereof; (ii) an 0X40 agonist; and (iii) a 4-1 BB agonist; for use in the treatment of cancer in a subject, wherein component (i) and component (ii); component (i) and component (iii); component (ii) and component (iii); or component (i), component (ii) and component (iii) are synergistic.

In another embodiment, the invention provides a synergistic combination comprising: a. (i) 6-(difluoromethyl)-8-((1 R,2R)-2-hydroxy-2-methylcyclopentyl)-2-(1- (methylsulfonyl)piperidin-4-ylamino)pyrido[2,3-d]pyrimidin-7 (8H)-one, or a pharmaceutically acceptable salt thereof; and (ii) an 0X40 agonist; for use in the treatment of cancer in a subject, wherein component (i) and component (ii) are synergistic; c. (i) 6-(difluoromethyl)-8-((1 R,2R)-2-hydroxy-2-methylcyclopentyl)-2-(1- (methylsulfonyl)piperidin-4-ylamino)pyrido[2,3-d]pyrimidin-7 (8H)-one, or a pharmaceutically acceptable salt thereof; (ii) a 4-1 BB agonist; for use in the treatment of cancer in a subject, wherein component (i) and component (ii) are synergistic; d. (i) 6- (difluoromethyl)-8-((1 R,2R)-2-hydroxy-2-methylcyclopentyl)-2-(1- (methylsulfonyl)piperidin-4-ylamino)pyrido[2,3-d]pyrimidin-7 (8H)-one, or a pharmaceutically acceptable salt thereof; (ii) an 0X40 agonist; and (iii) a 4-1 BB agonist; for use in the treatment of cancer in a subject, wherein component (i) and component (ii); component (i) and component (iii); component (ii) and component (iii); or component (ii) and component (iii); are synergistic.

In one embodiment, the present invention provides a combination comprising: a. palbociclib, or a pharmaceutically acceptable salt thereof, b. palbociclib, or a pharmaceutically acceptable salt thereof, and an 0X40 agonist; c. palbociclib, or a pharmaceutically acceptable salt thereof, and a 4-1 BB agonist; or d. palbociclib, or a pharmaceutically acceptable salt thereof, an 0X40 agonist and a 4-1 BB agonist, for use in the treatment of cancer in a subject.

In yet another embodiment, the present invention provides a combination comprising: a. 6-(difluoromethyl)-8-((1 R,2R)-2-hydroxy-2-methylcyclopentyl)-2-(1-

(methylsulfonyl)piperidin-4-ylamino)pyrido[2,3-d]pyrimidi n-7(8H)-one, or a pharmaceutically acceptable salt thereof, and an 0X40 agonist; b. 6-(difluoromethyl)-8- ((1 R,2R)-2-hydroxy-2-methylcyclopentyl)-2-(1-(methylsulfonyl)pi peridin-4- ylamino)pyrido[2,3-d]pyrimidin-7(8H)-one, or a pharmaceutically acceptable salt thereof, a 4-1 BB agonist; or c. 6-(difluoromethyl)-8-((1 R,2R)-2-hydroxy-2-methylcyclopentyl)-2- (1-(methylsulfonyl)piperidin-4-ylamino)pyrido[2,3-d]pyrimidi n-7(8H)-one, or a pharmaceutically acceptable salt thereof, an 0X40 agonist, and a 4-1 BB agonist, for use in the treatment of cancer in a subject. In a particular embodiment of each of the foregoing, the invention provides a combination wherein the 0X40 agonist is an anti-OX40 antibody; and/or the 4-1 BB agonist is an anti-4-1 BB antibody.

In some embodiments of the each of the foregoing, the subject is a subject, such as domesticated animals (e.g., cows, sheep, cats, dogs, and horses), primates (e.g., humans and non-human primates such as monkeys), rabbits, and rodents (e.g., mice and rats). In a particular embodiment, the subject is a human. In further embodiments of each of the foregoing, the cancer is a solid tumor. In In some embodiments, the cancer is a hematologic cancer. In some embodiments, the cancer is selected from the group consisting of brain cancer, head/neck cancer (including squamous cell carcinoma of the head and neck (SCCHN)), prostate cancer, ovarian cancer, bladder cancer (including 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, bone cancer, colorectal cancer, kidney cancer, liver cancer (including hepatocellular carcinoma (HCC)), stomach cancer, pancreatic cancer, esophageal cancer , cervical cancer, sarcoma, skin cancer (including melanoma and Merkel cell carcinoma (MCC)), multiple myeloma, mesothelioma, malignant rhabdoid tumors, neuroblastoma, diffuse intrinsic pontine glioma (DIPG), carcinoma, lymphoma, diffuse large B-cell lymphoma (DLBCL), primary mediastinal B-cell lymphoma (PMBCL), follicular lymphoma, acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), chronic myeloid leukemia (CML), follicular lymphoma, Hodgkin’s lymphoma (HL), classical Hodgkin lymphoma (cHL), mantle cell lymphoma (MCL), multiple myeloma (MM), myeloid cell leukemia-1 protein (Mcl-1), myelodysplastic syndrome (MDS), non-Hodgkin’s lymphoma (NHL), small lymphocytic lymphoma (SLL), and SWI/SNF-mutant cancer.

VIII. Kits

In one aspect, the invention provides a kit comprising: a. (i) a pharmaceutical composition comprising a CDK inhibitor and a pharmaceutically acceptable carrier; (ii) a pharmaceutical composition comprising an 0X40 agonist and a pharmaceutically acceptable carrier; b. (i) a pharmaceutical composition comprising a CDK inhibitor and a pharmaceutically acceptable carrier; (ii) a pharmaceutical composition comprising a 4- 1 BB agonist and a pharmaceutically acceptable carrier; c. (i) a pharmaceutical composition comprising a CDK inhibitor and a pharmaceutically acceptable carrier; (ii) a pharmaceutical composition comprising an 0X40 agonist and a pharmaceutically acceptable carrier; and (iii) a pharmaceutical composition comprising a 4-1 BB agonist and a pharmaceutically acceptable carrier; and instructions for dosing of the pharmaceutical compositions for the treatment of cancer. In one embodiment, the 0X40 agonist is an anti-OX40 antibody; and/or the 4-1 BB agonist is an anti-4-1 BB antibody.

In some embodiments, the kit further comprises package insert comprising instructions for using the CDK inhibitor in conjunction the 0X40 agonist (e.g., anti-human 0X40 agonist antibody) and/or 4-BB agonist (e.g., anti-human 4-1 BB agonist antibody) treat or delay progression of cancer in an individual or to enhance immune function of a subject having cancer. In further embodiment, any of the CDK inhibitors, 0X40 agonist and/or 4-1 BB agonists described herein may be included in the kits.

For example, in some embodiments, the CDK inhibitor is a CDK4/6 inhibitor. In some such embodiments, the CDK4/6 inhibitor is palbociclib, or a pharmaceutically acceptable salt thereof. In another embodiment, the CDK inhibitor is a CDK2/4/6 inhibitor. In a particular embodiment, the CD2/4/6 inhibitor is 6-(difluoromethyl)-8-((1 R,2R)-2- hydroxy-2-methylcyclopentyl)-2-(1 -(methylsulfonyl)piperidin-4-ylamino)pyrido[2,3- d]pyrimidin-7(8H)-one, or a pharmaceutically acceptable salt thereof. In specific embodiments, the 0X40 agonist is an anti-OX40 antibody; and/or the 4-1 BB agonist is an anti-4-1 BB antibody.

In some embodiments, the 0X40 binding agonist (e.g., anti-human 0X40 agonist antibody), and/or the 4-1 BB agonist are in the same container or 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 (such as stainless steel or hastelloy). 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 invention. Various modifications of the invention 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.

EXAMPLES

The invention will be more fully understood by reference to the following examples. They should not, however, be construed as limiting the scope of the invention. It is understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims.

Example 1 : The CDK2/4/6 Inhibitor (PF-068736000) Synergizes with 0X40/4-1 BB Immune Checkpoint Modulators in the MC38 Syngeneic Mouse Tumor Model

Overview

PF-06873600 was evaluated in the MC38 syngeneic mouse tumor model in combination with antibodies targeting 4-1 BB and 0X40 to assess efficacy on primary tumor growth and survival. PF-06873600 in combination with these immune checkpoint blockade agents led to significant tumor growth inhibition (p= 0.00005).

Materials and Methods

MC38 cells were obtained from American Type Culture Collection (ATCC) and cultured in Roswell Park Memorial Institute (RPMI 1640) supplemented with 10% fetal bovine serum (FBS). All cells were maintained in a humidified incubator at 37°C with 5% carbon dioxide (CO2). Female C57/BL6 mice were obtained from Jackson Laboratories at 8 weeks of age. To generate the syngeneic model, 0.5 million MC38 tumor cells were subcutaneously implanted into the right flank of female C57/BL6 mice. Tumor bearing mice were randomized into six treatment groups based on average tumor sizes of approximately 70 mm ³ per group, on Day 9 post tumor cell implantation. Study groups included vehicle, 30 mg/kg PF-06873600 (CDK 2/4/6 inhibitor) twice daily by oral gavage, combination of anti-OX40 antibody (PF-07201252) administered at 5mg/kg by intraperitoneal (IP) injection and anti-4-1 BB antibody (PF-07218859) administered at 3mg/kg by IP injection every three days for three doses and combination of PF- 06873600 twice daily by oral gavage with anti-OX40 antibody (PF-07201252) administered at 5mg/kg by intraperitoneal (IP) injection and anti-4-1 BB antibody (PF- 07218859) administered at 3mg/kg by IP injection every three days for three doses. All antibodies were administered as three doses; one dose every three days after the study initiation. All antibody formulations are phosphate buffered saline based while PF- 06873600 was administered in a 0.5% methocel/Tween suspension. The treatment groups and dose regimen information are summarized in Table 4. Table 4

Tumor volumes were measured three times a week. Tumor volume was calculated based on two-dimensional caliper measurement with cubic millimeter volume calculated using the formula (length x width2) x 0.5. Mice were sacrificed when the tumor volumes reached 2000 mm ³ , which was the survival endpoint for this study. Survival curves were plotted using GraphPad Prism 7 software. Statistical significance determined using the Holm-Sidak method, with alpha = 0.05.

Results

On Day 27 post-treatment initiation, tumor growth results show that treatment with the CDK2/4/6 inhibitor PF-06873600 monotherapy did not significantly inhibit tumor growth in the MC38 xenograft tumor model. However, PF-06873600 treatment in combination with anti-OX40 antibody and anti 4-1 BB antibody showed a trend to a combinatorial effect, with increase in tumor growth inhibition (p = 0.0005). These data are summarized as mean tumor volume in Figure 1 , individual tumor volumes in Figures 2A, 2B, 2C and 2D, and absolute values are shown in Table 5. Table 5

TGI = tumor growth inhibition

Conclusions

Combination of the CDK2/4/6 inhibitor PF-06873600 with checkpoint blockade antibodies led to greater tumor growth inhibition and significant improvement in survival relative to, PF-06873600 monotherapy, or the combination of anti-4-1 BB antibody and anti-OX40 antibody alone in the MC38 syngeneic tumor model.

Example 2: The CDK4/6 Inhibitor Palbociclib (PF-080665) Synergizes with 0X40/4- 1 BB Immune Checkpoint Modulators in the MC38 Syngeneic Mouse Tumor Model

Overview Palociclib (PF-080665) will be evaluated in the MC38 syngeneic mouse tumor model in combination with antibodies targeting 4-1 BB and 0X40 antigens to assess efficacy on primary tumor growth and survival.

Materials and Methods

MC38 cells will be obtained from American Type Culture Collection (ATCC) and cultured in Roswell Park Memorial Institute (RPMI 1640) supplemented with 10% fetal bovine serum (FBS). All cells will be maintained in a humidified incubator at 37°C with 5% carbon dioxide (CO2). Female C57/BL6 mice will be obtained from Jackson Laboratories at 8 weeks of age. To generate the syngeneic model, 0.5 million MC38 tumor cells will be subcutaneously implanted into the right flank of female C57/BL6 mice. Tumor bearing mice will be randomized into six treatment groups based on average tumor sizes of approximately 70 mm ³ per group, on Day 9 post tumor cell implantation. Study groups included vehicle, 15 mg/kg PF-080665 (CDK 4/6 inhibitor) twice daily by oral gavage, anti-OX40 antibody (PF-07201252) administered at 5mg/kg by intraperitoneal (IP) injection, anti-4- 1 BB antibody (PF-07218859) administered at 3mg/kg by IP injection, combination of 15 mg/kg PF-080665 (CDK 4/6 inhibitor) twice daily by oral gavage and anti-OX40 antibody (PF-07201252) administered at 5mg/kg by intraperitoneal (IP) injection, combination of 15 mg/kg PF-080665 (CDK 4/6 inhibitor) twice daily by oral gavage and anti-4- 1 BB antibody (PF-07218859) administered at 3mg/kg by IP injection, combination of anti-OX40 antibody (PF-07201252) administered at 5mg/kg by intraperitoneal (IP) injection and anti-4-1 BB antibody (PF-07218859) administered at 3mg/kg by IP injection and combination of PF-06873600 twice daily by oral gavage with anti-OX40 antibody (PF-07201252) administered at 5mg/kg by intraperitoneal (IP) injection and anti-4-1 BB antibody (PF-07218859) administered at 3mg/kg by IP injection every three days for three doses. All antibodies will be administered as three doses; one every three days after the study initiation. All antibody formulations are phosphate buffered saline based while PF-06873600 will be administered in a 0.5% methocel/Tween suspension. The treatment groups and dose regimen information are summarized in Table 6.

Table 6

Tumor volumes will be measured three times a week. Tumor volume will be calculated based on two-dimensional caliper measurement with cubic millimeter volume calculated using the formula (length x width2) x 0.5. Mice will be sacrificed when the tumor volumes reached 2000 mm ³ , which is the survival endpoint for this study. Survival curves will be plotted using GraphPad Prism 7 software and statistical significance determined using the Holm-Sidak method, with alpha = 0.05.