Anti-PD-1 antibodies and methods of use thereof

• US 10,323,091 B2
• Filed: 09/01/2016
• Issued: 06/18/2019
• Est. Priority Date: 09/01/2015
• Status: Active Grant

• Current Assignee: Agenus Inc., Ludwig Institute for Cancer Research, Ltd., Memorial Sloan-Kettering Cancer Center
• Original Assignee: Agenus Inc., Ludwig Institute for Cancer Research, Ltd., Memorial Sloan-Kettering Cancer Center
• Inventors: van Dijk, Marc, Wilson, Nicholas Stuart, Mundt, Cornelia Anne, Ritter, Gerd, Wolchok, Jedd David, Merghoub, Taha, Zappasodi, Roberta, Holmgaard, Rikke Baek, Schaer, David, Savitsky, David Adam
• Primary Examiner(s): Ouspenski, Ilia I
• Application Number:
  US15/254,315
• Publication Number:
  US 20170081409A1
• Time in Patent Office: 1,020 Days
• Field of Search: None
• CPC Class Codes: A61K 2039/507 Comprising a combination of two or more separate antibodies
• CPC Class Codes: A61K 2039/54 characterised by the route of administration
• CPC Class Codes: A61K 39/39558 against tumor tissues, cells, antigens
• CPC Class Codes: A61K 45/06 Mixtures of active ingredients without chemical characterisation, e.g. antiphlogistics and cardiaca
• CPC Class Codes: A61P 31/00 Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
• CPC Class Codes: A61P 35/00 Antineoplastic agents
• CPC Class Codes: A61P 37/04 Immunostimulants
• CPC Class Codes: A61P 43/00 Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00
• CPC Class Codes: C07K 16/2803 against the immunoglobulin superfamily
• CPC Class Codes: C07K 16/2818 against CD28 or CD152
• CPC Class Codes: C07K 2317/21 from primates, e.g. man
• CPC Class Codes: C07K 2317/33 Crossreactivity, e.g. for species or epitope, or lack of said crossreactivity
• CPC Class Codes: C07K 2317/34 Identification of a linear epitope shorter than 20 amino acid residues or of a conformational epitope defined by amino acid residues
• CPC Class Codes: C07K 2317/52 Constant or Fc region; Isotype
• CPC Class Codes: C07K 2317/565 Complementarity determining region [CDR]
• CPC Class Codes: C07K 2317/71 Decreased effector function due to an Fc-modification
• CPC Class Codes: C07K 2317/72 Increased effector function due to an Fc-modification
• CPC Class Codes: C07K 2317/76 Antagonist effect on antigen, e.g. neutralization or inhibition of binding
• CPC Class Codes: C07K 2317/92 Affinity (KD), association rate (Ka), dissociation rate (Kd) or EC50 value

Abstract

The instant disclosure provides antibodies that specifically bind to human PD-1 and antagonize PD-1 function. Also provided are pharmaceutical compositions comprising these antibodies, nucleic acids encoding these antibodies, expression vectors and host cells for making these antibodies, and methods of treating a subject using these antibodies.

Claims

1. An isolated antibody that specifically binds to human PD-1, comprising a heavy chain variable region comprising complementarity determining regions CDRH1, CDRH2, and CDRH3 and a light chain variable region comprising complementarity determining regions CDRL1, CDRL2, and CDRL3, wherein:

(a) CDRH1 comprises the amino acid sequence of SYGMH (SEQ ID NO;

     1);

(b) CDRH2 comprises the amino acid sequence of VIWX₁DGSNX₂YYADSVX₃G (SEQ ID NO;

     32), wherein

X₁ is Y or F;

X₂ is K or E; and

X₃ is K or M;

(c) CDRH3 comprises the amino acid sequence of NX₁DX₂ (SEQ ID NO;

     33), wherein

X₁ is G or V; and

X₂ is H or Y;

(d) CDRL1 comprises the amino acid sequence of RASQSVSSNLA (SEQ ID NO;

     4);

(e) CDRL2 comprises the amino acid sequence of GASTRAT (SEQ ID NO;

     5); and

(f) CDRL3 comprises the amino acid sequence of QQYNNWPRT (SEQ ID NO;

     6).

2. The isolated antibody of claim 1, wherein:

(a) CDRH2 comprises an amino acid sequence selected from the group consisting of SEQ ID NOs;

2 and 34-36; and

/or

(b) CDRH3 comprises an amino acid sequence selected from the group consisting of SEQ ID NOs;

3, 7, and 37.

3. The isolated antibody of claim 1, wherein CDRH1, CDRH2 and CDRH3 comprise the CDRH1, CDRH2 and CDRH3 amino acid sequences, respectively, set forth in SEQ ID NOs:

1, 2, and 3;

1, 2, and 7;

1, 2, and 37;

1, 34, and 7;

1, 35, and 7;

or 1, 36, and 7.

4. The isolated antibody of claim 1, wherein CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 comprise the amino acid sequences set forth in SEQ ID NOs:

1, 2, 3, 4, 5, and 6.

5. The isolated antibody of claim 1, wherein CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 comprise the amino acid sequences set forth in SEQ ID NOs:

1, 2, 7, 4, 5, and 6, respectively.

6. The isolated antibody of claim 1, wherein the heavy chain variable region comprises an amino acid sequence derived from a human IGHV3-33 germline sequence.

7. The isolated antibody of claim 1, wherein the antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:

49.

8. The isolated antibody of claim 1, wherein the antibody comprises a heavy chain variable region comprising an amino acid sequence which is at least 75%, 80%, 85%, 90%, 95%, or 100% identical to an amino acid sequence selected from the group consisting of SEQ ID NOs:

15, 17, and 26-31.

9. The isolated antibody of claim 1, wherein the heavy chain variable region comprises the amino acid sequence of SEQ ID NO:

17.

10. The isolated antibody of claim 9, wherein the amino acid sequence of the heavy chain variable region consists of the amino acid sequence of SEQ ID NO:

17.

11. The isolated antibody of claim 1, wherein the antibody comprises a heavy chain comprising the amino acid sequence of SEQ ID NO:

52, 53, 54, 55, or 56.

12. The isolated antibody of claim 11, wherein the heavy chain comprises the amino acid sequence of SEQ ID NO:

53.

13. The isolated antibody of claim 11, wherein the amino acid sequence of the heavy chain consists of the amino acid sequence of SEQ ID NO:

53.

14. The isolated antibody of claim 1, wherein the light chain variable region comprises an amino acid sequence derived from a human IGKV3-15 germline sequence.

15. The isolated antibody of claim 1, wherein the light chain variable region comprises an amino acid sequence which is at least 75%, 80%, 85%, 90%, 95%, or 100% identical to the amino acid sequence of SEQ ID NO:

16.

16. The isolated antibody of claim 1, wherein the light chain variable region comprises the amino acid sequence of SEQ ID NO:

16.

17. The isolated antibody of claim 16, wherein the amino acid sequence of the light chain variable region consists of the amino acid sequence of SEQ ID NO:

16.

18. The isolated antibody of claim 1, wherein the antibody comprises a light chain comprising the amino acid sequence of SEQ ID NO:

19.

19. The isolated antibody of claim 18, wherein the amino acid sequence of the light chain consists of the amino acid sequence of SEQ ID NO:

19.

20. The isolated antibody of claim 1, wherein the heavy chain variable region and the light chain variable region, respectively, comprise the amino acid sequences set forth in SEQ ID NOs:

15 and 16;

26 and 16;

27 and 16;

28 and 16;

29 and 16;

30 and 16;

or 31 and 16.

21. The isolated antibody of claim 1, wherein the amino acid sequences of the heavy chain variable region and the light chain variable region, respectively, consist of the amino acid sequences set forth in SEQ ID NOs:

15 and 16;

26 and 16;

27 and 16;

28 and 16;

29 and 16;

30 and 16;

or 31 and 16.

22. The isolated antibody of claim 1, comprising a heavy chain and a light chain, wherein the heavy chain and the light chain, respectively, comprise the amino acid sequences set forth in SEQ ID NOs:

52 and 19;

54 and 19;

55 and 19;

or 56 and 19.

23. The isolated antibody of claim 1, comprising a heavy chain and a light chain, wherein the amino acid sequences of the heavy chain and the light chain, respectively, consist of the amino acid sequences set forth in SEQ ID NOs:

52 and 19;

54 and 19;

55 and 19;

or 56 and 19.

37. The isolated antibody of claim 1, wherein the antibody comprises a heavy chain constant region selected from the group consisting of human IgG₁, IgG₂, IgG₃, IgG₄, IgA₁, and IgA₂, and/or a light chain constant region selected from the group consisting of human IgGκ

and IgGλ

.

38. The isolated antibody of claim 1, wherein the antibody comprises a human IgG heavy chain constant region that is a variant of a wild type human IgG heavy chain constant region, wherein the variant human IgG heavy chain constant region binds to human Fc gamma receptor with lower affinity than the wild type human IgG heavy chain constant region binds to the human Fc gamma receptor.

39. The isolated antibody of claim 38, wherein the variant human IgG heavy chain constant region is a variant human IgG₁, a variant human IgG₂, or a variant human IgG₄ heavy chain constant region.

40. The isolated antibody of claim 38, wherein the Fc gamma receptor is Fcγ

RIIB.

41. The isolated antibody of claim 1, comprising:

(a) a human IgG₁ heavy chain constant region that lacks a glycan moiety at position N297;

(b) a human IgG₁ heavy chain constant region comprising an N297A mutation;

(c) a human IgG₁ heavy chain constant region comprising an N297Q mutation;

(d) a human IgG₁ heavy chain constant region comprising a D265A mutation; and

/or

(e) a human IgG₄ heavy chain constant region comprising an S228P mutation,

wherein the amino acid positions are according to the EU numbering system.

42. The isolated antibody of claim 1, wherein the antibody is a human antibody.

43. The isolated antibody of claim 1, wherein the antibody is antagonistic to human PD-1.

44. The isolated antibody of claim 1, wherein the antibody deactivates, reduces, or inhibits an activity of human PD-1.

45. The isolated antibody of claim 1, wherein the antibody inhibits binding of human PD-1 to human PD-L1 or to human PD-L2.

46. The isolated antibody of claim 1, wherein the antibody increases IL-2 production by peripheral blood mononuclear cells (PBMCs) stimulated with staphylococcal enterotoxin A (SEA).

47. The isolated antibody of claim 1, wherein the antibody increases IFNγ

production of a co-culture of human T cells and allogenic dendritic cells.

48. The isolated antibody of claim 1, wherein the antibody increases proliferation of anti-CD3-antibody-stimulated CD4+ or CD8+ T cells co-cultured with ovarian cancer ascites fluid.

49. The isolated antibody of claim 1, wherein the antibody increases NFAT signaling in PD-1-expressing NFAT-luciferase reporter cells co-cultured with PD-L1-expressing target cells.

50. The isolated antibody of claim 1 conjugated to a cytotoxic agent, cytostatic agent, toxin, radionuclide, or detectable label.

51. A pharmaceutical composition comprising the antibody of claim 1 and a pharmaceutically acceptable carrier or excipient.

52. An isolated polynucleotide encoding a heavy and/or light chain variable region of the antibody of claim 1.

53. A vector comprising the polynucleotide of claim 52.

54. A recombinant host cell comprising the polynucleotide of claim 52.

55. A recombinant host cell comprising the vector of claim 53.

56. A method of producing an antibody that binds to human PD-1, the method comprising culturing the host cell of claim 54 so that the polynucleotide is expressed and the antibody is produced.

57. A method of producing an antibody that binds to human PD-1, the method comprising culturing the host cell of claim 55 so that the polynucleotide is expressed and the antibody is produced.

58. A method of increasing T cell activation in response to an antigen in a subject, the method comprising administering to the subject an effective amount of the pharmaceutical composition of claim 51.

59. A method of treating cancer in a subject, the method comprising administering to the subject an effective amount of the pharmaceutical composition of claim 51.

60. The method of claim 59, wherein the pharmaceutical composition is administered subcutaneously, intratumorally, or intravenously.

61. The method of claim 59, further comprising administering an additional therapeutic agent to the subject.

62. The method of claim 61, wherein the additional therapeutic agent is a chemotherapeutic, radiotherapeutic, or checkpoint targeting agent.

63. The method of claim 62, wherein the checkpoint targeting agent is selected from the group consisting of an antagonist anti-PD-1 antibody, an antagonist anti-PD-L1 antibody, an antagonist anti-PD-L2 antibody, an antagonist anti-CTLA-4 antibody, an antagonist anti-TIM-3 antibody, an antagonist anti-LAG-3 antibody, an antagonist anti-CEACAM1 antibody, an antagonist anti-TIGIT antibody, an agonist anti-CD137 antibody, an agonist anti-ICOS antibody, an agonist anti-GITR antibody, and an agonist anti-OX40 antibody.

64. The method of claim 61, wherein the additional therapeutic agent is an inhibitor of indoleamine-2,3-dioxygenase (IDO).

65. The method of claim 64, wherein the inhibitor is selected from the group consisting of epacadostat, F001287, indoximod, and NLG919.

66. The method of claim 61, wherein the additional therapeutic agent is a vaccine.

67. The method of claim 66, wherein the vaccine comprises a heat shock protein peptide complex (HSPPC) comprising a heat shock protein complexed with an antigenic peptide.

68. The method of claim 67, wherein the heat shock protein is hsc70 and is complexed with a tumor-associated antigenic peptide.

69. The method of claim 67, wherein the heat shock protein is gp96 protein and is complexed with a tumor-associated antigenic peptide, wherein the HSPPC is derived from a tumor obtained from a subject.

70. A pharmaceutical composition comprising the antibody of claim 5 and a pharmaceutically acceptable carrier or excipient.

71. A method of increasing T cell activation in response to an antigen in a subject, the method comprising administering to the subject an effective amount of the pharmaceutical composition of claim 70.

72. A method of treating cancer in a subject, the method comprising administering to the subject an effective amount of the pharmaceutical composition of claim 70.

88. The method of claim 59, wherein the cancer is selected from the group consisting of acute leukemia, acute lymphoblastic leukemia, acute myeloid leukemia, bladder cancer, bone cancer, brain stem glioma, breast cancer, cancer of the adrenal gland, cancer of the endocrine system, cancer of the kidney or ureter, cancer of the parathyroid gland, cancer of the small intestine, cancer of the thyroid gland, cancer of the urethra, cancers of the anus, cancers of the oropharynx, cancers of the penis, cancers of the rectum, cancers of the vagina, cancers of the vulva, cancers that express PD-L1, carcinoma of the cervix, carcinoma of the endometrium, carcinoma of the fallopian tubes, carcinoma of the renal pelvis, cervical cancer, chronic leukemia, chronic lymphocytic leukemia, chronic myeloid leukemia, colorectal cancer, endometrial cancer, environmentally induced cancers including those induced by asbestos, epidermoid cancer, esophageal cancer, glioblastoma multiforme, glioma, head and neck cancer, hepatocellular cancer, Hodgkin'"'"'s Disease, HPV-associated cancers, Kaposi'"'"'s sarcoma, leukemia, liver cancer, lung cancer, lymphocytic lymphoma, lymphoma, melanoma, metastatic cancers, multiple myeloma, neoplasm of the central nervous system (CNS), non-Hodgkin'"'"'s lymphoma, ovarian cancer, pancreatic cancer, pituitary adenoma, primary CNS lymphoma, prostate cancer, refractory or recurrent malignancies, renal cell carcinoma, sarcoma, sarcoma of soft tissue, skin cancer, solid tumors of childhood, spinal axis tumor, squamous cell cancer, stomach cancer, T-cell lymphoma, testicular cancer, and uterine cancer.

89. The method of claim 72, wherein the cancer is selected from the group consisting of acute leukemia, acute lymphoblastic leukemia, acute myeloid leukemia, bladder cancer, bone cancer, brain stem glioma, breast cancer, cancer of the adrenal gland, cancer of the endocrine system, cancer of the kidney or ureter, cancer of the parathyroid gland, cancer of the small intestine, cancer of the thyroid gland, cancer of the urethra, cancers of the anus, cancers of the oropharynx, cancers of the penis, cancers of the rectum, cancers of the vagina, cancers of the vulva, cancers that express PD-L1, carcinoma of the cervix, carcinoma of the endometrium, carcinoma of the fallopian tubes, carcinoma of the renal pelvis, cervical cancer, chronic leukemia, chronic lymphocytic leukemia, chronic myeloid leukemia, colorectal cancer, endometrial cancer, environmentally induced cancers including those induced by asbestos, epidermoid cancer, esophageal cancer, glioblastoma multiforme, glioma, head and neck cancer, hepatocellular cancer, Hodgkin'"'"'s Disease, HPV-associated cancers, Kaposi'"'"'s sarcoma, leukemia, liver cancer, lung cancer, lymphocytic lymphoma, lymphoma, melanoma, metastatic cancers, multiple myeloma, neoplasm of the central nervous system (CNS), non-Hodgkin'"'"'s lymphoma, ovarian cancer, pancreatic cancer, pituitary adenoma, primary CNS lymphoma, prostate cancer, refractory or recurrent malignancies, renal cell carcinoma, sarcoma, sarcoma of soft tissue, skin cancer, solid tumors of childhood, spinal axis tumor, squamous cell cancer, stomach cancer, T-cell lymphoma, testicular cancer, and uterine cancer.

24. An isolated antibody that specifically binds to human PD-1, comprising a heavy chain variable region comprising an amino acid sequence selected from the group consisting of SEQ ID NOs:

15, 17, and 26-31.

25. The isolated antibody of claim 24, wherein the heavy chain variable region comprises the amino acid sequence of SEQ ID NO:

17.

26. The isolated antibody of claim 24, wherein the amino acid sequence of the heavy chain variable region consists of the amino acid sequence of SEQ ID NO:

17.

73. A pharmaceutical composition comprising the antibody of claim 24 and a pharmaceutically acceptable carrier or excipient.

74. A method of increasing T cell activation in response to an antigen in a subject, the method comprising administering to the subject an effective amount of the pharmaceutical composition of claim 73.

75. A method of treating cancer in a subject, the method comprising administering to the subject an effective amount of the pharmaceutical composition of claim 73.

90. The method of claim 75, wherein the cancer is selected from the group consisting of acute leukemia, acute lymphoblastic leukemia, acute myeloid leukemia, bladder cancer, bone cancer, brain stem glioma, breast cancer, cancer of the adrenal gland, cancer of the endocrine system, cancer of the kidney or ureter, cancer of the parathyroid gland, cancer of the small intestine, cancer of the thyroid gland, cancer of the urethra, cancers of the anus, cancers of the oropharynx, cancers of the penis, cancers of the rectum, cancers of the vagina, cancers of the vulva, cancers that express PD-L1, carcinoma of the cervix, carcinoma of the endometrium, carcinoma of the fallopian tubes, carcinoma of the renal pelvis, cervical cancer, chronic leukemia, chronic lymphocytic leukemia, chronic myeloid leukemia, colorectal cancer, endometrial cancer, environmentally induced cancers including those induced by asbestos, epidermoid cancer, esophageal cancer, glioblastoma multiforme, glioma, head and neck cancer, hepatocellular cancer, Hodgkin'"'"'s Disease, HPV-associated cancers, Kaposi'"'"'s sarcoma, leukemia, liver cancer, lung cancer, lymphocytic lymphoma, lymphoma, melanoma, metastatic cancers, multiple myeloma, neoplasm of the central nervous system (CNS), non-Hodgkin'"'"'s lymphoma, ovarian cancer, pancreatic cancer, pituitary adenoma, primary CNS lymphoma, prostate cancer, refractory or recurrent malignancies, renal cell carcinoma, sarcoma, sarcoma of soft tissue, skin cancer, solid tumors of childhood, spinal axis tumor, squamous cell cancer, stomach cancer, T-cell lymphoma, testicular cancer, and uterine cancer.

27. An isolated antibody that specifically binds to human PD-1, comprising a heavy chain comprising the amino acid sequence of SEQ ID NO:

52, 53, 54, 55, or 56.

28. The isolated antibody of claim 27, wherein the heavy chain comprises the amino acid sequence of SEQ ID NO:

53.

29. The isolated antibody of claim 27, wherein the amino acid sequence of the heavy chain consists of the amino acid sequence of SEQ ID NO:

53.

76. A pharmaceutical composition comprising the antibody of claim 27 and a pharmaceutically acceptable carrier or excipient.

77. A method of increasing T cell activation in response to an antigen in a subject, the method comprising administering to the subject an effective amount of the pharmaceutical composition of claim 76.

78. A method of treating cancer in a subject, the method comprising administering to the subject an effective amount of the pharmaceutical composition of claim 76.

91. The method of claim 78, wherein the cancer is selected from the group consisting of acute leukemia, acute lymphoblastic leukemia, acute myeloid leukemia, bladder cancer, bone cancer, brain stem glioma, breast cancer, cancer of the adrenal gland, cancer of the endocrine system, cancer of the kidney or ureter, cancer of the parathyroid gland, cancer of the small intestine, cancer of the thyroid gland, cancer of the urethra, cancers of the anus, cancers of the oropharynx, cancers of the penis, cancers of the rectum, cancers of the vagina, cancers of the vulva, cancers that express PD-L1, carcinoma of the cervix, carcinoma of the endometrium, carcinoma of the fallopian tubes, carcinoma of the renal pelvis, cervical cancer, chronic leukemia, chronic lymphocytic leukemia, chronic myeloid leukemia, colorectal cancer, endometrial cancer, environmentally induced cancers including those induced by asbestos, epidermoid cancer, esophageal cancer, glioblastoma multiforme, glioma, head and neck cancer, hepatocellular cancer, Hodgkin'"'"'s Disease, HPV-associated cancers, Kaposi'"'"'s sarcoma, leukemia, liver cancer, lung cancer, lymphocytic lymphoma, lymphoma, melanoma, metastatic cancers, multiple myeloma, neoplasm of the central nervous system (CNS), non-Hodgkin'"'"'s lymphoma, ovarian cancer, pancreatic cancer, pituitary adenoma, primary CNS lymphoma, prostate cancer, refractory or recurrent malignancies, renal cell carcinoma, sarcoma, sarcoma of soft tissue, skin cancer, solid tumors of childhood, spinal axis tumor, squamous cell cancer, stomach cancer, T-cell lymphoma, testicular cancer, and uterine cancer.

30. An isolated antibody that specifically binds to human PD-1, comprising a heavy chain comprising the amino acid sequence of SEQ ID NO:

18, 20, 21, 22, or 23.

31. The isolated antibody of claim 30, wherein the heavy chain comprises the amino acid sequence of SEQ ID NO:

20.

32. The isolated antibody of claim 30, wherein the amino acid sequence of the heavy chain consists of the amino acid sequence of SEQ ID NO:

20.

79. A pharmaceutical composition comprising the antibody of claim 30 and a pharmaceutically acceptable carrier or excipient.

80. A method of increasing T cell activation in response to an antigen in a subject, the method comprising administering to the subject an effective amount of the pharmaceutical composition of claim 79.

81. A method of treating cancer in a subject, the method comprising administering to the subject an effective amount of the pharmaceutical composition of claim 79.

92. The method of claim 81, wherein the cancer is selected from the group consisting of acute leukemia, acute lymphoblastic leukemia, acute myeloid leukemia, bladder cancer, bone cancer, brain stem glioma, breast cancer, cancer of the adrenal gland, cancer of the endocrine system, cancer of the kidney or ureter, cancer of the parathyroid gland, cancer of the small intestine, cancer of the thyroid gland, cancer of the urethra, cancers of the anus, cancers of the oropharynx, cancers of the penis, cancers of the rectum, cancers of the vagina, cancers of the vulva, cancers that express PD-L1, carcinoma of the cervix, carcinoma of the endometrium, carcinoma of the fallopian tubes, carcinoma of the renal pelvis, cervical cancer, chronic leukemia, chronic lymphocytic leukemia, chronic myeloid leukemia, colorectal cancer, endometrial cancer, environmentally induced cancers including those induced by asbestos, epidermoid cancer, esophageal cancer, glioblastoma multiforme, glioma, head and neck cancer, hepatocellular cancer, Hodgkin'"'"'s Disease, HPV-associated cancers, Kaposi'"'"'s sarcoma, leukemia, liver cancer, lung cancer, lymphocytic lymphoma, lymphoma, melanoma, metastatic cancers, multiple myeloma, neoplasm of the central nervous system (CNS), non-Hodgkin'"'"'s lymphoma, ovarian cancer, pancreatic cancer, pituitary adenoma, primary CNS lymphoma, prostate cancer, refractory or recurrent malignancies, renal cell carcinoma, sarcoma, sarcoma of soft tissue, skin cancer, solid tumors of childhood, spinal axis tumor, squamous cell cancer, stomach cancer, T-cell lymphoma, testicular cancer, and uterine cancer.

33. An isolated antibody that specifically binds to human PD-1, comprising a light chain variable region comprising the amino acid sequence of SEQ ID NO:

16.

34. The isolated antibody of claim 33, wherein the amino acid sequence of the light chain variable region consists of the amino acid sequence of SEQ ID NO:

16.

82. A pharmaceutical composition comprising the antibody of claim 33 and a pharmaceutically acceptable carrier or excipient.

83. A method of increasing T cell activation in response to an antigen in a subject, the method comprising administering to the subject an effective amount of the pharmaceutical composition of claim 82.

84. A method of treating cancer in a subject, the method comprising administering to the subject an effective amount of the pharmaceutical composition of claim 82.

93. The method of claim 84, wherein the cancer is selected from the group consisting of acute leukemia, acute lymphoblastic leukemia, acute myeloid leukemia, bladder cancer, bone cancer, brain stem glioma, breast cancer, cancer of the adrenal gland, cancer of the endocrine system, cancer of the kidney or ureter, cancer of the parathyroid gland, cancer of the small intestine, cancer of the thyroid gland, cancer of the urethra, cancers of the anus, cancers of the oropharynx, cancers of the penis, cancers of the rectum, cancers of the vagina, cancers of the vulva, cancers that express PD-L1, carcinoma of the cervix, carcinoma of the endometrium, carcinoma of the fallopian tubes, carcinoma of the renal pelvis, cervical cancer, chronic leukemia, chronic lymphocytic leukemia, chronic myeloid leukemia, colorectal cancer, endometrial cancer, environmentally induced cancers including those induced by asbestos, epidermoid cancer, esophageal cancer, glioblastoma multiforme, glioma, head and neck cancer, hepatocellular cancer, Hodgkin'"'"'s Disease, HPV-associated cancers, Kaposi'"'"'s sarcoma, leukemia, liver cancer, lung cancer, lymphocytic lymphoma, lymphoma, melanoma, metastatic cancers, multiple myeloma, neoplasm of the central nervous system (CNS), non-Hodgkin'"'"'s lymphoma, ovarian cancer, pancreatic cancer, pituitary adenoma, primary CNS lymphoma, prostate cancer, refractory or recurrent malignancies, renal cell carcinoma, sarcoma, sarcoma of soft tissue, skin cancer, solid tumors of childhood, spinal axis tumor, squamous cell cancer, stomach cancer, T-cell lymphoma, testicular cancer, and uterine cancer.

35. An isolated antibody that specifically binds to human PD-1, comprising a light chain comprising the amino acid sequence of SEQ ID NO:

19.

36. The isolated antibody of claim 35, wherein the amino acid sequence of the light chain consists of the amino acid sequence of SEQ ID NO:

19.

85. A pharmaceutical composition comprising the antibody of claim 35 and a pharmaceutically acceptable carrier or excipient.

86. A method of increasing T cell activation in response to an antigen in a subject, the method comprising administering to the subject an effective amount of the pharmaceutical composition of claim 85.

87. A method of treating cancer in a subject, the method comprising administering to the subject an effective amount of the pharmaceutical composition of claim 85.

94. The method of claim 87, wherein the cancer is selected from the group consisting of acute leukemia, acute lymphoblastic leukemia, acute myeloid leukemia, bladder cancer, bone cancer, brain stem glioma, breast cancer, cancer of the adrenal gland, cancer of the endocrine system, cancer of the kidney or ureter, cancer of the parathyroid gland, cancer of the small intestine, cancer of the thyroid gland, cancer of the urethra, cancers of the anus, cancers of the oropharynx, cancers of the penis, cancers of the rectum, cancers of the vagina, cancers of the vulva, cancers that express PD-L1, carcinoma of the cervix, carcinoma of the endometrium, carcinoma of the fallopian tubes, carcinoma of the renal pelvis, cervical cancer, chronic leukemia, chronic lymphocytic leukemia, chronic myeloid leukemia, colorectal cancer, endometrial cancer, environmentally induced cancers including those induced by asbestos, epidermoid cancer, esophageal cancer, glioblastoma multiforme, glioma, head and neck cancer, hepatocellular cancer, Hodgkin'"'"'s Disease, HPV-associated cancers, Kaposi'"'"'s sarcoma, leukemia, liver cancer, lung cancer, lymphocytic lymphoma, lymphoma, melanoma, metastatic cancers, multiple myeloma, neoplasm of the central nervous system (CNS), non-Hodgkin'"'"'s lymphoma, ovarian cancer, pancreatic cancer, pituitary adenoma, primary CNS lymphoma, prostate cancer, refractory or recurrent malignancies, renal cell carcinoma, sarcoma, sarcoma of soft tissue, skin cancer, solid tumors of childhood, spinal axis tumor, squamous cell cancer, stomach cancer, T-cell lymphoma, testicular cancer, and uterine cancer.