4-1BB AND OX40 BINDING PROTEINS AND RELATED COMPOSITIONS AND METHODS, ANTIBODIES AGAINST 4-1BB, ANTIBODIES AGAINST OX40

1 . A bispecific antibody comprising a polypeptide comprising, in order from amino-terminus to carboxyl-terminus, (i) a first single chain variable fragment (scFv), (ii) a linker, optionally wherein the linker is a hinge region, (iii) an immunoglobulin constant region, and (iv) a second scFv, wherein (a) the first scFv comprises a human 4-1BB antigen-binding domain, and the second scFv comprises a human OX40 antigen-binding domain or (b) the first scFv comprises a human OX40 antigen-binding domain and the second scFv comprises a human 4-1BB antigen-binding domain.

2 . An antibody comprising a human 4-1BB antigen-binding domain, wherein the 4-1BB antigen-binding domain competitively inhibits binding of a reference antibody to human 4-1BB, said reference antibody comprising a heavy chain variable domain (VH) comprising SEQ ID NO:17 and a light chain variable domain (VL) comprising SEQ ID NO:18 to human 4-1BB.

3 . An antibody comprising a human 4-1BB antigen-binding domain, wherein the 4-1BB antigen-binding domain specifically binds to the same epitope of human 4-1BB as an antibody comprising a VH comprising the amino acid sequence of SEQ ID NO: 17 and a VL comprising the amino acid sequence of SEQ ID NO:18.

4 . An antibody comprising a human 4-1BB antigen-binding domain, wherein the human 4-1BB antigen-binding domain comprises the six complementarity determining regions (CDRs) in the VH of SEQ ID NO:17 and the VL of SEQ ID NO: 18 or the six CDRs in the VH of SEQ ID NO:19 and the VL of SEQ ID NO: 20.

5 . The antibody of claim 4 , wherein the CDRs are the IMGT-defined CDRs, the Kabat-defined CDRs, the Chothia-defined CDRs, or the AbM-defined CDRs.

6 . An antibody comprising a human 4-1BB antigen-binding domain, wherein the human 4-1BB antigen-binding domain comprises a VH and a VL, wherein the VH comprises an amino acid at least 75%, 80%, 85%, 90%, 95%, or 99% identical to the amino acid sequence of SEQ ID NO:17.

7 . The antibody of claim 6 , wherein the human 4-1BB antigen-binding domain comprises a VH and a VL, wherein the VH comprises the amino acid sequence of SEQ ID NO: 17.

8 . An antibody comprising a human 4-1BB antigen-binding domain, wherein the human 4-1BB antigen-binding domain comprises a VH and a VL, wherein the VL comprises an amino acid at least 75%, 80%, 85%, 90%, 95%, or 99% identical to the amino acid sequence of SEQ ID sequence of SEQ ID NO:18 and wherein the human 4-1BB antigen-binding domain specifically binds human 4-1BB.

9 . The antibody of claim 8 , wherein the human 4-1BB antigen-binding domain comprises a VH and a VL, wherein the VL comprises the amino acid sequence of SEQ ID NO:18.

10 . The antibody of claims 6 or 8 , wherein the VH comprises an amino acid at least 95% identical to the amino acid sequence of SEQ ID NO:17 and the VL comprises an amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO: 18.

11 . An antibody comprising a human OX40 antigen-binding domain, wherein the human OX40 antigen-binding domain competitively inhibits binding of a reference antibody to human OX40, said reference antibody comprising a VH comprising SEQ ID NO:29 and a VL comprising SEQ ID NO:28 to human OX40.

12 . An antibody comprising a human OX40 antigen-binding domain, wherein the human OX40 antigen-binding domain specifically binds to the same epitope of human OX40 as an antibody comprising a VH comprising the amino acid sequence of SEQ ID NO:29 and a VL comprising the amino acid sequence of SEQ ID NO:28.

13 . An antibody comprising a human OX40 antigen-binding domain, wherein the OX40 antigen-binding domain comprises the six CDRs in the VH of SEQ ID NO:29 and the VL of SEQ ID NO:28 and specifically binds human OX40.

14 . The antibody of claim 13 , wherein the CDRs are the IMGT-defined CDRs, the Kabat-defined CDRs, the Chothia-defined CDRs, or the AbM-defined CDRs.

15 . An antibody comprising a human OX40 antigen-binding domain, wherein the human OX40 antigen-binding domain comprises a VH and a VL, wherein the VH comprises an amino acid sequence at least 75%, 80%, 85%, 90%, 95%, or 99% identical to the amino acid sequence SEQ ID NO:29.

16 . The antibody of claim 15 , wherein the VH comprises the amino acid sequence of SEQ ID NO:29.

17 . An antibody comprising a human OX40 antigen-binding domain, wherein the OX40 antigen-binding domain comprises a VH and a VL, wherein the VL comprises an amino acid sequence at least 75%, 80%, 85%, 90%, 95%, or 99% identical to the amino acid sequence of SEQ ID NO:28.

18 . The antibody of claim 17 , wherein the VL comprises the amino acid sequence of SEQ ID NO:28.

19 . The antibody of claims 15 and 17 , wherein the VH comprises an amino acid at least 95% identical to the amino acid sequence of SEQ ID NO:29 and the VL comprises an amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO:28.

20 . An antibody comprising a human OX40 antigen-binding domain, wherein the human OX40 antigen-binding domain comprises a VH and a VL, wherein the VH comprises an amino acid sequence of at least 75%, 80%, 85%, 90%, 95%, or 99% identical to the amino acid sequence SEQ ID NO:31.

21 . The antibody of claim 20 , wherein the VH comprises the amino acid sequence of SEQ ID NO:31.

22 . An antibody comprising a human OX40 antigen-binding domain, wherein the OX40 antigen-binding domain comprises a VH and a VL, wherein the VL comprises an amino acid sequence of at least 75%, 80%, 85%, 90%, 95%, or 99% identical to the amino acid sequence SEQ ID NO:30.

23 . The antibody of claim 22 , wherein the VL comprises the amino acid sequence of SEQ ID NO:30.

24 . The antibody of claims 20 and 22 , wherein the VH comprises an amino acid at least 95% identical to the amino acid sequence of SEQ ID NO:31 and wherein the VL comprises an amino acid at least 95% identical to the amino acid sequence of SEQ ID NO:30.

25 . The antibody of any one of claims 2 - 24 , wherein the antibody is monospecific.

26 . The antibody of claim 25 , wherein the antibody is an IgG antibody, optionally wherein the IgG antibody is an IgG 1 antibody.

27 . The antibody of claim 25 , wherein the antibody further comprises a heavy chain constant region and a light chain constant region, optionally wherein the heavy chain constant region is a human IgG 1 heavy chain constant region, and optionally wherein the light chain constant region is a human IgG κ light chain constant region.

28 . The antibody of claim 25 , wherein the antibody is an single chain Fv (scFv).

29 . The antibody of claim 25 , wherein the antibody comprises an a Fab, Fab′, F(ab′) 2 , scFv, disulfide linked Fv, or scFv-Fc.

30 . The antibody of any one of claims 2 - 9 , wherein the antibody is bispecific.

31 . The antibody of claim 30 , wherein the bispecific antibody comprises a human OX40 antigen-binding domain.

32 . The antibody of claim 31 , wherein the human OX40 antigen-binding domain (a) competitively inhibits binding of an antibody comprising a VH comprising SEQ ID NO:29 and a VL comprising SEQ ID NO:28 to human OX40, (b) specifically binds to the same epitope of human OX40 as an antibody comprising a VH comprising the amino acid sequence of SEQ ID NO:29 and a VL comprising the amino acid sequence of SEQ ID NO:28, (c) comprises the six CDRs in the VH of SEQ ID NO:29 and the VL of SEQ ID NO:28, optionally wherein the CDRs are the IMGT-defined CDRs, the Kabat-defined CDRs, the Chothia-defined CDRs, or the AbM-defined CDRs, (d) comprises a VH and a VL, wherein the VH comprises an amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO:29, (e) comprises a VH and a VL, wherein the VH comprises the amino acid sequence of SEQ ID NO:29, (f) comprises a VH and a VL, wherein the VL comprises an amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO:28, (g) comprises a VH and a VL, wherein the VL comprises the amino acid sequence of SEQ ID NO:28, (h) comprises a VH and a VL, wherein the VH comprises an amino acid sequence at least at least 95% identical to the amino acid sequence of SEQ ID NO:31, (i) comprises a VH and a VL, wherein the VH comprises the amino acid sequence of SEQ ID NO:31, (j) comprises a VH and a VL, wherein the VL comprises the amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO:30, and/or (k) comprises a VH and a VL, wherein the VL comprises the amino acid sequence of SEQ ID NO:30.

33 . The antibody of any one of claims 11 - 24 , wherein the antibody is bispecific.

34 . The antibody of claim 33 , wherein the bispecific antibody comprises a human 4-1BB antigen-binding domain.

35 . The antibody of claim 34 , wherein the human 4-1BB antigen-binding domain (a) competitively inhibits binding of an antibody comprising a VH comprising SEQ ID NO:17 and a VL comprising SEQ ID NO:18 to human 4-1BB, (b) specifically binds to the same epitope of human 4-1BB as an antibody comprising a VH comprising the amino acid sequence of SEQ ID NO:17 and a VL comprising the amino acid sequence of SEQ ID NO:18, (c) comprises the six CDRs in the VH of SEQ ID NO:17 and the VL of SEQ ID NO:18 or the six CDRs in the VH of SEQ ID NO:19 and the VL of SEQ ID NO:20, optionally wherein the CDRs are the IMGT-defined CDRs, the Kabat-defined CDRs, the Chothia-defined CDRs, or the AbM-defined CDRs, (d) comprises a VH and a VL, wherein the VH comprises the amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO:17, (e) comprises a VH and a VL, wherein the VH comprises the amino acid sequence of SEQ ID NO:17, (f) comprises a VH and a VL, wherein the VL comprises the amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO:18, and/or (g) comprises a VH and a VL, wherein the VL comprises the amino acid sequence of SEQ ID NO:18.

36 . A bispecific antibody comprising (a) a human 4-1BB antigen-binding domain and (b) a human OX40 antigen-binding domain, wherein

the 4-1BB antigen-binding domain comprises a (i) a VH-CDR 1 comprising the amino acid sequence of GYTFTSYW (SEQ ID NO:5); (ii) a VH-CDR2 comprising the amino acid sequence of IYPGSSTT (SEQ ID NO:6); (iii) a VH-CDR3 comprising the amino acid sequence of ASFSDGYYAYAMDY (SEQ ID NO:7); (iv) a light chain variable domain (VL)-CDR1 comprising the amino acid sequence of QDISNY (SEQ ID NO:8); (v) a VL-CDR2 comprising the amino acid sequence of YTS (SEQ ID NO:9); and (vi) a VL-CDR3 comprising the amino acid sequence of QQGYTLPYT (SEQ ID NO:10); and

the OX40 antigen-binding domain comprises a (i) a VH-CDR1 comprising the amino acid sequence of GFTLSYYG (SEQ ID NO:11); (ii) a VH-CDR2 comprising the amino acid sequence of ISHDGSDK (SEQ ID NO: 12); (iii) a VH-CDR3 comprising the amino acid sequence of SNDQFDP (SEQ ID NO: 13); (iv) a VL-CDR1 comprising the amino acid sequence of NIGSKS (SEQ ID NO: 14); (v) a VL-CDR2 comprising the amino acid sequence of DDS (SEQ ID NO:15); and (vi) a VL-CDR3 comprising the amino acid sequence of QVWDSSSDHVV (SEQ ID NO:16).

37 . The antibody of claim 1 , wherein the human 4-1BB antigen-binding domain (a) competitively inhibits binding of an antibody comprising a VH comprising SEQ ID NO:17 and a VL comprising SEQ ID NO:18 to human 4-1BB, (b) specifically binds to the same epitope of human 4-1BB as an antibody comprising a VH comprising the amino acid sequence of SEQ ID NO:17 and a VL comprising the amino acid sequence of SEQ ID NO:18, (c) comprises the six CDRs in the VH of SEQ ID NO:17 and the VL of SEQ ID NO:18 or the six CDRs in the VH of SEQ ID NO:19 and the VL of SEQ ID NO:20, optionally wherein the CDRs are the IMGT-defined CDRs, the Kabat-defined CDRs, the Chothia-defined CDRs, or the AbM-defined CDRs, (d) comprises a VH and a VL, wherein the VH comprises the amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO:17, (e) comprises a VH and a VL, wherein the VH comprises the amino acid sequence of SEQ ID NO:17, (f) comprises a VH and a VL, wherein the VL comprises the amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO:18, and/or (g) comprises a VH and a VL, wherein the VL comprises the amino acid sequence of SEQ ID NO:18.

38 . The antibody of claim 1 or 37 , wherein the human OX40 antigen-binding domain (a) competitively inhibits binding of an antibody comprising a VH comprising SEQ ID NO:29 and a VL comprising SEQ ID NO:28 to human OX40, (b) specifically binds to the same epitope of human OX40 as an antibody comprising a VH comprising the amino acid sequence of SEQ ID NO:29 and a VL comprising the amino acid sequence of SEQ ID NO:28, (c) comprises the six CDRs in the VH of SEQ ID NO:29 and the VL of SEQ ID NO:28, optionally wherein the CDRs are the IMGT-defined CDRs, the Kabat-defined CDRs, the Chothia-defined CDRs, or the AbM-defined CDRs, (d) comprises a VH and a VL, wherein the VH comprises an amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO:29, (e) comprises a VH and a VL, wherein the VH comprises the amino acid sequence of SEQ ID NO:29, (f) comprises a VH and a VL, wherein the VL comprises an amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO:28, (g) comprises a VH and a VL, wherein the VL comprises the amino acid sequence of SEQ ID NO:28, (h) comprises a VH and a VL, wherein the VH comprises an amino acid sequence at least at least 95% identical to the amino acid sequence of SEQ ID NO:31, (i) comprises a VH and a VL, wherein the VH comprises the amino acid sequence of SEQ ID NO:31, (j) comprises a VH and a VL, wherein the VL comprises the amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO:30, and/or (k) comprises a VH and a VL, wherein the VL comprises the amino acid sequence of SEQ ID NO:30.

39 . The antibody of any one of claims 1 - 5 , 8 - 9 , 25 - 32 , and 34 , wherein the human 4-1BB binding domain comprises a VH comprising an amino acid sequence at least 75%, 80%, 85%, 90%, 95%, or 99% identical to an amino acid sequence selected from the group consisting of SEQ ID NOs:17, 19, 21, 23, 32, and 143.

40 . The antibody of any one of claims 1 - 5 , 8 - 9 , 25 - 32 and 34 , wherein the human 4-1BB binding domain comprises a VH comprising the amino acid sequence of any one of SEQ ID NOs:17, 19, 21, 23, 32, and 143.

41 . The antibody of any one of claims 1 - 7 , 25 - 32 , and 34 - 40 , wherein the human 4-1BB binding domain comprises a VL comprising an amino acid sequence at least 75%, 80%, 85%, 90%, 95%, or 99% identical to an amino acid sequence selected from the group consisting of SEQ ID NOs:18, 20, 22, and 24.

42 . The antibody of any one of claims 1 - 7 , 25 - 32 , and 34 - 41 , wherein the human 4-1BB binding domain comprises a VL comprising the amino acid sequence of any one of SEQ ID NOs:18, 20, 22, and 24.

43 . The antibody of any one of claims 1 - 10 , 25 - 32 , and 34 - 42 , wherein the human 4-1BB binding domain comprises (a) a VH comprising the amino acid sequence of SEQ ID NO:17 and a VL comprising the amino acid sequence of SEQ ID NO: 18, (b) a VH comprising the amino acid sequence of SEQ ID NO:19 and a VL comprising the amino acid sequence of SEQ ID NO:20, (c) a VH comprising the amino acid sequence of SEQ ID NO:21 and a VL comprising the amino acid sequence of SEQ ID NO:22, (d) a VH comprising the amino acid sequence of SEQ ID NO:23 and a VL comprising the amino acid sequence of SEQ ID NO:24, (e) a VH comprising the amino acid sequence of SEQ ID NO:32 and a VL comprising the amino acid sequence of SEQ ID NO:18, or (f) a VH comprising the amino acid sequence of SEQ ID NO:143 and a VL comprising the amino acid sequence of SEQ ID NO:20.

44 . The antibody of any one of claims 1 - 10 , 25 - 32 , and 34 - 43 , wherein the human 4-1BB binding domain comprises a VH comprising the amino acid sequence of SEQ ID NO: 17 and a VL comprising the amino acid sequence of SEQ ID NO:18.

45 . The antibody of any one of claims 1 - 10 , 25 - 32 , and 34 - 44 , wherein the human 4-1BB binding domain comprises a VH and a VL on the same polypeptide chain.

46 . The antibody of claim 45 , wherein the VH of the human 4-1BB binding domain is N-terminal to the VL of the human 4-1BB binding domain.

47 . The antibody of claim 45 , wherein the VH of the human 4-1BB binding domain is C-terminal to the VL of the human 4-BB binding domain.

48 . The antibody of any one of claims 45 - 47 , wherein the human 4-1BB binding domain comprises a linker between the VH and the VL.

49 . The antibody of claim 48 , wherein the linker comprises the amino acid (Gly 4 Ser) n , wherein n=1-5 (SEQ ID NO: 117).

50 . The antibody of claim 49 , wherein n=3-5 or n=4-5, optionally wherein n=4.

51 . The antibody of any one of claims 1 - 10 , 25 - 32 , and 34 - 44 , wherein the 4-1BB binding domain comprises an scFv comprising the amino acid sequence of any one of SEQ ID NOs:42, 44, 58, 63, 77, and 145.

52 . The antibody of claim 51 , wherein the human 4-1BB binding domain comprises an scFv comprising the amino acid sequence of SEQ ID NO:58.

53 . The antibody of any one of claims 1 - 10 , 25 - 32 , and 34 - 52 , wherein the human 4-1BB binding domain is capable of binding to cynomolgus 4-1BB.

54 . The antibody of any one of claims 1 - 10 , 25 - 32 , and 34 - 52 , wherein the human 4-1BB binding domain is capable of agonizing human 4-1BB activity.

55 . The antibody of any one of claims 1 - 10 , 25 - 32 , 34 , 41 , 34 - 39 , 53 , and 54 , wherein the human 4-1BB binding domain comprises humanized VH and VL sequences.

56 . The antibody of any one of claims 1 , 11 - 14 , 17 , 18 , 22 , 23 , 29 , and 31 - 55 , wherein the human OX40 binding domain comprises a VH comprising an amino acid sequence at least 75%, 80%, 85%, 90%, 95%, or 99% identical to an amino acid sequence selected from the group consisting of SEQ ID NOs:25, 27, 29, 31, and 33.

57 . The antibody of any one of claims 1 , 11 - 14 , 17 , 18 , 22 , 23 , 29 and 31 - 56 , wherein the human OX40 binding domain comprises a VH comprising the amino acid sequence of any one of SEQ ID NOs:25, 27, 29, 31, and 33.

58 . The antibody of any one of claims 1 , 11 - 16 , 20 , 21 , 25 - 29 , and 31 - 57 , wherein the human OX40 binding domain comprises a VL comprising an amino acid sequence at least 75%, 80%, 85%, 90%, 95%, or 99% identical to an amino acid sequence selected from the group consisting of SEQ ID NOs:26, 28, 30, and 34-41.

59 . The antibody of any one of claims 1 , 11 - 16 , 20 , 21 , 25 - 29 , and 31 - 58 , wherein the human OX40 binding domain comprises a VL comprising the amino acid sequence of any one of SEQ ID NOs:26, 28, 30, and 34-41.

60 . The antibody of any one of claims 1 , 11 - 29 , and 31 - 59 , wherein the human OX40 binding domain comprises (a) a VH comprising the amino acid sequence of SEQ ID NO:25 and a VL comprising the amino acid sequence of SEQ ID NO:26, (b) a VH comprising the amino acid sequence of SEQ ID NO:27 and a VL comprising the amino acid sequence of SEQ ID NO:28, (c) a VH comprising the amino acid sequence of SEQ ID NO:29 and a VL comprising the amino acid sequence of SEQ ID NO:26, (d) a VH comprising the amino acid sequence of SEQ ID NO:29 and a VL comprising the amino acid sequence of SEQ ID NO:30, (e) a VH comprising the amino acid sequence of SEQ ID NO:31 and a VL comprising the amino acid sequence of SEQ ID NO:28, (f) a VH comprising the amino acid sequence of SEQ ID NO:31 and a VL comprising the amino acid sequence of SEQ ID NO:30, (g) a VH comprising the amino acid sequence of SEQ ID NO:33 and a VL comprising the amino acid sequence of SEQ ID NO:28, (h) a VH comprising the amino acid sequence of SEQ ID NO:29 and a VL comprising the amino acid sequence of SEQ ID NO:34, (i) a VH comprising the amino acid sequence of SEQ ID NO:29 and a VL comprising the amino acid sequence of SEQ ID NO:35, (j) a VH comprising the amino acid sequence of SEQ ID NO:29 and a VL comprising the amino acid sequence of SEQ ID NO:36, (k) a VH comprising the amino acid sequence of SEQ ID NO:29 and a VL comprising the amino acid sequence of SEQ ID NO:37, (1) a VH comprising the amino acid sequence of SEQ ID NO:31 and a VL comprising the amino acid sequence of SEQ ID NO:34, (m) a VH comprising the amino acid sequence of SEQ ID NO:31 and a VL comprising the amino acid sequence of SEQ ID NO:35, (n) a VH comprising the amino acid sequence of SEQ ID NO:31 and a VL comprising the amino acid sequence of SEQ ID NO:36, (o) a VH comprising the amino acid sequence of SEQ ID NO:31 and a VL comprising the amino acid sequence of SEQ ID NO:37, (p) a VH comprising the amino acid sequence of SEQ ID NO:31 and a VL comprising the amino acid sequence of SEQ ID NO:38, (q) a VH comprising the amino acid sequence of SEQ ID NO:31 and a VL comprising the amino acid sequence of SEQ ID NO:39, (r) a VH comprising the amino acid sequence of SEQ ID NO:31 and a VL comprising the amino acid sequence of SEQ ID NO:40, or (s) a VH comprising the amino acid sequence of SEQ ID NO:31 and a VL comprising the amino acid sequence of SEQ ID NO:41.

61 . The antibody of any one of claims 1 , 11 - 29 , and 31 - 60 , wherein the human OX40 binding domain comprises (a) a VH comprising the amino acid sequence of SEQ ID NO:29 and a VL comprising the amino acid sequence of SEQ ID NO:28, (b) a VH comprising the amino acid sequence of SEQ ID NO:31 and a VL comprising the amino acid sequence of SEQ ID NO:30, or (c) a VH comprising the amino acid sequence of SEQ ID NO:29 and a VL comprising the amino acid sequence of SEQ ID NO:35.

62 . The antibody of any one of claims 1 , 11 - 29 , and 31 - 60 , wherein the human OX40 binding domain comprises a VH and a VL on the same polypeptide chain.

63 . The antibody of claim 62 , wherein the VH of the human OX40 binding domain is N-terminal to the VL of the human OX40 binding domain.

64 . The antibody of claim 62 , wherein the VH of the human OX40 binding domain is C-terminal to the VL of the human OX40 binding domain.

65 . The antibody of any one of claims 62 - 64 , wherein the human OX40 binding domain comprises a linker between the VH and the VL.

66 . The antibody of claim 65 , wherein the linker comprises the amino acid sequence (Gly 4 Ser) n , wherein n=1-5 (SEQ ID NO:117).

67 . The antibody of claim 66 , wherein n=3-5, optionally wherein n=4.

68 . The antibody of any one of claims 1 , 11 - 29 , and 31 - 61 , wherein the OX40 binding domain comprises an scFv comprising the amino acid sequence of any one of SEQ ID NOs:46, 47, 52, 54, 56, 59-62, 64-76, and 146.

69 . The antibody of claim 68 , wherein the human OX40 binding domain comprises an scFv comprising the amino acid sequence of any one of SEQ ID NOs:59, 62, or 66.

70 . The antibody of any one of claims 1 , 11 - 29 , and 31 - 69 , wherein the OX40 binding domain is capable of binding to cynomolgus OX40.

71 . The antibody of any one of claims 1 , 11 - 29 , and 31 - 70 , wherein the human OX40 binding domain is capable of agonizing human OX40 activity.

72 . The antibody of any one of claims 1 , 11 - 29 , 31 - 56 , 58 , 62 - 67 , 70 , and 71 , wherein the OX40 binding domain comprises murine or rat VH and VL sequences.

73 . An antibody comprising a human 4-1BB binding domain and a human OX-40 binding domain, wherein the human 4-1BB binding domain comprises a VH comprising an amino acid sequence at least 85%, 90%, 95%, or 99% identical to an amino acid sequence of SEQ ID NO:17 and a VL comprising an amino acid sequence at least 85%, 90%, 95%, or 99% identical to an amino acid sequence of SEQ ID NO:18 and wherein the human OX40 binding domain comprises (a) a VH comprising an amino acid sequence at least 85%, 90%, 95%, or 99% identical to an amino acid sequence of SEQ ID NO:29 and a VL comprising an amino acid sequence at least 85%, 90%, 95%, or 99% identical to an amino acid sequence of SEQ ID NO:28, (b) a VH comprising an amino acid sequence at least 85%, 90%, 95%, or 99% identical to an amino acid sequence SEQ ID NO:31 and a VL comprising an amino acid sequence at least 85%, 90%, 95%, or 99% identical to an amino acid sequence SEQ ID NO:30, or (c) a VH comprising an amino acid sequence at least 85%, 90%, 95%, or 99% identical to an amino acid sequence of SEQ ID NO:29 and a VL comprising an amino acid sequence at least 85%, 90%, 95%, or 99% identical to an amino acid sequence of SEQ ID NO:35.

74 . The antibody of claim 1 or 73 , wherein the human 4-1BB binding domain comprises a VH comprising the amino acid sequence of SEQ ID NO: 17 and a VL comprising the amino acid sequence of SEQ ID NO:18 and wherein the OX40 binding domain comprises (a) a VH comprising the amino acid sequence of SEQ ID NO:29 and a VL comprising the amino acid sequence of SEQ ID NO:28, (b) a VH comprising the amino acid sequence of SEQ ID NO:31 and a VL comprising the amino acid sequence of SEQ ID NO:30, or (c) a VH comprising the amino acid sequence of SEQ ID NO:29 and a VL comprising the amino acid sequence of SEQ ID NO:35.

75 . An antibody comprising a human 4-BB binding domain and a human OX40 binding domain, wherein the human 4-1BB binding domain comprises an scFv comprising an amino acid sequence at least 85%, 90%, 95%, or 99% identical to an amino acid sequence of SEQ ID NO:58 and wherein the human OX40 binding domain comprises an scFv comprising an amino acid sequence at least 85%, 90%, 95%, or 99% identical to an amino acid sequence of any one of SEQ ID NOs:59, 62, or 66.

76 . The antibody of claim 1 or 75 , wherein the human 4-1BB binding domain comprises an scFv comprising the amino acid sequence of SEQ ID NO:58 and wherein the human OX40 binding domain comprises an scFv comprising the amino acid sequence of any one of SEQ ID NOs:59, 62, or 66.

77 . The antibody of any one of claims 1 , 31 , 32 , and 34 - 76 , wherein the human 4-1BB binding domain and the human OX40 binding domain are on the same polypeptide.

78 . The antibody of claim 77 , wherein the human 4-1BB binding domain is N-terminal to the human OX40 binding domain.

79 . The antibody of claim 77 , wherein the human 4-1BB binding domain is C-terminal to the human OX40 binding domain.

80 . The antibody of any one of claims 1 - 79 , wherein the antibody comprises an immunoglobulin constant region.

81 . The antibody of claim 80 , wherein the immunoglobulin constant region comprises immunoglobulin CH2 and CH3 domains of IgG1, IgG2, IgG3, IgG4, IgA1, IgA2 or IgD.

82 . The antibody claim 81 , wherein the immunoglobulin constant region comprises immunoglobulin CH2 and CH3 domains of IgG1.

83 . The antibody of any one of claims 1 - 25 and 27 - 82 , wherein the antibody does not contain a CH1 domain.

84 . The antibody of any one of claims 80 - 83 , wherein the immunoglobulin constant region comprises one, two, three, four, five or more amino acid substitutions and/or deletions compared to a wild-type immunoglobulin constant region to prevent binding to FcγR1, FcγRIIa, FcγRIIb, FcγRIIa, and FcγRIIIb.

85 . The antibody of any one of claims 80 - 84 , wherein the immunoglobulin constant region comprises one, two, three, four, five or more amino acid substitutions and/or deletions compared to a wild-type immunoglobulin constant region to prevent or reduce Fe-mediated T-cell activation.

86 . The antibody of any one of claims 80 - 85 , wherein the immunoglobulin constant region comprises one, two, three, four, five or more amino acid substitutions and/or deletions compared to a wild-type immunoglobulin constant region to prevent or reduce CDC activity.

87 . The antibody of any one of claims 80 - 86 , wherein the immunoglobulin constant region comprises one, two, three, four, five or more amino acid substitutions and/or deletions compared to a wild-type immunoglobulin constant region to prevent or reduce ADCC activity.

88 . The antibody of any one of claims 80 - 87 , wherein the immunoglobulin constant region comprises a IgG1 CH2 domain comprising the substitutions E233P, L234A, L235A, G237A, and K322A and a deletion of G236 according to the EU numbering system.

89 . The antibody of any one of claims 80 - 87 , wherein the antibody comprises a linker between the immunoglobulin constant region and the human 4-1BB binding domain and/or between the immunoglobulin constant region and the human OX40 binding domain.

90 . The antibody of claim 89 , wherein the linker between the immunoglobulin constant region and the human 4-1BB binding domain and/or between the immunoglobulin constant region and the human OX40 binding domain comprises 10-30 amino acids, 15-30 amino acids, or 20-30 amino acids.

91 . The antibody of claim 90 , wherein the linker between the immunoglobulin constant region and the human 4-1BB binding domain or between the immunoglobulin constant region and the human OX40 binding domain comprises the amino acid sequence (Gly 4 Ser) n , wherein n=1-5 (SEQ ID NO:117), optionally wherein n=1.

92 . The antibody of any one of claims 1 , 31 , 32 , and 34 - 39 , wherein the antibody comprises a dimer of two polypeptides, each polypeptide comprising in order from amino-terminus to carboxyl-terminus, a first scFv, a hinge region, an immunoglobulin constant region, and a second scFv, wherein (a) the first scFv comprises a human 4-1BB antigen-binding domain, and the second scFv comprises a human OX40 antigen-binding domain or (b) the first scFv comprises a human OX40 antigen-binding domain and the second scFv comprises a human 4-1BB antigen-binding domain.

93 . The antibody of claim 92 , wherein the dimer is a homodimer.

94 . The antibody of any one of claims 1 and 37 - 72 , 74 , 76 - 93 , wherein the first scFv comprises a human 4-1BB binding domain and the second scFv comprises a human OX40 antigen-binding domain.

95 . The antibody of any one of claims 1 and 37 - 72 , 74 , 76 - 94 , wherein the hinge is an IgG1 hinge.

96 . The antibody of claim 95 , wherein the hinge comprises amino acids 1-15 of SEQ ID NO:115.

97 . The antibody of any one of claims 1 and 37 - 72 , 74 , 76 - 96 , wherein the hinge and immunoglobulin constant region comprise the amino acid sequence of SEQ ID NO:115.

98 . The antibody of any one of claims 92 - 96 , wherein the antibody comprises a linker between the immunoglobulin constant region and the human OX40 binding domain, wherein the linker comprises the amino acid sequence (Gly 4 Ser) n , wherein n=1-5 (SEQ ID NO: 117), optionally wherein n=1.

99 . The antibody of any one of claims 92 - 96 , wherein the human 4-1BB binding domain comprises a VH comprising an amino acid sequence at least 85%, 90%, 95%, or 99% identical to an amino acid sequence SEQ ID NO: 17 and a VL comprising an amino acid sequence at least 85%, 90%, 95%, or 99% identical to an amino acid sequence of SEQ ID NO:18 and wherein the human OX40 binding domain comprises (a) a VH comprising an amino acid sequence at least 85%, 90%, 95%, or 99% identical to an amino acid sequence SEQ ID NO:29 and a VL comprising an amino acid sequence at least 85%, 90%, 95%, or 99% identical to an amino acid sequence SEQ ID NO:28, (b) a VH comprising an amino acid sequence at least 85%, 90%, 95%, or 99% identical to an amino acid sequence SEQ ID NO:31 and a VL comprising an amino acid sequence at least 85%, 90%, 95%, or 99% identical to an amino acid sequence SEQ ID NO:30, or (c) a VH comprising an amino acid sequence at least 85%, 90%, 95%, or 99% identical to an amino acid sequence SEQ ID NO:29 and a VL comprising an amino acid sequence at least 85%, 90%, 95%, or 99% identical to an amino acid sequence SEQ ID NO:35.

100 . The antibody of any one of claims 92 - 96 and 99 , wherein the human 4-1BB binding domain comprises a VH comprising the amino acid sequence of SEQ ID NO:17 and a VL comprising the amino acid sequence of SEQ ID NO:18 and wherein the human OX40 binding domain comprises (a) a VH comprising the amino acid sequence of SEQ ID NO:29 and a VL comprising the amino acid sequence of SEQ ID NO:28, (b) a VH comprising the amino acid sequence of SEQ ID NO:31 and a VL comprising the amino acid sequence of SEQ ID NO:30, or (c) a VH comprising the amino acid sequence of SEQ ID NO:29 and a VL comprising the amino acid sequence of SEQ ID NO:35.

101 . The antibody of any one of claims 92 - 96 , wherein the human 4-1BB binding domain comprises an amino acid sequence at least 85%, 90%, 95%, or 99% identical to an amino acid sequence SEQ ID NO:58 and wherein the human OX40 binding domain comprises an amino acid sequence at least 85%, 90%, 95%, or 99% identical to any one amino acid sequence of SEQ ID NOs:59, 62, or 66.

102 . The antibody of any one of claims 92 - 96 and 101 , wherein the human 4-1BB binding domain comprises the amino acid sequence of SEQ ID NO:58 and wherein the human OX40 binding domain comprises the amino acid sequence of any one of SEQ ID NOs:59, 62, or 66.

103 . A bispecific antibody that comprises a human 4-1BB antigen-binding domain and a human OX40 antigen-binding domain, wherein the antibody comprises an amino acid sequence at least 75%, 80%, 85%, 90%, 95%, or 99% identical to an amino acid sequence selected from the group consisting of SEQ ID NOs:78-100 and 144.

104 . The antibody of claim 103 , wherein the antibody comprises an amino acid sequence selected from the group consisting of SEQ ID Nos:78-100 and 144.

105 . The antibody of claim 103 , wherein the antibody is a homodimer comprising two identical polypeptides, each polypeptide comprising an same amino acid sequence at least 85%, 90%, 95%, or 99% identical to an amino acid sequence selected from the group consisting of SEQ ID NOs:78-100 and 144.

106 . A bispecific antibody that comprises a human 4-1BB antigen-binding domain and a human OX40 antigen-binding domain, wherein the antibody comprises the amino acid sequence of SEQ ID NO:78.

107 . The antibody of claim 106 , wherein the antibody is a homodimer comprising two polypeptides, each polypeptide comprising the amino acid sequence of SEQ ID NO:78.

108 . A bispecific antibody that binds to human 4-1BB and binds to human OX40, wherein the antibody comprises an amino acid sequence at least 85%, 90%, 95%, or 99% identical to an amino acid sequence of SEQ ID NO:81.

109 . A bispecific antibody that binds to human 4-1BB and binds to human OX40, wherein the antibody comprises the amino acid sequence of SEQ ID NO:81.

110 . The antibody of claim 109 , wherein the antibody is a homodimer comprising two polypeptides, each polypeptide comprising the amino acid sequence of SEQ ID NO:81.

111 . A bispecific antibody that binds to human 4-1BB antigen-binding domain and human OX40 antigen-binding domain, wherein the antibody comprises the amino acid sequence of SEQ ID NO:90.

112 . The antibody of claim 111 , wherein the antibody is a homodimer comprising two polypeptides, each polypeptide comprising the amino acid sequence of SEQ ID NO:90.

113 . The antibody of any one of claims 1 , 31 , 32 , 34 - 36 , 39 - 74 and 83 - 91 , wherein the human 4-1BB binding domain and the human OX40 binding domain are on separate peptides.

114 . The antibody of any one of claims 1 - 7 , 25 - 27 , 29 - 32 , 34 - 44 , 53 - 61 , and 70 - 73 , wherein the human 4-1BB binding domain comprises a VH and VL on separate polypeptides.

115 . The antibody of any one of claims 1 , 11 - 27 , 29 , 31 - 44 , 53 - 61 , 70 - 73 and 114 , wherein the human OX40 binding domain comprises a VH and VL on separate polypeptides.

116 . The antibody of any one of claims 1 - 24 , 30 - 35 , 39 - 91 and 113 - 115 , wherein the antibody is a knob-in-hole (KIH) antibody, an IgG1 antibody comprising matched mutations in the CH3 domain, two engineered Fv fragments with exchanged VHs, a diabody, an scFv×scFv, an scFv-Fc-scFv, a quadroma, a CrossMab Fab, a CrossMab VH-VL, or a strand-exchange engineered domain body (SEEDbody).

117 . The antibody of any one of claims 1 , 31 , 32 , and 34 - 116 , wherein the antibody is capable of binding to human 4-1BB and human OX40 simultaneously.

118 . The antibody of any one of claims 1 , 31 , 32 , and 34 - 117 , wherein the antibody is capable of promoting a dose-dependent expansion of CD8 + T, CD4 + T, and/or NK cells.

119 . The antibody of any one of claims 1 , 31 , 32 , and 34 - 117 , wherein the antibody is capable of promoting a dose-dependent expansion of CD8+ T, CD4+ T, and NK cells.

120 . The antibody of any of claims 1 , 31 , 32 , and 34 - 118 , wherein the antibody is capable of activating CD8+T, CD4+T, and/or NK cells.

121 . The antibody of any of claims 1 , 31 , 32 , and 34 - 118 , wherein the antibody is capable of activating CD8+T, CD4+T, and NK cells.

122 . The antibody of any claims 1 , 31 , 32 , and 34 - 118 , wherein the antibody is capable of eliciting granzyme expression in CD8+T, CD4+T, and/or NK cells.

123 . The antibody of any of claims 1 , 31 , 32 , and 34 - 118 , where the antibody lyses tumor cells.

124 . The antibody of any of claims 1 , 31 , 32 , and 34 - 118 , wherein the antibody has a theoretical pI of less than 7.5, 7.6, 7.7, 7.8, 7.9 or 8.

125 . The antibody of any of claims 1 , 31 , 32 , and 34 - 118 , wherein the antibody exhibits a Tm of about 64-69, 64-68, 64-67, or 65-68.

126 . The antibody of any one of claims 1 , 31 , 32 , and 34 - 118 , wherein the antibody is capable of increasing secretion of IFN-γ, IL-2, and/or TNF-α from stimulated PBMCs.

127 . The antibody of any one of claims 1 , 31 , 32 , and 34 - 119 , wherein the antibody is agonistic to human 4-1BB and agonistic to human OX40.

128 . The antibody of any one of claims 1 - 120 , wherein the antibody is isolated.

129 . The antibody of any one of claims 1 - 128 , wherein the antibody is a monoclonal antibody.

130 . The antibody of any one of claims 1 - 129 , further comprising a detectable label.

131 . A polynucleotide encoding the antibody of any one of claims 1 - 130 .

132 . A vector comprising the polynucleotide of claim 131 , optionally wherein the vector is an expression vector.

133 . A host cell comprising the polynucleotide of claim 131 or the vector of claim 132 .

134 . A host cell comprising a combination of polynucleotides that encode the antibody of any one of claims 1 - 106 .

135 . The host cell of claim 134 , wherein the polynucleotides are encoded on a single vector.

136 . The host cell of claim 134 , wherein the polynucleotides are encoded on multiple vectors.

137 . The host cell of any one of claims 133 - 136 , which is selected from the group consisting of a CHO, HEK293, or COS cell.

138 . A method of producing an antibody that specifically binds to human 4-1BB and human OX40 comprising culturing the host cell of any one of claims 133 - 137 —so that the antibody is produced, optionally further comprising recovering the antibody.

139 . A method for detecting 4-1BB and OX40 in a sample, the method comprising contacting said sample with the antibody of any one of claim 1130 , optionally wherein the sample comprises cells.

140 . A pharmaceutical composition comprising the antibody of any one of claims 1 - 130 , and a pharmaceutically acceptable excipient.

141 . A method for increasing NK cell proliferation comprising contacting an NK cell with the antibody of any one of claims 1 - 130 or the pharmaceutical composition of claim 140 .

142 . A method for increasing T cell proliferation comprising contacting a T cell with the antibody of any one of claims 1 - 130 or the pharmaceutical composition of claim 140 .

143 . A method for increasing NK cell proliferation and T cell proliferation comprising contacting an NK cell and a T cell with the antibody of any one of claims 1 - 130 or the pharmaceutical composition of claim 140 .

144 . A method of agonizing a T cell co stimulatory pathway comprising contacting a T cell with antibody of any one of claims 1 - 130 or the pharmaceutical composition of claim 140 .

145 . The method of claim 143 or 144 or, wherein the T cell is a CD4+ T cell.

146 . The method of claim 143 or 144 , wherein the T cell is a CD8+ T cell.

147 . The method of any one of claims 141 - 146 , wherein the cell is in a subject and the contacting comprises administering the antibody or the pharmaceutical composition to the subject.

148 . A method for enhancing an immune response in a subject, the method comprising administering to the subject an effective amount of the antibody of any one of claims 1 - 130 or the pharmaceutical composition of claim 140 .

149 . A method of increasing the number of tumor infiltrating lymphocytes in a subject, the method comprising administering to the subject an effective amount of the antibody of any one of claims 1 - 130 or the pharmaceutical composition of claim 140 .

150 . A method of increasing the expression of granzymes by effector cells in a subject, the method comprising administering to the subject an effective amount of the antibody of any one of claims 1 - 130 or the pharmaceutical composition of claim 140 .

151 . A method of reducing the number tumor cells in a subject, the method comprising administering to the subject an effective amount of the antibody of any one of claims 1 - 130 or the pharmaceutical composition of claim 140 .

152 . A method of treating cancer in a subject, the method comprising administering to the subject an effective amount of the antibody of any one of claims 1 - 130 or the pharmaceutical composition of claim 140 .

153 . The method of claim 152 , wherein the cancer is a solid tumor cancer.

154 . The method of claim 152 or 153 , wherein the cancer is a sarcoma, a carcinoma, or a lymphoma.

155 . The method of any one of claims 152 - 154 , wherein the cancer is selected from the group consisting of a melanoma, kidney cancer, pancreatic cancer, lung cancer, stomach cancer, colon/intestinal cancer, prostate cancer, ovarian cancer, breast cancer, liver cancer, brain cancer, or a hematological cancer.

156 . The method of any one of claims 147 - 155 , wherein the subject is a human.

157 . The method of any one of claims 147 - 155 , wherein the subject expresses 4-1BB and OX40 on tumor infiltrating lymphocytes.

158 . The antibody of any one of claims 1 - 130 or the pharmaceutical composition of claim 140 for use in therapy.

159 . The antibody of any one of claims 1 - 130 or the pharmaceutical composition of claim 140 for use in the treatment of cancer.

160 . The antibody of any one of claims 1 - 130 or the pharmaceutical composition of claim 140 for use in the treatment of a solid tumor cancer.

161 . The antibody or the pharmaceutical composition for the use of claim 160 , wherein the solid tumor cancer is a sarcoma, carcinoma, or lymphoma.

162 . The antibody or the pharmaceutical composition for the use of claim 159 , wherein the cancer is selected from the group consisting of a melanoma, kidney cancer, pancreatic cancer, lung cancer, colon/intestinal cancer, stomach cancer, prostate cancer, ovarian cancer, breast cancer, liver cancer, brain cancer, or a hematological cancer.