Albumin-Binding Polypeptides and Uses Thereof

1 . A polypeptide comprising at least one VHH domain that binds albumin, wherein at least one VHH domain that binds albumin comprises a CDR1 sequence selected from SEQ ID NOs: 5-8, a CDR2 sequence selected from SEQ ID NOs: 9-21, and a CDR3 sequence of SEQ ID NO: 22.

2 . The polypeptide of claim 1 , wherein each VHH domain that binds albumin comprises, independently, a CDR1 sequence selected from SEQ ID NOs: 5-8, a CDR2 sequence selected from SEQ ID NOs: 9-21, and a CDR3 sequence of SEQ ID NO: 22.

3 . The polypeptide of claim 1 or claim 2 , wherein at least one VHH domain that binds albumin comprises CDR1, CDR2, and CDR3 sequences selected from: SEQ ID NOs: 5, 9, and 22; SEQ ID NOs: 5, 10, and 22; SEQ ID NOs: 5, 11, and 22; SEQ ID NOs: 5, 12, and 22; SEQ ID NOs: 5, 13, and 22; SEQ ID NOs: 5, 14, and 22; SEQ ID NOs: 5, 15, and 22; SEQ ID NOs: 6, 15, and 22; SEQ ID NOs: 7, 15, and 22; SEQ ID NOs: 8, 15, and 22; SEQ ID NOs: 6, 16, and 22; SEQ ID NOs: 6, 17, and 22; SEQ ID NOs: 6, 18, and 22; SEQ ID NOs: 6, 19, and 22; SEQ ID NOs: 6, 20, and 22; and SEQ ID NOs: 6, 21, and 22.

4 . The polypeptide of claim 3 , wherein each VHH domain that binds albumin comprises, independently, CDR1, CDR2, and CDR3 sequences selected from: SEQ ID NOs: 5, 9, and 22; SEQ ID NOs: 5, 10, and 22; SEQ ID NOs: 5, 11, and 22; SEQ ID NOs: 5, 12, and 22; SEQ ID NOs: 5, 13, and 22; SEQ ID NOs: 5, 14, and 22; SEQ ID NOs: 5, 15, and 22; SEQ ID NOs: 6, 15, and 22; SEQ ID NOs: 7, 15, and 22; SEQ ID NOs: 8, 15, and 22; SEQ ID NOs: 6, 16, and 22; SEQ ID NOs: 6, 17, and 22; SEQ ID NOs: 6, 18, and 22; SEQ ID NOs: 6, 19, and 22; SEQ ID NOs: 6, 20, and 22; and SEQ ID NOs: 6, 21, and 22.

5 . The polypeptide of any one of claims 1-4 , wherein at least one VHH domain that binds albumin is humanized.

6 . The polypeptide of claim 5 , wherein each VHH domain that binds albumin is humanized.

7 . The polypeptide of any one of claims 1-6 , wherein at least one VHH domain that binds albumin comprises a sequence at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% identical to a sequence selected from SEQ ID NOs: 23-43 and 71-74.

8 . The polypeptide of claim 7 , wherein each VHH domain that binds albumin comprises a sequence at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% identical to a sequence selected from SEQ ID NOs: 23-43 and 71-74.

9 . The polypeptide of any one of claims 1-7 , wherein at least one VHH domain that binds albumin comprises a sequence selected from SEQ ID NOs: 23-43 and 71-74.

10 . The polypeptide of any one of claims 1-9 , wherein each VHH domain that binds albumin comprises a sequence selected from SEQ ID NOs: 23-43 and 71-74.

11 . The polypeptide of any one of claims 1-10 , wherein at least one VHH domain that binds albumin binds human albumin and at least one albumin selected from cynomolgus monkey, mouse, and rat albumin.

12 . The polypeptide of any one of claims 1-11 , wherein each VHH domain that binds albumin binds human albumin and at least one albumin selected from cynomolgus monkey, mouse, and rat albumin.

13 . The polypeptide of any one of claims 1-12 , wherein at least one VHH domain that binds albumin binds human, cynomolgus monkey, mouse, and rat albumin.

14 . The polypeptide of any one of claims 1-13 , wherein each VHH domain that binds albumin binds human, cynomolgus monkey, mouse, and rat albumin.

15 . The polypeptide of any one of claims 1-14 , wherein at least one VHH domain that binds albumin binds human albumin with an affinity of less than 5 nM, less than 2 nM, less than 1 nM, or less than 0.5 nM.

16 . The polypeptide of any one of claims 1-15 , wherein at least one VHH domain that binds albumin binds each of human, cynomolgus monkey, mouse, and rat albumin with an affinity of less than 5 nM, less than 2 nM, less than 1 nM, or less than 0.5 nM.

17 . The polypeptide of any one of claims 1-16 , wherein each VHH domain that binds albumin binds human albumin with an affinity of less than 5 nM, less than 2 nM, less than 1 nM, or less than 0.5 nM.

18 . The polypeptide of any one of claims 1-17 , wherein each VHH domain that binds albumin binds each of human, cynomolgus monkey, mouse, and rat albumin with an affinity of less than 5 nM, less than 2 nM, less than 1 nM, or less than 0.5 nM.

19 . The polypeptide of any one of claims 1-18 , wherein the each VHH domain that binds albumin does not bind albumin domain 3.

20 . The polypeptide of any one of claims 1-19 , wherein the each VHH domain that binds albumin does not interfere with binding of albumin to FcRn.

21 . The polypeptide of any one of claims 1-20 , wherein the polypeptide comprises at least one binding domain that binds a protein other than albumin.

22 . The polypeptide of claim 21 , wherein at least one binding domain that binds a protein other than albumin is a VHH.

23 . The polypeptide of claim 22 , wherein each binding domain that binds a protein other than albumin is a VHH.

24 . The polypeptide of claim 21 , wherein at least one binding domain that binds a protein other than albumin comprises a heavy chain variable region and a light chain variable region.

25 . The polypeptide of claim 24 , wherein each binding domain that binds a protein other than albumin comprises a heavy chain variable region and a light chain variable region.

26 . The polypeptide of any one of claims 21-25 , wherein at least one binding domain that binds a protein other than albumin is a binding domain of a therapeutic antibody.

27 . The polypeptide of claim 26 , wherein each binding domain that binds a protein other than albumin is a binding domain of a therapeutic antibody.

28 . The polypeptide of claim 26 or claim 27 , wherein the therapeutic antibody is useful for treating a disease or disorder selected from an autoimmune disease or disorder, an inflammatory disease or disorder, an infection, and cancer.

29 . The polypeptide of any one of claim 1-28 , wherein the polypeptide comprises an amino acid sequence of a therapeutic protein.

30 . The polypeptide of claim 29 , wherein the therapeutic protein is useful for treating a disease or disorder selected from an autoimmune disease or disorder, an inflammatory disease or disorder, an infection, and cancer.

31 . The polypeptide of any one of claims 1-30 , wherein the polypeptide comprises an Fc region.

32 . The polypeptide of claim 31 , wherein the Fc region binds FcRn. 33 The polypeptide of claim 31 or claim 32 , wherein the Fc region is an IgG1 Fc region.

34 . The polypeptide of any one of claims 31-33 , wherein the Fc region comprises one or more substitutions that enhance half-life.

35 . The polypeptide of claim 34 , wherein the Fc region comprises one or more substitutions that enhance FcRn binding at at least one pH and/or reduce dissociation rate of Fc and FcRn.

36 . The polypeptide of any one of claims 31-35 , wherein the Fc region comprises substitutions at one or more amino acid positions selected from 252, 254, 256, 428, or 434.

37 . The polypeptide of claim 36 , wherein the Fc region comprises substitutions at amino acid positions 252, 254, and 256; or amino acid positions 252 and 428; or amino acid positions 428 and 434.

38 . The polypeptide of claim 37 , wherein the Fc region comprises substitutions M252Y, S254T, and T256E; M252Y and M428V; or M428L and N434S.

39 . The polypeptide of any one of claims 31-38 , wherein the Fc region comprises a sequence selected from SEQ ID NOs: 47-68 and 85-87.

40 . The polypeptide of any one of claims 1-39 , wherein the half-life of the polypeptide is greater than the half-life of the same polypeptide lacking a VHH domain that binds albumin.

41 . A pharmaceutical composition comprising the polypeptide of any one of claims 1-40 and a pharmaceutically acceptable carrier.

42 . An isolated nucleic acid that encodes the polypeptide of any one of claims 1-40 .

43 . A vector comprising the nucleic acid of claim 42 .

44 . A host cell comprising the nucleic acid of claim 42 or the vector of claim 43 .

45 . A host cell that expresses the polypeptide of any one of claims 1-40 .

46 . A method of producing the polypeptide of any one of claims 1-40 , comprising incubating the host cell of claim 44 or claim 45 under conditions suitable for expression of the polypeptide.

47 . The method of claim 46 , further comprising isolating the polypeptide.

48 . A method comprising administering to a subject the polypeptide of any one of claims 1-40 , or the pharmaceutical composition of claim 41 .

49 . A method of treating a disease or disorder comprising administering to a subject with the disease or disorder a pharmaceutically effective amount of the polypeptide of any one of claims 1-40 , or the pharmaceutical composition of claim 41 .

50 . The method of claim 49 , wherein the disease or disorder is selected from an autoimmune disease or disorder, an inflammatory disease or disorder, an infection, and cancer.