HER3 binding polypeptides
The disclosure provides a HER3 binding polypeptide, comprising a HER3 binding motif, BM, which motif consists of the amino acid sequence selected from i) EX 2 X 3 X 4 A X 6 X 7 EIW X 11 LPNL X 16 X 17 X 18 QX 20 X 21 AFIX 25 X 26 LX 28 D, and ii) an amino acid sequence which has at least 90% identity to the sequence defined in i), wherein the polypeptide binds to the extra-cellular domain of HER3. Also provided is a bispecific ligand having binding affinity for HER3 and for HER2, or for HER3 and for EGFR, and comprising a HER3. binding polypeptide as defined herein and a HER2 binding polypeptide or a EGFR binding polypeptide.
1. HER3 binding polypeptide, comprising a HER3 binding motif (BM), wherein the amino acid sequence of the BM is selected from the group consisting of SEQ ID NOs: 1 to 334, and
wherein the HER3 binding polypeptide binds to the extra-cellular domain of HER3.
2. HER3 binding polypeptide according to claim 1 , wherein the amino acid sequence of the BM is selected from the group consisting of SEQ ID NOs: 1 to 66.
3. HER3 binding polypeptide according to claim 2 , wherein the amino acid sequence of the BM is SEQ ID NO: 23-25, 27-28, 32, 35-36, 40, 42, 44-45, 53-54 or 56.
4. HER3 binding polypeptide according to claim 1 , which comprises the polypeptide sequence:
K-[BM]-DPSQS X a X b LLX C EAKKL NDX d Q (SEQ ID NO:1011); wherein
[BM] is the HER3 binding motif as defined in claim 1 ;
X a is selected from A and S;
X b is selected from N and E;
X c is selected from A, S and C;
X d is selected from A and S.
5. HER3 binding polypeptide according to claim 4 , wherein X a is A; X b is N; X c is A and X d is A.
6. HER3 binding polypeptide according to claim 4 , wherein X a is A; X b is N; X c is C and X d is A.
7. HER3 binding polypeptide according to claim 4 , wherein X a is S; X b is E; X c is S and X d is S.
8. HER3 binding polypeptide according to claim 4 , wherein X a is S; X b is E; X c is C and X d is S.
9. HER3 binding polypeptide according to claim 4 , wherein the HER3 binding polypeptide sequence comprises SEQ ID NO: 335-667 or 668.
10. HER3 binding polypeptide according to claim 9 , wherein the HER3 binding polypeptide sequence comprises SEQ ID NO: 335-399, or 400.
11. HER3 binding polypeptide according to claim 10 , wherein the HER3 binding polypeptide sequence comprises SEQ ID NO: 357-359, 361-362, 366-370, 374, 376, 378-379, 387-388, or 390.
12. HER3 binding polypeptide according to claim 1 , which comprises the polypeptide sequence:
YAK-[BM]-DPSQS SELLX c EAKKL NDSQA P (SEQ ID NO:1012);
wherein [BM] is a HER3 binding motif as defined in claim 1 and X c is selected from S and C.
13. HER3 binding polypeptide according to claim 1 , which comprises the polypeptide sequence:
FNK-[BM]-DPSQS ANLLX C EAKKL NDAQA P (SEQ ID NO:1013);
wherein [BM] is a HER3 binding motif as defined in claim 1 and X c is selected from A and C.
14. HER3 binding polypeptide according to claim 1 , the HER3 binding polypeptide comprising SEQ ID NO: 669-1001 or 1002.
15. HER3 binding polypeptide according to claim 14 , wherein the HER3 binding polypeptide comprises SEQ ID NO: 669-733, or 734.
16. HER3 binding polypeptide according to claim 15 , wherein the HER3 binding polypeptide comprises SEQ ID NO:691-693, 695-696, 700, 703-704, 708, 710, 712-713, 721, 722, or 724.
17. HER3 binding polypeptide according to claim 1 , wherein the HER3 binding polypeptide binds to HER3 such that the K D value of the interaction is at most 1×10 −6 M.
18. HER3 binding polypeptide according to claim 1 comprising further C terminal and/or N terminal amino acids.
19. HER3 binding polypeptide according to claim 18 , in which the further C terminal and/or N terminal amino acids improve production, purification, stability in vivo or in vitro, binding, or detection of the polypeptide.
20. HER3 binding polypeptide according to claim 1 in multimeric form, comprising at least two HER3 binding polypeptide monomer units, the amino acid sequences of which may be the same or different.
21. HER3 binding polypeptide according to claim 20 , in dimeric form.
22. A composition comprising the HER3 binding polypeptide according to claim 1 and a second moiety comprising a therapeutic agent.
23. The HER3 binding polypeptide according to claim 17 , wherein the HER3 binding polypeptide binds to HER3 such that the K D value of the interaction is at most 1×10 −7 M.
24. The HER3 binding polypeptide according to claim 23 , wherein the HER3 binding polypeptide binds to HER3 such that the K D value of the interaction is at most 1×10 −8 M.
25. A ligand having binding affinity for HER3 and for HER2, comprising a HER3 binding polypeptide according to claim 1 ; a HER2 binding polypeptide comprising an engineered protein comprising a protein Z derivative; and a linking moiety for linking the HER3 binding polypeptide with the HER2 binding polypeptide.
26. The ligand according to claim 25 , wherein the HER2 binding polypeptide binds to HER2 such that the K D value of the interaction is at most 1×10 −6 M.
27. The ligand according to claim 25 , wherein the engineered protein comprises the amino acid sequence
YAKEM RNAYW EIALL PNLTN QQKRA FIRKL YDDPS QSSEL LSEAK KLNDS Q (SEQ ID NO:1003).
28. The ligand according to claim 25 , wherein the linking moiety is a peptide comprising from 1 to 45 amino acids.
29. The ligand according to claim 25 , further comprising a half-life extending moiety for extension of ligand half-life in vivo.
30. The ligand according to claim 29 , wherein the half-life extending moiety is albumin.
31. The ligand according to claim 29 , wherein the half-life extending moiety is an albumin binding moiety.
32. The ligand according to claim 31 , wherein the albumin binding moiety is an engineered protein derived from domain GA3 of streptococcal Protein G.
33. The ligand according to claim 32 , wherein the albumin binding moiety comprises the amino acid sequence
LAEAK VLANR ELDKY GVSDF YKRLI NKAKT VEGVE ALKLH ILAAL P (SEQ ID NO:1005).
34. The ligand according to claim 29 , wherein the half-life extending moiety is polyethylene glycol.
35. The ligand according to claim 29 , wherein the ligand comprises at least one cysteine residue and the half-life extending moiety is attached to the ligand via said at least one cysteine residue.
36. The ligand according to claim 29 , wherein the half-life extending moiety is attached to the ligand via the linking moiety.
37. The ligand according to claim 25 , wherein the linking moiety comprises a half-life extending moiety.
38. The ligand according to claim 25 wherein the linking moiety is an amino acid linker.
39. A ligand having binding affinity for HER3 and for EGFR, comprising a HER3 binding polypeptide according to claim 1 ; an EGFR-binding polypeptide; and a linking moiety for linking the HER3 binding polypeptide with the EGFR binding polypeptide.