Biparatopic FR-α antibodies and immunoconjugates
The present disclosure provides biparatopic antibodies comprising polypeptides that bind to folate receptor alpha (FRα) compositions comprising such biparatopic antibodies. In a specific aspect, the biparatopic antibodies bind to FRα and modulate FRα activity. The present disclosure also provides methods for treating disorders, such as cancer, by administering a biparatopic antibody that specifically binds to FRα and modulates FRα activity.
1. An immunoconjugate represented by the following formula:
or a pharmaceutically acceptable salt thereof, wherein:
CBA is a biparatopic antibody or an antigen-binding fragment comprising the amino acid sequences of SEQ ID NOs: 41-43;
D 1 is represented by the following formula:
and
q is an integer from 1 to 10.
2. A composition comprising at least one immunoconjugate of claim 1 , wherein the composition comprises a drug antibody ratio (DAR) of 3 to 4.
3. An immunoconjugate represented by the following formula:
or a pharmaceutically acceptable salt thereof, wherein:
CBA is a bivalent biparatopic antibody or antigen-binding fragment thereof that specifically binds human folate receptor 1 (FRα), wherein the antibody or antigen-binding fragment comprises:
(i) a first FRα-binding domain comprising a first variable heavy chain (VH) and a first variable light chain (VL), wherein (a) the first VH comprises VH CDR1-3 comprising the amino acid sequences of SEQ ID NOs: 10-12, respectively, or SEQ ID NOs: 15, 16, and 12, respectively; and (b) the first VL comprises VL CDR1-3 comprising the amino acid sequences of SEQ ID NOs: 4-6, respectively; and
(ii) a second FRα-binding domain comprising a second VH and a second VL, wherein the second VH comprises VH CDR1-3 comprising the amino acid sequences of (a) SEQ ID NOs: 7-9, respectively, or (b) SEQ ID NOs: 13, 14, and 9, respectively; and the second VL comprises VL CDR1-3 comprising the amino acid sequences of SEQ ID NOs: 1-3, respectively;
wherein the first FRα-binding domain comprises an single-chain variable fragment (scFv) and the second FRα-binding domain comprises a VH and a VL on separate polypeptides or wherein the second FRα-binding domain comprises an single-chain variable fragment (scFv) and the first FRα-binding domain comprises a VH and a VL on separate polypeptides;
wherein the bivalent biparatopic antibody or antigen-binding fragment thereof comprises an IgG heavy chain constant region and a light chain constant region; and
wherein D 1 is represented by the following formula:
and
q is an integer from 1 to 10.
4. The immunoconjugate of claim 3 , wherein the first FRα-binding domain comprises a VH and a VL on separate polypeptides and the second FRα-binding domain comprises an scFv.
5. The immunoconjugate of claim 4 , wherein the scFv of the second FRα binding domain has a peptide orientation of VL-linker-VH.
6. The immunoconjugate of claim 5 , wherein the linker is a glycine-serine linker.
7. The immunoconjugate of claim 3 , wherein the bivalent biparatopic antibody or antigen-binding fragment thereof comprises a knob-in-hole (KIH) structure.
8. The immunoconjugate of claim 7 , wherein the second FRα-binding domain is on the knob side of the KIH structure and the first FRα-binding domain is on the hole side of the KIH structure.
9. The immunoconjugate of claim 4 , wherein the bivalent biparatopic antibody or antigen-binding fragment thereof comprises a knob-in-hole (KIH) structure.
10. The immunoconjugate of claim 9 , wherein the second FRα-binding domain is on the knob side of the KIH structure and the first FRα-binding domain is on the hole side of the KIH structure.
11. The immunoconjugate of claim 5 , wherein the bivalent biparatopic antibody or antigen-binding fragment thereof comprises a knob-in-hole (KIH) structure.
12. The immunoconjugate of claim 11 , wherein the second FRα-binding domain is on the knob side of the KIH structure and the first FRα-binding domain is on the hole side of the KIH structure.
13. The immunoconjugate of claim 3 , wherein the first VH of the bivalent biparatopic antibody or antigen-binding fragment comprises the amino acid sequence of SEQ ID NO:24, the first VL of the bivalent biparatopic antibody or antigen-binding fragment comprises the amino acid sequence of SEQ ID NO:19, the second VH of the bivalent biparatopic antibody or antigen-binding fragment comprises the amino acid sequence of SEQ ID NO:23, and the second VL of the bivalent biparatopic antibody or antigen-binding fragment comprises the amino acid sequence of SEQ ID NO:18.
14. The immunoconjugate of claim 13 , wherein the first FRα-binding domain comprises a VH and a VL on separate polypeptides and the second FRα-binding domain comprises an scFv.
15. The immunoconjugate of claim 14 , wherein the scFv of the second FRα binding domain has a peptide orientation of VL-linker-VH.
16. The immunoconjugate of claim 15 , wherein the linker is a glycine-serine linker.
17. The immunoconjugate of claim 13 , wherein the bivalent biparatopic antibody or antigen-binding fragment thereof comprises a knob-in-hole (KIH) structure.
18. The immunoconjugate of claim 17 , wherein the second FRα-binding domain is on the knob side of the KIH structure and the first FRα-binding domain is on the hole side of the KIH structure.
19. The immunoconjugate of claim 14 , wherein the bivalent biparatopic antibody or antigen-binding fragment thereof comprises a knob-in-hole (KIH) structure.
20. The immunoconjugate of claim 19 , wherein the second FRα-binding domain is on the knob side of the KIH structure and the first FRα-binding domain is on the hole side of the KIH structure.
21. The immunoconjugate of claim 15 , wherein the bivalent biparatopic antibody or antigen-binding fragment thereof comprises a knob-in-hole (KIH) structure.
22. The immunoconjugate of claim 21 , wherein the second FRα-binding domain is on the knob side of the KIH structure and the first FRα-binding domain is on the hole side of the KIH structure.
23. The immunoconjugate of claim 16 , wherein the bivalent biparatopic antibody or antigen-binding fragment thereof comprises a knob-in-hole (KIH) structure.
24. The immunoconjugate of claim 23 , wherein the second FRα-binding domain is on the knob side of the KIH structure and the first FRα-binding domain is on the hole side of the KIH structure.
25. A composition comprising at least one immunoconjugate of claim 3 , wherein the composition comprises a drug antibody ratio (DAR) of 3 to 4.
26. A composition comprising at least one immunoconjugate of claim 4 , wherein the composition comprises a drug antibody ratio (DAR) of 3 to 4.
27. A composition comprising at least one immunoconjugate of claim 5 , wherein the composition comprises a drug antibody ratio (DAR) of 3 to 4.
28. A composition comprising at least one immunoconjugate of claim 7 , wherein the composition comprises a drug antibody ratio (DAR) of 3 to 4.
29. A composition comprising at least one immunoconjugate of claim 8 , wherein the composition comprises a drug antibody ratio (DAR) of 3 to 4.
30. A composition comprising at least one immunoconjugate of claim 13 , wherein the composition comprises a drug antibody ratio (DAR) of 3 to 4.
31. A composition comprising at least one immunoconjugate of claim 14 , wherein the composition comprises a drug antibody ratio (DAR) of 3 to 4.
32. A composition comprising at least one immunoconjugate of claim 15 , wherein the composition comprises a drug antibody ratio (DAR) of 3 to 4.
33. A composition comprising at least one immunoconjugate of claim 16 , wherein the composition comprises a drug antibody ratio (DAR) of 3 to 4.
34. A composition comprising at least one immunoconjugate of claim 17 , wherein the composition comprises a drug antibody ratio (DAR) of 3 to 4.
35. A composition comprising at least one immunoconjugate of claim 18 , wherein the composition comprises a drug antibody ratio (DAR) of 3 to 4.
36. A composition comprising at least one immunoconjugate of claim 21 , wherein the composition comprises a drug antibody ratio (DAR) of 3 to 4.
37. A composition comprising at least one immunoconjugate of claim 22 , wherein the composition comprises a drug antibody ratio (DAR) of 3 to 4.
38. A composition comprising at least one immunoconjugate of claim 23 , wherein the composition comprises a drug antibody ratio (DAR) of 3 to 4.
39. A composition comprising at least one immunoconjugate of claim 24 , wherein the composition comprises a drug antibody ratio (DAR) of 3 to 4.
40. The immunoconjugate of claim 3 , wherein
(i) the VH CDR1-3 of the first FRα-binding domain comprise the amino acid sequences of SEQ ID NOs: 10-12, respectively; and
(ii) the VH CDR1-3 of the second first FRα-binding domain comprise the amino acid sequences of SEQ ID NOs: 7-9, respectively.
41. The immunoconjugate of claim 40 , wherein the first FRα-binding domain comprises a VH and a VL on separate polypeptides and the second FRα-binding domain comprises an scFv.
42. The immunoconjugate of claim 41 , wherein the scFv of the second FRα binding domain has a peptide orientation of VL-linker-VH.
43. A composition comprising at least one immunoconjugate of claim 40 , wherein the composition comprises a drug antibody ratio (DAR) of 3 to 4.
44. The immunoconjugate of claim 3 , wherein
(i) the VH CDR1-3 of the first FRα-binding domain comprise the amino acid sequences of SEQ ID NOs: 15, 16, and 12, respectively; and
(ii) the VH CDR1-3 of the second first FRα-binding domain comprise the amino acid sequences of SEQ ID NOs: 13, 14, and 9, respectively.
45. The immunoconjugate of claim 44 , wherein the first FRα-binding domain comprises a VH and a VL on separate polypeptides and the second FRα-binding domain comprises an scFv.
46. The immunoconjugate of claim 45 , wherein the scFv of the second FRα binding domain has a peptide orientation of VL-linker-VH.
47. A composition comprising at least one immunoconjugate of claim 44 , wherein the composition comprises a drug antibody ratio (DAR) of 3 to 4.