Human PAC1 antibodies
Antibodies and antigen-binding fragments thereof that bind to human PAC1 are provided. Nucleic acids encoding the antibodies and antigen-binding fragments thereof, vectors, and cells encoding the same are also provided. The antibodies and antigen-binding fragments thereof can inhibit binding of PAC1 to PACAP, and are useful in a number of PAC1 related disorders, including the treatment and/or prevention of headache disorders, including migraine.
1. An isolated antibody or antigen-binding fragment thereof that specifically binds human pituitary adenylate cyclase-activating polypeptide type I receptor (PAC1), comprising (i) a heavy chain variable region comprising complementarity determining regions CDRH1, CDRH2, and CDRH3, and (ii) a light chain variable region comprising complementarity determining regions CDRL1, CDRL2, and CDRL3, wherein CDRH1 comprises the sequence of SEQ ID NO: 165, CDRH2 comprises the sequence of SEQ ID NO: 179, CDRH3 comprises the sequence of SEQ ID NO: 189, CDRL1 comprises the sequence of SEQ ID NO: 139 or SEQ ID NO: 140, CDRL2 comprises the sequence of SEQ ID NO: 151, and CDRL3 comprises the sequence of SEQ ID NO: 157.
2. The isolated antibody or antigen-binding fragment thereof of claim 1 , wherein CDRL1 comprises the sequence of SEQ ID NO: 140.
3. The isolated antibody or antigen-binding fragment thereof of claim 1 , wherein CDRL1 comprises the sequence of SEQ ID NO: 139.
4. The isolated antibody or antigen-binding fragment thereof of claim 1 , wherein the light chain variable region comprises (i) the amino acid sequence of SEQ ID NO: 78 or SEQ ID NO: 80, (ii) an amino acid sequence at least 90% identical to an amino acid sequence of SEQ ID NO: 78 or SEQ ID NO: 80, or (iii) an amino acid sequence at least 95% identical to an amino acid sequence of SEQ ID NO: 78 or SEQ ID NO: 80; and the heavy chain variable region comprises (i) an amino acid sequence selected from SEQ ID NOs: 108, 110, or 112, (ii) an amino acid sequence at least 90% identical to an amino acid sequence selected from SEQ ID NOs: 108, 110, or 112, or (iii) an amino acid sequence at least 95% identical to an amino acid sequence selected from SEQ ID NOs: 108, 110, or 112.
5. The isolated antibody or antigen-binding fragment thereof of claim 4 , wherein:
(a) the light chain variable region comprises the sequence of SEQ ID NO: 78 and the heavy chain variable region comprises the sequence of SEQ ID NO: 108;
(b) the light chain variable region comprises the sequence of SEQ ID NO: 80 and the heavy chain variable region comprises the sequence of SEQ ID NO: 110;
(c) the light chain variable region comprises the sequence of SEQ ID NO: 80 and the heavy chain variable region comprises the sequence of SEQ ID NO: 112; and
(d) the light chain variable region comprises the sequence of SEQ ID NO: 78 and the heavy chain variable region comprises the sequence of SEQ ID NO: 112.
6. The isolated antibody or antigen-binding fragment thereof of claim 5 , wherein the light chain variable region comprises the sequence of SEQ ID NO: 80 and the heavy chain variable region comprises the sequence of SEQ ID NO: 110.
7. The isolated antibody or antigen-binding fragment thereof of claim 5 , wherein the light chain variable region comprises the sequence of SEQ ID NO: 78 and the heavy chain variable region comprises the sequence of SEQ ID NO: 112.
8. The isolated antibody or antigen-binding fragment thereof of claim 1 , comprising (A) a light chain comprising (i) the sequence of SEQ ID NO: 6 or SEQ ID NO: 8, (ii) a sequence at least 90% identical to a sequence of SEQ ID NO: 6 or SEQ ID NO: 8, or (iii) a sequence at least 95% identical to a sequence of SEQ ID NO: 6 or SEQ ID NO: 8; and (B) a heavy chain comprising (i) a sequence selected from SEQ ID NOs: 38, 40, 42, or 44, (ii) a sequence at least 90% identical to a sequence selected from SEQ ID NOs: 38, 40, 42, or 44, or (iii) a sequence at least 95% identical to a sequence selected from SEQ ID NOs: 38, 40, 42, or 44.
9. The isolated antibody or antigen-binding fragment thereof of claim 8 , comprising a light chain comprising the sequence of SEQ ID NO: 6 and a heavy chain comprising the sequence of SEQ ID NO: 38.
10. The isolated antibody or antigen-binding fragment thereof of claim 8 , comprising a light chain comprising the sequence of SEQ ID NO: 8 and a heavy chain comprising the sequence of SEQ ID NO: 40.
11. The isolated antibody or antigen-binding fragment thereof of claim 8 , comprising a light chain comprising the sequence of SEQ ID NO: 8 and a heavy chain comprising the sequence of SEQ ID NO: 42.
12. The isolated antibody or antigen-binding fragment thereof of claim 8 , comprising a light chain comprising the sequence of SEQ ID NO: 8 and a heavy chain comprising the sequence of SEQ ID NO: 44.
13. The isolated antibody or antigen-binding fragment thereof of claim 8 , comprising a light chain comprising the sequence of SEQ ID NO: 6 and a heavy chain comprising the sequence of SEQ ID NO: 44.
14. The isolated antibody or antigen-binding fragment thereof of claim 1 , wherein the isolated antibody or antigen-binding fragment thereof is selected from the group consisting of a monoclonal antibody, a Fab fragment, an Fab′ fragment, an F(ab′)2 fragment, an Fv fragment, a diabody, and a single chain antibody.
15. The isolated antibody or antigen-binding fragment thereof of claim 14 , wherein the isolated antibody is a monoclonal antibody selected from the group consisting of a fully human antibody, a humanized antibody and a chimeric antibody.
16. The isolated antibody or antigen-binding fragment thereof of claim 15 , wherein the monoclonal antibody is an IgG1-, IgG2-, IgG3-, or IgG4-type antibody.
17. The isolated antibody or antigen-binding fragment thereof of claim 16 , wherein the monoclonal antibody is an aglycosylated IgG1 antibody.
18. The isolated antibody or antigen-binding fragment thereof of claim 17 , wherein the monoclonal antibody has an N297G mutation in its heavy chain.
19. The isolated antibody or antigen-binding fragment thereof of claim 1 , wherein the antibody or antigen-binding fragment thereof selectively inhibits human PAC1 relative to human VPAC1 and human VPAC2.
20. An isolated polynucleotide that encodes an antibody or antigen-binding fragment thereof of claim 1 .
21. The isolated polynucleotide of claim 20 , wherein the polynucleotide comprises a sequence selected from SEQ ID NOs: 5, 7, 37, 39, 41, or 43.
22. The isolated polynucleotide of claim 20 , wherein the polynucleotide comprises a sequence selected from SEQ ID NOs: 77, 79, 107, 109, or 111.
23. An expression vector comprising an isolated nucleic acid or polynucleotide encoding an antibody or antigen-binding fragment thereof of claim 1 .
24. A cell line transformed with the expression vector of claim 23 .
25. A method of making an antibody or antigen binding fragment thereof that specifically binds human PAC1, comprising preparing the antibody or antigen binding fragment thereof from the cell line of claim 24 that secretes the antibody or antigen binding fragment thereof.
26. A pharmaceutical composition comprising an antibody or antigen binding fragment thereof of claim 1 and a pharmaceutically acceptable excipient.
27. The isolated antibody or antigen-binding fragment thereof of claim 1 , wherein the isolated antibody or antigen-binding fragment thereof of claim 1 specifically binds to human PAC1 with an equilibrium binding affinity of less than 1 nM.