Anti-5T4 antibodies and uses thereof
Anti-5T4 antibodies, anti-5T4 antibody/drug conjugates, and methods for preparing and using the same.
1. An isolated antibody, or fragment thereof, that specifically binds human 5T4 antigen, wherein the antibody or antibody fragment comprises an antigen binding domain of, or binds a 5T4 epitope bound by, an antibody comprising a heavy chain variable region having an amino acid sequence set forth as SEQ ID NO:10 and a light chain variable region having an amino acid sequence set forth as SEQ ID NO:12; wherein the antibody or antibody fragment comprises human constant regions; and wherein the antibody or antibody fragment is a chimeric antibody, a humanized antibody, a single chain antibody, a tetrameric antibody, a tetravalent antibody, a multispecific antibody, or a fusion protein.
2. An isolated antibody, or fragment thereof, that specifically binds human 5T4 antigen, which is a murine monoclonal antibody comprising:
(a) a heavy chain variable region comprising an amino acid sequence of residues 20-141 of SEQ ID NO: 10; and
(b) a light chain variable region comprising an amino acid sequence of residues 21-127 of SEQ ID NO: 12.
3. The antibody of claim 1 , which has a binding affinity for human 5T4 antigen of at least about 1×10 −7 M to about 1×10 −12 M.
4. The antibody of claim 1 , which is a chimeric or humanized anti-5T4 antibody.
5. The chimeric or humanized antibody of claim 4 , which comprises a human IgG1, IgG2, IgG3, or IgG4 heavy chain constant region.
6. The chimeric or humanized antibody of claim 5 , wherein the human IgG4 heavy chain constant region comprises proline at position 241.
7. The humanized antibody of claim 4 , which comprises:
(a) a heavy chain variable region comprising framework regions comprising three CDRs of SEQ ID NO: 10 and residues of a human antibody framework region; and
(b) a light chain variable region comprising framework regions comprising three CDRs of SEQ ID NO: 12 and residues of a human antibody framework region.
8. The humanized antibody of claim 7 , wherein the human antibody framework region is selected from the group consisting of:
(a) a human antibody heavy chain framework region of any one of SEQ ID NOs:14-23, 77, and 88-93;
(b) a human antibody light chain framework region of any one of SEQ ID NOs:28-44 and 94-99;
(c) a consensus sequence of a heavy chain framework region of (a); and
(d) a framework region that is at least 63% identical to a framework region of (a)-(c).
9. The chimeric or humanized antibody of claim 4 , which comprises a heavy chain variable region comprising:
(a) an amino acid sequence of residues 20-141 of SEQ ID NO:10; or
(b) an amino acid sequence of SEQ ID NO:81 or 82.
10. The chimeric or humanized antibody of claim 4 , which comprises a light chain variable region sequence comprising:
(a) an amino acid sequence of residues 21-127 of SEQ ID NO:12; or
(b) an amino acid sequence of SEQ ID NO:83 or 84.
11. An antibody/drug conjugate for drug delivery comprising:
(a) an antibody according to claim 1 ; and
(b) a drug, which is directly or indirectly bound to the antibody.
12. The antibody/drug conjugate of claim 11 , wherein the drug is a therapeutic agent selected from the group consisting of a cytotoxin, a radioisotope, an immunomodulatory agent, an anti-angiogenic agent, an anti-proliferative agent, a pro-apoptotic agent, a chemotherapeutic agent, and a therapeutic nucleic acid.
13. The antibody/drug conjugate of claim 12 , wherein the cytotoxin is an antibiotic, an inhibitor of tubulin polymerization, an alkylating agent, a protein synthesis inhibitor, a protein kinase inhibitor, a phosphatase inhibitor, a topoisomerase inhibitor, or an enzyme.
14. The antibody/drug conjugate of claim 12 , wherein the cytotoxin is an antibiotic.
15. The antibody/drug conjugate of claim 14 , wherein the antibiotic is calicheamicin.
16. The antibody/drug conjugate of claim 15 , wherein the calicheamicin is an N-acetyl derivative or disulfide analog of calicheamicin.
17. The antibody/drug conjugate of claim 11 , wherein the drug is bound to the antibody via a linker selected from the group consisting of 4-(4′acetylphenoxy)butanoic acid (AcBut), 3-acetylphenyl acidic acid (AcPac), 4-mercapto-4-methyl-pentanoic acid (Amide), and derivatives thereof.
18. A humanized antibody, or antibody fragment thereof, that specifically binds human 5T4 antigen, wherein the antibody or antibody fragment comprises an antigen binding domain of, or binds a 5T4 epitope bound by, an antibody comprising a heavy chain variable region having an amino acid sequence set forth as SEQ ID NO:10 and a light chain variable region having an amino acid sequence set forth as SEQ ID NO:12.
19. The humanized antibody or antibody fragment of claim 18 , which is a Fab fragment, a F(ab) 2 fragment, or a Fv fragment.
20. The humanized antibody or antibody fragment of claim 18 , which has a binding affinity for human 5T4 antigen of at least about 1×10 −7 M to about 1×10 −12 M.
21. The humanized antibody or antibody fragment of claim 18 , which comprises a human IgG1, IgG2, IgG3, or IgG4 heavy chain constant region.
22. The humanized antibody or antibody fragment claim 21 , wherein the human IgG4 heavy chain constant region comprises proline at position 241 .
23. The humanized antibody or antibody fragment of claim 18 , which comprises:
(a) a heavy chain variable region comprising framework regions comprising three CDRs of SEQ ID NO: 10 and residues of a human antibody framework region; and
(b) a light chain variable region comprising framework regions comprising three CDRs of SEQ ID NO: 12 and residues of a human antibody framework region.
24. The humanized antibody or antibody fragment of claim 23 , wherein the human antibody framework region is selected from the group consisting of:
(a) a human antibody heavy chain framework region of any one of SEQ ID NOs:14-23, 77, and 88-93;
(b) a human antibody light chain framework region of any one of SEQ ID NOs:28-44 and 94-99;
(c) a consensus sequence of a heavy chain framework region of (a); and
(d) a framework region that is at least 63% identical to a framework region of (a)-(c).
25. The humanized antibody or antibody fragment of claim 18 , which comprises a heavy chain variable region comprising:
(a) an amino acid sequence of residues 20-141 of SEQ ID NO:10; or
(b) an amino acid sequence of SEQ ID NO:81 or 82.
26. The humanized antibody or antibody fragment of claim 18 , which comprises a light chain variable region sequence comprising:
(a) an amino acid sequence of residues 21-127 of SEQ ID NO:12; or
(b) an amino acid sequence of SEQ ID NO:83 or 84.
27. An antibody/drug conjugate for drug delivery comprising:
(a) an antibody or antibody fragment according to claim 18 ; and
(b) a drug, which is directly or indirectly bound to the antibody.
28. The antibody/drug conjugate of claim 27 , wherein the drug is a therapeutic agent selected from the group consisting of a cytotoxin, a radioisotope, an immunomodulatory agent, an anti-angiogenic agent, an anti-proliferative agent, a pro-apoptotic agent, a chemotherapeutic agent, and a therapeutic nucleic acid.
29. The antibody/drug conjugate of claim 28 , wherein the cytotoxin is an antibiotic, an inhibitor of tubulin polymerization, an alkylating agent, a protein synthesis inhibitor, a protein kinase inhibitor, a phosphatase inhibitor, a topoisomerase inhibitor, or an enzyme.
30. The antibody/drug conjugate of claim 29 , wherein the cytotoxin is an antibiotic.
31. The antibody/drug conjugate of claim 30 , wherein the antibiotic is calicheamicin.
32. The antibody/drug conjugate of claim 31 , wherein the calicheamicin is an N-acetyl derivative or disulfide analog of calicheamicin.
33. The antibody/drug conjugate of claim 27 , wherein the drug is bound to the antibody via a linker selected from the group consisting of 4-(4′acetylphenoxy)butanoic acid (AcBut), 3-acetylphenyl acidic acid (AcPac), 4-mercapto-4-methyl-pentanoic acid (Amide), and derivatives thereof.