EPHB3-Specific Antibody and Uses Thereof

• US 20090142261A1
• Filed: 08/03/2007
• Published: 06/04/2009
• Est. Priority Date: 08/04/2006
• Status: Active Grant

• Current Assignee: Xoma Technology Ltd. (Xoma Corp.)
• Original Assignee: Novartis Ag, Xoma Technology Ltd. (Xoma Corp.)
• Inventors: Hsu, Jeff, Schleyer, Siew, Abraham, Judy, Masat, Linda, Handa, Masahisa
• Granted Patent: US 8,586,716 B2
• Time in Patent Office: Days
• US Class Current: 424/1.490
• CPC Class Codes: A61P 35/00 Antineoplastic agents
• CPC Class Codes: A61P 43/00 Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00
• CPC Class Codes: C07K 16/2866 against receptors for cytokines, lymphokines, interferons
• CPC Class Codes: C07K 16/30 from tumour cells
• CPC Class Codes: C07K 2317/56 variable (Fv) region, i.e. VH and/or VL
• CPC Class Codes: C07K 2317/75 Agonist effect on antigen
• CPC Class Codes: C07K 2317/77 Internalization into the cell
• CPC Class Codes: C07K 2317/92 Affinity (KD), association rate (Ka), dissociation rate (Kd) or EC50 value

Abstract

EphB3-specific antibodies are provided, along with pharmaceutical compositions containing such antibody, kits containing a pharmaceutical composition, and methods of preventing and treating cancer.

Claims

1. An antibody that binds the extracellular domain of EphB3 with an affinity (K_D) of 10⁻

6 M or less and competes with any of antibodies XPA.04.001, XPA.04.013, XPA.04.018, XPA.04.048, XHA.05.337, XHA.05.200, XHA.05.111, XHA.05.005, XHA.05.228, XHA.05.030, XHA.05.964, or XHA.05.885 for binding to EphB3 by more than 75%.

4. The antibody of any of claims 1-3 wherein the antibody is a chimeric antibody, a humanized antibody, a human engineered antibody, a human antibody, a single chain antibody or an antibody fragment.

5. The antibody of any of the preceding claims in which at least one amino acid within a CDR is substituted by a corresponding residue of a corresponding CDR of another anti-EphB3 antibody.

6. The antibody of any of the preceding claims in which one or two amino acids within a CDR have been modified.

7. The antibody of any of the preceding claims that retains at least 60, 65, 70, 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, or 99% identity over either the variable light or heavy region to the antibodies of XPA.04.001, XPA.04.013, XPA.04.018, XPA.04.048, XHA.05.337, XHA.05.200, XHA.05.111, XHA.05.005, XHA.05.228, XHA.05.030, XHA.05.964, or XHA.05.885.

8. The antibody of any of the preceding claims that comprises a constant region of a human antibody sequence and one or more heavy and light chain variable framework regions of a human antibody sequence.

9. The antibody of claim 8 wherein the human antibody sequence is an individual human sequence, a human consensus sequence, an individual human germline sequence, or a human consensus germline sequence.

10. The antibody of any of the preceding claims wherein the heavy chain constant region is a modified or unmodified IgG, IgM, IgA, IgD, IgE, a fragment thereof, or combinations thereof.

11. The antibody of any of the preceding claims that has a binding affinity of 10⁻

7, 10<sup>−

8</sup> or 10<sup>−

9</sup> M or less to EphB3.

12. The antibody of any of the preceding claims comprising a conservative substitution in the CDRs.

13. The antibody of any of the preceding claims comprising a conservative or non-conservative change in low and moderate risk residues.

14. The antibody of any of the preceding claims wherein the light chain constant region is a modified or unmodified lambda light chain constant region, a kappa light chain constant region, a fragment thereof, or combinations thereof.

15. The antibody of any of the preceding claims that induces EphB3 phosphorylation.

16. The antibody of any of the preceding claims that induces EphB3 oligomerization.

17. The antibody of any of the preceding claims that induces EphB3 internalization.

18. The antibody of any of the preceding claims that induces EphB3 degradation.

19. The antibody of any of the preceding claims that induces EphB3 signaling.

20. The antibody of any of the preceding claims that inhibits the binding of an ephrinB to EphB3.

21. The antibody of any of the preceding claims that inhibits the proliferation of a cancer cell.

22. The antibody of claim 21 that inhibits proliferation of a lung, ovarian, esophageal, colon or breast cancer cell.

23. The antibody of any of the preceding claims that is conjugated to another diagnostic or therapeutic agent.

27. A method of treating a subject suffering from cancer comprising the step of administering an antibody of any of the preceding claims in a therapeutically effective amount.

28. The method of claim 27 wherein the cancer is lung, ovarian, esophageal, colon or breast cancer.

29. The method of claim 28 wherein a second therapeutic agent is administered.

30. The method of claim 28 wherein the subject is further treated with radiation therapy or surgery.

31. A method of targeting a tumor cell expressing EphB3 comprising the step of administering an antibody of any of the preceding claims, conjugated to a radionuclide or other toxin.

32. The method of claims 27-31 wherein the subject is a mammal.

33. The method of claim 32 wherein the subject is a human.

34. An isolated nucleic acid molecule comprising a nucleotide sequence that encodes the heavy chain or light chain of an antibody of any of claims 1-23.

35. An expression vector comprising the nucleic acid molecule of claim 34 operably linked to a regulatory control sequence.

36. A host cell comprising the vector of claim 35 or a nucleic acid molecule of claim 48.

37. A method of using the host cell of claim 36 to produce an antibody, comprising culturing the host cell of claim 36 under suitable conditions and recovering said antibody.

38. An antibody produced by the method of claim 37.

39. The antibody of any of claims 1-23 or 38 that is purified to at least 95% homogeneity by weight.

40. A pharmaceutical composition comprising the antibody of claim 39 and a pharmaceutically acceptable carrier.

41. A kit comprising an antibody of any of the preceding claims comprising a therapeutically effective amount of an antibody of the invention, packaged in a container, said kit optionally containing a second therapeutic agent, and further comprising a label attached to or packaged with the container, the label describing the contents of the container and providing indications and/or instructions regarding use of the contents of the container to treat cancer.

42. The kit of claim 41 wherein the container is a vial or bottle or prefilled syringe.

2. The antibody of claim 2 that binds to the same epitope of EphB3 as any of antibodies XPA.04.001, XPA.04.013, XPA.04.018, XPA.04.048, XHA.05.337, XHA.05.200, XHA.05.111, XHA.05.005, XHA.05.228, XHA.05.030, XHA.05.964, or XHA.05.885.

3. An antibody that comprises 1, 2, 3, 4, 5 or 6 CDRs of any of antibodies XPA.04.001, XPA.04.013, XPA.04.018, XPA.04.048, XHA.05.337, XHA.05.200, XHA.05.111, XHA.05.005, XHA.05.228, XHA.05.030, XHA.05.964, or XHA.05.885.

24. A method of screening for an antibody to the extracellular domain of a EphB3 protein useful for the treatment of cancer comprising the steps of:

contacting a polypeptide comprising the ECD of EphB3 with a candidate antibody that contains at least 1, 2, 3, 4, 5 or 6 CDRs of antibodies XPA.04.001, XPA.04.013, XPA.04.018, or XPA.04.048;

detecting binding affinity of the candidate antibody to the polypeptide, and identifying said candidate antibody as an antibody useful for the treatment of cancer if a binding affinity of at least 10<sup>−

6</sup> M is detected.

25. A method of systematically altering antibodies and screening for an antibody to the extracellular domain of a EphB3 protein useful for the treatment of cancer comprising the steps of:

preparing a candidate antibody that contains modifications to one or two amino acids within the CDRs of antibodies XPA.04.001, XPA.04.013, XPA.04.018, XPA.04.048, XHA.05.337, XHA.05.200, XHA.05.111, XHA.05.005, XHA.05.228, XHA.05.030, XHA.05.964, or XHA.05.885,

contacting a polypeptide comprising the ECD of EphB3 with said candidate antibody

detecting binding affinity of the candidate antibody to the polypeptide, and

identifying said candidate antibody as an antibody useful for the treatment of cancer if a binding affinity of at least 10<sup>−

6</sup> M is detected.

26. A method of screening for an antibody to the extracellular domain of a EphB3 protein useful for the treatment of cancer comprising the steps of:

contacting a lung, ovarian, esophageal, colon or breast cell with a candidate antibody that contains at least 1, 2, 3, 4, 5 or 6 CDRs of antibodies XPA.04.001, XPA.04.013, XPA.04.018, XPA.04.048, XHA.05.337, XHA.05.200, XHA.05.111, XHA.05.005, XHA.05.228, XHA.05.030, XHA.05.964, or XHA.05.885 or an antibody that contains a modification of one or two amino acids within one or more CDRs;

detecting proliferation or survival of said cell; and

identifying said candidate antibody as an antibody useful for the treatment of cancer if a decrease in cell proliferation or survival is detected.