ILT3 binding molecules and uses therefor

• US 20080038260A1
• Filed: 06/19/2007
• Published: 02/14/2008
• Est. Priority Date: 06/19/2006
• Status: Active Grant

• Current Assignee: Merck Sharp & Dohme LLC (Merck & Co., Inc.)
• Original Assignee: Tolerx Incorporated
• Inventors: Ponte, Jose, Rosenzweig, Michael, Ponath, Paul
• Granted Patent: US 7,777,008 B2
• Time in Patent Office: Days
• US Class Current: 424/133.1
• CPC Class Codes: A61K 2039/505 comprising antibodies
• CPC Class Codes: A61P 35/00 Antineoplastic agents
• CPC Class Codes: A61P 35/02 specific for leukemia
• CPC Class Codes: A61P 37/02 Immunomodulators
• CPC Class Codes: C07K 14/70503 Immunoglobulin superfamily
• CPC Class Codes: C07K 16/2803 against the immunoglobulin superfamily
• CPC Class Codes: C07K 2317/24 containing regions, domains or residues from different species, e.g. chimeric, humanized or veneered

Abstract

The present invention provides binding molecules that specifically bind to ILT3, e.g., human ILT3 (hILT3), on antigen presenting cells, such as for example, monocytes, macrophages and dendritic cells (DC), e.g., monocyte-derived dendritic cells (MDDC). The binding molecules of the invention are characterized by binding to hILT3 with high affinity and downmodulating immune responses in vitro, e.g., downmodulating alloimmune responses; the production of inflammatory cytokines by dendritic cells, e.g., monocyte-derived dendritic cells (MDDC); the upregulation of costimulatory molecules by DC, e.g., MDDC; and/or calcium flux in monocytes. In addition, the binding molecules upregulate the expression of inhibitory receptors on dendritic cells, e.g., immature dendritic cells. Surprisingly, these same binding molecules which downmodulate immune responses in vitro, are immunostimulatory in vivo. Various aspects of the invention relate to binding molecules, and pharmaceutical compositions thereof. Methods of using the binding molecules of the invention to detect human ILT3 or to modulate human ILT3 activity, either in vitro or in vivo, are also encompassed by the invention.

Claims

1. An ILT3 binding molecule comprising amino acid residues 20-135 of the amino acid sequence of SEQ ID NO:

1.

25. A composition comprising the binding molecule of any one of claims 1-4, 9-10, or 13 and a pharmaceutically acceptable carrier.

26. The composition of claim 25, further comprising at least one additional therapeutic agent which upmodulates an immune response in a subject.

2. An ILT3 binding molecule comprising amino acid residues 21-127 of the amino acid sequence of SEQ ID NO:

2.

3. An ILT3 binding molecule comprising at least one complementarity determining region (CDR) amino acid sequence selected from the group consisting of:

SEQ ID NO;

3, SEQ ID NO;

4, and SEQ ID NO;

5.

4. The binding molecule of claim 3, comprising at least 2 CDRs.

5. The binding molecule of claim 3, comprising three CDRs.

6. A binding molecule comprising at least one CDR amino acid sequence selected from the group consisting of:

SEQ ID NO;

6, SEQ ID NO;

7, and SEQ ID NO;

8.

7. The binding molecule of claim 6, comprising at least 2 CDRs.

8. The binding molecule of claim 6, comprising three CDRs.

9. An ILT3 binding molecule comprising the CDRs shown in SEQ ID NOs.:

3, 4, 5, 6, 7 or 8.

28. A method for downmodulating transplant rejection in a subject, comprising contacting a cell from the subject with a binding molecule of claim 9, and reintroducing the cell into the subject at the time of or prior to transplantation such that transplant rejection in a subject is downmodulated.

10. A binding molecule comprising a heavy chain variable region comprising amino acid residues 20-135 of the amino acid sequence of SEQ ID NO:

1 and further comprising a light chain variable region comprising amino acid residues 21-127 of the amino acid sequence of SEQ ID NO;

2.

11. The binding molecule of any one of claims 3-10 comprising substantially human heavy and light chain framework regions.

12. The binding molecule of claim 11, wherein one or more human framework amino acid residues is backmutated to the corresponding murine amino acid residue.

13. A binding molecule that binds to ILT-3 on human monocyte-derived dendritic cells (MDDC) and has a binding constant (Kd) of 0.9×

10<sup>−

9</sup> or less.

14. The binding molecule of claim 9 or 13, wherein the binding molecule downmodulates immune cell activation in vitro.

15. The binding molecule of claim 9 or 13, wherein the binding molecule upmodulates an immune response in vivo.

16. The binding molecule of claim 9 or 13, wherein the constant region comprises an IgG1 heavy chain constant region.

17. The binding molecule of claim 9 or 13, wherein the binding molecule binds to human ILT-3 on dendritic cells

18. The binding molecule of claim 9 or 13, wherein the binding molecule binds to human ILT-3 on monocytes.

19. The binding molecule of claim 9 or 13, wherein the binding molecule downmodulates the production of inflammatory cytokines by dendritic cells in vitro.

20. The binding molecule of claim 9 or 13, wherein the binding molecule downmodulates the upregulation of costimulatory molecules on dendritic cells in vitro.

21. The binding molecule of claim 9 or 13, wherein the binding molecule upmodulates the expression of inhibitory receptors on dendritic cells in vitro.

22. The binding molecule of claim 9 or 13, wherein said binding molecule is a mouse antibody.

23. The binding molecule of claim 9 or 13, wherein said binding molecule is a monoclonal antibody or antigen binding fragment thereof.

24. The binding molecule of claim 9 or 13, wherein said binding molecule is a humanized or chimeric antibody.

29. A method for treating cancer in a subject, comprising contacting a cell with the binding molecule of claim 9 or 13, such that cancer is treated in a subject.

30. The method of claim 29, wherein the type of cancer is selected from the group consisting of:

pancreatic cancer, melanomas, breast cancer, lung cancer, bronchus cancer, colorectal cancer, prostate cancer, pancreas cancer, stomach cancer, ovarian cancer, urinary bladder cancer, brain or central nervous system cancer, peripheral nervous system cancer, esophageal cancer, cervical cancer, uterine or endometrial cancer, cancer of the oral cavity or pharynx, liver cancer, kidney cancer, testicular cancer, biliary tract cancer, small bowel or appendix cancer, salivary gland cancer, thyroid gland cancer, adrenal gland cancer, osteosarcoma, chondrosarcoma, and cancer of hematological tissues.

41. A recombinant expression vector comprising one or more nucleotide molecules having a nucleotide sequence encoding the binding molecule of claim 13.

42. A host cell into which the recombinant expression vector of claim 41 has been introduced.

43. A method for producing a binding molecule that binds human ILT3, comprising culturing the host cell of claim 42 in a culture medium until a binding molecule that binds human ILT3 is produced by the cell.

27. A method for upmodulating an immune response in a subject, comprising contacting a cell from the subject with an anti-ILT3 antibody that inhibits immune cell activation in vitro.

31. An isolated nucleic acid molecule comprising a nucleotide sequence encoding a heavy chain variable region comprising the nucleotide sequence of SEQ ID NO:

9.

40. A recombinant expression vector comprising the nucleic acid molecules of any one of claims 31-39.

32. An isolated nucleic acid molecule comprising a nucleotide sequence encoding a light chain variable region comprising the nucleotide sequence of SEQ ID NO:

10.

33. An isolated nucleic acid molecule comprising a nucleotide sequence encoding at least one CDR selected from the group consisting of:

SEQ ID NO;

11, SEQ ID NO;

12, and SEQ ID NO;

13.

34. The isolated nucleic acid molecule of claim 33, comprising at least two CDRs.

35. The isolated nucleic acid molecule of claim 33, comprising three CDRs.

36. An isolated nucleic acid molecule comprising a nucleotide sequence encoding at least one CDR selected from the group consisting of:

SEQ ID NO;

14 SEQ ID NO;

15 and SEQ ID NO;

16.

37. The isolated nucleic acid molecule of claim 36, comprising at least two CDRs.

38. The isolated nucleic acid molecule of claim 36, comprising three CDRs.

39. An isolated nucleic acid molecule comprising the nucleotide sequences shown in SEQ ID NOs:

11-16.