Anti-SIRP-alpha antibodies and related methods
Anti-SIRPα antibodies, including multi-specific anti-SIRPα antibodies, are provided, as are related compositions and methods. The antibodies of the disclosure bind to SIRPα and can block the interaction of CD47 on one cell with SIRPα on a phagocytic cell.
1. A method of treating a subject having a CD20+ cancer, comprising administering an effective amount of an isolated humanized anti-SIRPα antibody and one or more additional therapeutic agents to the subject,
wherein the antibody comprises a heavy chain comprising a variable heavy (V H ) chain sequence comprising three heavy chain CDR sequences, CDR-H1, CDR-H2, and CDR-H3, and a light chain comprising a variable light (V L ) chain sequence comprising three light chain CDR sequences, CDR-L1, CDR-L2, and CDR-L3, wherein:
(a) CDR-H1 comprises the sequence set forth in SEQ ID NO:1; CDR-H2 comprises the sequence set forth in SEQ ID NO:2; CDR-H3 comprises the sequence set forth in SEQ ID NO:3; and
(b) CDR-L1 comprises the sequence set forth in SEQ ID NO:4; CDR-L2 comprises the sequence set forth in SEQ ID NO:5; and CDR-L3 comprises the sequence set forth in SEQ ID NO:6.
2. The method of claim 1 , wherein the one or more additional therapeutic agents is an antibody, radiation, a cytotoxic agent, a chemotherapeutic agent, a cytostatic agent, an anti-hormonal agent, an EGFR inhibitor, an immunostimulatory agent, an anti-angiogenic agent, or a combination thereof.
3. The method of claim 2 , wherein the one or more additional therapeutic agents is an antibody.
4. The method of claim 3 , wherein the antibody binds CD20.
5. The method of claim 4 , wherein the antibody is at least one of Rituximab, Ibritumomab, Obinutuzumab, Ofatumumab, or Tositumomab.
6. The method of claim 5 , wherein the antibody is Rituximab.
7. The method of claim 1 , wherein the one or more additional therapeutic agents is administered contemporaneously with the antibody, prior to administering the antibody, or after administering the antibody.
8. The method of claim 1 , wherein one or both of the antibody and the one or more additional therapeutic agents are administered intravenously.
9. The method of claim 1 , wherein the CD20+ cancer is a lymphoma.
10. The method of claim 9 , wherein the lymphoma is Hodgkin lymphoma (HL) or non-Hodgkin lymphomas (NHL).
11. The method of claim 10 , wherein the HL is nodular sclerosis classical Hodgkin lymphoma (CHL), mixed cellularity CHL, lymphocyte-depletion CHL, lymphocyte-rich CHL, or nodular lymphocyte predominant HL.
12. The method of claim 10 , wherein the NHL is AIDS-related lymphoma, anaplastic large-cell lymphoma, angioimmunoblastic lymphoma, blastic NK-cell lymphoma, Burkitt's lymphoma, Burkitt-like lymphoma (small non-cleaved cell lymphoma), chronic lymphocytic leukemia/small lymphocytic lymphoma, cutaneous T-cell lymphoma, diffuse large B-cell lymphoma, enteropathy-type T-cell lymphoma, follicular lymphoma, hepatosplenic gamma-delta T-cell lymphoma, T-cell leukemias, lymphoblastic lymphoma, mantle cell lymphoma, marginal zone lymphoma, nasal T-cell lymphoma, pediatric lymphoma, peripheral T-cell lymphoma, primary central nervous system lymphoma, transformed lymphoma, treatment-related T-Cell lymphoma, or Waldenstrom's macroglobulinemia.
13. The method of claim 1 , wherein the subject is a human.
14. The method of claim 1 , wherein the V H chain sequence comprises or consists of the V H sequence set forth in SEQ ID NO:7 and the V L chain sequence comprises or consists of the V L sequence set forth in SEQ ID NO:8.
15. The method of claim 14 , wherein the heavy chain comprises or consists of the heavy chain sequence set forth in SEQ ID NO:17 and the light chain comprises or consists of the light chain sequence set forth in SEQ ID NO:18.
16. The method of claim 1 , wherein the antibody comprises a human Fc region with one or more reduced Fc-dependent functions.
17. The method of claim 16 , wherein the human Fc region is IgG1 or IgG4.
18. The method of claim 16 , wherein the human Fc region comprises at least one modification that reduces binding to a human Fc receptor.
19. The method of claim 16 , wherein the human Fc region is IgG1 and the Fc region modification comprises a modification at EU index position asparagine 297.
20. The method of claim 19 , wherein the human IgG1 Fc region modification comprises an N297A amino acid substitution, numbering according to EU index.
21. The method of claim 1 , wherein the antibody:
a. competes for binding to human SIRPα with a 1H9 antibody;
b. does not compete for binding to human SIRPα with KWar antibody;
c. partially competes for binding to human SIRPα with KWar antibody;
d. inhibits binding of human CD47 to human SIRPα;
e. inhibits binding of human SP-A to human SIRPα;
f. inhibits binding of human SP-D to human SIRPa;
g. binds to rhesus monkey SIRPα;
h. binds to cynomolgus SIRPα;
i. increases phagocytosis relative to control;
j. binds each of human SIRPα alleles V1 and V2;
k. binds each of human SIRPα alleles V1, V2, and V1/V5;
l. binds human SIRPα allele V1;
m. binds human SIRPα allele V2; or
n. is capable of any combination of (a)-(m).
22. The method of claim 1 , wherein the antibody is pan-specific for human SIRPα isotypes.
23. The method of claim 1 , wherein the antibody binds greater than one antigen or greater than one epitope on a single antigen.