CD47 blockade with PARP inhibition for disease treatment
CD47+ disease cells such as cancer cells are treated using a combination of CD47 blocking agent and poly-(ADP-ribose) polymerase (PARP) inhibitor. The CD47 blocking agent can be SIRPαFc and the PARP inhibitor niraparib. The anti-cancer effect of niraparib is enhanced in the presence of SIRPαFc. Specific combinations include SIRPαFc forms that comprise an Fc that is either IgG1 or preferably IgG4 isotype. These combinations are useful particularly to treat solid tumours and blood cancers including lymphomas, leukemias and myelomas.
1. A method for treating a subject presenting with CD47+ disease cells, comprising administering to the subject a PARP inhibitor and a CD47 blocking agent in combination with radiation therapy, wherein the CD47 blocking agent is a CD47-binding SIRPα polypeptide and wherein the CD47-binding SIRPα polypeptide is an Fc fusion protein comprising a CD47-binding region of soluble human SIRPα.
2. The method according to claim 1 , wherein the PARP inhibitor is an inhibitor of PARP-1.
3. The method according to claim 1 , wherein the PARP inhibitor is talazoparib, veliparib, niraparib, olaparib, rucaparib, or iniparib.
4. The method according to claim 1 , wherein the Fc fusion protein comprises SEQ ID NO: 8.
5. The method according to claim 1 , wherein the Fc fusion protein comprises SEQ ID NO: 9.
6. The method according to claim 1 , wherein the Fc fusion protein comprises soluble SIRPα having one or more activity-enhancing amino acid substitutions selected from L 4 V/I, V 6 I/L, A 21 V, V 27 |/L, I 31 T/S/F, E 47 V/L, K 53 R, E 54 Q, H 56 P/R, S 66 T/G, K 68 R, V 92 I, F 94 V/L, V 63 I, and F 103 V.
7. The method according to claim 1 , wherein the radiation therapy is external beam radiation therapy.
8. The method according to claim 1 , wherein the CD47+ disease cells are CD47+ cancer cells.
9. The method according to claim 8 , wherein the CD47+ cancer cells are blood cancers or solid tumours.
10. The method according to claim 8 , wherein the cancer cells are cells of a cancer type selected from acute lymphocytic leukemia (ALL); acute myeloid leukemia (AML); chronic lymphocytic leukemia (CLL); chronic myelogenous leukemia (CML); myeloproliferative disorder/neoplasm (MPDS); and myelodysplastic syndrome.
11. The method according to claim 8 wherein the cancer is a lymphoma selected from a non-Hodgkin's lymphoma, both indolent and aggressive non-Hodgkin's lymphoma, T cell lymphoma, CD20+ lymphoma, Burkitt's lymphoma, and small cell follicular lymphoma, and large cell follicular lymphoma.
12. The method according to claim 8 , wherein the cancer is a myeloma selected from multiple myeloma (MM), giant cell myeloma, heavy-chain myeloma, and light chain or Bence-Jones myeloma.
13. The method according to claim 8 , wherein the cancer is melanoma, ovarian cancer, CTCL, mycosis fungoides, breast cancer, or glioblastoma.