CD47 antibodies, methods, and uses
The present disclosure relates generally to monoclonal antibodies that specifically bind to CD47, more specifically to CD47 antibodies that do not have significant platelet aggregation activity and do not have significant hemagglutination activity. Methods of generating these antibodies and methods of using these monoclonal antibodies as therapeutics are also provided.
1. An isolated antibody or antigen binding fragment thereof comprising the following properties:
a. the antibody or antigen binding fragment specifically binds to CD47 by interacting with CD47 (SEQ ID NO: 21 excluding the signal sequence) amino acid residues:
i. Q1, L3, N27, E29, E97, L101, T102, R103, and E104;
ii. Y37, K39, R45, D46, T49, A53, L54, N55, K56, S57, T58, V59, P60, T61, T564, A66, and K67;
iii. E35, K39, Y37, D46, 49, D51, A53, L54, K56, T58, V59, T99, L101, and T102; or
iv. E29, Q31, N32, E35, V36, Y37, K39, N41, D46, D51, A53, E97, T99, E100, L101, T102, R103, and E104;
b. the antibody or antigen binding fragment thereof prevents CD47 from interacting with signal-regulatory protein alpha (SIRP alpha);
c. the antibody or antigen binding fragment thereof does not have significant platelet aggregation activity and
wherein the antibody or antigen binding fragment thereof comprises a VH complementarity determining region 1 (CDR1) sequence set forth in SEQ ID NO: 9 or SEQ ID NO: 10, a VH CDR2 sequence set forth in SEQ ID NO: 11 or SEQ ID NO: 12, a VH CDR3 sequence set forth in SEQ ID NO: 13 or SEQ ID NO: 14, a VL CDR1 sequence set forth in SEQ ID NO: 15 or SEQ ID NO: 16, a VL CDR2 sequence set forth in SEQ ID NO: 17 or SEQ ID NO: 18 and a VL CDR3 sequence set forth in SEQ ID NO: 19 or SEQ ID NO: 20.
2. The antibody of claim 1 wherein the antibody or antigen binding fragment specifically binds to human or cyno CD47, and comprises a variable heavy (VH) chain region selected from the group consisting of SEQ ID NOs: 4-6.
3. The antibody of claim 2 , wherein the antibody or antigen binding fragment thereof comprises a variable light (VL) chain region selected from the group consisting of SEQ ID NOs: 7 and 8.
4. The antibody of claim 2 , wherein the antibody or antigen binding fragment thereof comprises a VH region selected from the group consisting of SEQ ID NOs: 4-6 and a VL region selected from the group consisting of SEQ ID NOs: 7 and 8.
5. The antibody of claim 4 , wherein the VH chain region comprises SEQ ID NO: 4 or SEQ ID NO: 5 paired with a VL chain region comprising SEQ ID NO: 7.
6. The antibody of claim 4 , wherein the VH chain region comprises SEQ ID NO: 6 paired with a VL chain region comprising SEQ ID NO: 8.
7. The antibody of claim 1 , wherein the antibody or antigen binding fragment thereof comprises a VH CDR1 sequence set forth in SEQ ID NO: 9, a VH CDR2 sequence set forth in SEQ ID NO: 11, a VH CDR3 sequence set forth in SEQ ID NO: 13, a VL CDR1 sequence set forth in SEQ ID NO: 15, a VL CDR2 sequence set forth in SEQ ID NO: 17, and a VL CDR3 sequence set forth in SEQ ID NO: 19.
8. The antibody of claim 1 , wherein the antibody or antigen binding fragment thereof comprises a VH CDR1 sequence set forth in SEQ ID NO: 10, a VH CDR2 sequence set forth in SEQ ID NO: 12, a VH CDR3 sequence set forth in SEQ ID NO: 14, a VL CDR1 set forth in SEQ ID NO: 16, a VL CDR2 sequence set forth in SEQ ID NO: 18, and a VL CDR3 sequence set forth in SEQ ID NO: 20.
9. The antibody of claim 2 , wherein the VH chain of the antibody has more extensive contacts with CD47 than the VL chain of the antibody.
10. The antibody of claim 2 , wherein the epitope bound by the VH chain of the antibody is positioned near the membrane of a CD47 expressing cell, and wherein the VL chain of the antibody occludes a SIRP alpha binding site on CD47.
11. The antibody of claim 2 , wherein the antibody does not have significant hemagglutination activity.
12. The antibody of claim 2 , wherein the platelet-aggregation activity of the antibody is no more than 10% greater than the degree of platelet-aggregation observed in the absence of the antibody.
13. The antibody of claim 2 , wherein the antibody is chimeric, humanized, or fully human.
14. The antibody of claim 2 , wherein the CD47 is human CD47 or cyno CD47.
15. The antibody of claim 2 , wherein the antibody or antigen binding fragment thereof promotes macrophage-mediated phagocytosis of a CD47-expressing cell.
16. The antibody of claim 2 , wherein the antibody or antigen binding fragment thereof comprises an IgG isotype selected from the group consisting of IgG1 isotype and IgG2 isotype.
17. A pharmaceutical composition comprising the antibody of claim 2 and a pharmaceutical acceptable carrier.