Anti-PD-L1 monoclonal antibodies and fragments thereof
The present invention is based, in part, on the discovery of monoclonal antibodies that specifically bind to the cytoplasmic domain of PD-L1 antibodies useful for diagnostic, prognostic, and therapeutic applications, as well as immunoglobulins polypeptides, and nucleic acids thereof.
1. A monoclonal antibody, or antigen-binding fragment thereof, that specifically binds human PD-L1 and comprises:
(a) a light chain variable region (VL) comprising a complementarity determining region (“CDR”)-L1 as set forth in SEQ ID NO: 7, a CDR-L2 as set forth in SEQ ID NO: 10, and a CDR-L3 as set forth in SEQ ID NO: 13; and
(b) a heavy chain variable region (VH) comprising a CDR-H1 as set forth in SEQ ID NO: 20, a CDR-H2 as set forth in SEQ ID NO: 23, and a CDR-H3 as set forth in SEQ ID NO: 26.
2. The monoclonal antibody, or antigen-binding fragment thereof, of claim 1 that is murine, chimeric, or humanized.
3. The antigen-binding fragment of claim 1 , wherein the antigen-binding fragment is a Fv, F(ab′)2, Fab′, sdFv, scFv, sc(Fv)2, or a diabody.
4. The monoclonal antibody of claim 1 , wherein the monoclonal antibody comprises an Fc domain.
5. The monoclonal antibody, or antigen-binding fragment thereof, of claim 1 , wherein the VL comprises the amino acid sequence set forth in SEQ ID NO: 2.
6. The monoclonal antibody, or antigen-binding fragment thereof, of claim 1 , wherein the VH comprises the amino acid sequence set forth in SEQ ID NO: 15.
7. The monoclonal antibody, or antigen-binding fragment thereof, of claim 6 , that also comprises the VL set forth in SEQ ID NO: 2.
8. A composition comprising the monoclonal antibody, or antigen-binding fragment thereof, of claim 7 and a physiologically acceptable carrier, excipient, or stabilizer.
9. A composition comprising the monoclonal antibody, or antigen-binding fragment thereof, of claim 1 and a physiologically acceptable carrier, excipient, or stabilizer.
10. A device or kit for detecting membrane-bound PD-L1, the device or kit comprising at least one monoclonal antibody, or antigen-binding fragment thereof, according to claim 1 and a label to detect the at least one monoclonal antibody, or antigen-binding fragment thereof.
11. An immunoconjugate comprising:
(a) a monoclonal antibody, or antigen-binding fragment thereof, that specifically binds the cytoplasmic region of PD-L1 and that comprises:
(i) a light chain variable region (VL) comprising a comple mentarity determining region (“CDR”)-L1 as set forth in SEQ ID NO: 7, a CDR-L2 as set forth in SEQ ID NO: 10, and a CDR-L3 as set forth in SEQ ID NO: 13; and
(ii) a heavy chain variable region (VH) comprising a CDR-H1 as set forth in SEQ ID NO: 20, a CDR-H2 as set forth in SEQ ID NO: 23, and a CDR-H3 as set forth in SEQ ID NO: 26; and
(b) a cytotoxin, a drug, a radioisotope, an enzyme, a prosthetic group, fluorescent material, luminescent material, or bioluminescent material.
12. A method of detecting the presence or level of PD-L1 polypeptide in a sample, the method comprising obtaining a sample and detecting the polypeptide in the sample by contacting the sample with the monoclonal antibody, or antigen-binding fragment thereof, of claim 1 or with the immunoconjugate of claim 11 .
13. The method of claim 12 , wherein the method is an enzyme-linked immunosorbent assay (ELISA), radioimmune assay (RIA), a flow assay, or an immunohistochemistry (IHC) assay.
14. The method of claim 12 , wherein the method is an immunohistochemistry (IHC) assay and the sample is formalin-fixed, paraffin-embedded tumor tissue.
15. An isolated nucleic acid encoding:
(a) a light chain variable region (VL) comprising a complementarity determining region (“CDR”)-L1 as set forth in SEQ ID NO: 7, a CDR-L2 as set forth in SEQ ID NO: 10, and a CDR-L3 as set forth in SEQ ID NO: 13; and
(b) a heavy chain variable region (VH) comprising a CDR-H1 as set forth in SEQ ID NO: 20, a CDR-H2 as set forth in SEQ ID NO: 23, and a CDR-H3 as set forth in SEQ ID NO: 26; wherein the VH and VL, when expressed together, form an antibody Fv that binds human PD-L1.
16. The isolated nucleic acid of claim 15 , comprising (a) the nucleotide sequence set forth in SEQ ID NO: 3, (b) the nucleotide sequence set forth in SEQ ID NO: 16, or (c) both the nucleotide sequence set forth in SEQ ID NO: 3 and the nucleotide sequence set forth in SEQ ID NO: 16.
17. A vector comprising an isolated nucleic acid of claim 15 or an isolated nucleic acid of claim 16 .
18. An isolated host cell comprising the vector of claim 17 .
19. A method of producing an antibody, or antigen-binding fragment thereof, comprising culturing the host cell of 45 under conditions to allow expression of said antibody or antigen-binding fragment thereof, and recovering the expressed antibody or antigen-binding fragment thereof.