Anti-pd-l1 antibodies and uses thereof

Abstract

Provided are anti-PD-L1 antibodies or fragments thereof. The antibodies or fragments thereof specifically bind to the immunoglobulin C domain of the PD-L1 protein. In various example, the antibodies or fragments thereof include a VH CDR1 of SEQ ID NO: 1, a VH CDR2 of SEQ ID NO: 2, a VH CDR3 of SEQ ID NO: 3, a VL CDR1 of SEQ ID NO: 4, a VL CDR2 of SEQ ID NO: 5, and a VL CDR3 of SEQ ID NO: 6, or variants of each thereof. Methods of using the antibodies or fragments thereof for treating and diagnosing diseases such as cancer and infectious diseases are also provided.

What is claimed is: 
     
         1 . A method for treating cancer in a human patient having a cancer cell that expresses, over-expresses, or is induced to express PD-L1, comprising inhibiting the interaction between the immunoglobulin C (Ig C) domain of the PD-L1 protein and PD-1 in the patient. 
     
     
         2 . The method of  claim 1 , wherein the interaction is inhibited by an anti-PD-L1 antibody or fragment thereof that specifically binds to the Ig C domain. 
     
     
         3 . The method of  claim 2 , wherein the anti-PD-L1 antibody or fragment thereof does not specifically bind to the immunoglobulin V (Ig V) domain of the PD-L1 protein. 
     
     
         4 . The method of  claim 3 , wherein anti-PD-L1 antibody or fragment thereof binds to amino acid residues Y134, K162, and N183 in the Ig C domain. 
     
     
         5 . The method of  claim 1 , wherein the antibody or fragment thereof is a humanized antibody or a fragment thereof. 
     
     
         6 . The method of  claim 1 , wherein the cancer is a solid tumor. 
     
     
         7 . The method of  claim 1 , wherein the cancer is selected from the group consisting of bladder cancer, liver cancer, colon cancer, rectal cancer, endometrial cancer, leukemia, lymphoma, pancreatic cancer, small cell lung cancer, non-small cell lung cancer, breast cancer, urethral cancer, head and neck cancer, gastrointestinal cancer, stomach cancer, oesophageal cancer, ovarian cancer, renal cancer, melanoma, prostate cancer and thyroid cancer.