BMS-202 (PD1-PDL1 inhibitor 2) is an inhibitor of the PD-1 (Programmed death- 1) /PD-Ll (Programmed death-ligand 1) protein/protein interaction.

BMS-202 inhibits PD-1/PD-Ll interaction, and may augment therapeutic immune response to a number of histologically distinct tumors. Blockade of the PD-1/PD-Ll ligation using antibodies to PD-Ll has been shown to restore and augment T cell activation in many systems[1].

All binding studies are performed in an HTRF assay buffer consisting of dPBS supplemented with 0.1% (with v) bovine serum albumin and 0.05% (v/v) Tween-20. For the PD-l-Ig/PD-Ll-His binding assay, inhibitors are pre-incubated with PD-Ll-His (10 nM final) for 15 m in 4 μL of assay buffer, followed by addition of PD-l-Ig (20 nM final) in 1 μL of assay buffer and further incubation for 15 m. PD-L1 from either human, cyno, or mouse are used. HTRF detection is achieved using europium crypate-labeled anti- Ig (1 nM final) and allophycocyanin (APC) labeled anti-His (20 nM final). Antibodies are diluted in HTRF detection buffer and 5 μL is dispensed on top of binding reaction. The reaction mixture is allowed to equilibrate for 30 minutes and signal (665 nm/620 nm ratio) is obtained using an En Vision fluorometer. Additional binding assays are established between PD-1-Ig/PD-L2-His (20, 5 nM, respectively), CD80-His/PD-Ll-Ig (100, 10 nM, respectively) and CD80-His/CTLA4-Ig (10, 5 nM, respectively).