In vitro activity: PD1-PDL1 inhibitor 1 (also known as PD1-PDL1-IN1, or PD1/PD-L1 inhibitor 1) is a small molecule inhibitor of PD-1/PD-L1 protein/protein interaction with IC50 of 6 nM. It was first discovered by BMS (Bristol-Myers-Squibb) as an immunomodulator for the Programmed death-ligand 1 (PD-L1) with potential anticancer activities. PD-L1 is known as cluster of differentiation 274 (CD274) or B7 homolog 1 (B7-H1) is a protein that in humans is encoded by the CD274 gene. It is reported that the overexpression of PD-L1 may allow cancers to escape the surveilance of host immune system.

Kinase Assay: The HTRF PD1/PD-L1 Binding Assay is designed to measure the interaction between PD1 and PD-L1 proteins. Utilizing HTRF (Homogeneous Time-resolved Fluorescence) technology, the assay enables simple and rapid characterization of compound and antibody blockers in a high throughput format.