An Imaging-Based Assay to Measure the Location of PD-1 at the Immune Synapse for Testing the Binding Efficacy of Anti-PD-1 and Anti-PD-L1 Antibodies.

PD-1 is an immune checkpoint on T cells. Antibodies to PD-1 or its ligand PD-L1 are gaining popularity as a leading immunotherapy approach. In the US, 40% of all cancer patients will be treated with anti-PD-1 or anti-PD-L1 antibodies but, unfortunately, only 30% will respond, and many will develop immune-related adverse events.