Advances on biological evaluation methods of programmed cell death protein-1/ligand-1 inhibitors

Immuno-oncology represents a groundbreaking and well-established field within cancer treatment. Among the various immuno-oncology targets, the exploration of programmed cell death-1/ligand-1 for drug discovery has proven to be one of the most successful endeavors. Remarkably, it took nearly 30 years from the initial target identification to the clinical approval of monoclonal antibodies. Providing suitable and reliable bioassays for drug candidate evaluation is of paramount importance throughout the early stages of drug discovery, from lead compound identification to in vivo efficacy testing. This assay review aims to shed light on diverse assays reported in the literature for testing antagonism activity and efficacy of programmed cell death-1/ligand-1 inhibitors. Each of these assays possesses inherent advantages and can be applied in different research scenarios. The insights presented in this summary can serve as a valuable resource for scientists in this field, aiding in the selection of appropriate assays for their specific investigations.