The FDA granted priority review for Merck’s Keytruda (pembrolizumab), the company’s anti-PD-1 immunotherapy used in the treatment of certain cancers.

Merck has more than 10 studies investigating Keytruda in gastrointestinal cancers, including hepatocellular carcinoma.

A humanized monoclonal antibody, Keytruda works by bolstering the body’s ability to detect and combat tumor cells. It blocks the interaction between PD-1 and its ligands, PD-L1 and PD-L2, thus activating T-cells.