[Comment] Pembrolizumab as a first-line treatment for advanced gastric cancer

The efficacy of incorporating PD-1 antibodies in first-line therapy for advanced gastric or gastro-esophageal junction adenocarcinoma was established in the CHECKMATE 649 study.1,2 However, the results of the CHECKMATE 649 study met statistical significance in the PD-L1 combined positive score (CPS) of 5 or higher, PD-L1 CPS of 1 or higher, and intention-to-treat populations, which has led to geographical variations in regulatory approvals and international guidelines on the addition of nivolumab to chemotherapy regimens in advanced gastric or gastro-esophageal junction adenocarcinoma.