Evolution of checkpoint inhibitors for the treatment of metastatic gastric cancers: Current status and future perspectives

•Treatment of advanced gastric cancers remains an area of great unmet need.•Anti–PD-1/PD-L1 antibodies have shown clinical activity in gastric cancers.•Phase 3 trials are assessing anti–PD-1/PD-L1 monotherapy and combination regimens.•First-line, maintenance, and later-line treatment strategies are being evaluated.•Anti–PD-1 agents have received initial approvals for later-line treatment.