Multicenter phase 3 trial of first-line sugemalimab plus chemotherapy for advanced gastric cancer

Sugemalimab is a fully human anti-PD-L1 antibody. The phase 3 GEMSTONE-303 trial, at 54 centers in China, evaluated addition of sugemalimab or placebo to first-line CAPOX for unresectable, locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma with a PD-L1 combined positive score 5 or more. In this randomized clinical trial of 479 patients, sugemalimab plus chemotherapy significantly prolonged overall survival (median 15.6 versus 12.6 months; HR 0.75; p=0.006) and progression-free survival (median 7.6 versus 6.1 months; HR 0.66; p<0.001) compared with placebo plus chemotherapy, with a manageable safety profile. The authors conclude that GEMSTONE-303 is the first trial demonstrating a significant survival benefit with addition of an anti-PD-L1 antibody to standard first-line chemotherapy for advanced gastric and gastroesophageal junction adenocarcinoma (visual abstract).