A randomized phase 3 trial compared camrelizumab plus CAPOX followed by camrelizumab plus apatinib (camre+CAPOX/camre+apa), CAPOX alone, and camrelizumab plus CAPOX followed by camrelizumab (camre+CAPOX/camre) as initial treatment in 885 adult patients with HER2-negative, unresectable, locally advanced or metastatic adenocarcinoma of the stomach or gastroesophageal junction. Patients were randomized in a 2:2:1 ratio, stratified by ECOG status, peritoneal metastasis, and PD-L1 CPS. The primary endpoint was overall survival (OS) for camre+CAPOX/camre+apa versus CAPOX in the PD-L1 positive population (CPS >1) and overall population. In the PD-L1 positive group, median OS was 15.0 months versus 12.5 months (HR 0.80; 95% CI 0.65-0.98; one-sided P=0.02); in the overall population, 13.5 months versus 12.1 months (HR 0.80; 95% CI 0.68-0.94; one-sided P=0.004). Camre+CAPOX/camre showed longer OS versus CAPOX in the PD-L1 positive group (15.3 versus 12.5 months; HR 0.76; 95% CI 0.58-0.97; nominal P=0.01) and overall (14.2 versus 12.1 months; HR 0.80; 95% CI 0.65-0.98; nominal P=0.01). P=0.02). There was no benefit in OS between camre+CAPOX/camre+apa and camre+CAPOX/camre. Grade ≥3 serious adverse events occurred in 67.9% of patients in camre+CAPOX/camre+apa, 45.3% in CAPOX, and 46.9% in camre+CAPOX/camre.