Sintilimab

Adding sintilimab to bevacizumab and chemotherapy is hypothesised to improve remission rates and prolong survival compared with immunotherapy plus chemotherapy alone, particularly in PD-L1-low or PD-L1-negative patients. Prior evidence from ORIENT-32 and ORIENT-31 establishes the feasibility and preliminary efficacy of the sintilimab-IBI305 combination in solid tumours, providing a scientific foundation for the triple regimen. Anti-PD-1 plus chemotherapy has provided inconsistent survival benefit across major gastric cancer trials, particularly in patients with low or absent PD-L1 expression. Sintilimab is an intravenous anti-PD-1 monoclonal antibody used as the immunotherapy component of the trial regimen.