Phase 2 study of neoadjuvant toripalimab plus chemotherapy in localized dMMR/MSI-H gastric or esophagastric junction adenocarcinoma

In locally advanced gastric or gastroesophageal junction adenocarcinoma (GC/EGJC), dMMR/MSI-H tumors exhibit high responsiveness to immunotherapy. The phase 2 NICE study, at six hospitals in China, evaluated the neoadjuvant combination of toripalimab (anti-PD-1) and CapeOx chemotherapy for these tumors. Given the small sample size of the study (n=16), the findings should be interpreted with caution. Nonetheless, neoadjuvant toripalimab combined with CapeOx regimen was feasible for locally advanced dMMR/MSI-H GC/EGJC, demonstrating high major pathological response and pathological complete response rates without unexpected adverse events.