Perioperative Toripalimab Improves Survival in Resectable Gastric/GEJ Cancer : J Clin Oncol | May 2026
Introduction
Perioperative chemotherapy remains the standard treatment approach for locally advanced resectable gastric and gastroesophageal junction (GEJ) adenocarcinoma. However, recurrence rates remain high despite curative-intent surgery and systemic therapy, particularly because of peritoneal metastasis. Immune checkpoint inhibitors have demonstrated meaningful survival benefits in advanced gastric cancer, prompting investigation in earlier perioperative settings.
Problem Statement
Although early studies suggested improved pathological response with perioperative immunotherapy, robust long-term survival data in resectable gastric and GEJ cancer remain limited. It is unclear whether addition of PD-1 blockade to perioperative chemotherapy translates into durable event-free and overall survival benefit.
Summary
This 3-year follow-up analysis of the randomized phase II NEOSUMMIT-01 trial demonstrated significant long-term survival benefits with perioperative toripalimab plus oxaliplatin-based chemotherapy in patients with locally advanced gastric or GEJ adenocarcinoma. Compared with chemotherapy alone, the addition of the PD-1 inhibitor toripalimab significantly improved both event-free survival and overall survival, with approximately three-quarters of patients remaining event-free at 3 years. Importantly, the survival benefit persisted even after excluding patients with deficient mismatch repair tumors, indicating efficacy beyond highly immunotherapy-sensitive MSI-H/dMMR disease subsets. The therapeutic advantage was also consistently observed across most predefined clinical subgroups. A particularly notable finding was the marked reduction in peritoneal metastasis, historically one of the most challenging recurrence patterns in gastric cancer. The toripalimab-containing regimen nearly halved overall relapse rates and substantially reduced peritoneal dissemination compared with chemotherapy alone, suggesting improved micrometastatic disease control. The study further strengthens growing evidence supporting oxaliplatin-based chemotherapy backbones as favorable partners for perioperative immunotherapy in gastric cancer. Unlike the negative survival findings observed with perioperative pembrolizumab in KEYNOTE-585, the NEOSUMMIT-01 results align more closely with the positive MATTERHORN trial, collectively supporting integration of immunotherapy into curative-intent treatment paradigms. Although limited by its phase II design and predominantly Asian study population, the trial provides compelling evidence that perioperative toripalimab combined with SOX or CapOx chemotherapy may represent a promising new treatment strategy for resectable locally advanced gastric and GEJ cancers.
