Perioperative Toripalimab Plus Chemotherapy Versus Chemotherapy Alone in Locally Advanced Gastric or Gastroesophageal Junction Cancer: 3-Year Follow-Up of NEOSUMMIT-01 Trial.

Abstract

The NEOSUMMIT-01 trial previously showed that adding the PD-1 antibody toripalimab to perioperative chemotherapy improved the pathologic response in patients with locally advanced gastric or gastroesophageal junction cancer. Here, we present the event-free survival (EFS) and overall survival (OS) after extended follow-up. A total of 108 patients were enrolled (toripalimab plus chemotherapy, n = 54; chemotherapy alone, n = 54). At the data cutoff date (August 29, 2025), the median follow-up was 43.2 months (interquartile range: 36.6-53.7). The 3-year EFS was 74.7% (95% CI, 63.6% to 87.7%) in the toripalimab plus chemotherapy group and 56.2% (95% CI, 43.3% to 73.0%) in the chemotherapy group, with a hazard ratio (HR) of 0.51 (95% CI, 0.27 to 0.98; <i>P</i> = .044). The 3-year OS was 81.3% (95% CI, 71.4% to 92.4%) versus 72.2% (95% CI, 61.2% to 85.2%), respectively, with an HR of 0.45 (95% CI, 0.21 to 0.95; <i>P</i> = .036). The survival benefits were consistent across most predefined subgroups and were maintained in the analysis excluding patients with dMMR. In conclusion, perioperative toripalimab plus chemotherapy significantly improved 3-year EFS and OS compared with chemotherapy alone, suggesting it as a promising treatment option for patients with locally advanced gastric or gastroesophageal junction cancer.