A Phase II, Multicenter, Randomized, Controlled Clinical Study Comparing the Efficacy and Safety of Sintilimab Plus SOX Versus SOX Alone as Adjuvant Therapy for PD-L1-Positive, Stage pN3 Gastric Cancer

This study intends to enroll gastric cancer patients who are PD-L1 positive and pathologically confirmed as Stage N3. Enrolled patients will be randomly assigned to receive either standard adjuvant SOX regimen or SOX regimen combined with sintilimab. The objective of the study is to determine whether adding a PD-1 inhibitor to postoperative chemotherapy can improve the Disease-Free Survival (DFS) rate in patients with Stage N3 gastric cancer.