PD1 Combined With Chemotherapy for Adjuvant Treatment of Gastric Cancer

This multicenter, randomized, double-blind phase III study intends to recruit about 878 patients, including PD-L1 positive 660 patients, who have received radical gastrectomy (R0 resection, D2 or more extended lymphadenectomy) with postoperative pathological stage IIB or III (AJCC Cancer Staging Manual, 8th Edition) gastric or EGJ adenocarcinoma to evaluate the efficacy and safety of JS001 combined with postoperative adjuvant chemotherapy versus placebo combined with postoperative adjuvant chemotherapy.

INCLUSION CRITERIA 1. Age 18-75 years. 2. No residual tumor (R0) after D2 or greater lymphadenectomy through laparotomy. 3. According to the definition of the 8th edition of the AJCC Cancer Staging Manual, patients with gastric adenocarcinoma confirmed by histopathology, pathological stage II (T4aN0M0) and stage III, including gastroesophageal junction adenocarcinoma (GEJ) patients. 4. Patients need to provide sufficient formalin-fixed paraffin-embedded (FFPE) neoplasm tissue specimens or sections that are confirmed to be PD-L1 positive (CPS ≥ 1) by lab test at the central laboratory. 5. ECOG performance status 0-1. 6. No metastasis or recurrence as radiologically confirmed. 7. Patients must have adequate organ function as assessed in the laboratory tests. 8. Patients must provide informed consent for this study, and sign the written informed consent form voluntarily before the initiation of the study, and are willing and able to comply with the scheduled visits, treatment plan, laboratory examinations and other study procedures in the study. 9. Female patients of childbearing age must take a serum pregnancy test within 7 days before randomization with negative results, and agree to adopt reliable and effective contraceptive methods during the study. EXCLUSION CRITERIA 1. Previous use of non-surgical therapy (e.g., radiotherapy, chemotherapy, hormone therapy) for gastric adenocarcinoma. 2. Having liver, peritoneal or other distant metastasis. 3. Having malignant tumors other than gastric adenocarcinoma within 5 years before randomization. 4. Pevious treatment targeting PD-1 receptor or its ligand PD-L1 or cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) receptor; 5. Previous history of serious allergy to monoclonal antibody or other biological preparations.