This study aims to explore the efficacy and safety of sintilimab combined with SOX versus SOX alone as adjuvant therapy for patients with pIIIC stage or dMMR/MSI-H pIIIA/IIIB stage gastric/gastroesophageal junction adenocarcinoma. A total of 276 subjects are planned to be enrolled in this study. Patients will be randomly assigned in a 1:1 ratio to receive up to 8 cycles of sintilimab combined with SOX or SOX alone as adjuvant therapy.
Signed written informed consent.
Male or female, age ≥18 years.
Histopathologically confirmed adenocarcinoma of the stomach or gastroesophageal junction (GEJ).
Diagnosed with pTNM stage IIIC or pTNM stage IIIA/IIIB.
Cancers involving the EGJ with the tumor center located in the proximal stomach ≤2 cm from the EGJ.
Diagnosis of any other malignant disease other than gastric cancer within 5 years prior to first dose (excluding curatively treated basal cell carcinoma of the skin, squamous cell carcinoma of the skin, and/or curatively resected carcinoma in situ).
Currently participating in interventional clinical study treatment, or has received other investigational drugs or used investigational devices within 4 weeks prior to first dose.
Prior receipt of the following therapies: anti-PD-1, anti-PD-L1, or drugs targeting another stimulatory or co-inhibitory T-cell receptor (including but not limited to CTLA-4, OX-40, CD137, etc.).