A Study on the Efficacy and Safety of Sintilimab Combined With Ramucirumab and Paclitaxel in the Treatment of Gastric Cancer Patients With Short-term Recurrence After Adjuvant Therapy

Inclusion Criteria: * Age ≥18 years at the time of informed consent. * Histologically confirmed gastric or gastroesophageal junction (GEJ)adenocarcinoma. * HER2-negative disease, as determined by standard testing methods. * Prior D2 radical gastrectomy with R0 resection. * Disease recurrence during adjuvant chemotherapy or within 6 months after completion of adjuvant chemotherapy. * At least one measurable lesion according to RECIST version 1.1. * Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2. * Adequate organ and bone marrow function. * Life expectancy of at least 3 months. * Ability to understand and willingness to sign written informed consent. Exclusion Criteria: * Active malignancy within the past 5 years, except for adequately treated in situ carcinoma or other cancers with a negligible risk of recurrence. * Prior participation in another investigational drug study within 4 weeks prior to enrollment. * Symptomatic central nervous system (CNS) metastases. * Active autoimmune disease requiring systemic treatment. * Uncontrolled cardiovascular disease or uncontrolled hypertension. * History of thromboembolic events or clinically significant bleeding disorders within 6 months prior to enrollment. * Active tuberculosis or interstitial lung disease. * Known hypersensitivity to monoclonal antibodies or any excipients of the study drug.