Perioperative Fruquintinib Combined With Sintilimab and SOX for Locally Advanced Gastric or GEJ Adenocarcinoma

The purpose of this clinical trial is to evaluate whether perioperative fruquintinib combined with sintilimab and SOX is effective in treating locally advanced gastric or gastroesophageal junction (GEJ) adenocarcinoma. The study will also assess the safety profile of this treatment regimen. Primary Objective: To determine whether perioperative fruquintinib combined with sintilimab and SOX improves the pathological complete response (pCR) rate compared with sintilimab plus SOX in patients with locally advanced gastric or GEJ adenocarcinoma. Study Design: Participants will be randomly assigned to receive either fruquintinib combined with sintilimab and SOX or sintilimab plus SOX to evaluate the potential added benefit of fruquintinib in this setting. Participation Details: Participants will receive the assigned treatment (fruquintinib combined with sintilimab and SOX or sintilimab plus SOX) every 21 days for approximately 3 months. They will visit the clinic once every 3 weeks for evaluations, laboratory tests, and monitoring. Participants will be asked to keep a daily diary to record any symptoms or side effects experienced during the study.