RecruitingPhase 2Drug trialPerioperative Chemotherapy Combined With Serplulimab or Placebo for pMMR Locally Advanced Gastric Adenocarcinoma (FOCUS-05)This phase II study is a prospective, multi-center, double-blinded, and randomized trial to compare the efficacy and safety of perioperative SOX plus serplulimab with SOX plus placebo for locally advanced gastric adenocarcinoma with proficient mismatch repair