Locally Advanced Unresectable or Metastatic Gastroesophageal Junction (GEJ) Adenocarcinoma Clinical Trials in Beijing, Beijing Municipality

M108 Plus CAPOX Versus Placebo Plus CAPOX as First-line Treatment for Claudin (CLDN) 18.2-Positive, HER2-Negative, PD-L1 CPS<5, Locally Advanced Unresectable or Metastatic Gastric or Gastroesophageal Junction (GEJ) Adenocarcinoma.