Advanced Gastric or Gastroesophageal Junction Adenocarcinoma

This is a multicenter, randomized, controlled, open-label, Phase III study, designed to evaluate the efficacy and safety of JS107 versus investigator-selected therapy in the second-line or later treatment of patients with advanced gastric or gastroesophageal junction adenocarcinoma positive for CLDN18.2. The study population consists of patients with CLDN18.2-positive, HER2-negative, locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma who have received at least one prior line of systemic therapy. The primary endpoints of the study are BICR-assessed progression-free survival and overall survival. Number of subjects and allocation:This study plans to enroll approximately 560 subjects, who will be randomized in a 1:1 ratio to receive either JS107 (experimental group) or investigator-selected therapy (control group).