This is a multicenter, open-label, single-arm phase II study evaluating the efficacy and safety of mannatide in combination with CAPOX chemotherapy and tislelizumab as first-line treatment for patients with recurrent or metastatic gastric adenocarcinoma or gastroesophageal junction adenocarcinoma.
Eligible patients will receive oxaliplatin, capecitabine, tislelizumab, and oral mannatide. Tumor response will be assessed according to RECIST version 1.1. Patients without disease progression after induction treatment may continue maintenance therapy with capecitabine, tislelizumab, and mannatide.
The primary objective is to evaluate objective response rate (ORR). Secondary objectives include progression-free survival (PFS), overall survival (OS), disease control rate (DCR), duration of response (DoR), and safety. Exploratory analyses will investigate immune microenvironment changes and potential predictive biomarkers using blood, tumor tissue, and stool samples.