Phase 2 tislelizumab PD-1 inhibitor plus platinum/fluoropyrimidine chemo in PD-L1+ gastroesophageal cancers.

This open-label, single-arm Phase 2 study sponsored by BeOne Medicines evaluates tislelizumab (a PD-1/CD279–blocking monoclonal antibody designed to restore anti-tumor T-cell activity) combined with standard platinum/fluoropyrimidine chemotherapy in first-line, locally advanced unresectable or metastatic disease. Eligible patients are US racial and ethnic minority participants with HER2-negative, PD-L1–positive gastric or gastroesophageal adenocarcinoma (GAC/GEA) or esophageal squamous cell carcinoma (ESCC). For GAC/GEA, investigators pair tislelizumab with one of three common backbones (FOLFOX, CAPOX, or cisplatin + 5-FU); for ESCC, tislelizumab is combined with FOLFOX. The key angle is not a new regimen per se, but characterizing pharmacokinetics, activity, and safety specifically in underrepresented US populations while using widely used chemotherapy partners (oxaliplatin or cisplatin DNA crosslinkers plus fluoropyrimidines that inhibit thymidylate synthase). Today’s care for HER2-negative, PD-L1+ metastatic GAC/GEA or ESCC is PD-1–based immunotherapy plus platinum/fluoropyrimidine chemotherapy up front, with later-line options including additional chemotherapy and (in some settings) antibody–drug conjugates.