Phase 3 Zolbetuximab (CLDN18.2 mAb) trial in advanced gastric/GEJ cancer

This study compares zolbetuximab combined with pembrolizumab and chemotherapy versus placebo in adults with unresectable or metastatic stomach or GEJ adenocarcinoma that are HER2-negative, CLDN18.2-positive, and PD-L1-positive. Zolbetuximab, a CLDN18-directed monoclonal antibody, is administered in 42-day cycles alongside a PD-1 inhibitor and standard chemotherapies under double-blind randomization. Sponsored by Astellas Pharma Global Development, Inc., the trial assesses overall survival as its primary endpoint. Current first-line SoC in HER2-negative, PD-L1-positive disease is PD-1 + chemotherapy; prior CLDN18.2 + chemo data improved outcomes in CLDN18.2-positive tumors, and this adds CLDN18.2 to PD-1 + chemo to test for further OS gains.