BeOne Medicines reports ‘positive’ results from Phase 3 HERIZON-GEA-01 trial

BeOne Medicines (ONC) announced positive top-line results from the Phase 3 HERIZON-GEA-01 trial evaluating ZIIHERA, a HER2-targeted bispecific antibody, in combination with chemotherapy, with or without PD-1 inhibitor TEVIMBRA, as first-line treatment for HER2-positive locally advanced or metastatic gastroesophageal adenocarcinoma, including cancers of the stomach, gastroesophageal junction, and esophagus. Both ZIIHERA plus TEVIMBRA and chemotherapy and ZIIHERA plus chemotherapy demonstrated clinically meaningful and highly statistically significant improvements in progression-free survival compared to the control arm, trastuzumab plus chemotherapy. ZIIHERA plus TEVIMBRA and chemotherapy also demonstrated clinically meaningful and statistically significant improvements in overall survival, and ZIIHERA plus chemotherapy demonstrated a clinically meaningful effect with a strong trend toward statistical significance for OS compared to the control arm at the time of this first analysis. The trial is ongoing with an additional planned OS interim analysis for ZIIHERA plus chemotherapy currently expected in mid-2026. These PFS and OS benefits were observed in the ZIIHERA plus TEVIMBRA and chemotherapy arm versus the control arm in both PD-L1 positive and PD-L1 negative subgroups. Supportive of the primary efficacy endpoints, both combination arms demonstrated improvements in the key secondary endpoints of objective response rate and duration of response versus the control arm.