HERIZON-GEA-01 Zanidatamab Data in HER2-Positive Gastroesophageal Cancer

This discussion opens with the big-picture themes from the gastrointestinal oncology data presented at the ESMO Congress. New agents such as bispecific antibodies, T-cell engagers and therapies targeting costimulatory molecules drew attention, but chemotherapy and checkpoint inhibitors remained the backbone of care in both the adjuvant and metastatic settings. The conversation then turns to the final analysis of HERIZON-GEA-01. The trial compared zanidatamab plus chemotherapy, with or without tislelizumab, against trastuzumab plus chemotherapy as first-line treatment for HER2-positive gastroesophageal adenocarcinoma. The panel reviews overall survival results that favored both zanidatamab-containing arms, with consistent benefit across subgroups, including patients with PD-L1-negative disease. An exploratory comparison of the triplet and doublet showed a numerical trend without statistical significance. They also consider how the control arm reflected an earlier standard of care and the limits of PD-L1 as a way to select patients. They explain why the unprecedented survival with the triplet regimen supports using it in practice until data suggest otherwise.