FDA approves zanidatamab for HER2-positive gastric cancer treatment

The U.S. Food and Drug Administration (FDA) has approved zanidatamab-hrii (Ziihera) for the first-line treatment of patients with unresectable, locally advanced, or metastatic HER2-positive gastric, gastroesophageal junction, or esophageal adenocarcinoma.

Zanidatamab is a bispecific monoclonal antibody designed to bind to two different extracellular sites on the HER2 receptor. This dual-targeting mechanism promotes receptor internalization and reduces surface expression, leading to the inhibition of cancer cell growth and death. In clinical applications, it can be used in combination with chemotherapy and, for certain patients, with immunotherapy (such as tislelizumab).

The approval is based on results from the Phase III HERIZON-GEA-01 study. The research demonstrated that a combination of zanidatamab, chemotherapy, and immunotherapy significantly improved outcomes compared to the standard trastuzumab and chemotherapy regimen. Key findings included a 28% reduction in the risk of death and a median overall survival of 26.4 months, compared to 19.2 months with the previous standard of care.