Jazz Ziihera trial shows survival improvement in cancer

• Jazz Pharmaceuticals reported Phase 3 HERIZON-GEA-01 data showing Ziihera plus chemotherapy improved overall survival compared with trastuzumab plus chemotherapy.
• The trial also showed an improved overall survival hazard ratio for the Ziihera, Tevimbra, and chemotherapy combination after longer follow-up.
• The FDA approved Ziihera-based regimens on August 25, 2026, for first-line HER2-positive gastroesophageal adenocarcinoma.

Jazz Pharmaceuticals (NASDAQ:JAZZ) reported second interim overall survival results from the Phase 3 HERIZON-GEA-01 trial showing Ziihera (zanidatamab-hrii) plus chemotherapy improved overall survival compared with trastuzumab plus chemotherapy in first-line HER2-positive gastroesophageal adenocarcinoma.

The results build on the first interim analysis, with longer follow-up showing an improved overall survival hazard ratio for both Ziihera plus chemotherapy and the Ziihera, Tevimbra, and chemotherapy combination.

The HERIZON-GEA-01 trial evaluated Ziihera-based treatment combinations in patients with HER2-positive locally advanced or metastatic gastroesophageal adenocarcinoma, while safety monitoring included risks such as diarrhea, left ventricular dysfunction, infusion-related reactions, and serious adverse events.

Jazz Pharmaceuticals said the data support its proposed use of the Ziihera and Tevimbra combination as a potential new standard of care in the U.S.

Jazz Pharmaceuticals develops medicines across neuroscience and oncology areas, including therapies targeting cancers and other serious conditions.

The FDA approved Ziihera regimens on August 25, 2026, for first-line treatment of HER2-positive gastroesophageal adenocarcinoma, with Ziihera carrying boxed warnings for severe diarrhea and embryo-fetal toxicity.