Dublin – September 03, 2026 -- Jazz Pharmaceuticals plc (Nasdaq: JAZZ) reported that Ziihera (zanidatamab-hrii) plus chemotherapy achieved a statistically significant and clinically meaningful overall survival benefit over trastuzumab plus chemotherapy in first-line treatment of HER2-positive advanced gastroesophageal adenocarcinoma (GEA), based on a second interim analysis of the Phase 3 HERIZON-GEA-01 trial.