Roche secured expanded FDA authorization for companion diagnostic tests used to identify patients eligible for Jazz Pharmaceuticals’ Ziihera (zon). The additional clearance allows Roche’s PATHWAY HER2 (4B5) and VENTANA HER2 Dual ISH DNA Probe Cocktail tests to be used in metastatic gastroesophageal adenocarcinoma settings, including gastric, gastroesophageal junction, and esophageal cancers. The update builds on prior FDA approvals for Ziihera, including a new U.S. indication for first-line HER2-positive stomach cancer patients. Roche framed the move as addressing a testing gap for esophageal cancer patients, where targeted therapy access depended on HER2 status determination. For clinicians and developers, expanded diagnostic labeling tightens the clinical pathway for selecting patients for a targeted oncology regimen, particularly in aggressive cancers where timely identification is critical.