Jazz Pharmaceuticals plc has announced that pivotal Phase 3 results from the HERIZON-GEA-01 study evaluating Ziihera® (zanidatamab-hrii) combinations in first-line HER2-positive locally advanced or metastatic gastroesophageal adenocarcinoma will be presented at the 2026 American Society of Clinical Oncology Gastrointestinal Cancers Symposium (ASCO GI), scheduled for January 8-10, 2026, in San Francisco. The late-breaking presentation will highlight data on Ziihera in combination with chemotherapy, with or without the PD-1 inhibitor Tevimbra® (tislelizumab). According to the company, both Ziihera plus chemotherapy and Ziihera plus tislelizumab and chemotherapy demonstrated statistically significant and clinically meaningful improvements in progression-free survival compared to the control arm of trastuzumab plus chemotherapy. The combination with tislelizumab also showed statistically significant improvement in overall survival. The results will be presented during an oral abstract session on January 8, 2026.