FDA Approves Two Ziihera-Containing First-Line Regimens for HER2-Positive Advanced Gastroesophageal Adenocarcinoma – Jazz Pharmaceuticals
Jazz Pharmaceuticals plc announced that the U.S. Food and Drug Administration (FDA) approved two Ziihera (zanidatamab-hrii)-containing regimens for the first-line treatment of adults with unresectable locally advanced or metastatic HER2-positive (HER2+) gastroesophageal adenocarcinoma (GEA): Ziihera plus Tevimbra (tislelizumab-jsgr) and fluoropyrimidine- and platinum-containing chemotherapy (HER2+ IHC 3+ and IHC 2+/ISH+), and Ziihera plus fluoropyrimidine- and platinum-containing chemotherapy (HER2+ IHC 3+).
“This approval is a major step forward for people with HER2+ advanced GEA. Ziihera is now the first and only bispecific HER2-targeted antibody combined with a PD-1 inhibitor and chemotherapy approved for all HER2+ advanced GEA patients, regardless of PD-L1 status, establishing a new standard of care in first-line treatment.” – Rob Iannone, M.D., M.S.C.E., executive vice president, global head of research and development, and chief medical officer of Jazz Pharmaceuticals. “The HERIZON-GEA-01 results include the longest median overall survival reported in a Phase 3 trial in this setting, at 26.4 months. We are grateful to the gastric cancer community, including patients, caregivers, investigators and advocacy organizations, whose partnership made this possible.”
GEA, which includes gastric, gastroesophageal junction and esophageal cancers, is the fifth most common cancer worldwide and remains associated with poor outcomes despite advances in treatment. Approximately 20% of patients have HER2+ disease. In the United States, more than 31,000 new stomach cancer cases are diagnosed each year.
“People with advanced HER2+ GEA deserve treatment options that reflect the unique biology of their disease. Understanding what a HER2+ diagnosis means is an important part of navigating treatment decisions and helping patients and families make informed choices about care. Today’s approval gives people diagnosed with HER2+ GEA a much-needed new treatment option and more choice in how their cancer is treated.” – Martha Raymond, MA, CEO and founder of GI Cancers Alliance.
The approval is based on results from the Phase 3 HERIZON-GEA-01 trial, which were published in the New England Journal of Medicine and first presented at ASCO GI 2026, with PD-L1 subgroup data presented at ASCO 2026. The trial remains ongoing, with additional analyses planned.




