FDA accepts and grants Priority Review to Jazz Pharmaceuticals’ sBLA for zanidatamab in first-line HER2-positive gastroesophageal adenocarcinoma, with a decision expected by August 2026.
Written By: Fariha Sameen, PharmD
Reviewed By: Pharmacally Editorial Team
Jazz Pharmaceuticals announced that the U.S. Food and Drug Administration (FDA) has accepted for filing, with Priority Review, a supplemental Biologics License Application (sBLA) for zanidatamab (Ziihera®) in combination regimens for the first-line treatment of adults with HER2-positive unresectable locally advanced or metastatic gastroesophageal adenocarcinoma (GEA), including gastric and gastroesophageal junction cancers.
The FDA has set a target action date of August 25, 2026.
The submission is supported by data from the Phase 3 HERIZON-GEA-01 trial (NCT05152147), which evaluated zanidatamab in combination with standard chemotherapy, with or without the PD-1 inhibitor tislelizumab.
The application is being reviewed under the FDA’s Real-Time Oncology Review (RTOR) program, designed to streamline the evaluation of oncology therapies and accelerate patient access to effective treatments.
HERIZON-GEA-01 is a global, randomized, open-label Phase 3 study that enrolled 914 patients across approximately 300 sites in more than 30 countries. The trial compared zanidatamab plus chemotherapy with or without tislelizumab against trastuzumab plus chemotherapy in patients with HER2-positive advanced or metastatic GEA, with progression-free survival and overall survival as dual primary endpoints.
Results presented in January 2026 suggest that the zanidatamab-based regimens may improve clinical outcomes in this setting.
According to Rob Iannone, M.D., M.S.C.E Chief Medical Officer, Jazz Pharmaceuticals the findings support zanidatamab as a potential HER2-targeted option in the first-line setting, with additional clinical benefit observed when tislelizumab is added, including activity across both PD-L1–positive and PD-L1–negative tumors.
Zanidatamab has received Breakthrough Therapy designation for this indication, reflecting its potential to offer meaningful improvement over existing therapies, along with Fast Track and Orphan Drug designations across HER2-expressing cancers.
Gastroesophageal adenocarcinoma remains a high-burden disease and the fifth most common cancer globally, with approximately 20% of cases being HER2-positive. Prognosis remains poor, with five-year survival rates below 30% for gastric cancer and around 19% for GEA.
Zanidatamab is a bispecific HER2-targeted antibody designed to bind two extracellular domains of the receptor and induce tumor cell death through multiple immune-mediated mechanisms, and it is currently approved in the United States under accelerated approval for previously treated HER2-positive biliary tract cancer, pending confirmatory data. In late April, NICE approved zanidatamab for use in patients with previously treated biliary tract cancer.”
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