Jazz Pharmaceuticals (NASDAQ: JAZZ) is moving closer to a major label expansion after the FDA accepted and granted Priority Review to its supplemental Biologics License Application (sBLA) for Ziihera® (zanidatamab-hrii) combinations in first-line HER2-positive locally advanced or metastatic gastroesophageal adenocarcinoma (GEA). The agency has set a PDUFA target action date of August 25, 2026.
The sBLA draws on data from the pivotal HERIZON-GEA-01 trial, which examined zanidatamab paired with standard-of-care chemotherapy — with or without the PD-1 inhibitor Tevimbra® (tislelizumab) — in patients with advanced or metastatic GEA. Notably, the FDA is reviewing the submission through its Real-Time Oncology Review (RTOR) program, an initiative designed to fast-track access to safe and effective cancer treatments.
“The HERIZON-GEA-01 trial results are practice changing,” said Rob Iannone, M.D., Executive Vice President and Chief Medical Officer at Jazz Pharmaceuticals. He highlighted that adding tislelizumab to zanidatamab plus chemotherapy further boosted clinical benefit — and marked the first immuno-oncology combination to demonstrate efficacy across both PD-L1–positive and PD-L1–negative tumors in this setting. Jazz says it looks forward to working with the FDA to bring zanidatamab to GEA patients quickly.
Underpinning the application is the FDA’s own Breakthrough Therapy designation for zanidatamab in this setting — a designation reserved for therapies showing preliminary evidence of substantial improvement over existing options for serious conditions with high unmet need.
A Large and Underserved Patient Population
The stakes are significant. GEA — encompassing cancers of the stomach, gastroesophageal junction, and esophagus — ranks as the fifth most common cancer worldwide, and roughly 20% of those patients carry HER2-positive disease. Despite those numbers, outcomes remain grim: the five-year survival rate sits below 30% for gastric cancer and around 19% for GEA overall, making new treatment options urgently necessary.
About the Trial
HERIZON-GEA-01 is a global, randomized, open-label Phase 3 trial conducted jointly with BeOne Medicines across approximately 300 sites in more than 30 countries. It enrolled 914 patients and compared three arms: zanidatamab plus chemotherapy and tislelizumab; zanidatamab plus chemotherapy alone; and trastuzumab plus chemotherapy. The trial tracks dual primary endpoints — progression-free survival and overall survival — with results first presented at the 2026 ASCO Gastrointestinal Cancers Symposium in January.
About Ziihera
Ziihera works by binding to two distinct extracellular sites on the HER2 receptor, triggering internalization and reducing HER2 expression on tumor cell surfaces. It also activates multiple immune-mediated mechanisms — including CDC, ADCC, and ADCP — that together inhibit tumor growth and drive cell death. Jazz and BeOne are currently developing zanidatamab across multiple solid tumor types expressing HER2, with the molecule originally developed by Zymeworks.
In the U.S., Ziihera already holds accelerated approval for previously treated, unresectable or metastatic HER2-positive biliary tract cancer. A confirmed approval in GEA would represent a meaningful expansion of the drug’s reach.
The post Jazz Pharmaceuticals Scores FDA Priority Review for Ziihera Combinations in First-Line HER2+ Gastroesophageal Cancer appeared first on PRISM MarketView.
