Jazz Pharmaceuticals has announced that the U.S. Food and Drug Administration has accepted for filing, with Priority Review, its supplemental Biologics License Application (sBLA) for Ziihera (zanidatamab-hrii) as a first-line treatment for adult patients with HER2-positive unresectable or metastatic gastroesophageal adenocarcinoma (GEA). The FDA has set a target decision date of August 25, 2026.

The application is supported by results from the pivotal Phase III HERIZON-GEA-01 trial, which evaluated zanidatamab in combination with standard chemotherapy, with or without the PD-1 inhibitor Tevimbra. The study demonstrated improved clinical outcomes, with the addition of immunotherapy further enhancing treatment efficacy across both PD-L1–positive and negative tumours.

The submission is being reviewed under the FDA’s Real-Time Oncology Review (RTOR) programme, designed to accelerate the availability of promising cancer therapies. Zanidatamab has also received Breakthrough Therapy designation, reflecting its potential to significantly improve outcomes in a disease with high unmet medical need.

Gastroesophageal adenocarcinoma, which includes cancers of the stomach and esophagus, is among the most common and aggressive cancers globally, with HER2-positive cases accounting for around 20 percent of patients. Survival rates remain low, underscoring the need for more effective first-line treatment options.

Ziihera is a bispecific HER2-targeted antibody that binds to two distinct sites on the HER2 receptor, triggering multiple immune responses that inhibit tumour growth and promote cancer cell death. The therapy is already approved in the US for certain biliary tract cancers and is being studied across a range of HER2-expressing solid tumours.

Jazz Pharmaceuticals stated that it will continue to work closely with regulators to expedite approval and bring the therapy to patients in need, as it advances its oncology pipeline focused on innovative targeted treatments.