Jazz Pharmaceuticals (JAZZ) FDA announcement summary

Introduction and purpose

• FDA approved Ziihera (zanidatamab-hrii) for first-line treatment of adults with unresectable locally advanced or metastatic HER2-positive gastroesophageal adenocarcinoma (GEA), with or without tislelizumab plus chemotherapy, regardless of PD-L1 status.

• The approval is described as a paradigm shift and a pivotal moment for the company’s oncology strategy, establishing a new standard of care for all HER2-positive advanced GEA patients.

Details of approval or decision

• Ziihera is the first and only bispecific HER2-targeted antibody approved with a PD-1 inhibitor and chemotherapy for all HER2-positive advanced GEA patients, regardless of PD-L1 status.

• Two regimens are approved: with tislelizumab and chemotherapy for IHC 2+/ISH+ or IHC 3+ disease, and with chemotherapy alone for IHC 3+ disease.

• Approval is based on Phase 3 HERIZON-GEA-01 trial results, showing significant improvements in progression-free and overall survival.

• Dosing is weight-based, with flexible administration schedules to align with common chemotherapy regimens.

• Ziihera became commercially available in the U.S. on August 25, 2026, with immediate supply to treatment centers.

Impact on industry and stakeholders

• Ziihera is expected to become the new standard of care and the HER2-targeted therapy of choice in first-line HER2-positive GEA, replacing previous regimens.

• The approval supports a peak sales potential of $3 billion-$5 billion, reflecting confidence in broader HER2-expressing tumor indications.

• The commercial launch leverages established reimbursement pathways, infrastructure, and comprehensive support services to ensure rapid adoption and patient access.

• The U.S. market for eligible patients is estimated at 3,000-4,000 annually, with a broader global incidence of 63,000 across the U.S., EU, and Japan.

• Approval may influence HER2 testing practices and treatment selection at diagnosis, setting a precedent for bispecific antibody and immunotherapy combinations in solid tumors.