Positive HERIZON-GEA-01 Phase 3 Results Support Ziihera® (zanidatamab-hrii) as HER2-Targeted Agent-of-Choice and Ziihera Combination Regimens as New Standard of Care in First-Line HER2-Positive Locally Advanced or Metastatic Gastroesophageal Adenocarcinoma
Positive HERIZON-GEA-01 Phase 3 Results Support Ziihera® (zanidatamab-hrii) as HER2-Targeted Agent-of-Choice and Ziihera Combination Regimens as New Standard of Care in First-Line HER2-Positive Locally Advanced or Metastatic Gastroesophageal Adenocarcinoma |
| [17-November-2025] |
Ziihera plus chemotherapy showed a clinically meaningful and statistically significant improvement in PFS versus trastuzumab and chemotherapy, and a clinically meaningful effect with a strong trend toward statistical significance for OS at the first OS interim analysis Ziihera plus the PD-1 inhibitor Tevimbra® (tislelizumab) and chemotherapy demonstrated clinically meaningful and statistically significant improvements in OS and PFS versus trastuzumab and chemotherapy Company plans to submit a supplemental BLA for this indication in first half of 2026 For U.S. media and investors only DUBLIN, Nov. 17, 2025 /PRNewswire/ -- Jazz Pharmaceuticals plc (Nasdaq: JAZZ) today announced positive top-line results from the Phase 3 HERIZON-GEA-01 trial evaluating Ziihera® (zanidatamab-hrii) in combination with chemotherapy, with or without the PD-1 inhibitor Tevimbra® (tislelizumab), as first-line treatment for HER2-positive (HER2+) locally advanced or metastatic gastroesophageal adenocarcinoma (GEA), including cancers of the stomach, gastroesophageal junction and esophagus.
"Advanced GEA represents one of the most common tumor types worldwide and remains an aggressive cancer with a poor prognosis," said Dr. Kohei Shitara, director of the Department of Gastrointestinal Oncology, and principal trial investigator at the National Cancer Center Hospital East, Kashiwa, Japan. "Based on the positive results seen in the HERIZON-GEA-01 trial, the zanidatamab plus chemotherapy combination, with and without tislelizumab, has the potential to become the new standard of care for patients in HER2+ first-line locally advanced unresectable or metastatic GEA. This is the first Phase 3 trial to demonstrate a benefit for a novel HER2-targeted therapy compared to trastuzumab as part of a combination regimen in HER2+ first-line GEA." "We believe these results will be practice changing, and highlight the potential impact of Ziihera for patients who are facing a devastating diagnosis and limited options in locally advanced or metastatic GEA," said Rob Iannone, M.D., M.S.C.E., executive vice president, global head of research and development, and chief medical officer of Jazz Pharmaceuticals. "We expect Ziihera to become the new standard of care anti-HER2 therapy for patients with HER2+ first-line metastatic GEA regardless of PD-L1 status. We plan to quickly engage FDA and expect to submit a supplemental Biologics License Application (sBLA) in the U.S. in first half of 2026 to support Ziihera as a first-line treatment for patients with HER2+ locally advanced or metastatic GEA for use as part of a standard chemotherapy regimen with and without tislelizumab. We thank the patients and investigators who are involved in this trial." The safety profile of Ziihera in combination with chemotherapy, with or without tislelizumab, was generally consistent with the known safety profile of each agent with no new safety signals observed in the two investigational combination arms and supports the overall benefit risk of Ziihera for use in this indication. Jazz plans to submit these data for presentation at a major medical meeting in the first quarter of 2026 and for publication in a peer-reviewed journal, and will rapidly submit for adoption in the National Comprehensive Cancer Network® Guidelines (NCCN Guidelines®). HERIZON-GEA-01 marks the first Phase 3 trial results for Ziihera. Ongoing research for Ziihera includes the Phase 3 HERIZON-BTC-302 trial evaluating Ziihera and CisGem (cisplatin plus gemcitabine) with or without the addition of a PD-1/L-1 inhibitor versus CisGem with or without a PD-1/L1 inhibitor in adult participants with HER2+ biliary tract cancer; the Phase 3 EmpowHER-303 trial evaluating Ziihera compared to trastuzumab, each in combination with physician's choice of chemotherapy, for the treatment of participants with metastatic HER2+ breast cancer who have progressed on, or are intolerant to, previous T-DXd treatment; the DiscovHER PAN-206 basket trial evaluating Ziihera monotherapy in previously-treated patients with HER2+ (IHC 3+) cancers; and the Phase 2 EmpowHER-208 trial evaluating Ziihera in patients with HER2+ neoadjuvant and adjuvant breast cancer. About the HERIZON-GEA-01 Phase 3 Trial About Gastroesophageal Adenocarcinoma About Ziihera® (zanidatamab-hrii) Zanidatamab is being developed in multiple clinical trials as a targeted treatment option for patients with solid tumors that express HER2. Zanidatamab is being developed by Jazz and BeOne under license agreements from Zymeworks, which first developed the molecule. The FDA granted Breakthrough Therapy designation for zanidatamab's development in patients with previously treated HER2 gene-amplified BTC, and two Fast Track designations for zanidatamab: one as a single agent for refractory BTC and one in combination with standard-of-care chemotherapy for first-line gastroesophageal adenocarcinoma (GEA). Additionally, zanidatamab has received Orphan Drug designations from the FDA for the treatment of BTC and GEA, as well as Orphan Drug designation from the European Medicines Agency for the treatment of BTC and gastric cancer. Important Safety Information for ZIIHERA
WARNINGS AND PRECAUTIONS Embryo-Fetal Toxicity ZIIHERA can cause fetal harm when administered to a pregnant woman. In literature reports, use of a HER2-directed antibody during pregnancy resulted in cases of oligohydramnios and oligohydramnios sequence manifesting as pulmonary hypoplasia, skeletal abnormalities, and neonatal death. Verify the pregnancy status of females of reproductive potential prior to the initiation of ZIIHERA. Advise pregnant women and females of reproductive potential that exposure to ZIIHERA during pregnancy or within 4 months prior to conception can result in fetal harm. Advise females of reproductive potential to use effective contraception during treatment with ZIIHERA and for 4 months following the last dose of ZIIHERA. Left Ventricular Dysfunction ZIIHERA can cause decreases in left ventricular ejection fraction (LVEF). LVEF declined by >10% and decreased to <50% in 4.3% of 233 patients. Left ventricular dysfunction (LVD) leading to permanent discontinuation of ZIIHERA was reported in 0.9% of patients. The median time to first occurrence of LVD was 5.6 months (range: 1.6 to 18.7). LVD resolved in 70% of patients. Assess LVEF prior to initiation of ZIIHERA and at regular intervals during treatment. Withhold dose or permanently discontinue ZIIHERA based on severity of adverse reactions. The safety of ZIIHERA has not been established in patients with a baseline ejection fraction that is below 50%. Infusion-Related Reactions ZIIHERA can cause infusion-related reactions (IRRs). An IRR was reported in 31% of 233 patients treated with ZIIHERA as a single agent in clinical studies, including Grade 3 (0.4%), and Grade 2 (25%). IRRs leading to permanent discontinuation of ZIIHERA were reported in 0.4% of patients. IRRs occurred on the first day of dosing in 28% of patients; 97% of IRRs resolved within one day. Prior to each dose of ZIIHERA, administer premedications to prevent potential IRRs. Monitor patients for signs and symptoms of IRR during ZIIHERA administration and as clinically indicated after completion of infusion. Have medications and emergency equipment to treat IRRs available for immediate use. If an IRR occurs, slow, or stop the infusion, and administer appropriate medical management. Monitor patients until complete resolution of signs and symptoms before resuming. Permanently discontinue ZIIHERA in patients with recurrent severe or life-threatening IRRs. Diarrhea ZIIHERA can cause severe diarrhea. Diarrhea was reported in 48% of 233 patients treated in clinical studies, including Grade 3 (6%) and Grade 2 (17%). If diarrhea occurs, administer antidiarrheal treatment as clinically indicated. Perform diagnostic tests as clinically indicated to exclude other causes of diarrhea. Withhold or permanently discontinue ZIIHERA based on severity. ADVERSE REACTIONS Serious adverse reactions occurred in 53% of 80 patients with unresectable or metastatic HER2-positive BTC who received ZIIHERA. Serious adverse reactions in >2% of patients included biliary obstruction (15%), biliary tract infection (8%), sepsis (8%), pneumonia (5%), diarrhea (3.8%), gastric obstruction (3.8%), and fatigue (2.5%). A fatal adverse reaction of hepatic failure occurred in one patient who received ZIIHERA. The most common adverse reactions in 80 patients with unresectable or metastatic HER2-positive BTC who received ZIIHERA (≥20%) were diarrhea (50%), infusion-related reaction (35%), abdominal pain (29%), and fatigue (24%). USE IN SPECIFIC POPULATIONS Pediatric Use Safety and efficacy of ZIIHERA have not been established in pediatric patients. Geriatric Use Of the 80 patients who received ZIIHERA for unresectable or metastatic HER2-positive BTC, there were 39 (49%) patients 65 years of age and older. Thirty-seven (46%) were aged 65-74 years old and 2 (3%) were aged 75 years or older. No overall differences in safety or efficacy were observed between these patients and younger adult patients. The full U.S. Prescribing Information for ZIIHERA, including BOXED Warning, is available at: https://pp.jazzpharma.com/pi/ziihera.en.USPI.pdf ® TEVIMBRA (tislelizumab) is a registered trademark of BeOne Medicines. About Jazz Pharmaceuticals Jazz Pharmaceuticals plc Caution Concerning Forward-Looking Statements Contacts: Media Contact: Jazz Investor Contact: 1 Abrahao-Machado I.F., et al. HER2 testing in gastric cancer: An update WorldJGastroenterol. 2016;22(19):4619-4625.
SOURCE Jazz Pharmaceuticals plc | |||
Company Codes: NASDAQ-NMS:JAZZ |
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