Zanidatamab

The PATHWAY HER2 (4B5) test and VENTANA HER2 Dual ISH DNA Probe Cocktail help identify HER2-positive metastatic gastric, gastroesophageal junction and esophageal adenocarcinoma. Differential diagnosis of these cancers, often aggressive and diagnosed at an advanced stage, is critical to improving patient outcomes. Together, the tests enable precise assessment of HER2-positive status to help identify patients eligible for treatment with ZIIHERA. TUCSON, Ariz., Aug. 26, 2026 /PRNewswire/ -- Roche (SIX: RO, ROG; OTCQX: RHHBY) announced today that it has received FDA approval for expanded use of its PATHWAY® HER2 (4B5) and VENTANA® HER2 Dual ISH DNA Probe Cocktail tests. These companion diagnostics are now approved to assess HER2-positive status in metastatic gastroesophageal adenocarcinoma (GEA) patients, including those with gastric, gastroesophageal junction, and esophageal adenocarcinoma. The approval enables clinicians to identify HER2-positive GEA patients who may be eligible for HER2-targeted treatment with Jazz Pharmaceuticals' ZIIHERA® (zanidatamab-hrii). Two ZIIHERA-containing regimens are now FDA approved for the first-line treatment of adults with unresectable locally advanced or metastatic HER2-positive GEA. Gastroesophageal adenocarcinoma encompasses a group of related cancers originating in the gastrointestinal tract, including gastric and esophageal cancer. These closely-related, aggressive cancers are typically diagnosed late1,2 and are the fifth (gastric) and sixth (esophageal) leading causes of cancer deaths worldwide.3 Despite advances in diagnosis and treatment, the prognosis for these cancers remains poor, with limited therapeutic options available.4,5 "GEA can be a difficult diagnosis for patients to face, with most cases only being detected once the disease has progressed to an advanced stage," said Laura Apitz, Head of Pathology Lab at Roche Diagnostics. "By adding GEA to the approved indications for our widely-available HER2 assay, we expand the patient population eligible for targeted therapy and potentially improve patient outcomes." This FDA approval broadens the population of patients eligible for HER2-targeted therapies to include those with HER2-positive GEA.6 Until now, no tests had been approved to determine HER2 status in esophageal cancer, meaning patients were unable to access targeted therapy. Already widely used and trusted in breast and gastric cancers, these tests are an important step forward in providing access to new treatment options for this hard-to-treat disease. About the PATHWAY HER2 (4B5) test and VENTANA HER2 Dual ISH DNA Probe Cocktail The PATHWAY® HER2 (4B5) Rabbit Monoclonal Primary Antibody test and VENTANA® HER2 Dual ISH DNA Probe Cocktail work together to assess HER2 status, delivering diagnostic precision and enabling timely therapeutic decisions for patients with HER2-positive cancers. Together, these tests provide labs and pathologists with reliable, actionable insights to support personalised treatment approaches. The PATHWAY HER2 (4B5) test is the most widely adopted HER2-immunohistochemistry (IHC) primary antibody globally,7 achieving consistently high proficiency assessment scores,7 and demonstrating high concordance with HER2 FISH testing.8,9 Its design ensures accuracy and reproducibility, with integration into the fully automated VENTANA BenchMark slide staining platform to minimise variability and reduce manual steps across all IHC processes. The VENTANA HER2 Dual ISH DNA Probe Cocktail enables the advanced detection of HER2 gene amplification. With its dual-colour technology, pathologists can easily compare HER2 status with H&E and other GI panel markers within the same case,10 ensuring consistent and confident diagnoses. The test also maintains high concordance with HER2 FISH testing,11 making it a reliable component of HER2 diagnostic workflows. Together, the tests strengthen Roche's comprehensive HER2 diagnostic portfolio. By delivering reliable and actionable results, they support diagnostic precision across multiple cancer types, expanding access to personalised treatment options and improving outcomes for patients facing HER2-positive cancers. For more information about the portfolio, please visit the Roche Diagnostics Pathology Lab companion diagnostics page. About Roche Roche (SIX: RO, ROP; OTCQX: RHHBY) is a healthcare company uniquely placed to prevent, stop and cure diseases by uniting leading science and technology across diagnostics, medicines and digital solutions. Roche was founded in Basel, Switzerland in 1896 and today is a leading provider of transformative medicines and diagnostics for millions of people in over 150 countries around the world. It is dedicated to tackling healthcare challenges that place the greatest strain on patients, families, communities and healthcare systems. Across its Diagnostics and Pharmaceutical divisions, Roche focuses on areas including oncology, neurology, cardiovascular and metabolic diseases, ophthalmology, infectious diseases and immunology with the aim of providing real and positive change for patients, the people they love and the professionals who care for them. Genentech in the United States is a fully owned subsidiary in the Roche Group. Roche is the majority shareholder in Chugai Pharmaceutical, a major innovator in the Japanese therapeutic antibody market. For more information, please visit . All trademarks used or mentioned in this release are protected by law. References [1] Casamayor, Morlock, et al (2018) ecancer 12:883. [2] Joseph, A. et al. Esophageal adenocarcinoma: A dire need for early detection and treatment. Cleveland Clinic Journal of Medicine May 2022, 89 (5) 269-279; DOI: [3] Ferlay J, Ervik M, Lam F, Laversanne M, Colombet M, Mery L, Piñeros M, Znaor A, Soerjomataram I, Bray F (2024). Global Cancer Observatory: Cancer Today. [4] Mamun, TI, Younus, S, Rahman, Md.H (2024). Gastric cancer—Epidemiology, modifiable and non-modifiable risk factors, challenges and opportunities: An updated review. Cancer Treatment and Research Communications 41 (2024) 100845. [5] Akumaga, T. et al. 2025. Targeting Esophageal Cancer: Promising Drugs for the Clinical Landscape and Key Knowledge Gaps. Drug Design, Development and Therapy 2025:19 12049–12076. [6] Roche. PATHWAY anti-HER2/neu (4B5) Rabbit Monoclonal Primary Antibody, Package Insert Rev Q. 2026. 2Roche. VENTANA HER2 Dual ISH DNA Probe Cocktail (US), PMA Package Insert. Rev E. 2026. [7] NordiQC Assessments. . Accessed September 19, 2024. [8] Mayr D, et al. Comprehensive immunohistochemical analysis of Her-2/neu oncoprotein overexpression in breast cancer: HercepTest™ (Dako) for manual testing and Her-2/neu Test 4B5 (VENTANA) for VENTANA BenchMark automatic staining system with correlation to results of BenchMark automatic staining system with correlation to results of fluorescence in situ hybridisation (FISH). Virchows Archiv. 2009; 454(3):241–248. [9] Brügmann A, Lelkaitis G, Nielsen S, et al. Testing HER2 in breast cancer: a comparative study on BRISH, FISH, and IHC. Appl Immunohistochem Mol Morphol. 2011;19(3):203-211. [10] Roche DISH product page. Accessed 23Jan26. [11] Rathi, A. et al. 2024. Validation of Dual-Color Dual In Situ Hybridization for HER2/neu Gene in Breast Cancer. Arch Pathol Lab Med—Vol 148. Roche Media Relations Yvette Petillon Mobile: +41 79 961 92 50 Email: [email protected] Roche Diagnostics Communications Jo Lynn Garing Phone: +1 317-363-7286 Email: [email protected] Kathryn Ager Mobile: +44 7745 115046 Email: [email protected] SOURCE Roche 21% more press release views with Request a Demo

iStock, Nuthawut Somsuk Gastroesophageal adenocarcinoma presents the biggest market opportunity for Jazz Pharmaceuticals’ Ziihera, according to Truist Securities, which forecasts peak sales of the drug to reach $2.5 billion. The FDA has given its blessing to Jazz Pharmaceuticals’ bispecific antibody Ziihera, allowing its use in newly diagnosed patients with gastroesophageal adenocarcinoma. In particular, Ziihera is now indicated as a first-line treatment for patients with unresectable locally advanced or metastatic gastroesophageal adenocarcinoma (GEA) who harbor HER2 mutations, according to a Tuesday release . Ziihera is meant to be used with or without BeOne Medicines’ Tevimbra on top of chemotherapy. Analysts at Truist Securities were unsurprised by the approval, calling the decision “anticipated” in a Tuesday note to investors. Still, the firm is encouraged by the verdict, saying that it “de-risks the largest piece of our Ziihera build for JAZZ.” Ziihera was first approved in November 2024 for biliary tract cancer under the FDA’s accelerated pathway, but the GEA market represents around 90% of Truist’s peak $2.5 billion sales projection. “GEA is where the bulk of the franchise opportunity sits,” the analysts wrote said, adding that the company’s “setup for launch is favorable.” Following Ziihera’s approval in what is likely its largest indication, investor focus has now shifted to the drug’s launch, which Truist anticipates to be “smooth sailing,” according to a follow-up note on Monday afternoon. “From our investor conversations and checks, Ziihera stands as the 1L preferred option in GEA off the approval.” The firm nevertheless cautions that there “could be looming future threats,” pointing to regimens using AstraZeneca and Daiichi Sankyo’s Enhertu . The antibody-drug conjugate is currently indicated for the second-line treatment of HER2+ locally advanced or metastatic gastric cancer, and the companies are working to push the asset into the first-line setting. Stomach cancer Jazz’s Ziihera Shows ‘Practice-Changing’ Efficacy in Stomach Cancer Jazz’s Ziihera and BeOne’s Tevimbra plus chemotherapy led to what Truist Securities dubbed one of the strongest overall survival signals ever reported in a type of gastroesophageal cancer. January 7, 2026 · 2 min read · Tristan Manalac Read more For Ziihera, data from the Phase 3 HERIZON-GEA-01 trial supported the FDA’s approval on Tuesday. Results released in January showed a 35% reduction in the risk of disease progression or death in patients given Ziihera plus chemotherapy, as compared with the active control of trastuzumab plus chemotherapy. Adding Tevimbra to the Ziihera regimen slightly improved the treatment benefit to 37%. Truist at the time called these findings “practice-changing.” Jazz picked up rights to Ziihera from Canadian biotech Zymeworks before the drug secured U.S. approval. Jazz paid $50 million upfront, with different potential milestone fees down the line that could reach a deal total up to $1.76 billion. Under the terms of the deal, Jazz gained global rights to the drug across all indications, excluding certain Asia/Pacific areas previously licensed by Zymeworks.