- The VENTANA HER2 (4B5) test is now CE-IVDR approved to aid in the assessment of HER2-ultralow status to identify metastatic breast cancer patients who may be eligible for treatment with ENHERTU.
- The VENTANA HER2 (4B5) test is also now approved to help identify patients with previously-treated, unresectable or metastatic HER2-positive biliary tract cancer (BTC) who may be eligible for treatment with ZIIHERA.
- Roche continues to break ground as the leader in breast cancer diagnostics, helping to expand patient access to personalised treatment.
TUCSON, Ariz., Sept. 5, 2025 /PRNewswire/ -- Roche (SIX: RO, ROG; OTCQX: RHHBY) announced today it has received CE IVDR approval for two label expansions for its VENTANA® HER2 (4B5) Rabbit Monoclonal Primary Antibody RxDx* assay. HER2 is a receptor protein expressed in a variety of cancers and serves as a predictive biomarker to help determine if a patient will respond to HER2-targeted therapy.

The VENTANA HER2 (4B5) test is the first and only companion diagnostic approved to identify patients with HR-positive metastatic breast cancer that are HER2-ultralow. These patients may be eligible for treatment with ENHERTU® (trastuzumab deruxtecan), a specifically engineered HER2-directed antibody drug conjugate (ADC) discovered by Daiichi Sankyo and being jointly developed and commercialised by Daiichi Sankyo and AstraZeneca. In addition, this test is now the first and only companion diagnostic to aid in the assessment of HER2-positive status to identify biliary tract cancer patients with an immunohistochemistry score of 3+ who are eligible for treatment with Jazz Pharmaceuticals' ZIIHERA® (zanidatamab-hrii).
"This is about creating new options for patients facing some of the toughest cancers," said Jill German, Head of Pathology Lab at Roche Diagnostics. "Our understanding of HER2 is rapidly evolving, and this expanded approval ensures our diagnostics are leading the way. We're enabling clinicians to unlock personalized, life-altering treatments for patients who urgently need them."
Advancing Science in HER2-ultralow Breast Cancer
In Europe this year, more than 564,000 people will be diagnosed with breast cancer, and more than 145,000 are estimated to die from the disease.1 Metastatic breast cancer incidence is rising in younger populations and is the leading cause of breast cancer related death.2,3
HER2 interpretation in breast cancer continues to evolve beyond the traditional "positive" or "negative" classifications. The test now enables the identification of a new patient population designated as "HER2-ultralow," referring to patients who have very low levels of HER2 expression, even lower than the existing HER2-low category. Approximately 20-25 percent of hormone receptor (HR)-positive, HER2-negative breast cancer patients may be considered HER2-ultralow.4 These patients may now be eligible for ENHERTU.
The VENTANA HER2 (4B5) test was used in the DESTINY-Breast06 trial,5 which demonstrated a significant improvement in progression-free survival with ENHERTU compared to standard of care chemotherapy in patients with HER2-low and HER2-ultralow metastatic breast cancer.6
Addressing Unmet Needs in Biliary Tract Cancer
In Europe, the incidence of biliary tract cancer (BTC) and mortality rates from the disease have been increasing in the past few decades.7 BTC is often diagnosed at an advanced stage, and patients currently have very few treatment options.8 The prognosis for these patients is generally poor.9 The VENTANA HER2 (4B5) test is now approved to identify BTC patients with HER2-positive status who may be eligible for treatment with ZIIHERA.
About VENTANA HER2 (4B5) Rabbit Monoclonal Primary Antibody RxDx
The VENTANA HER2 (4B5) Rabbit Monoclonal Primary Antibody RxDx assay delivers timely, clear and reliable results, driving diagnostic certainty and enabling therapeutic decisions that can lead to better outcomes for patients. Previously indicated as an aid to identify certain breast cancer patients eligible for HER2-targeted treatment with Herceptin®, KADCYLA®, PERJETA®, or ENHERTU,10 and gastric cancer patients eligible for treatment with Herceptin, the test is used in combination with the fully automated VENTANA BenchMark slide staining instrument.
The assay standardizes all immunohistochemistry (IHC) processes from baking through staining, and reduces the possibility of human error.10 It also minimizes inherent variability resulting from individual reagent dilution and other processes found in manual and semi-automated IHC methods. The HER2 (4B5) clone achieves consistently high proficiency assessment scores compared to other clones11 and demonstrates high concordance with HER2 FISH,12,13 empowering laboratories to employ the most widely adopted and reliable HER2 IHC primary antibody.
For more information about the portfolio, please visit the Roche Diagnostics Pathology Lab companion diagnostics page.
About Roche
Founded in 1896 in Basel, Switzerland, as one of the first industrial manufacturers of branded medicines, Roche has grown into the world's largest biotechnology company and the global leader in in-vitro diagnostics. The company pursues scientific excellence to discover and develop medicines and diagnostics for improving and saving the lives of people around the world. We are a pioneer in personalised healthcare and want to further transform how healthcare is delivered to have an even greater impact. To provide the best care for each person we partner with many stakeholders and combine our strengths in Diagnostics and Pharma with data insights from the clinical practice.
For over 125 years, sustainability has been an integral part of Roche's business. As a science-driven company, our greatest contribution to society is developing innovative medicines and diagnostics that help people live healthier lives. Roche is committed to the Science Based Targets initiative and the Sustainable Markets Initiative to achieve net zero by 2045.
Genentech, in the United States, is a wholly owned member of the Roche Group. Roche is the majority shareholder in Chugai Pharmaceutical, Japan.
For more information, please visit www.roche.com.
* Hereafter referred to as VENTANA HER2 (4B5) test
All trademarks used or mentioned in this release are protected by law.
References
[1] International agency for research on cancer [Internet, cited 2025 August 25]
[2] Breast Cancer Resource Foundation [Internet; cited 2024 Oct 8] Available from: https://www.bcrf.org/blog/metastatic-breast -cancer-symptoms-treatment/#:~:text=In%20the%20U.S.%20today%2C%20there,cancer%20diagnoses%20in%20young%20women.
[3] Hendrick RE, Helvie MA, Monticciolo DL. Breast Cancer Mortality Rates Have Stopped Declining in U.S. Women Younger than 40 Years. Radiology. 2021 Apr;299(1):143-149. doi:
[4] Salgado RF, et al. LBA21 - Human epidermal growth factor receptor 2 (HER2)-low and HER2-ultralow status determination in tumors of patients (pts) with hormone receptor-positive (HR+) metastatic breast cancer (mBC) in DESTINY-Breast06 (DB-06). Annals of Oncology. (2024) 35 (suppl_2): 1-72. 10.1016/annonc/annonc1623.
[5] Analytical and clinical validation of PATHWAY HER2 (4B5) Assay for assessment of HER2-low/HER2-ultralow status and eligibility for trastuzumab deruxtecan in DESTINY-Breast06; Supplementary Materials. Shami, R. et al. ESMO Open, Volume 10, Issue 6, 105310
[6] Bardia A, et. al. Trastuzumab Deruxtecan after Endocrine Therapy in Metastatic Breast Cancer, New England Journal of Medicine. 2024; 391:2110-2122
[7] Banales, J.M., Marin, J.J.G., Lamarca, A. et al. Cholangiocarcinoma 2020: the next horizon in mechanisms and management. Nat Rev Gastroenterol Hepatol 17, 557-588 (2020).
[8] Valle JW, Lamarca A, Goyal L, Barriuso J, Zhu AX. New Horizons for Precision Medicine in Biliary Tract Cancers. Cancer Discov. 2017 Sep;7(9):943-962. doi: 10.1158/2159-8290.CD-17-0245. Epub 2017 Aug 17. PMID: 28818953; PMCID: PMC5586506.
[9] Aaron J. Scott et al. Precision Medicine in Biliary Tract Cancer. JCO 40, 2716-2734(2022). DOI:10.1200/JCO.21.02576
[10] VENTANA HER2 (4B5) Rabbit Monoclonal Primary Antibody RxDx Package Insert (1021867EN Rev D), 2025
[11] NordiQC Assessments
[12] Mayr D, et al. Comprehensive immunohistochemical analysis of Her-2/neu oncoprotein overexpression in breast cancer: HercepTest (Dako) for manual testing and Her-2/neuTest 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 hybridization (FISH). Virchows Archiv. 2009; 454(3):241-248.
[13] 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.
Roche Media Relations
Jo Lynn Garing
Phone: +1 317-363-7286
Email: jo_lynn.garing@roche.com
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