Five reasons why our HER2 (4B5) assay continues to be the trusted diagnostic assay of choice

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Roche’s portfolio of immunohistochemistry (IHC) and in situ hybridization (ISH) breast cancer diagnostic assays provide high sensitivity, specificity and consistency. We continue to innovate to broaden clinical utility of these assays to include new indications – and support clinicians in making decisions that lead to better care for more patients.

Here are five reasons why the Roche HER2 (4B5) assayremains the trusted IHC predictive assay of choice for laboratories and clinicians alike.

1. Globally proven to deliver optimal performance
  • HER2 (4B5) antibody2 has shown the most consistent performance when compared to other on-market HER2 clones3
  • Achieve consistently high proficiency assessment scores with HER2 (4B5) antibody, compared to other clones3
Area of Focus
Area of Focus
2. Widely available
  • Registered and commercialized in more than 100 countries
  • The Roche HER2 (4B5) assay runs on Benchmark IHC/ISH instruments, one of the largest installed bases of IHC/ISH staining platforms globally
  • Partnership with Roche connects you with an established global network with expert local support capabilities
3. Broad and expanding line of therapeutic indications
  • US FDA approved as a screening assay for breast cancer patients who may be eligible for (trastuzumab), (ado-trastuzumab emtansine) and now (trastuzumab deruxtecan)4
  • CE IVD approved as a screening assay for breast cancer patients who may be eligible for (trastuzumab),  (ado-trastuzumab emtansine), (pertuzumab) and now (trastuzumab deruxtecan)5
  • Approved in ex-US markets as a screening assay for gastric cancer patients who may be eligible for (trastuzumab)4
  • Ongoing collaboration to expand the Roche HER2 (4B5) assay to aid in identifying patients with other cancer types who may be eligible for targeted therapy
Comprehensive scoring algorithms for PD-L1 testing animation
The VENTANA PD-L1 (SP263) Assay is digital algorithm assisted
4. Digital algorithm assisted
  • The uPath HER2 (4B5) image analysis breast algorithm is validated for use with the VENTANA® anti-HER2/neu (4B5) Rabbit Monoclonal Primary Antibody and CE marked for use as an aid in the assessment of breast cancer patients for whom (trastuzumab), (ado-trastuzumab emtansine) or (pertuzumab) treatments are being considered
  • Pathologist trained artificial intelligence algorithm allows for quick analysis and provides objective and reproducible results to support confident decision-making
  • Whole slide analysis (WSA) with automated pre-computing of the entired slide image prior to pathologist assessment provides fast results for user-defined regions of interest (ROI)
5. Fully automated on BenchMark IHC/ISH platforms
  • Automated workflow requires minimal hands-on time for high-quality staining
  • Automation increases efficiency and productivity, allowing laboratory staff to focus on other value-added tasks
  • Ready-to-use, ensuring accurate, repeatable results with no calculations, dilutions, or pipetting4
  • Fewer touch-points reduce the potential for human error while increasing safety, due to limited exposure to chemicals4
Area of Focus

Talk to your Roche representative for more information.


  1. Refers to the PATHWAY anti-HER2/neu (4B5) Rabbit Monoclonal Primary Antibody and VENTANA anti-HER2/neu (4B5) Rabbit Monoclonal Primary Antibody products.
  2. The widely adopted HER2 IHC primary antibody.
  3. NordiQC Assessments.; Accessed 11/13/23.
  4. PATHWAY/VENTANA anti-HER2/neu (4B5) Rabbit Monoclonal Primary Antibody Package Insert, 2022/2019.
  5. VENTANA HER2 (4B5) Rabbit Monoclonal Primary Antibody RxDx Package Insert, 2023.