Now FDA approved as a companion diagnostic for the breakthrough designated therapy ENHERTU®* (fam-trastuzumab deruxtecan-nxki), PATHWAY anti-HER2/neu (4B5) Rabbit Monoclonal Antibody is the FIRST and ONLY test to identify metastatic breast cancer (mBC) patients with low expression of HER2 who may be eligible for targeted therapy.
PATHWAY anti-HER2/neu (4B5) Rabbit Monoclonal Primary Antibody Identifying HER2-low expression


*For more information on ENHURTU® please refer to the FDA-approved product labeling
Complete the form to receive the PATHWAY anti-HER2/neu (4B5) Rabbit Monoclonal Primary Antibody Interpretation Guide and the new Package Insert.
FDA approved PATHWAY anti-HER2/neu (4B5) Rabbit Monoclonal Antibody to identify metastatic breast cancer patients with low HER2 expression for whom ENHERTU may be considered
- The Roche PATHWAY HER2 (4B5) assay1 has shown the most consistent performance and superior quality when compared to other on-market HER2 clones.2
- The new HER2-low indication uses the proven technology of the PATHWAY anti-HER2/neu (4B5) Rabbit Monoclonal Primary Antibody. The FDA approved HER2-low indication uses a lower scoring cut-off, allowing patient stratification within a new subtype of breast cancer that has some HER2 proteins on the cell surface, but not enough to be classified as HER2-positive.12
- Indicated as an aid in the assessment of patients with HER2-low status for whom ENHERTU is being considered as a treatment option.
1. Tarantino, P. et al. (2020). Journal of Clinical Oncology, 8(17):1951-1962. All Accessed 7/15/2022
2. Based on data from a leading external quality assessment scheme. Retrieved from http://www.nordiqc.org/epitope.php
PATHWAY anti-HER2/neu (4B5) is a registered trademark of Roche Diagnostics
Confidently Navigate the Complexities of HER2 IHC Testing in Breast Cancer
View this webinar to learn more about scoring and clinical significance of the newest companion diagnostic indication of PATHWAY anti-HER2 (4B5) for HER2-low.
Indication for use: Breast cancer
View Full TableIndication for use: Breast cancer
Staining Pattern | Score | Recommended Reporting Status | Clinical Application |
---|---|---|---|
No membrane staining is observed OR Faint, partial staining of the membrane in 10% or LESS of the cancer cells* |
0 | HER2 Negative | None |
Faint, partial staining of the membrane in greater than 10% of the cancer cells* | 1+ | HER2-low expression | ENHERTU® (fam-trastuzumab deruxtecan-nxki) |
Weak to moderate complete staining of the membrane in greater than 10% of the cancer cells Positve Weak to moderate complete staining of the membrane in greater than 10% of the cancer cells Positve | 2+* Reflex test: HER2 Non-Amplified |
HER2-low expression | |
2+* Reflex test: HER2 Amplified |
HER2 Positive/overexpression | Herceptin® (trastuzumab), KADCYLA® (trastuzumab emtansine) |
|
Intense complete staining of the membrane in greater than 10% of the cancer cells | 3+ | HER2 Positive/overexpression |
**Recommend reflex test to assess gene amplification per ASCO/CAP guidance
References
- Wolff, A., Hammond, E., Allison, K., Harvey, B. et al. . Human Epidermal Growth Factor Receptor 2 Testing in Breast Cancer: American Society of Clinical Oncology/ College of American Pathologists Clinical Practice Guideline Focused Update. J Clin Onco 36, 2105-2122, doi:10.1200/JCO10.1200/JCO.2018 (2018).
- Tarantino, P. et al. HER2-Low Breast Cancer: Pathological and Clinical Landscape. J Clin Oncol 38, 1951-1962, doi:10.1200/JCO.19.02488 (2020).
- Zhang, H., Katerji, H., Turner, B. M. & Hicks, D. G. HER2-Low Breast Cancers. Am J Clin Pathol 157, 328-336, doi:10.1093/ajcp/aqab117 (2022).
- Modi, S. et al. Trastuzumab Deruxtecan in Previously Treated HER2-Low Advanced Breast Cancer. N Engl J Med 387, 9-20, doi:10.1056/NEJMoa2203690 (2022).
- Scott, M., Vandenberghe, M. E., Scorer, P., Boothman, A.-M. & Barker, C. Prevalence of HER2-low in breast cancer subtypes using the VENTANA anti-HER2/neu (4B5) assay. Journal of Clinical Oncology 39, 1021-1021, doi:10.1200/JCO.2021.39.15_suppl.1021 (2021).
- Wolff, A. C. et al. Recommendations for Human Epidermal Growth Factor Receptor 2 Testing in Breast Cancer: American Society of Clinical Oncology/College of American Pathologists Clinical Practice Guideline Update. Journal of Clinical Oncology 31, 3997-4013, doi:10.1200/jco.2013.50.9984 (2013).
- Wolff, A. C. et al. American Society of Clinical Oncology/College of American Pathologists Guideline Recommendations for Human Epidermal Growth Factor Receptor 2 Testing in Breast Cancer. Journal of Clinical Oncology 25, 118-145, doi:10.1200/jco.2006.09.2775 (2007).
- Arnould, L. et al. Pathologic complete response to trastuzumab-based neoadjuvant therapy is related to the level of HER-2 amplification. Clin Cancer Res 13, 6404-6409, doi:10.1158/1078-0432.CCR-06-3022 (2007).
- Ormerod, M. G. & Imrie, S. F. Enzyme-antienzyme method for immunohistochemistry. Methods Mol Biol 10, 117-124, doi:10.1385/0-89603-204-3:117 (1992).
- Van Eycke, Y. R., Allard, J., Salmon, I., Debeir, O. & Decaestecker, C. Image processing in digital pathology: an opportunity to solve inter-batch variability of immunohistochemical staining. Sci Rep 7, 42964, doi:10.1038/srep42964 (2017).
- PATHWAY HER2/neu Rabbit Monoclonal Primary Antibody Method Sheet 14427US Rev H 22-04-29
- https://www.fda.gov/news-events/press-announcements/fda-approves-first-targeted-therapy-her2-low-breast-cancer : Accessed October 2, 2022.