
The FDA has granted approval for Roche’s PATHWAY HER2 (4B5) test to identify HER2-ultralow status in metastatic breast cancer patients, expanding its existing use for detecting HER2-low cases. This approval follows AstraZeneca and Daiichi Sankyo’s recent FDA clearance for Enhertu (trastuzumab deruxtecan) in HER2-ultralow patients, marking a significant advancement in breast cancer treatment. Enhertu is the first HER2-targeting antibody-drug conjugate (ADC) approved for patients with an immunohistochemistry (IHC) score of zero with faint staining in 10% or fewer tumor cells.
The reclassification of HER2 status from a simple HER2-positive or HER2-negative system to include HER2-low and HER2-ultralow categories allows for a more refined approach to treatment. This shift enables more patients to benefit from HER2-targeted therapies, opening up new treatment pathways that were previously unavailable. According to Roche, the evolving interpretation of HER2 status provides a better understanding of breast cancer biology and aids clinicians in making more precise treatment decisions.
Matt Sause, CEO of Roche Diagnostics, highlighted the urgent need for improved diagnostic tools, particularly with the rising incidence of metastatic breast cancer in younger populations. The approval of the HER2-ultralow test offers hope by expanding treatment options for patients who previously had limited alternatives.
Enhertu’s recent FDA approval was based on the DESTINY-Breast06 trial, which demonstrated its effectiveness as a second-line treatment for HER2-low patients following endocrine therapy failure. Originally approved in 2019 for advanced HER2-positive breast cancer, Enhertu has since received multiple label expansions across breast, gastric, and lung cancer, as well as a tumor-agnostic indication for HER2-positive tumors.
With worldwide sales surpassing $2.7 billion in the first nine months of 2024—up from $1.8 billion in the previous year—Enhertu is on track to become a blockbuster drug. AstraZeneca projects that recent approvals from the DESTINY-Breast06 study could make Enhertu a viable option for over 90% of breast cancer patients, reinforcing its potential to reshape the treatment landscape.
Source: pharmaphorum.com/news/boost-enhertus-prospects-fda-clears-roche-diagnostic