Roche secures FDA approval for HER2-ultralow metastatic breast cancer diagnostic

Roche has received FDA approval for an expanded use of its PATHWAY HER2 (4B5) test, marking a significant breakthrough in breast cancer diagnostics. This development makes it the first companion diagnostic tool capable of identifying patients with HER2-ultralow metastatic breast cancer, a newly defined category within HER2-negative breast cancer. With this approval, patients with hormone receptor (HR)-positive, HER2-ultralow metastatic breast cancer may now be eligible for targeted treatment with ENHERTU, a HER2-directed antibody-drug conjugate (ADC) developed by Daiichi Sankyo and AstraZeneca.

The HER2-ultralow classification represents a crucial evolution in breast cancer diagnosis, building upon the previous HER2-low designation introduced in 2022. Historically, breast cancer patients were classified as either HER2-positive or HER2-negative, limiting access to HER2-targeted therapies. However, research, including findings from the DESTINY-Breast06 trial, has demonstrated that approximately 20-25% of HR-positive, HER2-negative breast cancer patients exhibit HER2-ultralow expression. The approval of Roche’s diagnostic test addresses this gap, ensuring that a previously ineligible patient population can now be considered for advanced treatment.

Why is the HER2-ultralow category a game-changer in breast cancer treatment?

The introduction of HER2-ultralow status is poised to redefine breast cancer treatment strategies. HER2, a receptor protein responsible for cancer cell growth, has traditionally been a key biomarker in determining patient eligibility for HER2-targeted therapies. Patients with HER2-ultralow metastatic breast cancer express even lower levels of HER2 than those in the HER2-low category, yet new clinical data suggests they may still respond to targeted therapy.

The DESTINY-Breast06 trial played a pivotal role in validating the significance of this classification. In the study, patients with HER2-low and HER2-ultralow metastatic breast cancer who received ENHERTU experienced a median progression-free survival of 13.2 months, compared to 8.1 months for those undergoing standard chemotherapy. The findings indicate that HER2-ultralow patients could benefit from HER2-directed therapies, offering new hope for those with limited treatment options.

How does the Roche HER2 test enhance diagnostic precision?

The Roche HER2 test, officially known as the PATHWAY anti-HER2/neu (4B5) Rabbit Monoclonal Primary Antibody, is a pre-diluted immunohistochemistry (IHC) assay designed to standardize HER2 testing and minimize human error. The test is performed using Roche’s fully automated BenchMark IHC/ISH slide staining instrument, ensuring accuracy and reproducibility by eliminating variability in manual and semi-automated testing methods.

One of the key advantages of the Roche HER2 test is its high concordance with HER2 fluorescence in situ hybridization (FISH) assays, a widely accepted gold standard for HER2 evaluation. The PATHWAY HER2 (4B5) clone has consistently achieved high proficiency assessment scores, reinforcing its reliability as a companion diagnostic tool. By integrating this advanced testing method, clinicians can confidently differentiate HER2-ultralow patients from HER2-negative cases, allowing for more personalized treatment strategies.

What does FDA approval mean for breast cancer patients and clinicians?

The FDA approval of Roche’s HER2-ultralow diagnostic test expands the reach of targeted breast cancer treatments, giving patients previously considered HER2-negative access to potentially life-extending therapies. The ability to accurately classify patients as HER2-ultralow not only broadens treatment options but also ensures more precise disease management, reducing the risk of undertreatment or overtreatment.

According to Matt Sause, CEO of Roche Diagnostics, this approval is a milestone in precision medicine, reflecting the urgent need for enhanced breast cancer diagnostics. With one in eight women in the United States facing an invasive breast cancer diagnosis, and a rising incidence of metastatic cases, the demand for innovative testing solutions is higher than ever.

For oncologists and pathologists, the FDA approval Roche HER2 test simplifies the process of identifying HER2-ultralow metastatic breast cancer, allowing for quicker, more accurate clinical decisions. The expanded label approval reinforces Roche’s position as a leader in breast cancer diagnostics, while also setting the stage for future advancements in HER2-targeted treatments.

What’s next for HER2 diagnostics and breast cancer treatment?

As the landscape of HER2 diagnostics continues to evolve, the focus will likely shift toward further refining HER2 classifications and identifying additional biomarkers that influence treatment response. Ongoing research aims to determine whether patients with even lower HER2 expression levels could benefit from antibody-drug conjugates like ENHERTU or other emerging therapies.

Roche’s FDA approval HER2-ultralow test represents just the beginning of a new era in breast cancer treatment, where precision diagnostics enable highly personalized care. By ensuring that every patient receives the most appropriate therapy for their specific HER2 status, the future of breast cancer treatment looks increasingly promising, with higher survival rates and improved quality of life on the horizon.