Roche has secured a new FDA approval for its first companion diagnostic test aimed at identifying breast cancer patients with so-called “HER2-ultralow” status.
The company’s PATHWAY HER2 antibody test—used to help screen patients for treatment with Enhertu (trastuzumab deruxtecan-nxki), the antibody-drug conjugate jointly developed by Daiichi Sankyo and AstraZeneca—previously received a U.S. green light for patients with HER2-low status.
According to Roche, the diagnostic’s expansion into the ultralow category may allow between 20% to 25% of patients whose breast tumors were previously labeled as HR-positive and HER2-negative to become candidates for the targeted therapy.
“One in eight women in the United States will face invasive breast cancer in their lifetime,” Roche Diagnostics CEO Matt Sause said in a statement. “The rising incidence of metastatic breast cancer, particularly among younger populations, underscores the urgent need for new diagnostic options.”
“The approval of our test for determining HER2-ultralow status offers new hope to patients by providing a possible path to HER2-targeted treatment where none existed before, helping clinicians transform outcomes for many facing this challenging disease,” Sause added.
Before the advent of the HER2-low characterization in 2022, patients received only the binary classification of either positive or negative following a pathologist’s biopsy review.
Enhertu received an FDA nod in HER2-ultralow breast cancer in late January, its seventh agency approval, for treatment following the disease’s progression after endocrine therapy.
Roche’s PATHWAY test was used in Enhertu’s DESTINY-Breast06 clinical trial, which demonstrated a median progression-free survival of 13.2 months with the antibody-drug conjugate compared to 8.1 months in standard-of-care chemotherapy, including patients with low and ultralow HER2 expression.
The PATHWAY anti-HER2/neu (4B5) Rabbit Monoclonal Primary Antibody test is used with Roche’s fully automated BenchMark IHC/ISH slide-staining instrument.