Roche receives FDA approval for the first companion diagnostic to identify patients with HER2-ultralow metastatic breast cancer eligible for ENHERTU

Feb. 3, 2025
The PATHWAY HER2 (4B5) test, the first and only FDA-approved companion diagnostic for assessing HER2-low status since 2022, is now also approved to aid in the assessment of HER2-ultralow status for patients with metastatic breast cancer.

Roche announced that the U.S. Food and Drug Administration (FDA) has approved a label expansion for the PATHWAY anti-HER2/neu (4B5) Rabbit Monoclonal Primary Antibody to identify patients with HR-positive, HER2-ultralow metastatic breast cancer who may be eligible for treatment with ENHERTU.

ENHERTU is a specifically engineered HER2-directed antibody drug conjugate (ADC) discovered by Daiichi Sankyo and being jointly developed and commercialized by Daiichi Sankyo and AstraZeneca.

Until the introduction of HER2-low status in 2022, HER2 status was categorized as either “positive” or “negative” based on the level of HER2 expression. The PATHWAY HER2 (4B5) test has now received approval to identify a new patient population designated as "HER2-ultralow." HER2-ultralow refers to patients who have very low levels of HER2 expression, even lower than the existing HER2-low category.

Roche release