October 4, 2022 – Roche announced that the FDA approved the PATHWAY anti-HER2/neu (4B5) Rabbit Monoclonal Primary Antibody* to identify metastatic breast cancer patients with low HER2 expression for whom ENHERTU® (fam-trastuzumab deruxtecan-nxki) may be considered as a targeted treatment. ENHERTU is a specifically engineered HER2-directed antibody drug conjugate (ADC) being jointly developed and commercialised by AstraZeneca and Daiichi Sankyo.
HER2 is a receptor protein that helps cancer cells grow quickly. To determine a patient’s HER2 status, pathologists evaluate, or score, the level of HER2 receptor protein expressed in breast cancer tissue samples. If a patient’s tumour expresses high levels of HER2, the patient is identified as HER2-positive and may be considered for HER2-targeted treatment. However, half of all patients with metastatic breast cancer express low levels of HER2 which historically classified them as HER2-negative.
The PATHWAY anti-HER2 (4B5) test now includes a scoring algorithm that helps pathologists to identify “low expressors” of HER2, assigning a HER2 low status to this group of patients. With this lower cutoff, the test is able to identify patients who may benefit from ENHERTU as a treatment option.
The PATHWAY anti-HER2 (4B5) test was used as part of the DESTINY-Breast04 trial sponsored by AstraZeneca and Daiichi Sankyo to identify patients whose tumours expressed low levels of HER2 protein. The trial reported a 50% reduction in the risk of disease recurrence or death and an overall gain of six months over standard of care in patients treated with ENHERTU whose tumours had low levels of HER2 expression.
Breast cancer has surpassed lung cancer as the most commonly diagnosed cancer, with an estimated 2.3 million new cases diagnosed worldwide each year. More than 620,000 people die from breast cancer every year.4,5
The FDA approval of the new HER2 low indication expands on the intended use for Roche’s proven, on-market PATHWAY anti-HER2 (4B5) test, delivering timely, clear and confident results. The launch exemplifies Roche’s commitment to continuing to innovate integrated, high medical value solutions that help to advance personalised healthcare.