Oct. 5, 2022—Roche announced that the FDA has approved the Pathway anti-HER2/neu (4B5) Rabbit Monoclonal Primary Antibody to identify patients with HER2-low metastatic breast cancer for whom Enhertu (fam-trastuzumab deruxtecan-nxki) may be considered as a targeted treatment. Enhertu is a specifically engineered HER2-directed antibody drug conjugate developed and commercialized by AstraZeneca and Daiichi Sankyo.
The Pathway anti-HER2 (4B5) test includes a scoring algorithm that helps pathologists identify low expressors of HER2, the company says, 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 test was used as part of the DESTINY-Breast04 trial sponsored by AstraZeneca and Daiichi Sankyo to identify patients whose tumors expressed low levels of HER2 protein. The trial reported a 50 percent 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 tumors had low levels of HER2 expression.