Japan-based Daiichi Sankyo Inc. (TYO: 4568) announced that its market approval filing for Enhertu (T-DXd, trastuzumab deruxtecan), a HER2 antibody drug conjugate (ADC), has been accepted for review by the Center for Drug Evaluation (CDE) in China. The filing seeks approval for the treatment of adult patients with unresectable or metastatic HER2-low expression (IHC 1+ or IHC 2+/ISH-) breast cancer who have previously received at least one systemic treatment or experienced progression during or after adjuvant chemotherapy. Hormone receptor-positive (HR+) patients should have received endocrine therapy in the past or been unsuitable for endocrine therapy.
Drug Overview
Enhertu, co-developed by UK-based AstraZeneca, consists of a HER2 monoclonal antibody attached to a topoisomerase I inhibitor payload, an exatecan derivative, via a stable tetrapeptide-based cleavable linker. The drug was approved for marketing in the US earlier this month for the same indication, making it the world’s first and only HER2 ADC for use in HER2-low breast cancer.
Clinical Trial Results
The filing is based on the key results of the Phase III DESTINY-Breast04 study, which demonstrated that T-DXd significantly reduced the risk of disease progression or death by nearly 50% compared with chemotherapy in all patients with metastatic breast cancer with low HER2 expression (including HR+ and HR- disease patients), regardless of HER2 expression level (IHC1+ and IHC 2+/ISH-). Additionally, the median survival was six months longer in all patients assessed in the DESTINY-Breast04 study compared to prior chemotherapy.-Fineline Info & Tech
