On January 17, 2025, the U.S. Food and Drug Administration (FDA) approved Datroway® (datopotamab deruxtecan) for the treatment of certain patients with unresectable or metastatic hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer. HR+/HER2- is the most common subtype and accounts for approximately 70% of breast cancer cases. Datroway® is an antibody-drug conjugate (ADC) administered as an intravenous infusion every three weeks that selectively targets and kills tumor cells expressing the cell surface antigen Trop-2 while sparing healthy cells from damage, unlike traditional chemotherapy. Datroway® is the first ADC approved in the U.S.
Approval was based on the results of the TROPION-Breast01 clinical trial. The study enrolled 732 patients considered unsuitable for further endocrine therapy and who had received up to two lines of prior chemotherapy. Results showed that patients treated with Datroway® had a median progression-free survival (PFS) of 6.9 months compared to 4.9 months for those receiving chemotherapy with eribulin, capecitabine, vinorelbine or gemcitabine. Median overall survival was similar between the Datroway® and chemotherapy groups at 18.6 and 18.3 months, respectively. Side effects of the medication include mouth ulceration, nausea, vomiting, fatigue, hair loss, constipation, inflammation of the cornea, dry eye, increased liver enzymes and decreased white blood cell counts, calcium and hemoglobin.