The top-line findings from the DESTINY-Breast06 phase 3 trial reveal a significant advancement with ENHERTU® (trastuzumab deruxtecan). Compared to standard chemotherapy, ENHERTU demonstrated both statistically and clinically significant enhancements in progression-free survival (PFS) for patients with HR positive, HER2 low metastatic breast cancer after receiving one or more lines of endocrine therapy.
The analysis also indicated notable PFS improvements across the entire trial population, including patients with both HER2 low and HER2 ultralow metastatic breast cancer. A subgroup analysis further confirmed consistent benefits across these categories.
While overall survival (OS) data were not fully developed during the analysis, early indications suggest a positive trend towards OS improvement with ENHERTU compared to standard chemotherapy, particularly in patients with HER2 low metastatic breast cancer and across the entire trial cohort. The trial will continue as planned to further evaluate OS and other secondary endpoints.
ENHERTU, an engineered HER2-directed DXd antibody drug conjugate (ADC) developed by Daiichi Sankyo and AstraZeneca, shows promise in addressing the treatment challenges faced by patients with HR positive, HER2 low metastatic breast cancer. Endocrine therapies, commonly used in early treatment stages, often show limited efficacy after multiple lines of therapy, leading to chemotherapy as the current standard of care, which presents its own challenges in terms of response rates and outcomes.
Ken Takeshita, MD, Global Head of R&D at Daiichi Sankyo, emphasized the significance of these findings in redefining treatment approaches for HR positive, HER2 expressing metastatic breast cancer. Susan Galbraith, MBBChir, PhD, Executive Vice President of Oncology R&D at AstraZeneca, highlighted the potential of ENHERTU to set a new standard of care for patients with HER2 low and HER2 ultralow metastatic breast cancer.
The safety profile of ENHERTU remained consistent with previous breast cancer clinical trials, with no new safety concerns identified. Data from DESTINY-Breast06 will be presented at upcoming medical meetings and shared with regulatory authorities worldwide.
DESTINY-Breast06, a global phase 3 trial, assessed the efficacy and safety of ENHERTU compared to chemotherapy in patients with HR positive, HER2 low, or HER2 ultralow advanced or metastatic breast cancer who had not received prior chemotherapy for advanced disease. The trial, which enrolled 866 patients across multiple regions, focused on various endpoints including PFS, OS, objective response rate, and safety parameters.
