AstraZeneca and Daiichi Sankyo’s Enhertu (trastuzumab deruxtecan) has been approved in the European Union (EU) as a monotherapy for the treatment of adult patients with unresectable or metastatic hormone receptor (HR)-positive, HER2-low or HER2-ultralow breast cancer who have received at least one endocrine therapy in the metastatic setting and who are not considered suitable for endocrine therapy as the next line of treatment.

The approval by the European Commission follows the positive opinion of the Committee for Medicinal Products for Human Use and is based on results from the DESTINY-Breast06 Phase III trial, which were presented at the 2024 American Society of Clinical Oncology (ASCO) Annual Meeting and published in The New England Journal of Medicine.

Giuseppe Curigliano, MD, PhD, Professor of Medical Oncology at the University of Milan and the Head of the Division of Early Drug Development at the European Institute of Oncology, IRCCS, Italy and principal investigator for the trial, said: “This approval introduces a new treatment option for HR-positive metastatic breast cancers that express HER2. In DESTINY-Breast06, Enhertu outperformed chemotherapy, providing progression-free survival of more than one year for patients with HR-positive, HER2-low or HER2-ultralow metastatic breast cancer, demonstrating the benefit of treating these patients with Enhertu instead of chemotherapy.” 

Dave Fredrickson, Executive Vice President, Oncology Haematology Business Unit, AstraZeneca, said: “Enhertu continues to open up new approaches to the diagnosis and treatment of patients with metastatic breast cancer. This approval underscores the importance of testing metastatic breast cancer tumours for any IHC staining to identify patients with HR-positive, HER2-low or HER2-ultralow disease who may be eligible for Enhertu once sustained responses are no longer achieved with endocrine-based therapy.”

Ken Keller, Global Head of Oncology Business, and President and CEO, Daiichi Sankyo, said: “Enhertu continues to evolve what is possible with breast cancer treatment, becoming the first HER2-directed medicine approved in the EU for patients with HR-positive metastatic breast cancer with HER2-low or HER2-ultralow expression following endocrine therapy. Today’s approval expands the use of Enhertu to now include an earlier treatment setting of HER2-low metastatic breast cancer and broadens the patient population eligible for treatment to those with HER2-ultralow disease.”