The European Medicines Agency (EMA) has validated the Type II Variation marketing authorization application for ENHERTU^® (trastuzumab deruxtecan) in combination with pertuzumab for the first-line treatment of adult patients with unresectable or metastatic HER2 positive breast cancer.

ENHERTU is a specifically engineered HER2 directed DXd antibody drug conjugate (ADC) discovered by Daiichi Sankyo (TSE: 4568) and being jointly developed and commercialized by Daiichi Sankyo and AstraZeneca (LSE/STO/Nasdaq: AZN).

The validation confirms the completion of the application and commences the scientific review process by the EMA’s Committee for Medicinal Products for Human Use (CHMP). The application is based on data from the DESTINY-Breast09 phase 3 trial presented during a special late-breaking oral session at the 2025 American Society of Clinical Oncology (#ASCO25) Annual Meeting and subsequently published in The New England Journal of Medicine. In the trial, ENHERTU in combination with pertuzumab demonstrated a statistically significant and clinically meaningful improvement in progression-free survival (PFS) compared to taxane, trastuzumab and pertuzumab (THP) as a first-line treatment for patients with HER2 positive metastatic breast cancer.

“This validation in the EU is an important step in moving us closer to offering ENHERTU in combination with pertuzumab as a potential new first-line treatment option for patients with HER2 positive metastatic breast cancer,” said Ken Takeshita, MD, Global Head, R&D, Daiichi Sankyo. “Following the recent approval in the U.S. for this indication, we look forward to working closely with the EMA to bring ENHERTU to eligible patients in the EU who may benefit from improved outcomes in a setting where the standard of care has not changed in more than a decade.”