Japanese healthcare company Daiichi Sankyo Co Ltd (TYO:4568) announced on Monday that the European Medicines Agency has validated a Type II Variation marketing authorisation application for ENHERTU (trastuzumab deruxtecan) in combination with pertuzumab as a first-line treatment for adult patients with unresectable or metastatic HER2 positive breast cancer.

This validation confirms completion of the submission and initiates the scientific review by the EMA's Committee for Medicinal Products for Human Use.

ENHERTU is a specifically engineered HER2-directed antibody drug conjugate discovered by Daiichi Sankyo and jointly developed and commercialised with British-Swedish biopharmaceutical company AstraZeneca plc (STO:AZN) (LON:AZN) (Nasdaq:AZN). The application is supported by data from the DESTINY-Breast09 phase 3 trial, which showed that ENHERTU plus pertuzumab significantly improved progression-free survival versus taxane, trastuzumab and pertuzumab as first-line therapy. Trial results were presented at the 2025 American Society of Clinical Oncology Annual Meeting and published in The New England Journal of Medicine.