AstraZeneca (NASDAQ: AZN) and Daiichi Sankyo's Enhertu (trastuzumab deruxtecan) combined with pertuzumab has received a positive opinion from the European Medicines Agency's Committee for Medicinal Products for Human Use (CHMP), recommending its approval in the European Union as a first-line treatment for adult patients with unresectable or metastatic HER2-positive breast cancer.

The CHMP based its recommendation on results from the DESTINY-Breast09 Phase III trial, which were presented at the 2025 American Society of Clinical Oncology Annual Meeting and published in The New England Journal of Medicine.

In the trial, Enhertu combined with pertuzumab reduced the risk of disease progression or death by 44% compared with a taxane, trastuzumab and pertuzumab regimen, based on a hazard ratio of 0.56. Median progression-free survival was 40.7 months with the Enhertu combination versus 26.9 months with the comparator treatment.

The trial enrolled patients with HER2-positive metastatic breast cancer who had not received prior chemotherapy or HER2-targeted therapy, or who had received neoadjuvant or adjuvant HER2-targeted therapy more than six months before diagnosis of advanced or metastatic disease. The progression-free survival benefit was consistent across subgroups, including hormone receptor status, de novo or recurrent disease, and PIK3CA mutation status.

No new safety concerns were identified, with the safety profile consistent with the known profiles of each individual therapy.

Enhertu combined with pertuzumab is already approved in the United States, Switzerland, and other countries as a first-line treatment for metastatic HER2-positive breast cancer based on the same trial data. Enhertu is also under separate EU review for patients with HER2-positive breast cancer who have residual invasive disease following neoadjuvant HER2-targeted treatment, based on data from the DESTINY-Breast05 trial.

Enhertu is a HER2-directed antibody drug conjugate discovered by Daiichi Sankyo and jointly developed and commercialized by AstraZeneca and Daiichi Sankyo.