AstraZeneca (AZN) and Daiichi Sankyo had its European Medicines Agency marketing application validated for their targeted therapy Enhertu to treat a specific type of early-stage breast cancer, Daiichi Sankyo said Thursday.

The regulatory approval initiates the formal scientific review process for the medication's use as a standalone option in patients who still have breast cancer following prior treatments, the company said.

The submission relies on late-stage clinical trial data from the Destiny trial showing the drug reduced the likelihood of disease return or mortality by 53% compared to an older treatment, Daiichi Sankyo said.

The drugmakers are also pursuing additional European regulatory approvals for the medication to address other forms of advanced breast cancer and solid tumors, the company added.