The European Union approved a drug developed by British-Swedish pharmaceutical company AstraZeneca and Japanese Daiichi Sankyo to treat an aggressive form of breast cancer.

The drug was approved for the treatment of patients with unresectable or metastatic HER2-positive breast cancer who have received one or more prior anti-HER2-based regimens, AstraZeneca said.

It is being jointly developed and commercialized by AstraZeneca and Daiichi Sankyo.

AstraZeneca noted that, following the approval, an amount of $75 million is due from the company to Daiichi Sankyo as a milestone payment in second-line HER2-positive metastatic breast cancer.

The European Medicines Agency (EMA) gave its endorsement late last month. The EMA said Enhertu was effective at shrinking the tumor in patients with metastatic breast cancer or breast cancer that could not be removed by surgery.