AstraZeneca and Daiichi Sankyo secured European Commission (EC) conditional approval for their cancer drug Enhertu (trastuzumab deruxtecan) to treat a type of breast cancer.

The European regulator indicated Enhertu as a monotherapy for the treatment of unresectable or metastatic HER2-positive breast cancer in adults, who previously received two or more anti-HER2-based regimens.

Enhertu is an antibody drug conjugate (ADC), that acts against HER2 protein. It is the lead ADC in Daiichi Sankyo’s oncology portfolio and advanced programme in AstraZeneca’s ADC scientific platform.

Daiichi Sankyo and AstraZeneca initiated a global collaboration in March 2019, to co-develop and commercialise Enhertu.

In relation with the EU approval, AstraZeneca is expected to make a payment of $75m to Daiichi Sankyo as a milestone payment for HER2-positive breast cancer.

AstraZeneca oncology business unit executive vice president Dave Fredrickson said: “Enhertu is already transforming outcomes for patients with HER2-positive metastatic breast cancer in the US and Japan, and this approval enables us to bring the benefits of this medicine to patients in the EU.

“We will continue to explore the potential of Enhertu in this setting, as well as in earlier lines of treatment and stages of disease, with the ambition of improving the lives of patients with HER2-targetable breast cancer.”

EC approval of Enhertu is based on Phase 2 DESTINY-Breast01 trial results

EC approval was supported by the positive results from the Phase 2 single-arm DESTINY-Breast01 trial, which is an open-label, global, multicentre, two-part study of Enhertu.

In the Phase 2 study, treatment using Enhertu showed clinically meaningful and durable antitumour activity in patients with HER2-positive metastatic breast cancer, who previously received two or more anti-HER2-based regimens.

Also, the European Medicines Agency (EMA)’s Committee for Medicinal Products for Human Use (CHMP) reviewed the regulatory application under its accelerated assessment procedure, and granted recommendation for approval in December 2020.

Daiichi Sankyo oncology development global head senior vice president Gilles Gallant said: “This expedited review underscores the practice-changing potential of Enhertu for patients in the metastatic setting.

“Enhertu is the first-ever new medicine to be approved in breast cancer in Europe on the basis of Phase II single-arm data, and one of the fastest accelerated assessment procedures for an application in oncology.”

Recently, the US food and Drug Administration (FDA) has approved the drug to treat adult patients with a type of gastric cancer.