AstraZeneca and Daiichi Sankyo have received the US Food and Drug Administration (FDA) priority review for the application of breast cancer drug, trastuzumab deruxtecan.

Trastuzumab deruxtecan is an antibody-drug conjugate (ADC) designed to target the HER2 tyrosine kinase receptor. It is being developed to treat HER2-positive metastatic breast cancer.

AstraZeneca signed a deal worth up to $6.9bn with Daiichi Sankyo in March to develop and commercialise the drug globally, except in Japan, where the latter holds exclusive rights.

AstraZeneca oncology R&D executive vice-president José Baselga said: “Trastuzumab deruxtecan has the potential to transform the treatment landscape for patients with HER2-positive metastatic breast cancer who have limited treatment options today.

“This priority review draws on the strength and the consistency of results seen in the Phase I and Phase II trials and is a critical step on the journey to deliver this potential new medicine to patients.”

The biologics licence application (BLA) submitted to the FDA is supported by results from the Phase I trial and Phase II DESTINY-Breast01 study.

AstraZeneca and Daiichi Sankyo noted that the response rate demonstrated by trastuzumab deruxtecan in DESTINY-Breast01 validated its clinical activity in the Phase I trial.

DESTINY-Breast01 is an open-label, global, multi-centre, two-part trial, which investigated the safety and efficacy of the drug in HER2-positive unresectable and metastatic breast cancer patients who previously received trastuzumab emtansine treatment.

Daiichi Sankyo oncology R&D global head Antoine Yver said: “We are pleased that the FDA has accepted the application and granted priority review, as we believe trastuzumab deruxtecan has the potential to redefine the treatment of patients with HER2-positive metastatic breast cancer.

“Following the recent regulatory submission in Japan, we look forward to working closely with regulatory authorities to bring trastuzumab deruxtecan to patients in the US and Japan as soon as possible.”

The drug already has breakthrough therapy and fast track designations in the US.