AstraZeneca and Daiichi Sankyo have received the US Food and Drug Administration (FDA) Priority Review for Enhertu (trastuzumab deruxtecan) to treat a type of breast cancer in adults.

The US health agency has accepted the companies’ supplemental Biologics License Application (sBLA) for Enhertu to treat unresectable or metastatic HER2-low breast cancer.

Enhertu is a HER2-directed ADC therapy, designed using Daiichi Sankyo’s unique DXd ADC technology, and the most advanced programme in AstraZeneca’s ADC platform.

The US FDA has finalised the fourth quarter of 2022, as the Prescription Drug User Fee Act date action date for the regulatory decision.

Enhertu is being reviewed under the FDA’s Real-Time Oncology Review (RTOR) programme and Project Orbis.

AstraZeneca oncology R&D executive vice president Susan Galbraith said: “The data from DESTINY-Breast04 represent the first time a HER2-targeted therapy has shown a survival benefit in patients with HER2-low metastatic breast cancer.

“For more than two decades, only patients with HER2-positive breast cancer have been able to benefit from HER2-targeted therapies.

“If approved, Enhertu will redefine how we classify and treat metastatic breast cancer, enabling patients whose tumours have lower levels of HER2 expression the opportunity to benefit from a HER2-directed therapy.”

The sBLA for Enhertu is supported by data from the Phase 3 DESTINY-Breast04 trial in patients previously treated with HER2-low metastatic breast cancer.

In the Phase 3 study, the ADC therapy showed superior and clinically meaningful efficacy in progression-free survival (PFS) and overall survival (OS).

Enhertu showed a safety profile consistent with previous clinical trials, with no new safety concerns reported.

The drug showed pneumonitis rates consistent with that observed in late-line HER2-positive breast cancer trials, as determined by an independent adjudication committee.

The current Priority Review follows the FDA Breakthrough Therapy Designation (BTD) for Enhertu in metastatic HER2-low breast cancer, granted in April this year.

In a separate development, AstraZeneca’s drugs Tezspire and Ultomiris have been recommended for regulatory approval in the European Union (EU).

The European Medicines Agency (EMA)’s Committee for Medicinal Products for Human Use (CHMP) has separately recommended the two drugs.

EMA recommended Tezspire as an add-on therapy for severe asthma in adults and adolescents aged 12 years and above, who are inadequately controlled with current treatment.

Ultomiris is indicated as an add-on to standard therapy to treat generalised myasthenia gravis (gMG) who are anti-acetylcholine receptor (AChR) antibody-positive.