AstraZeneca Enhertu granted priority review in US for metastatic HER2-positive solid tumours

The sBLA is based on data from the ongoing DESTINY-PanTumor02 Phase II trial where Enhertu demonstrated clinically meaningful and durable responses leading to a clinically meaningful survival benefit in previously treated patients across HER2-expressing metastatic solid tumours, including biliary tract, bladder, cervical, endometrial, ovarian cancers, and other tumours. Data from other supporting trials in patients with HER2-positive IHC3+ tumours in the Enhertu clinical development programme, including DESTINY-Lung01 and DESTINY-CRC02, were also included in the submission.

Enhertu is a specifically engineered HER2-directed antibody drug conjugate (ADC) being jointly developed and commercialised by AstraZeneca and Daiichi Sankyo.

The Food and Drug Administration (FDA) grants Priority Review to applications for medicines that, if approved, would offer significant improvements over available options by demonstrating safety or efficacy improvements, preventing serious conditions or enhancing patient compliance. The Prescription Drug User Fee Act date, the FDA action date for their regulatory decision, is during the second quarter of 2024.

Susan Galbraith, Executive Vice President, Oncology R&D, AstraZeneca, said, “The Priority Review for the first tumour-agnostic submission for Enhertu reflects the potential of this medicine to redefine the treatment of HER2-expressing cancers. Biomarkers for HER2 expression are already established in breast and gastric cancers, but we must now define them across tumour types. We will continue working closely with the FDA to bring this potential first tumour-agnostic HER2-targeted medicine and biomarker to patients as quickly as possible.”

Ken Takeshita, MD, Global Head, R&D, Daiichi Sankyo, said, “The clinical benefit seen across HER2-expressing metastatic solid tumours in the DESTINY-PanTumor02 trial and ongoing data from the Enhertu clinical development programme continues to demonstrate the potential of this medicine beyond its approved indications. If approved, Enhertu could become the first HER2-directed therapy and antibody drug conjugate with a tumour-agnostic indication, providing patients with a potential new treatment option.”

The sBLA is being reviewed under the Real-Time Oncology Review (RTOR) programme and Project Orbis, two initiatives of the FDA which are designed to bring safe and effective cancer treatments to patients as early as possible. RTOR allows the FDA to review components of an application before submission of the complete application. Project Orbis provides a framework for concurrent submission and review of oncology medicines among participating international partners.

Results from DESTINY-PanTumor02 were presented at the 2023 European Society for Medical Oncology Congress and simultaneously published in the Journal of Clinical Oncology.

The safety profile observed across the trials was consistent with previous clinical trials of Enhertu with no new safety concerns identified.

The Priority Review follows receipt of Breakthrough Therapy Designation (BTD) in the US in August 2023 for Enhertu in metastatic HER2-positive solid tumours.