enhertu granted priority review in the US for patients with HER2-low or HER2-ultralow metastatic breast cancer who have received at least one line of endocrine therapy

The 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 anticipated during the first quarter of 2025.

Enhertu was also recently granted Breakthrough Therapy Designation (BTD) by the FDA in this setting. BTD accelerates the development and regulatory review of potential new medicines intended to treat a serious condition and address a significant unmet medical need.

HR-positive, HER2-negative is the most common breast cancer subtype, accounting for approximately 70% of all breast cancers.  Despite being classified as HER2-negative, many of these tumours still carry some level of HER2 expression.² It is estimated that up to 85-90% of tumours historically classified as HR-positive, HER2-negative, may be HER2-low or HER2-ultralow.

Susan Galbraith, Executive Vice President, Oncology R&D, AstraZeneca, said: “While endocrine therapies are widely used in the initial treatment of HR-positive metastatic breast cancer, most patients see limited benefit with additional lines of treatment, and subsequent chemotherapy is associated with poor response rates and outcomes. The results from DESTINY-Breast06 show that Enhertu has the potential to evolve the current HR-positive treatment landscape and become the first targeted treatment for patients with HER2-low or HER2-ultralow expression following endocrine therapy.”

The sBLA is based on data from the DESTINY-Breast06 Phase III trial presented at the 2024 American Society of Clinical Oncology (ASCO) Annual Meeting and recently published in The New England Journal of Medicine.