The US Food and Drug Administration (FDA) has accepted and granted Priority Review to a Biologics License Application (BLA) submitted by Alexion, a unit of AstraZeneca (NASDAQ: AZN), for efzimfotase alfa as a treatment for hypophosphatasia (HPP) in patients aged two years and older.

HPP is a rare, inherited metabolic disease caused by deficient activity of the enzyme alkaline phosphatase, resulting in defective bone mineralization, impaired calcium and phosphate regulation, muscle weakness, neurologic symptoms, fatigue, and pain.

The FDA assigns Priority Review to applications for medicines that, if approved, would offer significant improvements in safety or efficacy, prevent serious conditions, or enhance patient compliance over existing treatments. The Prescription Drug User Fee Act (PDUFA) target action date is set for the first half of 2027.

The BLA is supported by results from three Phase III trials: HICKORY, which enrolled adolescents and adults aged 12 and older not previously treated with Strensiq (asfotase alfa); MULBERRY, involving children aged 2 to under 12 not previously treated with Strensiq; and CHESTNUT, which enrolled children previously treated with Strensiq. Efzimfotase alfa was described as generally well-tolerated across all three trials.

Results from the MULBERRY and CHESTNUT trials were presented at the 12th International Conference on Children's Bone Health. Results from the HICKORY trial are expected to be presented at the 2026 American Society for Bone and Mineral Research Annual Meeting.

Regulatory submissions for efzimfotase alfa are also under review in Japan and other markets, according to a company statement.