fidanacogene elaparvovec

Fidanacogene elaparvovec is an adeno-associated virus (AAV) vector-based gene therapy designed for the treatment of hemophilia B. It utilizes a bioengineered hepatotropic AAV capsid (Spark100) to deliver a high-activity human coagulation Factor IX (FIX) gene variant, known as FIX-R338L or the Padua variant, to the liver. This one-time intravenous infusion enables the patient's own liver cells to produce functional Factor IX, thereby reducing or eliminating the need for regular prophylactic infusions of FIX replacement therapy. Originally developed by Spark Therapeutics and licensed to Pfizer, the therapy received FDA approval in 2024 under the brand name BEQVEZ. However, in early 2025, Pfizer announced the discontinuation of its commercialization and further development globally, citing limited market interest and commercial challenges.

Brand names

BEQVEZ

Other names

rAAV-Spark100-hFIX-R338LrAAV-Spark-100-hFIX-R338LrAAV-Spark 100-hFIX-R338L