FDA accepts BLA for hemophilia B gene therapy fidanacogene elaparvovec

Fidanacogene elaparvovec is a novel, investigational gene therapy that contains a bio-engineered adeno-associated virus (AAV) capsid (protein shell) and a high-activity variant of human coagulation Factor IX (FIX) gene. For people living with hemophilia B, the goal of this gene therapy is to enable them to produce FIX themselves via this one-time treatment rather than needing regular intravenous infusions of FIX, as is the current standard of care.

The submissions for fidanacogene elaparvovec are based on efficacy and safety data from the Phase III BENEGENE-2 study (NCT03861273). As previously reported, the BENEGENE-2 study met its primary endpoint of non-inferiority and superiority in the annualized bleeding rate (ABR) of total bleeds post-fidanacogene elaparvovec infusion versus prophylaxis regimen with FIX, administered as part of usual care. Fidanacogene elaparvovec was generally well-tolerated, with a safety profile consistent with Phase 1/II results.

The FDA has set a Prescription Drug User Fee Act (PDUFA) goal date in the second quarter of 2024. Fidanacogene elaparvovec has been granted Breakthrough, Regenerative Medicines Advanced Therapy (RMAT) and orphan drug designations from the FDA.

Pfizer currently has three Phase III programs investigating gene therapy in populations where there is a high unmet need: hemophilia B, hemophilia A, and Duchenne muscular dystrophy. A Phase III trial is also ongoing investigating marstacimab, a novel, investigational anti-tissue factor pathway inhibitor (anti-TFPI) being studied for the treatment of people with hemophilia A and B with and without inhibitors.