Pfizer announced Friday morning that the FDA approved its gene therapy for the rare genetic bleeding disorder hemophilia B.
The one-time treatment, known generically as fidanacogene elaparvovec, is indicated for adults with moderate-to-severe hemophilia B. The pharma company will market the gene therapy as Beqvez. The treatment was first approved in Canada in January.
It’s the second gene therapy approved for hemophilia B, after CSL received a regulatory nod for Hemgenix in 2022. Pfizer said Friday that it would price its therapy at $3.5 million, the same amount as Hemgenix.
People with hemophilia B have a deficiency in a blood-clotting protein called factor IX. That means they may experience prolonged bleeding episodes. Traditional treatment involves receiving infusions of factor IX. Pfizer’s gene therapy is designed to deliver a version of the gene for factor IX, so patients with moderate-to-severe disease no longer have to get frequent infusions.
In clinical trials, the gene therapy reduced yearly bleeding rates by 71% compared to before treatment, and 60% of patients who received Beqvez saw their bleeds eliminated compared to 29% of patients on prophylactic factor IX therapy.
The indication includes adults who receive factor IX prophylaxis therapy or have experienced life-threatening hemorrhage or repeated, serious spontaneous bleeding episodes. People who want to receive the therapy also cannot have antibodies to the AAV capsid — the viral envelope used to deliver the gene — used by the therapy.
How payers foot the high one-time cost of gene therapies has been a major concern. Pfizer said it is launching a warranty program, based on durability of patient response, to help pay for the treatment.
The company is awaiting a regulatory decision on the gene therapy from Europe.
Pfizer is also developing gene therapies for hemophilia A and Duchenne muscular dystrophy, with Phase 3 readouts expected later this year.
Beyond those late-stage candidates, the only other clinical program in Pfizer’s gene therapy pipeline is in Phase 1 for Wilson disease. As part of a “refocusing” effort last year, Pfizer had sold multiple early-stage gene therapy assets to AstraZeneca.
In hemophilia, Pfizer has an experimental antibody treatment called marstacimab for hemophilia A and B, where it is expecting an FDA decision in the fourth quarter of the year. The FDA rejected Novo Nordisk’s application for a similar antibody last year. In hemophilia A, Pfizer hopes to compete with Roche’s blockbuster Hemlibra.
Editor’s note: This story was updated throughout to add information about hemophilia B and the cost of Beqvez.