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# Pfizer Hemophilia B Gene Therapy Approved
- URL: https://www.fdaweb.com/pfizer-hemophilia-b-gene-therapy-approved/
- Published: 2024-04-26T12:00:00.000Z
- Updated: 2026-09-14T14:29:16.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5156864

FDA has approved Pfizer’s Beqvez (fidanacogene elaparvovec-dzkt), a gene therapy for treating adults with moderate to severe hemophilia B who currently use factor IX (FIX) prophylaxis therapy, or have current or historical life-threatening hemorrhage, or have repeated, serious spontaneous bleeding episodes. “Beqvez is a one-time treatment that is designed to enable people living with hemophilia B to produce FIX themselves rather than the current standard of care, which requires regular intravenous infusions of FIX that are often administered multiple times a week or multiple times a month,” the company says.

The adeno-associated virus-based gene therapy is “designed to introduce in the transduced cells a functional copy of the FIX gene encoding a high-activity FIX variant,” Pfizer says. It enables patients to produce FIX on their own without having to receive frequent infusions of FIX, which is the current standard of care.

Approval was based on data from the pivotal Phase 3 [BENEGENE-2 study](https://cts.businesswire.com/ct/CT?id=smartlink&url=https%3A%2F%2Fclinicaltrials.gov%2Fct2%2Fshow%2FNCT03861273&esheet=53957175&newsitemid=20240425269649&lan=en-US&anchor=BENEGENE-2+study&index=2&md5=7e364fcdb238245d03fd6ee0a5f6f809&ref=fdaweb.com) which evaluated 45 patients and the annualized bleeding rate for participants treated with gene therapy versus FIX prophylaxis replacement regimen, administered as part of usual care. “Bleeds were eliminated in 60% of patients compared to 29% in the prophylaxis arm,” Pfizer says.