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# BioMarin Gene Therapy for Hemophilia A OK’d
- URL: https://www.fdaweb.com/biomarin-gene-therapy-for-hemophilia-a-okd/
- Published: 2023-06-29T12:00:00.000Z
- Updated: 2026-09-14T18:41:53.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5154802

FDA has approved a BioMarin Pharmaceutical BLA for Roctavian (valoctocogene roxaparvovec-rvox) gene therapy for treating adults with severe hemophilia A without antibodies to adeno-associated virus serotype 5 (AAV5) detected by an agency-approved test. Hemophilia A is a rare, genetic condition caused by a mutation in the gene responsible for producing the Factor VIII protein (FVIII), which is necessary for blood clotting, according to the company. The one-time, single-dose infusion is designed to replace the function of the mutated gene, allowing people with severe hemophilia A to produce their own FVIII and thereby limit bleeding episodes.

Approval was based on data from the Phase 3 GENEr8-1 study. Data showed that the 112 patients in whom six-month baseline annualized bleeding rate (ABR) data was collected “prospectively experienced a mean ABR reduction of 52% after receiving Roctavian (2.6 bleeds/year) through end of follow-up (median of three years) compared to their baseline ABR while receiving routine FVIII prophylaxis (5.4 bleeds/year),” the company says. “These patients also reported a substantial reduction in the rate of spontaneous bleeds and joint bleeds following treatment with Roctavian (observed mean ABR of 0.5 bleeds/year for spontaneous bleeds and 0.6 bleeds/year for joint bleeds) compared to their baseline rate while receiving routine FVIII prophylaxis (observed mean ABR of 2.3 bleeds/year for spontaneous bleeds and 3.1 bleeds/year for joint bleeds).”

BioMarin says that the majority of study participants continued to respond to treatment through year three and beyond without relying on regular prophylaxis. “BioMarin will continue to monitor the long-term effects of treatment with an extension study that will follow all clinical trial participants for up to 15 years, as well as post-approval studies to follow those dosed in a real-world setting for 15 years or more,” it says.