BioMarin’s AAV5-hFVIII-SQ Gene Therapy Shows Durable Efficacy and Safety at Five Years for Severe Hemophilia A

WASHINGTON, D.C. – June 24, 2025 – BioMarin Pharmaceutical Inc. (Nasdaq: BMRN) today announced compelling five-year data for ROCTAVIAN® (valoctocogene roxaparvovec-rvox), its gene therapy for severe hemophilia A, presented at the 33rd ISTH Congress. The Phase 3 GENEr8-1 trial demonstrated sustained bleed control and durable factor VIII (FVIII) expression, with no new safety signals observed.

Valoctocogene roxaparvovec (AAV5-hFVIII-SQ) is an adeno-associated virus 5 (AAV5)–based gene-therapy vector containing a coagulation factor VIII complementary DNA driven by a liver-selective promoter.

At five years, ROCTAVIAN maintained mean FVIII activity in the mild hemophilia range, with 73.5% of participants achieving mild to normal FVIII levels. The mean annualized bleeding rate (ABR) for treated bleeds was remarkably low at 0.6 bleeds/year, and during year five, 77.8% of participants had zero treated bleeds. Crucially, 81.3% of participants remained off prophylaxis. No participants developed FVIII inhibitors, experienced thromboembolic events, or had treatment-related malignancies.

“The strong efficacy and safety results for ROCTAVIAN are sustained five years after individuals with severe hemophilia A received gene therapy,” said Andrew Leavitt, M.D., University of California San Francisco. “These results highlight the role gene therapy may play in addressing the burdens of chronic disease management.”

BioMarin also presented data on the “hemophilia-free mind,” showing that ROCTAVIAN recipients experienced significant improvements in health-related quality of life, easing both physical and psychological burdens.

“These five-year data reinforce our confidence in ROCTAVIAN’s profile, showing that people can experience long-term bleed control without the need for prophylaxis,” added Greg Friberg, M.D., Executive Vice President and Chief Research & Development Officer at BioMarin.