Gene Therapy for Hemophilia: Are Expectations Matching Reality?

BioMarin Pharmaceuticals’ ongoing phase 3 trial (ClinicalTrials.gov: NCT03370913) is designed to test a single dose (6E13 vg/kg) of valoctocogene roxaparvovec (an adeno-associated viral serotype 5 vector expressing B-domain deleted coagulation factor VIII [AAV5-FVIII]) in men with severe hemophilia A. In 2019, BioMarin reached an agreement with the US Food and Drug Administration (FDA), as part of the breakthrough therapy designation, that they could submit data for provisional approval on 16/134 participants at 6 months, rather than the full study results at the 1 year mark.