Biogen Idec and Swedish Orphan Biovitrum advance long-lasting hemophilia A therapy into registrational trial

US biotech firm Biogen Idec and Stockholm-based Swedish Orphan Biovitrum (SOBI) say they plan to advance the companies' long-lasting, fully-recombinant factor VIII Fc fusion protein (rFVIIIFc) into a registrational clinical trial in people with hemophilia A.

The decision is based on promising data from a Phase I/IIa open-label, cross-over, multi-center, dose-escalation study that evaluated the safety and pharmacokinetics of an intravenous injection of rFVIIIFc in 16 previously-treated patients with severe hemophilia A. In the study, rFVIIIFc was well tolerated and demonstrated a prolonged half-life compared to Baxter Healthcare's currently marketed Advate (antihemophilic factor recombinant, plasma/albumin-free method, rFVIII), supporting advancement of the program.

The primary objective of the Phase I/IIa study was to assess the safety of rFVIIIFc at different doses; the secondary objective was to estimate the pharmacokinetic (PK) parameters of rFVIIIFc at doses ranging from 25 to 65 IU/kg. Preliminary results demonstrated that rFVIIIFc's prolonged half-life compared to Advate was seen consistently across all patients and dose levels, and other measures of pharmacokinetics including mean residence time and area under the curve were also increased. There were no signs of injection site reactions, inhibitor development or anti-rFVIIIFc drug antibodies in the single-dose study, and there have been no reports of drug-related serious adverse events.