Health Canada has approved a recombinant factor IX Fc fusion protein (rFIXFc, Alprolix), for adults and children aged 12 and older with hemophilia B.
The product is intended to prevent or reduce the frequency of bleeding episodes via prophylactic infusions, starting at once weekly or once every 10 to 14 days.
This is the first regulatory approval of rFIXFc, which is under review by regulatory authorities in several other countries.
Health Canada’s approval of the product is based on results from the phase 3 B-LONG study, which was funded by Biogen Idec and Sobi, the companies developing rFIXFc.
Results of the B-LONG study
In this multicenter, open-label trial, researchers evaluated the efficacy, safety, and pharmacokinetics of rFIXFc in 123 males aged 12 years and older with hemophilia B.
Patients were assigned to 1 of 4 treatment arms: weekly prophylaxis, individualized-interval prophylaxis, on-demand treatment to control bleeding, and perioperative management.
The overall median annualized bleeding rates were 2.95 for the weekly prophylaxis arm, 1.38 for the individualized-interval prophylaxis arm, and 17.69 in the on-demand treatment arm.
The overall median dosing interval with individualized-interval prophylaxis was 12.5 days. During the last 6 months of the study, the median dosing interval was 13.8 days.
Of the patients who received rFIXFc for perioperative management, 85.7% required a single injection of the product to maintain hemostasis during their operation. The median dose was 90.9 IU/kg per injection.
Most patients required 1 to 2 injections of the product the day before and the day of surgery. And most required 2 to 3 injections from days 1 to 3 after surgery.
The most common adverse events associated with rFIXFc (incidence of ≥ 5% in a pooled analysis of treatment arms 1, 2, and 3) were nasopharyngitis, influenza, arthralgia, upper respiratory tract infection, hypertension, and headache.
Results of this study were released by Biogen Idec and Sobi in September 2012, presented at ISTH 2013, and published in NEJM in December 2013.
