The results of a study published last month in the journal Haemophilia demonstrated that a prophylactic treatment regimen for children with severe hemophilia B using a recombinant factor IX (rFIX) product may be employed safely and effectively. The lead author of the study was Paul Monahan, MD, Gene Therapy Center, University of North Carolina at Chapel Hill. Monahan is a member of the National Hemophilia Foundation's Medical and Scientific Advisory Council (MASAC).

The study included 25 children, six years old or younger, with severe hemophilia B. In all, 22 of 25 (88%) of the children received routine prophylactic therapy (one to two infusions per week) with BeneFIX®, a rFIX product manufactured by Wyeth (part of Pfizer), which also sponsored the study.

The therapy was typically continued for more than six months. Investigators reported an average of less than one bleed per year and a "near complete prevention of spontaneous breakthrough hemorrhages."

The majority of the children (77%) exhibited no spontaneous breakthrough bleeds, while approximately a third (32%) experienced no bleeding. Breakthrough bleeds that did occur were resolved with 1 or 2 infusions of rFIX in 89% of episodes. Though the patient group included children who had previously experienced multiple joint bleeds, 68% of the study subjects experienced no joint hemorrhaging. Investigators also reported that safety had been established "by the low incidence of treatment-related adverse events."

The study, "Safety and Efficacy of Investigator-Prescribed BeneFIX® Prophylaxis in Children Less Than 6 Years of Age with Severe Haemophilia B," was published online January 4, 2010, in the journal Haemophilia.