BeneFIX Again Preventive Therapy for Children With Hemophilia B
Marketed by Pfizer, BeneFIX is a lab-made version of factor IX (FIX), the blood clotting protein that is missing or defective in people with hemophilia B. The therapy is designed to control or prevent bleeds caused by its absence.
BeneFIX was initially given FDA approval as an on-demand treatment to manage spontaneous bleeds, and bleeding episodes occurring during surgeries in adults and children with hemophilia B in 1997.
The FDA expanded the use of BeneFIX to include prophylaxis, or treatment taken routinely to prevent bleeds, last year. Ixinity, a similar product previously approved as an on-demand and surgery management treatment, also received expanded approval for prophylactic indications.
After reviewing its records, however, the agency realized that it had acted in error. Another FIX product already on the market — Rixubis by Takeda — held the legal right to be the only approved product for prophylaxis in children and adolescents with hemophilia B under 16 in the U.S.
The FDA had designated Rixubis an orphan drug a few years earlier during its development. This designation is given to therapies with the potential to substantially improve medical care for patients with rare conditions, and it confers certain incentives — including seven years of marketing exclusivity — to the designated treatment upon approval.
After realizing its mistake, the FDA partly rescinded its approval expansions for BeneFIX and Ixinity. Essentially, both medications were allowed to be used as a routine preventive therapy but only in adults, in addition to controlling surgery bleeds and treating spontaneous bleeds.
According to a National Hemophilia Foundation release, Rixubis’ period of marketing exclusivity ended on Sept. 12. The following day, the FDA fully restored the pediatric prophylaxis indication to BeneFIX.
The full set of approved indications for BeneFIX now includes its use in adults and children with hemophilia B as an on-demand treatment during surgeries or to control spontaneous bleeds, as well as a routine prophylactic treatment to lower the frequency of bleeding episodes.
Whether approval of Ixinity (first developed by Aptevo Therapeutics and now part of Medexus Pharmaceuticals) as a pediatric prophylactic treatment will also be restored is not known.