After 15 Years, First New Recombinant Coagulation Factor IX (Rixubis) Gains Orphan Drug Approval

By: Tamara Yunusova, Senior Staff Editor

After a lengthy fifteen-year hiatus in recombinant drug approvals, FDA-approved Recombinant Coagulation Factor IX (Rixubis) has mounted to the forefront of Hemophilia B drug therapy. The recombinant coagulation factor gained orphan drug approval on June 26, 2013 for routine prophylaxis, control of bleeding episodes, and perioperative management in adults with Hemophilia B.1

Hemophilia B is characterized by a deficiency of clotting factor IX, a naturally occurring protein in the blood that controls bleeding.2 Rixubis, developed by Baxter International, is a purified protein produced by recombinant DNA technology. It is administered by an intravenous injection twice weekly for six months in order to prevent bleeding episodes.2 According to Baxter Int., it is the only recombinant factor IX product in the U.S. market for both prophylaxis and control.3

Based upon a Phase I/III study, a twice-weekly prophylactic treatment with Rixubis for six months achieved a median annualized bleed rate (ABR) of 2.0, with 43% patients experiencing no bleeding at all over the period. According to the FDA, in comparison to patients receiving on-demand treatment, patients in the prophylaxis study had a 75% lower annual bleeding rate.2

Karan Midthun, M.D., director of the FDA’s Center for Biologics Evaluation and Research, says, “As the first recombinant coagulation factor IX indicated specifically for routine prophylaxis to prevent bleeding, Rixubis becomes a new weapon in our arsenal to protect Hemophilia B patients… This approval provides patients and physicians with an alternative treatment option to prevent or reduce the frequency of bleeding episodes.”1

Current drug therapy for Hemophilia B requires dosing 2-3 injections per week for prophylaxis.1 With the development of factor IX products on the horizon, the search for a longer-acting recombinant factor continues. Biogen Idec has developed a fusion protein product that will require dosing once every one to two weeks. The product was submitted for approval in the U.S. earlier this year.  In addition are two other long-acting factor IX products from Novo Nordisk and CSL Behring, both of which are undergoing phase III testing.1

†Annualized Bleed Rate (ABR) refers to the number of bleeding episodes per year.


  1. FDA approves Baxter’s Rixubis for hemophilia B. Genetic Engineering & Biotechnology News.  Published July 1, 2013. Accessed August 10, 2013.
  2. Baxter. FDA approves Baxter’s Rixubis as first recombinant factor IX treatment for routine prophylaxis of hemophilia B. Baxter.            Published June 27, 2013. Accessed August 10, 2013.
  3. PMLive. Baxter gets ok for BeneFix competitor in US. PMLive.  Published June 28, 2013. Accessed August 10, 2013.
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