FDA Approves First Coagulation Factor-Albumin Fusion Protein to Treat Hemophilia B

In March, the U.S. Food and Drug Administration (FDA) approved CSL Behring’s Idelvion (coagulation factor IX [recombinant], albumin fusion protein) for on-demand control and prevention of bleeding episodes, management of bleeding following surgery and as a routine preventive measure to reduce the frequency of bleeding episodes in children and adults with hemophilia B. It is the first coagulation factor-albumin fusion protein product to be approved and the second factor IX fusion protein product approved in the U.S. that is modified to last longer in the blood.

Idelvion is used to replace factor IX, a naturally occurring clotting factor that is missing or defective in people with hemophilia B (also called congenital factor IX deficiency, or Christmas disease). It is produced by recombinant DNA technology linking factor IX to albumin, which accounts for the product lasting longer when given intravenously. Idelvion potentially requires less frequent injections than unmodified factor IX when used for prevention.

In two multicenter studies evaluating the safety and efficacy of Idelvion in 90 adult and pediatric patients with hemophilia B between age 1 year and 61 years, Idelvion was demonstrated to be effective in controlling bleeding episodes and in managing perioperative bleeding. In addition, Idelvion used as prophylaxis led to a significant reduction in the rate of spontaneous bleeding episodes per year despite less frequent infusions. No safety concerns were identified in the studies, and the most common side effect was headache.