FDA Approves Hemophilia B Therapy Idelvion

Patients can go up to two weeks between infusions

The FDA has given the nod to Idelvion (coagulation factor IX [recombinant], albumin fusion protein, CSL Behring), a long-acting albumin fusion protein linking recombinant coagulation factor IX with recombinant albumin for the treatment of patients with hemophilia B. Idelvion is the first factor IX therapy that delivers protection with up to 14-day dosing in appropriate patients, according to Behring. This dosing interval is achieved while maintaining high levels of factor activity (greater than 5% over 14 days at 75 IU/kg), thereby reducing the monthly number of units needed for prophylaxis therapy.

Behring engineered Idelvion to extend the half-life of recombinant factor IX through fusion with recombinant albumin. The company selected recombinant albumin as the fusion partner for its coagulation-factor proteins because of its long physiologic half life.

Idelvion is a recombinant protein that temporarily replaces the missing coagulation factor IX needed for effective hemostasis. It is indicated for children and adults with hemophilia B for routine prophylaxis to prevent or reduce the frequency of bleeding episodes; for on-demand control and prevention of bleeding episodes; and for the perioperative management of bleeding (around the time of surgery). Appropriate patients 12 years of age and older can go up to 14 days between infusions. Idelvion is only for intravenous use after reconstitution.

The product is expected to be available later this month.

Hemophilia B is a congenital bleeding disorder characterized by deficient or defective factor IX; nearly all affected patients are male. Patients with hemophilia B may experience prolonged or spontaneous bleeding, especially into the muscles, joints, or internal organs. According to the Centers for Disease Control and Prevention, the condition affects approximately one in 25,000 male births.

Sources: CSL Behring; March 4, 2016; and Idelvion Prescribing Information; March 2016.