FDA approves Idelvion [Coagulation Factor IX (Recombinant) for the treatment of hemophilia B- CSL Behring

CSL Behring announced that the FDA has approved Idelvion [Coagulation Factor IX (Recombinant), Albumin Fusion Protein], its novel, long-acting albumin fusion protein linking recombinant coagulation factor IX with recombinant albumin for the treatment of hemophilia B. It is the first and only factor IX therapy that delivers high-level protection with up to 14-day dosing in appropriate patients. This dosing interval has been achieved while maintaining high levels of factor activity, above 5 percent over 14 days at 75 IU/kg. This reduces the monthly number of units needed for prophylaxis therapy.

The approval of Idelvion is based on results from the PROLONG-9FP clinical development program. PROLONG-9FP includes Phase I through Phase III open-label, multicenter studies evaluating the safety and efficacy of Idelvion in children and adults (ages 1 to 61 years) with hemophilia B (factor IX levels below 2%). The data from PROLONG-9FP showed median annualized spontaneous bleeding rates (AsBR) of zero and factor IX activity levels above 5 percent in patients using IDELVION prophylactically. According to the World Federation of Hemophilia, patients with factor IX activity levels above 5 percent (and below 50 percent) are considered to have mild hemophilia. This result was achieved for both 14-day dosing and 7-day dosing. The data for on-demand therapy showed that 94 percent of bleeds were controlled with one infusion, while 99 percent were controlled with one or two infusions. The most common adverse reaction in clinical trials was headache. Data from PROLONG-9FP were recently published in the American Society of Hematology's publication Blood.