Novel Therapy for Hemophilia A and B Receives FDA Orphan Drug Designation

CSL Behring announced today that it has been granted orphan drug designation by the U.S. Food and Drug Administration (FDA) for its novel recombinant fusion protein linking coagulation factor VIIa with albumin (rVIIa-FP). The Orphan Drug Designation is granted for the treatment and prophylaxis of bleeding episodes in patients with congenital hemophilia and inhibitors to coagulation factor VIII or IX.

CSL Behring is developing this therapy in collaboration with its parent company CSL Limited. The
FDA’s Orphan Drug Designation program provides orphan status to unique drugs and biologics, defined as those intended for the safe and effective treatment or prevention of rare diseases that affect fewer than 200,000 people in the U.S.

The CSL Behring rVIIa-FP clinical program will be initiated shortly with the intention of demonstrating that an extended half-life rVIIa-FP will result in a requirement for fewer doses, while providing adequate therapeutic response in patients who have hemophilia A and B with inhibitors.

"CSL Behring’s albumin fusion technology uses albumin as the ideal recombinant genetic fusion partner for coagulation factor proteins because of its high tolerability, inherently long half-life, low potential for immunogenic reactions and known mechanism of clearance," said Russell Basser, M.D., Senior Vice President, Global Clinical R&D at CSL Behring. "CSL Behring’s rVIIa albumin fusion protein is expected to exhibit a good tolerability profile and improved pharmacokinetics that may enable prophylaxis. We welcome Orphan Drug Designation for our rVIIa-FP and will work closely with the FDA to make this important therapy available for people in the U.S. with hemophilia A and hemophilia B with inhibitors."