Swedish Orphan Biovitrum AB (publ) (Sobi), n international specialty healthcare company dedicated to rare diseases, has received orphan drug designation in Switzerland for its extended half-life haemophilia drug candidate Alprolix (rFIXFc) developed for the treatment of haemophilia B. An orphan drug designation is to encourage the development of medicines for rare diseases and provides orphan status to drugs and biologics under development.

Haemophilia B is caused by having substantially reduced or no factor IX activity, which is needed for normal blood clotting. People with haemophilia B may experience bleeding episodes in joints and muscles that cause pain, decreased mobility,  and irreversible joint damage, and in worst cases organ bleeds and life-threatening haemorrhages. Infusions of factor IX temporarily replace clotting factors necessary to resolve bleeding and when used prophylactically to prevent new bleeding episodes. Alprolix, a recombinant factor IX concentrate candidate with prolonged circulation in the body, is believed to offer improved and prolonged protection in the control and prevention against such bleeding episodes.

The World Federation of Hemophilia global survey conducted in 2013 estimates that approximately 28,430 people are currently diagnosed with haemophilia B worldwide.

Alprolix (rFIXFc) is an extended half-life recombinant factor IX Fc fusion protein product candidate for people with haemophilia B. Alprolix was submitted to the European Medicines Agency (EMA) for regulatory approval in Europe in June 2015. Alprolix was developed by fusing factor IX to the Fc portion of immunoglobulin G subclass 1, or IgG1 (a protein commonly found in the body). This enables Alprolix to use a naturally occurring pathway to prolong the time the therapy remains in the body.

Alprolix [Coagulation Factor IX (Recombinant), Fc Fusion Protein], is the first recombinant, clotting factor therapy with prolonged circulation in the body for adults and children with haemophilia B, approved in the United States, Canada, Australia and Japan.

Sobi and Biogen are collaboration partners in the development and commercialisation of Alprolix/rFIXFc for haemophilia B. Sobi has final development and commercialisation rights for rFIXFc in the Sobi territory (essentially Europe, North Africa, Russia and most Middle Eastern markets). Biogen leads development for Alprolix/rFIXFc, has manufacturing rights, and has commercialisation rights in North America and all other regions in the world excluding the Sobi territory.