coagulation factor therapy coagulation factor VIII replacement therapy Deficiency of the coagulation cofactor factor VIII (FVIII) leads to the X‐chromosomal inherited bleeding disorder hemophilia A. Current therapy for hemophilia is based on the infusion of clotting factor concentrates either at the time of bleeding (on demand therapy) or in a prophylactic schedule to prevent bleeding episodes. Intravenous infusion with coagulation factor VIII.