[New hemophilia treatment employing a bispecific antibody to factors IXa and X].

Unmet needs of current hemophilia A treatment include the requirement for frequent intravenous infusions, inhibitor development, and containment of high medical costs. In order to overcome these issues, we produced FVIII which mimics a bispecific antibody against FIXa/FX. ACE910 demonstrated hemostatic effects on both ongoing and spontaneous joint bleeding in the primate acquired hemophilia A model. Recently, a phase 1 study for PK, PD, and the safety of ACE910 was initiated. The t1/2 was approximately 30 days. There were no severe ACE910 related adverse events. Furthermore, bleeding was remarkably decreased by weekly subcutaneous administration in patients with severe hemophilia A, regardless of whether an inhibitor was used. ACE910 has the remarkable advantages of prophylactic efficacy which can be achieved by convenient subcutaneous administrations at a markedly reduced frequency.