Importantly, rFVIIIFc showed equivalent effectiveness to rBDD FVIII and rflFVIII in acute clot formation ex vivo immediately following treatment of mice with hemophilia A. Furthermore, rFVIIIFc showed prolonged improvement in clot formation relative to rBDD FVIII and rflFVIII following a single intravenous injection in mice with hemophilia A, which is consistent with the extended pharmacokinetics of rFVIIIFc in hemophilic mice and dogs [6]. Here, F8 is linked to hemophilia A.