Comparable acute activity of rFVIIIFc and rFVIII in the tail-clip bleeding model. Male HemA mice received a tail vein injection of rFVIIIFc or rFVIII as specified followed by a 10-mm tail clip 5 minutes after dosing. Results presented are individual and median blood loss over 30 minutes following the tail clip from 20 mice in each treatment group. P < .05 for vehicle vs all other treatments, and P > .05 for C57Bl/6 vs HemA mice treated with 72 or 216 IU/kg rFVIIIFc, or 216 IU/kg rFVIII.