Figure 5. Hemostatic effect of recombinant human factor VIII (hFVIII) variants in severe hemophilia A mice.

Mice received PBS or 10 μg/kg recombinant hFVIII protein immediately prior to injury. (A) In the tail-clip challenge, blood loss over 10 minutes was determined after complete tail transection at 3-mm diameter. Median blood loss for mice that received PBS, hFVIII-BDD, and hFVIII-ΔF was 460 ± 60, 520 ± 80, and 120 ± 40 μL, respectively. FVIII antigen levels after infusion were similar, as shown in Supplemental Figure 2. (B) In the FeCl₃ challenge, time to occlusion of the carotid artery was measured after 7.5% FeCl₃–induced injury. Median time to occlusion for mice that received hFVIII-BDD and hFVIII-ΔF was 12 ± 1 and 7 ± 1 minutes, respectively. Each data point represents an individual animal. Horizontal markers in whisker plots represent the mean and 1 SEM.