Effect of SerpinPC on spontaneous bleeding in HA mice. (A) A Kaplan-Meier survival curve is plotted for HA mice treated with either vehicle or 0.01, 0.1, or 1 mg/kg SerpinPC by subcutaneous injection 3 times per week for a maximum of 8 weeks (56 days). The vehicle and 0.01 mg/kg groups were euthanized early after reaching the humane end point. Only 2 mice from the 0.1 mg/kg group died, and none died in the 1 mg/kg group. (B) Surviving mice at the end of the treatment periods were examined to detect overt internal bleeding. Vehicle-treated mice experienced bleeding into many tissues, whereas those treated with 0.1 or 1 mg/kg SerpinPC did not exhibit any signs of internal bleeding.