Pharmacokinetics and pharmacodynamics of SCT800, a new recombinant FVIII, in hemophilia A mice

Aim： SCT800 is a new third-generation recombinant FVill agent that is undergoing promising preclinical study. This study aimed to investigate the pharmacokinetic and pharmacodynamic profiles of SCT800 in hemophilia A mice. Methods： After hemophilia A mice were intravenously injected with single dose of SCT800 （80, 180, and 280 IU/kg） or the commercially available product Xyntha （280 IU/kg）, pharmacokinetics profiles were evaluated based on measuring plasma FVIIh C. For pharmacodynamics study, dose-response curves of SCT800 and Xyntha （1-200 IU/kg） were constructed using a tail bleeding model monitoring both bleeding time and blood loss. Results： Pharmacokinetics profile analysis showed a dose independency of SCT800 ranging from 80 to 280 IU/kg and comparable pharmacokinetic profiles between SCT800 and Xyntha at the doses tested. Pharmacodynamics study revealed comparable ED50 values of SCT800 and Xyntha in the tail bleeding model： 14.78 and 15.81 IU/kg for bleeding time, respectively; 13.50 and 13.58 IU/kg for blood loss, respectively. Moreover, at the doses tested, the accompanying dose-related safety evaluation in the tail bleeding model showed lower hypercoagulable tendency and wider dosage range potential for SCT800 than Xyntha. Conclusion： In hemophilia A mice, SCT800 shows comparable pharmacokinetics and pharmacodynamics to Xyntha at the doses tested, and possibly with better safety properties.