Blood: A new model that evaluates Emicizumab's functionality!

Bispecific antibody Emicizumab (Amyzumab) is increasingly used in the treatment of haemophilia Type AHowever, its specificity to human factors IX and X factor (FIX, FX) limited its invivia functional analysis to primate acquired haemophilia modelsrecently,Ferrisre et alhave created a new mouse model that can be used to study the function of Amy bead sebutaIn short, the FVIII defective mice were given 24h intra-intravenous injections of Emicizumab before performing the tail clip hemorrhagic model, and again to human FIX and FX before bleeding 5minThis method maintains Emicizumab and FIX and FX at a certain level (Emicizumab: 0.7-19 mg/dL; FIX: 85 U/dL; FX: 101 U/dL)the mice's plasma showed FVIII-like activity in diluted aPTT and clotting enzyme production tests, similar to human samples containing EmicizumabEmicizumab 1.5 mg/kg and higher doses can significantly reduce the amount of bleeding in the tail clip hemorrhage mouse modelHowever, the reduction was incomplete compared to mice treated with human FVIII concentrate, and no difference in efficacy was observed between dosesfrom this model, the researchers deducted FVIII-like Emicizumab activity, equivalent to a dose of 4.5 U FVIII/kg (i.e9.0 U/dL)Interestingly, combined with low doses of FVIII (5 U/kg), Emicizumab brings additional activity and causes the bleeding to stop completelyThe model may be used for further invivia analysis of Emicizumab