A simulation exercise provided by the company of steady-state FVIII activity in patients with moderate haemophilia A (5 IU/dL) and severe haemophilia A (0 IU/dL) receiving weekly prophylaxis with efanesoctocog alfa (50 IU/kg) gave assurance that overexposure is unlikely in subjects with moderate haemophilia A (5 IU/dL) and that the percentage fraction above threshold is comparable to that of subjects with severe haemophilia A (0 IU/dL). Here, F8 is linked to hemophilia A.