In a prospective, noncontrolled, open label, multinational, multi-centre Phase III study (GENA-03) efficacy and safety of Nuwiq® were assessed in a pediatric study that enrolled 59 children aged 2 to 12 years. Fifty-seven (57) of these patients had at least 50 EDs. All patients had at least 50 previous EDs to a FVIII concentrate. The mean prophylactic dose was 38.9 IU/kg, administrated every other day or 3 times per week. A total of 45.8% of the patients did not experience any bleeding while receiving Nuwiq® prophylaxis. The annualized median (range) rate of all bleeding episodes (BEs) was 1.9 (0-20.7), with spontaneous BE rates of 0 (0-13.8) and traumatic BE rates of 1.57 (0-18.6). Prophylaxis with Nuwiq® was assessed to be excellent or good for spontaneous BEs in 96.6% of the patients, for traumatic in 98.3% and for all BEs 91.5% of the patients. Efficacy of Nuwiq® in the treatment of breakthrough bleeding was rated excellent or good for 82.4% of BEs. One or two infusions were sufficient to treat 81.3% of BEs and the median (range) number of infusions required to stop a BE was 1.0 (range 1–22). The mean dose for breakthrough bleeding treatment was 45.1 IU/kg.