- Confirmed diagnosis of congenital haemophilia A or B with a FVIII:C (Activated Coagulation Factor VIIa Clotting activity) or FIX:C (Coagulation Factor IX Clotting activity) one stage activity, respectively, at less than 5% of normal (based on medical records) plus/minus inhibitors (a positive inhibitor status defined as 0.6 Bethesda units)