High-dose recombinant factor VIIa therapy in hemophilia patients with inhibitors

Recombinant activated factor VII (rFVIIa; NovoSeven®, Novo Nordisk, Bagsvaerd, Denmark) is well established as an effective hemostatic agent for the management and prophylaxis of hemorrhage in hemophilia patients with inhibitors. Treatment schedules usually involve multiple bolus doses of 90 to 120 μg/kg administered every 2 to 3 hours, but recent evidence suggests that the use of higher doses might be justified. Such high-dose regimens may overcome the rapid clearance rate observed in pediatric patients, and may be more convenient for patients with poor venous access. It has been suggested that individually tailored high-dose therapies might be beneficial in selected groups of patients, although careful monitoring of such patients is advised. Thrombelastography has demonstrated considerable success in this regard, allowing accurate assessment of both hemostatic efficacy and individual response to rFVIIa. To date, no safety issues associated with high-dose rFVIIa have been identified. However, it is hoped that further research will support these favorable observations and thus contribute towards more effective dose optimization of rFVIIa in hemophilic inhibitor patients.