Dose optimization of recombinant factor VIIa in the treatment of acute bleeding in haemophilia-associated inhibitors

Recombinant coagulation factor VIIa (rFVIIa; NovoSeven®) represents an important advance in the therapy for haemophilia patients with inhibitors. Since licensure, the standard dosing has been perceived as 90-120 μg/kg every 2-3 h until cessation of bleeding. There has been an accumulation of anecdotal experience with the use of higher, less frequent dosing of rFVIIa, and a controlled clinical trial is underway to assess the safety and efficacy of the current dosing recommendation and a single dose of 270 μg/kg. Furthermore, a post-licensure database is being analysed to evaluate the current dosing in acute bleeding episodes. Treatment, efficacy, and safety data from haemophilia patients with inhibitors treated with rFVIIa in a variety of contexts, including the on-demand treatment of acute bleeding, were entered into the registry. Data from patients treated with bolus infusion of rFVIIa were analysed and bleeding episodes were grouped according to total rFVIIa dose administered. Registry data suggest that rFVIIa is both safe and effective at doses >200 μg/kg and that efficacy improves with increased dose. The database is currently being analysed to determine if increasing dose is associated with an elimination of the need for repeat dosing.