Critical appraisal of the role of recombinant activated factor VII in the treatment of hemophilia patients with inhibitors

Ampaiwan Chuansumrit¹, Pantep Angchaisuksiri², Nongnuch Sirachainan¹

¹Departments of Pediatrics and ²Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University,  Bangkok, Thailand

Abstract: Hemophilia patients with inhibitors faced the constraint of inadequate treatment for several years before the era of recombinant factor VIIa (rFVII). Initially, rFVIIa was used in the compassionate-use programs. After a worldwide license was issued, more than 1.5 million doses were administered. Bleeding of joints and muscles was controlled effectively by means of an early home treatment program, with either a standard dose of 90 μg/kg every 2 to 3 hours for a few doses or a single dose of 270 μg/kg. For more serious bleeding episodes or minor surgery, an initial dose of 90 μg/kg was given every 2 hours for 24 to 48 hours followed by increased intervals of 3 to 6 hours according to the severity of bleeding and efficacy of bleeding control. In cases of major surgery such as orthopedic procedures, the same regimen can be applied except for a higher initial dose of 120 to 180 μg/kg. However, increasing the dose should be considered if there are unexpected bleeding complications since the half-life and clearance of rFVIIa differ between individuals. In addition, prophylaxis is administered to a small number of patients. Finally, the reported thromboembolic events found in hemophilia patients with inhibitors receiving rFVIIa are extremely low, much less than 1%.

Keywords: bleeding disorder, hemophilia, inhibitor, NovoSeven, recombinant factor VIIa