Objective:
To evaluate efficacy of IB1001 with respect to breakthrough bleeding during prophylaxis and with respect to control of hemorrhaging in prophylaxis and on-demand treatment regimens in previously treated patients (PTPs) with hemophilia B.
Methods:
The efficacy of IB1001 has been evaluated in a prospective, open-label, uncontrolled multicenter international study in which a total of 68 male PTPs between 7 and 64 years of age received IB1001 either as prophylaxis or on-demand treatment. All subjects had severe or moderately severe (factor IX level ≤ 2 IU/dL) hemophilia B without inhibitors. There were 61 subjects who received prophylaxis [predominantly secondary or tertiary prophylaxis as defined by World Federation of Hemophilia (WFH) guidelines] and 12 were treated on-demand during the study conduct. Both, the subjects and the study investigators rated the efficacy of IB1001 in management of bleeding episodes.
Summary:
The mean number of exposure days (ED) was 138.2 (median: 127.5 ED), including 55 subjects with ≥ 50 ED and 45 subjects with ≥ 100 ED. Subjects on prophylaxis received a mean intravenous dose of 55.0 ± 12.8 IU/kg IB1001 twice weekly, while subjects in the on- demand regimen received a mean dose of 60.0 ± 18.2 IU/kg IB1001. In the prophylaxis group, median annualized bleed rate (ABR) was 1.52, and in the on-demand group, median ABR was 16.39. There were 19/61 (31.1%) subjects on IB1001 prophylaxis who reported no bleeding episodes. A total of 508 bleeding episodes were treated with IB1001; 286 bleeds were recorded for patients on prophylaxis and 222 in the on-demand regimen. Majority of the bleeds (70.9%) resolved after a single IB1001 infusion, while 13% of the bleeds required two infusions. A minority of the bleeds (4.7%) required 5 or more infusions; these bleeds were predominantly related to trauma, target joints and/or muscle bleeds. Subjects rated efficacy of IB1001 as ‘excellent’ or ‘good’ in 84% of all treated bleeding episodes. Of 414 subject visits where the efficacy of IB1001 was evaluated by the study investigators, 92% were rated as ‘effective’ in prevention and treatment of bleeding by IB1001.
Conclusions:
IB1001 is effective for the treatment of hemophilia B either as secondary or tertiary prophylaxis or on an episodic (on-demand) basis. Based on clinical trial data, IB1001 is effective in controlling breakthrough or episodic bleeding episodes.