Abstract Number: PB0889
Meeting: ISTH 2020 Congress
Background: Safety and efficacy of the extended half-life rFIXFc were established in phase 3 trials in patients with severe haemophilia B (HB). These trials showed low annualised bleeding rates (ABR) with 7 to ≥ 14 days prophylaxis dosing interval as well as efficacy in treatment of acute bleeds and perioperative management. rFIXFc was launched in France March 2018. The B-SURE study will evaluate real-world effectiveness and usage of rFIXFc in HB patients in France.
Aims: To describe baseline data from the ongoing B-SURE study of rFIXFc.
Methods: B-SURE (NCT03655340), a 24-month prospective, non-interventional, multicentre study, enrolled HB patients in France between September 2018 and September 2019. Eligible patients had received previous FIX treatment and were prescribed on-demand or prophylactic rFIXFc treatment prior to or at enrolment. Patients are routinely monitored according to local practice. At enrolment, baseline characteristics and 6 months retrospective data prior to switch to rFIXFc were collected, including ABR, joint ABR, factor usage and reason for initiating rFIXFc.
Results: Ninety-one male patients were enrolled at 21 Haemophilia treatment centres in France. Baseline data and characteristics are shown in Table 1 and treatment regimens before and after initiation of rFIXFc are shown in Figure 1.
The main reasons for initiating prophylactic treatment with rFIXFc was to ‘Reduce injection frequency while maintaining protection from bleeds’ (47%) and ‘Protection from bleeds’ (39%). Prior to rFIXFc initiation, median ABR and joint ABR in the pre-study prophylaxis group (n=55) were 2.0 (IQR 0.0-4.0) and 0.0 (IQR 0.0-2.0), respectively. The median number of injections on conventional FIX prophylaxis was two per week.
Conclusions: Baseline data from the ongoing B-SURE study provides insights into demographics and clinical characteristics, and the rationale for initiating prophylaxis with rFIXFc, in HB patients. The study population appears well suited to evaluate real-world use of rFIXFc in France.
|Age [years], mean (min-max)
<18 years, n (%)
≥18 years, n (%)
|Severity of haemophilia
|At least one target joint at enrolment, n (%)||26 (28.9)|
|Prior to rFIXFc initiation||n (%)|
|History of inhibitors (tolerized prior to rFIXFc initiation)||2 (2.2)|
|Prophylaxis FIX regimen||64 (71.1)|
|On demand FIX regimen||24 (26.7)|
|*Ninety-one patients enrolled, but data for one patient not available for this analysis|
[Baseline demographic data and characteristics]
To cite this abstract in AMA style:Chambost H, Wibaut B, Borel Derlon A, Claeyssens S, Castet S, d'Oiron R, Negrier C, Andersson H, Bergenstråle S, Gandossi C, Martinez C. A French Multicentre Prospective, Non-Interventional Study (B-SURE) Evaluating Real-World Usage and Effectiveness of Recombinant Factor IX Fc Fusion Protein (rFIXFc) in People with Haemophilia B: Baseline Data [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/a-french-multicentre-prospective-non-interventional-study-b-sure-evaluating-real-world-usage-and-effectiveness-of-recombinant-factor-ix-fc-fusion-protein-rfixfc-in-people-with-haemophilia-b-base/. Accessed May 16, 2021.
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