Long-term impact of RFVIIIFC prophylaxis in paediatric, adolescent, and adult subjects with target joints and severe haemophilia a

Abstract

Background: Long-term safety and efficacy of rFVIIIFc are being evaluated in the ongoing ASPIRE extension study of subjects with severe haemophilia A who completed A-LONG or Kids A-LONG. Aims: To present data on re-bleeds and target joint resolution from subjects with target joints at entry into the parent study through the third ASPIRE interim data cut. Methods: Subjects with ≥1 target joint (major joint with ≥3 bleeding episodes in a 6-mo period) at parent study entry with available pre-parent study data and on-study data were evaluated. ASPIRE treatment groups (≥12 y) were: individualised prophylaxis (IP), weekly prophylaxis (WP), modified prophylaxis (MP) or episodic treatment (ET); or (< 12 y) IP or MP. Outcomes were analysed over the duration of the parent study through the third ASPIRE interim data cut (11 Jan 2016). Results: 113 A-LONG subjects had target joints at baseline; 111 with evaluable data had 287 target joints at baseline and a cumulative median (IQR) 4.0 (2.8, 4.1) y on rFVIIIFc. 13 Kids A-LONG subjects had 15 target joints at baseline and 3.0 (0.5, 3.1) y on rFVIIIFc. Target joint annualised bleeding rates were low for subjects on rFVIIIFc prophylaxis (Table 1). 43.9% of IP, 42.3% of WP and 6.3% of MP A-LONG subjects and 53.8% of Kids A-LONG subjects (all IP) had no target joint bleeding episodes. Among prophylaxis subjects with target joints at baseline and 12 mo follow-up, 100% of A-LONG and Kids A-LONG subjects had ≥1 target joint resolved (≤2 spontaneous bleeding episodes in 12 consecutive mo); 99.6% and 100% of evaluable target joints in A-LONG and Kids A-LONG subjects were resolved, respectively. Table 2 shows prophylactic dose and dosing intervals. In adults/ adolescents, 96.4% of target joint bleeding episodes were controlled with ≤2 rFVIIIFc injections; patients rated 82.0% of injections to control a bleeding episode as excellent or good. Conclusions: Low target joint ABRs and effective target joint resolution occurred in children, adolescents, and adults on long-term rFVIIIFc prophylaxis.L6241557302018-10-09 <br />