SummaryIn the phase 3 B-LONG (Recombinant Factor IX Fc Fusion Protein [rFIXFc] in Subjects With Haemophilia B) study, rFIXFc demonstrated a prolonged half-life compared with recombinant factor IX (rFIX), and safety and efficacy for prophylaxis and treatment of bleeding in subjects with moderately-severe to severe haemophilia B. In this B-LONG sub-analysis, rFIXFc was evaluated for efficacy in subjects requiring major surgery. Dosing was investigator-determined. Assessments included dosing, consumption, bleeding, transfusions and haemostatic response. A population pharmacokinetics model of rFIXFc was used to predict FIX activity. Twelve subjects underwent 14 major surgeries (including 11 orthopaedic surgeries); most subjects (11/12) received rFIXFc prophylaxis before surgery (range, 2 weeks-12 months). Investigators/surgeons rated haemostatic responses as excellent (n = 13) or good (n = 1). In most surgeries (85Á7%), haemostasis from the pre-surgical dose until the end of surgery was maintained with a single rFIXFc infusion. Blood loss was consistent with similar surgeries in subjects without haemophilia. The strong correlation (R 2 = 0Á9586, P < 0Á001) between observed and population pharmacokinetic model-predicted FIX activity suggests surgery did not impact rFIXFc pharmacokinetics. No unique safety concerns or inhibitors were observed. In conclusion, rFIXFc was safe and efficacious, with prolonged dosing intervals and low consumption, when used perioperatively in haemophilia B. Surgery did not appear to alter rFIXFc pharmacokinetics.
Introduction
The safety, efficacy and prolonged half‐life of recombinant factor VIII Fc fusion protein (rFVIIIFc) in previously treated patients with severe haemophilia A was demonstrated in the phase 3 A‐LONG and Kids A‐LONG studies. Here, we report interim safety and efficacy data from the rFVIIIFc extension study, ASPIRE (ClinicalTrials.gov #NCT01454739).
Methods
Eligible subjects could enrol in ASPIRE upon completing A‐LONG or Kids A‐LONG. There were four treatment groups: individualized prophylaxis; weekly prophylaxis; modified prophylaxis (for subjects in whom optimal treatment could not be achieved with individualized or weekly prophylaxis); and episodic treatment. The primary endpoint was development of inhibitors.
Results
A total of 150 A‐LONG subjects and 61 Kids A‐LONG subjects enrolled in ASPIRE. As of the interim data cut (6 January 2014), the median time on study was 80.9 (A‐LONG) and 23.9 (Kids A‐LONG) weeks. The majority of subjects (A‐LONG, 92.0%; Kids A‐LONG, 57.4%) had ≥100 cumulative rFVIIIFc exposure days. No inhibitors were observed. Adverse events were generally consistent with those expected in the general haemophilia A population. Median annualized bleeding rates (ABRs) were low with individualized [A‐LONG: 0.66; Kids A‐LONG: 0.00 (<6 years old), 1.54 (6 to <12 years old)], weekly (A‐LONG: 2.03) and modified (A‐LONG: 1.97) prophylaxis. There was no change in prophylactic infusion frequency or total weekly prophylactic dose in the majority of subjects from A‐LONG and Kids A‐LONG.
Conclusion
Interim data from ASPIRE confirm the long‐term safety of rFVIIIFc and the maintenance of a low ABR with extended‐interval prophylactic dosing in patients with severe haemophilia A.
Eradication of Helicobacter pylori (H. pylori ) from the gastric mucosa has been associated with improvement of several systemic diseases, including immune thrombocytopenic purpura (ITP). Over the last 5 years, several studies have reported improved platelet counts in H. pylori-positive ITP patients following standard triple H. pylori eradication therapy. Review of published studies in which eradication of H. pylori has been performed in the ITP population indicates an overall response rate of 52% in 193 subjects in whom H. pylori was eradicated. Cohorts from Japan and Italy report higher response rates. There is no established mechanism to explain how this organism, which does not invade the gastric mucosa, could be implicated in the pathogenesis of this immune-based platelet disorder. Several theories including molecular mimicry, platelet aggregation, and immunomodulatory effects of macrolides have been proposed to explain the platelet response to anti-H. pylori therapy. Large randomized-controlled studies enrolling patients from various ethnic backgrounds will be necessary to determine the response rate and mechanism of response and to gain a better understanding of the pathogenesis of ITP. Am.
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