Bleeding Episodes in Patients With Haemophilia B Receiving Prophylactic Factor IX Treatment: A Systematic Review and Meta-Analysis

Background: Prophylaxis with coagulation factor concentrates is the mainstay of treatment in severe hemophilia A and B. Data on bleeding rates in persons with congenital haemophilia B (PwcHB) receiving prophylaxis are inconsistent. Aim: This systematic review and meta-analysis were aimed at assessing bleeding outcomes, including annualised bleeding rates (ABR) and the proportion of patients with zero bleeding events, in PwcHB receiving prophylaxis with plasma-derived or recombinant FIX products with standard (rSHL) or extended half-life (rEHL). Methods: A systematic search was conducted using the bibliographic database Medline, Embase and Cochrane Central Register. The protocol was registered on PROSPERO (registration number: CRD42024592785). Results: The search yielded 2440 citations and a total of 42 studies (2 randomised and 40 nonrandomised) were included in the final analysis. The pooled estimated mean (95% confidence interval [CI]) ABR was significantly lower in PwcHB treated prophylactically with rEHL FIX than in those receiving rSHL FIX products (1.29 [95% CI: 0.91, 1.66] vs. 3.12 [95% CI: 2.63, 3.62], p < 0.01). The proportion of participants with zero bleeding events was significantly higher in PwcHB treated prophylactically with rEHL FIX than in those receiving rSHL FIX (0.53 [95% CI: 0.37, 0.69] vs. 0.24 [95% CI: 0.14, 0.39], p = 0.01). The ABR did not differ according to age groups (more or less than 12 years). Conclusion: The results of this meta-analysis suggest that compared to standard half-life FIX concentrates, prophylaxis with rEHL FIX products is associated with a reduction in ABR and a higher proportion of patients with no bleeding episodes.