Abstract

BACKGROUND Continuous prophylaxis for patients with hemophilia B requires frequent injections that are burdensome and that may lead to suboptimal adherence and outcomes. Hence, therapies requiring less-frequent injections are needed. In the absence of head-to-head comparisons, we compared the first extended-half-life-recombinant factor IX (rFIX) product- recombinant factor IX Fc fusion protein (rFIXFc) - with conventional rFIX products based on annualized bleed rates (ABRs) and factor consumption reported in studies of continuous prophylaxis. METHODS We compared ABRs and weekly factor consumption rates in clinical studies of continuous prophylaxis treatment with rFIXFc and conventional rFIX products (identified by systematic literature review) in previously-treated adolescents and adults with moderate-to-severe hemophilia B. Meta-analysis was used to pool ABRs reported for conventional rFIX products for comparison. Comparisons of weekly factor consumption were based on the mean, reported or estimated from the mean dose per injection. RESULTS Five conventional rFIX studies (injections 1 to >3 times/week) met the criteria for comparison with once-weekly rFIXFc reported by the B-LONG study. The pooled mean ABR for conventional rFIX was slightly higher than but comparable to rFIXFc (difference = 0.71; P = 0.210). Weekly factor consumption was significantly lower with rFIXFc than in conventional rFIX studies (difference in means = 42.8-74.5 IU/kg/week [93-161%], P<0.001). CONCLUSION Comparisons of clinical study results suggest weekly injections with rFIXFc result in similar bleeding rates and significantly lower weekly factor consumption compared with more-frequently-injected conventional rFIX products. The real-world effectiveness of rFIXFc may be higher based on results from a model of the impact of simulated differences in adherence.

Abstract

Several analyses have shown that recombinant activated factor VII (rFVIIa) is a cost-effective intervention compared with plasma-derived activated prothrombin complex concentrate (pd-aPCC) for the on-demand treatment of mild-to-moderate bleeds in haemophilia patients with inhibitors. The aim of the study was to assess the cost-effectiveness of rFVIIa vs. pd-aPCC in the treatment of bleeding episodes in severe haemophilia A patients with inhibitors in Spain. A decision analytic model was designed to evaluate the costs and clinical outcomes of using rFVIIa or pd-aPCC to treat mild-to-moderate joint bleeds in children (<=14 years old) and adults with inhibitors. Data were obtained from a published meta-analysis and a panel of haemophilia experts. The analysis was conducted from the perspective of the Spanish National Healthcare System. One-way sensitivity analyses were performed to assess the impact of model assumptions on study results. In the Treur meta-analysis, rFVIIa resulted in cumulative joint bleed resolution of 88% and 95% after 24 and 36 h, respectively, compared with 62% and 76%, respectively, with pd-aPCC (Treur et al. Haemophilia 2009; 15: 420-36). Here, the mean cost per bleed was estimated at 8473 and 15 579 in children and adults treated with rFVIIa, vs. 8627 and 15 677 in children and adults treated with pd-aPCC. rFVIIa treatment was found to be the dominating option (cheaper and more effective). The one-way sensitivity analysis also confirmed that rFVIIa was less costly than pd-aPCC. The model suggests that rFVIIa is a cost-effective option compared with pd-aPCC for the treatment of mild-to-moderate bleeding episodes in a Spanish setting. 2013 John Wiley & Sons Ltd.

Abstract

Objective: Two bypassing agents, activated prothrombin complex concentrates (aPCC) and recombinant factor VIIa (rFVIIa), have shown similar efficacy and safety in the treatment of bleeding episodes in patients with hemophilia and inhibitors as demonstrated through the only two head-to-head clinical trials. Given the economic burden of bypassing treatment, it is crucial to have a valid estimate of cost effectiveness of alternative treatments. The aims of this study were to conduct a systematic review of published pharmacoeconomic literature on the cost-effectiveness of aPCC versus rFVIIa to treat mild-to-moderate bleeds in patients with hemophilia and inhibitors, with a focus on the model assumptions and their impact on results. Methods: An English language search was conducted for original economic studies comparing aPCC and rFVIIa published between 1995 and July 2010. Detailed information on sponsorship, study design, assumptions and their impact on results was collected for each study. Results: A total of 11 economic studies were included in the review. Nine studies assessed cost per bleeding episode (eight cost-minimization analysis (CMA) and one cost-effectiveness analysis (CEA)). Two studies were from longitudinal perspective. Studies on cost per bleeding episode were evaluated and systematically compared. All studies were from a third-party payer perspective. Most analyses, except one study, used a similar decision-tree model. The assumptions for all CMA studies were obtained from non-comparable single-armed trials or observational data. All studies were sponsored by the two competing manufacturers of rFVIIa (seven studies) and aPCC (two studies). The crucial parameter assumptions on treatment efficacy and dosing drove their reported findings. Eight of these nine studies favored their sponsor's product. Conclusion: With one exception, published economic studies tend to favor their sponsor's product primarily by assuming a higher efficacy and lower dosing for the sponsored agent, even though the two existing head-to-head clinical studies do not support superior efficacy for either product.