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.