Cost minimization model for treatment of minor bleeding episodes in inhibitor patients - methodological issues

Systematic literature review of economics analysis on treatment of mild-to-moderate bleeds with aPCC versus rFVIIa

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.

Cost and effectiveness of treatments for mild-to-moderate bleeding episodes in haemophilia patients with inhibitors in Korea

First-line treatment for mild-to-moderate bleeding episodes in patients with haemophilia and inhibitors in Korea is currently activated prothrombin complex concentrate (aPCC) with recombinant activated factor VII (rFVIIa) as second-line therapy or as a last resort. The aim of this study was to estimate the cost and effectiveness of aPCC vs. rFVIIa for treating mild-to-moderate bleeds in inhibitor patients from the Korean reimbursement authorities' perspective. Clinical outcomes and resource utilization data (number of doses, average dose, number of outpatient visits, inpatient stays, ambulance transport and concomitant medications) were collected from an observational study involving four Korean paediatric haemophilia centres. Cost-effectiveness was modelled using a decision analysis approach and sensitivity analyses undertaken. rFVIIa was a more effective haemostatic therapy (87.1% efficacy in bleed resolution) than aPCC (64.0%). rFVIIa effected more rapid haemostasis, resolving bleeding in a mean of 6.6 h vs. 25.2 h for aPCC. Fewer rFVIIa doses were required per bleed vs. aPCC (means 1.7 and 2.3). Mean total direct medical costs from bleed initiation to cessation were estimated at Korean Won (KRW)12 460 thousand (US$12 311) for rFVIIa given as first-line therapy and KRW18 304 thousand (US$18 085) for aPCC given as first-line therapy. Sensitivity analyses confirmed the cost-effectiveness of rFVIIa vs. aPCC given as first-line therapy. In Korea, use of rFVIIa as first-line therapy for treatment of mild-to-moderate bleeding episodes in inhibitor patients is both clinically effective and cost-effective compared with initial aPCC treatment. rFVIIa should be considered as the first-line treatment for mild-to-moderate bleeding episodes in patients with haemophilia and inhibitors in Korea.

Health economic review of recombinant activated factor VII for treatment of bleeding episodes in hemophilia patients with inhibitors

Severe hemophilia with inhibitors is a rare disease with substantial clinical, humanistic and economic consequences. This review provides an overview of the role of recombinant activated factor VII (rFVIIa) versus plasma-derived bypassing agents for hemophilia with inhibitors and summarizes the 13 formal economic analyses (6 burden of illness and 7 comparative studies) that have been published in this indication. The findings suggest that the economic impact of rFVIIa has occurred primarily during hospitalization to manage major bleeding episodes and to allow for elective orthopedic surgeries that would not have been attempted prior to rFVIIa. Comparative analyses for on-demand treatment suggest that the total cost of treating a bleeding episode with rFVIIa may be lower than with plasma-based agents due to faster bleeding resolution, higher initial efficacy rates and avoidance of second and third lines of treatment.