The Cost Effectiveness of a New Formulation of Recombinant Factor VIIa in the Home Treatment of Mild to Moderate Bleeding Episodes in Haemophilia a Patients with Inhibitors in the United Kingdom.

The introduction of room temperature stable recombinant Factor VIIa (rFVIIa) (eptacog alfa, activated, [NovoSeven^®]) in the United Kingdom (UK) provides a step forward in care for haemophilia A patients with inhibitors through enabling greater patient independence and freedom. It allows patients to treat bleeds earlier which has been shown to be associated with a greater rate of success and fewer injections being required¹. Delayed treatment resulting in prolonged bleeding may result in longer hospitalization, and in some patients, a subsequent need for surgical procedures which results in an increase in direct medical costs. The objective of this analysis was to assess whether the benefits of room temperature stable rFVIIa would offset the small price premium associated with the new formulation compared to the original formulation as well as remain cost-effective compared to the other bypassing agent, activated prothrombin complex concentrate (aPCC). The study used a decision analytic approach, similar to a published economic modeling study², to model the expected costs and outcomes of room temperature stable rFVIIa, original rFVIIa and aPCC in the home treatment of a mild to moderate bleeding episode in haemophilia A patients with inhibitors. The mean weight of patients was assumed to be 70kg. Each treatment regimen comprised first-, second- and third- line treatment:

• original rFVIIa - original rFVIIa - original rFVIIa ;

• room temperature stable rFVIIa - room temperature stable rFVIIa – room temperature stable rFVIIa; and

• aPCC – aPCC – room temperature stable rFVIIa.

The efficacy and dosing of aPCC and original rFVIIa were obtained from the published literature. The efficacy of room temperature stable rFVIIa was assumed to be slightly higher than that for original rFVIIa and the dose of room temperature stable rFVIIa was assumed to be slightly less than that for original rFVIIa. Patients whose mild to moderate bleeding episodes were not resolved with first-line home treatment were admitted to hospital for second- and third-line treatment. All bleeding episodes resolved with third-line treatment. The outcome used in the analysis was resolved mild to moderate bleeding episode. Only the costs of the haemostatic agents were included in the base-case analysis. The different treatment regimens for the treatment of a mild to moderate bleeding episode of haemophilia A patients with inhibitors in the UK resulted in different costs attributable to resolving a mild to moderate bleeding episode:

• £9,644 (EUR 12,151);

• £9,458 (EUR 11,917); and

• £14,097 (EUR 17,762).

Sensitivity analysis showed the results to be robust to changes in key parameters. The results show that both original rFVIIa and room temperature stable rFVIIa are cost-effective compared to aPCC, in the home treatment of a mild to moderate bleeding episode, in haemophilia A patients with inhibitors. In addition, the analysis highlights the fact that price alone does not determine overall treatment costs, and that even small improvements in efficacy and dosing associated with earlier treatment may reduce overall treatment costs.