A RETROSPECTIVE COST-EFFECTIVENESS ANALYSIS OF INTERFERON AS ADJUVANTTHERAPY IN HIGH-RISK RESECTED CUTANEOUS MELANOMA

To assess the cost per life year gained of alpha interferon (IFN) as a djuvant therapy for patients with high-risk resected melanoma, we cond ucted a retrospective, incremental cost-effectiveness analysis on clin ical data from a previously published ECOG trial [9]. The Gompertz mod el was used to estimate the total Lifetime values of patient-gears of subjects receiving IFN in comparison with subjects given no adjuvant t reatment. The ECOG trial involved 143 patients treated with high-dose IFN and 137 given no adjuvant treatment. Estimated drug expenditures w ere based on the assumption of a cost of $109.25 per 10 MU of IFN. Our analysis of the ECOG results showed that the adjuvant treatment of 10 0 subjects with high-dose IFN improved survival expectancy by 133.6 di scounted life years or 308 undiscounted life years. The use of IFN (co mpared with no adjuvant treatment) implied an incremental cost of $164 67 per discounted life year saved (95% Cl of $4752-50000) or $7143 per undiscounted life year saved (95% CI of $3226-33846). Sensitivity tes ting, in which variations were introduced in the main factors influenc ing cost and effectiveness, showed that this value always remained bel ow $50000. Our pharmacoeconomic analysis indicates that adjuvant treat ment with high-dose IFN in patients with high-risk resected melanoma i mplies a favourable cost-effectiveness ratio. Because two other studie s showed no significant survival benefit in patients receiving adjuvan t IFN at lower values of total dose per patient, the controversy remai ns and confirmation data are needed for the ECOG trial's results. If t hese clinical results are confirmed, our analysis shows that the dosag e of IFN given in this trial has a favourable pharmacoeconomic profile . (C) 1997 Elsevier Science Ltd.