Economic analysis of adjuvant interferon alfa-2b in high-risk melanoma based on projections from Eastern Cooperative Oncology Group 1684

Interferon alfa-2b (IFN) in a randomized clinical trial (E1684) prolonged relapse-free and total survival in high-risk resected melanoma. However, the costs and toxicities of IFN are barriers to its widespread use. This study was undertaken to analyze the projected costs and long-term benefits of IFN by combining prospectively collected data on IFN actual dosage, time of recurrence, and survival with secondary data on long-term melanoma recurrence risks to project the cost-effectiveness of adjuvant IFN compared with observation.

Two hypothetical cohorts of 50-year-old melanoma patients whose mean IFN dosage and clinical results were directly taken from E1684 were included in the study. Melanoma recurrence risks beyond 5 years were derived from international databases. Melanoma recurrence care costs and quality-of-life adjustments, when considered, were based on expert consensus. End points were incremental costs, life-years gained, and cost per life-year gained with and without quality-of-life adjustments.

The IFN cohort was projected to have an increased (undiscounted) survival of 0.52 years at 7 years and 1.90 years over a lifetime. The projected incremental cost (in 1996 United States dollars) per life-year gained in the IFN cohort ranged from $13,700 after 35 years to $32,600 at 7 years, the median follow-up of E1684. Using assigned quality-of-life values for IFN and recurrence, the lifetime cost per quality adjusted life-year increased to $15,200. Even if treatment costs for recurrence were excluded, the lifetime incremental cost per life-year gained was $21,600.

The cost and toxicity of IFN must be balanced against its projected benefits in high-risk melanoma. The derived cost-effectiveness and cost-utility ratios for IFN were comparable to other cancer interventions for which cost-effectiveness analysis has been performed.