Cost effectiveness and cost utility of adjuvant interferon alpha in cutaneous melanoma: a review

Although interferon alpha (IFN) has been approved since 1995 in the US as adjuvant therapy for high-risk melanoma patients, its cost effectiveness and economic value have only been recently addressed. There are very few papers that address the overall cost and cost components of treating melanoma patients, all of them focusing on the US. These studies showed the large cost of treatment of stage III and IV patients (around $US40,000-60,000 [1997/8 values]). Chemotherapy and adjuvant immunomodulators comprised a large part of this cost. Cost-effectiveness studies performed for the US, Spain and Italy have been largely based on the results of the pivotal Eastern Cooperative Oncology Group (ECOG) 1684 trial using high-dose (10-20 Megaunits [MU]/m(2)) IFN in mainly stage III patients. Incremental cost-effectiveness ratios for adjuvant IFN versus observation from these studies fall in the range of $US13,000-40,000 per life-year gained (1998 values), depending on the time horizon, discount rate and cost of IFN, with an extrapolated life-gain over lifetime ranging between 1.9 and 3 years. Only one study, the French Cooperative Melanoma Group trial in stage IIA/B patients, used low-dose (3 MU(2)) IFN and yielded a quite favourable incremental cost effectiveness ratio (cost per life-year gained) ranging from $US12,954 over 5 years (survival gain 3 months) to $US1,544 over a lifetime (extrapolated survival gain 2.6 years) [1995 values]. Although these results could be seen as supporting the more widespread use of adjuvant IFN in melanoma, it should be stressed that they were based on the only two positive clinical trials out of a total of ten. Moreover, the impact on survival was lost in both positive trials at > or = 8 years' follow-up and thus the costs assessments are likely to be overly optimistic. The eight negative high-dose (HDI) and low-dose (LDI) IFN trials have failed to show an impact on survival (HDI: ECOG 1690 and North Central Cancer Treatment Group [NCCTG]; LDI: ECOG 1690, WHO-16, UK Coordinating Committee on Cancer Research [UKCCRC] and Austrian, Scottish and European Organisation for Research and Treatment of Cancer trials). Mature results from more recent trials are pending. A definitive appraisal of the cost effectiveness of IFN in melanoma patients will have to await these results and their economic analyses.