Recent clinical trial evidence has demonstrated that nivolumab in combination with ipilimumab improves progression free survival versus ipilimumab in previously untreated patients with advanced melanoma. The aim of this study was to evaluate the cost-effectiveness of nivolumab in combination with ipilimumab for treatment of these patients from an Australian health system perspective.
A state-transition Markov model developed to address the requirements of Australian decision makers was used to simulate the follow-up of Australian patients with advanced melanoma. The time horizon was 10 years with costs and outcomes discounted at 5% annually. Decision analysis was applied to compare nivolumab plus ipilimumab versus ipilimumab alone. For the nivolumab plus ipilimumab group, risk of progression was based on those observed in the nivolumab plus ipilimumab arms of two clinical trials. For the ipilimumab group, risk of progression was derived from application of hazard ratios to equivalent risks in the nivolumab plus ipilimumab group. Progression free survival beyond the trial period was extrapolated using a validated statistical model. Long term overall survival was derived using published equations for advanced melanoma. Costs of managing advanced melanoma were estimated from a survey of Australian clinicians. Quality of life data were obtained from within-trial EQ-5D information. Probabilistic sensitivity analyses were undertaken using variations to key inputs.
Compared to ipilimumab, nivolumab plus ipilimumab therapy over 10 years was estimated to yield 2.37 life years and 1.99 quality adjusted life years per person, at a discounted net cost of USD$89,325 per person. These equated to incremental cost-effectiveness ratios of USD$37,684 per year of life gained and USD$44,867 per quality adjusted life year gained.
Nivolumab in combination with ipilimumab represents a cost-effective means of preventing downstream mortality and morbidity among advanced melanoma patients in Australia.
Clinical trial identification
M.A. Bohensky: financial support from Bristol Myers Squibb. H. Kim: employed by Bristol Myers Squibb Australia. All other authors have declared no conflicts of interest.