Cost Effectiveness of Pembrolizumab for Advanced Melanoma Treatment in Portugal

Background: The aim of this study was to assess the cost-effectiveness of pembrolizumab in treating patients with ipilimumab-naive advanced melanoma in Portugal. Methods: A cost-effectiveness model was developed to analyze the costs and consequences of treatment with pembrolizumab compared to treatment with ipilimumab in patients with advanced melanoma not previously treated with ipilimumab. The model was parameterized by using data from a head to-head phase III randomized clinical trial, KEYNOTE-006. Extrapolation of long-term outcomes was based on approaches previously applied, combining ipilimumab data and melanoma patients' registry data. The analysis was conducted from the perspective of the Portuguese National Health Service, and a lifetime horizon (40 years) was used. Portugal-specific disease management costs were estimated by convening a panel of six clinical experts to derive health state resource use and multiplying the results by national unit costs. To test for the robustness of the conclusions, we conducted deterministic and probabilistic sensitivity analyses. Results: Pembrolizumab increases life expectancy in 1.57 undiscounted life-years (LYs) and is associated with an increase in costs versus that of ipilimumab. The estimated incremental cost-effectiveness ratio is 47,221 per quality-adjusted life-year (QALY) and 42,956 per LY. Deterministic sensitivity analysis showed that the results were robust to the change of most input values or assumptions and were sensitive to time on treatment scenarios. According to the probabilistic sensitivity analysis performed, pembrolizumab is associated with a cost per QALY gained inferior to 50,000 in 75% of the cases. Conclusions: Considering the usually accepted thresholds in oncology, pembrolizumab is a cost-effective alternative for treating patients with advanced melanoma in Portugal.