Cost-Effectiveness of Pembrolizumab as an Adjuvant Treatment for Adults and Adolescents Aged 12 Years and Older With Resected Stage IIB/IIC Melanoma in France

OBJECTIVES: To assess the cost-effectiveness of adjuvant pembrolizumab versus active surveillance for adults and adolescents aged 12 years and older with resected stage IIB/IIC melanoma, from the French healthcare system perspective, over a 30-year time horizon.

METHODS: A four-state Markov transition model (recurrence-free (RF), locoregional recurrence (LR), distant metastasis (DM), and death) was developed to determine the cost-effectiveness of pembrolizumab versus active surveillance over a 30-year time horizon. Clinical data were derived from the KEYNOTE-716 randomized trial for RF and LR, and from KEYNOTE-006 and a network meta-analysis (NMA) for DM. Utility data from KEYNOTE-716 and from KEYNOTE-006 were used to populate RF/LR and DM utility scores respectively. Utilities were mapped and converted to French population-based utilities using the French value sets. Only direct medical costs were considered, based on public sources. Costs and health outcomes were discounted at 2.5% per year.

RESULTS: Model simulations demonstrated that pembrolizumab as an adjuvant treatment for resected stage IIB/IIC melanoma versus active surveillance in France is associated with 1,06 life years (LYs) gained and 0,82 additional quality adjusted life years (QALYs) (12,72 months with 9,84 in perfect health), as well as incremental costs of €27,258. Incremental cost-effectiveness ratios were €33,110/QALY and €25,706/LY. Based on the model, 5 years after pembrolizumab adjuvant treatment (period with the highest risk of recurrence), the proportion of patients remaining RF increased by 27% versus active surveillance, and progression to stage III or IV melanoma decreased by 65% versus active surveillance. With a willingness-to-pay (WTP) threshold up to €93,000/QALY, pembrolizumab has at least an 80% probability of being cost-effective relative to active surveillance.

CONCLUSIONS: Model-based analysis suggests that pembrolizumab as an adjuvant treatment is cost-effective, as it improves life expectancy, QALYs and reduces risk of recurrence and progression to more severe melanoma stage.