OBJECTIVES: To assess the cost-effectiveness of mepolizumab in severe eosinophilic asthma (SEA) patients in France. Mepolizumab is indicated as an add-on treatment for severe refractory eosinophilic asthma in adult patients.

METHODS: A cost-utility model was developed and adapted to the French setting and the all payers perspective. Mepolizumab combined to standard therapy was compared to standard therapy (SoC) alone in the base case analysis, and to omalizumab combined to SoC in a scenario analysis. The lifetime markovian model considered four health states and three undercurrent events. The model parameters sources were a multicentre randomized controlled trial, a French cohort and literature. Results are defined as cost per quality-adjusted life year (QALY) gained.

RESULTS: Over a lifetime horizon, mepolizumab reduced the number of exacerbations compared to standard therapy (15.2 versus 19.6 exacerbations, respectively) which induced a lower mortality, and a better life expectancy for patients treated with mepolizumab in combination with standard therapy (13.9 years) as compared to standard therapy alone (12.7 years). Improvement in health conditions and lower exacerbation and mortality rates translated in terms of better quality of life and higher QALYs for mepolizumab (10.3 versus 9.3 QALYs). The incremental cost-utility ratio (ICUR) of mepolizumab combined to standard therapy versus standard therapy alone is of €105,610 per QALY gained. Versus omalizumab, mepolizumab is dominant.

CONCLUSIONS: Mepolizumab is a non-dominant strategy compared to the standard therapy alone, and a dominant strategy compared to add-on omalizumab and standard therapy. (Funding: GSK (HO-15-16522))