Assessing the value of mepolizumab for severe eosinophilic asthma: a cost-effectiveness analysis

Background Adding mepolizumab to standard treatment with inhaled corticosteroids and controller medications could decrease asthma exacerbations and use of long-term oral steroids in patients with severe disease and increased eosinophils; however, mepolizumab is costly and its cost effectiveness is unknown. Objective To estimate the cost effectiveness of mepolizumab. Methods A Markov model was used to determine the incremental cost per quality-adjusted life year (QALY) gained for mepolizumab plus standard of care (SoC) and for SoC alone. The population, adults with severe eosinophilic asthma, was modeled for a lifetime time horizon. A responder scenario analysis was conducted to determine the cost effectiveness for a cohort able to achieve and maintain asthma control. Results Over a lifetime treatment horizon, 23.96 exacerbations were averted per patient receiving mepolizumab plus SoC. Avoidance of exacerbations and decrease in long-term oral steroid use resulted in more than $18,000 in cost offsets among those receiving mepolizumab, but treatment costs increased by more than $600,000. Treatment with mepolizumab plus SoC vs SoC alone resulted in a cost-effectiveness estimate of $386,000 per QALY. To achieve cost effectiveness of approximately $150,000 per QALY, mepolizumab would require a more than 60% price discount. At current pricing, treating a responder cohort yielded cost-effectiveness estimates near $160,000 per QALY. Conclusion The estimated cost effectiveness of mepolizumab exceeds value thresholds. Achieving these thresholds would require significant discounts from the current list price. Alternatively, treatment limited to responders improves the cost effectiveness toward, but remains still slightly above, these thresholds. Payers interested in improving the efficiency of health care resources should consider negotiations of the mepolizumab price and ways to predict and assess the response to mepolizumab.