Long-term retention rate of mepolizumab treatment in severe asthma: a 36-months real-life experience.

Mepolizumab is an anti-IL-5 monoclonal antibody that has shown, in different trials, the capacity to induce a reduction of exacerbations, an improvement of asthma control and a significant oral corticosteroid (OCS)-sparing effect. At present, there is limited real-life data about its long-term effects. The aim of the study was to evaluate the long-term effects of mepolizumab in real-life. We conducted a 36-months single-center retrospective study in 51 patients suffering from severe eosinophilic asthma treated with mepolizumab 100 mg/4 weeks. Clinical outcomes (symptoms, annual asthma exacerbation rates) were monitored. Additionally, we estimated annualized OCS dosage before and after mepolizumab treatment. Mepolizumab retention rate in the follow-up period was also evaluated. A significant decrease of the annual rate of asthma exacerbations in association with significant changes in asthma control was observed. Specifically, the exacerbation rate significantly fell from 5.1 ± 4 per person/year in the pre-mepolizumab treatment period to 0.8 ± 1.2 per person/year in the 12-follow-up. The clinical benefit was maintained throughout the study follow up period of 36 months. Mepolizumab treatment induced significant changes in both ACT and ACQ5 scores. The majority of patients (65.2%) experienced a more pronounced improvement of 50% or more in SNOT-22. A mean cumulative OCS exposure reduction of 5365.5 mg over a 3-year period for patients receiving mepolizumab was estimated. The drug retention rate was: 96% at 12 months; 93.7% at 18 months, 88.9% at 24 months and 82.3% at 36 months. Our real-life results confirm that mepolizumab treatment allows to control asthma symptoms, reduce exacerbations and OCS exposure in a significant and sustained manner.