Effectiveness of mepolizumab therapy in patients with severe eosinophilic asthma: Austrian real-life data

Background: Mepolizumab was effective in several randomized clinical trials (RCTs) in patients with severe eosinophilic asthma, but evidence for symptom control in a real-world population is scarce. Objective: To assess asthma symptom control, lung function, use of oral corticosteroids, and biomarkers after mepolizumab initiation in real-world clinical practice. Methods: Thirty-five adult patients with severe eosinophilic asthma and inadequate asthma symptom control, including former smokers and patients with cardiac disease, were enrolled in a prospective single-arm real-world study. Asthma control tests (ACT), exacerbations, spirometry (pre-bronchodilator forced expiratory volume in 1 s [FEV1]), and oral corticosteroid doses were documented. Further assessments included peripheral blood eosinophil counts and adverse events. Results: After mepolizumab initiation asthma symptom control was significantly improved with the median ACT score of 12.5 at baseline (interquartile range [IQR ]10.5-19.5) rising to 19 (15-22.5) after 4 weeks. The improvement was maintained throughout the observation period of 20 weeks. Likewise, exacerbations were reduced. After 8 weeks of mepolizumab daily OCS doses were reduced from 6.25 mg daily (0-20) at baseline to 2.5 mg daily (0-11.9) at week 8 (P < 0.001). FEV1 remained generally unchanged during the course of the study. Eosinophil counts rapidly declined and remained at a low level during the observation period. No new safety signals were observed in this study. Conclusion: Mepolizumab improved asthma symptom control and had a steroid-sparing effect. Efficacy in this real-world study was comparable to RCTs, despite a history of smoking and comorbidities in many of the patients included.