Supplementary Material for: Mepolizumab in Severe Eosinophilic Asthma: A 2-Year Follow-Up in Specialized Asthma Clinics in Greece: An Interim Analysis

Introduction: Mepolizumab is a monoclonal antibody against IL-5 for the treatment of severe eosinophilic asthma. The aim of the current study was to present a predesigned interim analysis of the data of patients who have completed 1 year of therapy with mepolizumab. Methods: This study is a prospective multicenter, noninterventional 2-year observational study and aims to describe the clinical benefit and safety profile of mepolizumab in patients with severe eosinophilic asthma. Results: Compared to the year preceding the initiation of treatment, the annual rate of exacerbations decreased significantly, from 4.3 ± 2.3 to 1.3 ± 1.8; p < 0.0001. Forty-two patients received maintenance dose of oral corticosteroids (OCS) at baseline. From these patients at the end of 1 year of therapy with mepolizumab, 17 patients (40%) had achieved OCS discontinuation. A reduction in the median dose of OCS was also achieved. After 1 year of treatment with mepolizumab, the asthma control test score significantly increased from 16.3 ± 3.7 to 21.2 ± 3.8 (p < 0.0001). This marked clinical improvement was paralleled by a significant reduction of blood eosinophil count. All patients showed a considerable improvement of airflow limitation. In respect to adverse events of treatment with mepolizumab, 19 patients (27%) were recorded to have at least one such occurrence during their 1-year treatment. Conclusions: We have shown that in patients with severe eosinophilic asthma, 1 year of treatment with mepolizumab was safe, resulted in significant reduction of the annual exacerbation rate, reduction (or even discontinuation) of the needed dose of OCS, and improvements of asthma control and lung function.