Mepolizumab Is an Effective Option in Severe Eosinophilic Asthma Regardless of Baseline Features: Single-Center Real-Life Data

Abstract Background: Mepolizumab has been approved as a treatment option for severe eosinophilic asthma (SEA) patients in our country. We aimed to evaluate the clinical and functional efficacy of mepolizumab in this group of patients in real life as well as the response rates to mepolizumab and the possible factors affecting the response. Methods: The study was a retrospective chart review of patients with SEA treated with mepolizumab. The data were collected at baseline, and at the 6th and 12th month. Results: A total of 62 patients (41F/21M) with a mean age of 44.41 ± 13.24 years were included in the study. They had poor symptom control with a mean asthma control test (ACT) score of 16.61 ± 5.59, frequent exacerbations with a mean of 3.4 ± 3.7 in the previous 12 months, and 80.6% required daily oral corticosteroid (OCS) with a median dosage of 8 mg/day as methylprednisolone. The ACT score increased to 22.47 ± 3.18 and 22.03 ± 4.31, respectively, and blood eosinophil count decreased from 1,146/μL to 89/μL and 85/μL at the 6th and 12th month, respectively. The mean FEV1 at baseline was 2.102 L there was an increase of 0.373 L at 6th month and 0.596 L at 12th month. The percentage of regular users of OCS decreased to 66.0% at 6th month with a median dosage of 4 mg and 52.6% at 12th month with a median dosage of 2 mg. Mepolizumab reduced the rate of exacerbations compared with the previous year from a mean of 3.40 to 0.15 at 6th month and 0.36 at 12th month. There was a significant improvement in Asthma Quality of Life Questionnaire (AQLQ), Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), and Sino-nasal Outcome Test (SNOT-22) scores at both of time points. The rate of responders and super-responders at 6th month was 60% and 28%, respectively, and consequently, the overall response rate was 88%. At the 12th month, the super-responder rate increased to 44.7% as well as the overall response to 89.4%. The only difference between the nonresponders, responders, and super-responders at the 6th and 12th month was whether regular daily OCS was used pre-mepolizumab. All nonresponders at both 6th and 12th month were using OCS regularly, whereas most of super-responder used the OCS only during exacerbations. Conclusion: Mepolizumab effectively reduced asthma exacerbations, steroid requirement, blood eosinophil counts and improved asthma control, pulmonary function, sinonasal symptoms and quality of life. Our data suggest that mepolizumab would be effective in s