Efficacy of mepolizumab in elderly patients with severe asthma and overlapping COPD in real-world settings: A retrospective observational study

Abstract Background Asthma and chronic obstructive pulmonary disease (COPD) are the most common respiratory diseases, presenting overlapping prevalence with age. Mepolizumab is a humanized monoclonal antibody targeting interleukin-5. In major randomized clinical trials, this antibody reportedly reduced the circulating eosinophil count, exacerbation rate, and oral corticosteroid (OCS) dosage in patients with severe eosinophilic asthma. However, data regarding the efficacy of mepolizumab in elderly patients with asthma and overlapping COPD are limited. Methods This was a single-center, retrospective, observational study. Elderly patients (age ≥65 years) administered mepolizumab between August 2016 and March 2019 were enrolled and the effects of mepolizumab on the eosinophil level, exacerbation numbers, OCS dosage, and lung functions were assessed. We compared treatment responses in patients with asthma and COPD overlap (ACO) with responses observed in patients with severe asthma alone. Adverse events were also evaluated. Results Twenty patients (10 men and 10 women), with a mean age of 77.5 ± 1.3 years, were included. Mepolizumab significantly reduced the blood eosinophil count, as well as significantly decreased clinically significant exacerbation, in both populations. The OCS dosage was significantly reduced in patients treated receiving maintenance OCS therapy. However, mepolizumab did not improve lung function in either population, and no significant difference was observed in treatment responses between patients with asthma alone and ACO. Conclusions Mepolizumab may be effective in elderly patients with eosinophilic asthma and ACO.