The following is the summary of  “Corticosteroid Responsiveness Following Mepolizumab in Severe Eosinophilic Asthma—A Randomized, Placebo-Controlled Crossover Trial (MAPLE)”  published in the November 2022 issue of Allergy and Clinical Immunology: In Practice by Yang, et al.

In individuals with severe eosinophilic asthma (SEA), mepolizumab inhibits IL-5 activity and decreases both the frequency of exacerbations and the amount of oral corticosteroid (OCS) needed for maintenance. In spite of anti-IL-5 medication, some individuals continue to require OCS, which suggests that there are lingering corticosteroid-responsive mechanisms. Therefore, in patients with SEA taking mepolizumab, assess the clinical and anti-inflammatory effects of OCS. Following 12 weeks of mepolizumab treatment for adults with SEA, we conducted a randomized, triple-blind, placebo-controlled crossover trial with prednisolone (0.5 mg/kg/d, maximum 40 mg/d, for 14±2 days).

Researchers examined the effects of prednisolone and placebo on a variety of asthma-related metrics, including symptom severity, quality of life, lung function as determined by spirometry and airwave oscillometry, fractional exhaled nitric oxide, and eosinophil cell count in blood and sputum. About 27 participants finished the study. Scores on the 5-item Asthma Control Questionnaire (mean difference in change for prednisolone vs. placebo, -0.23; 95% CI,-0.58 to 0.11), the mini-Asthma Quality of Life Questionnaire (0.03; 95% CI, -0.26 to 0.42), the St. George’s Respiratory Questionnaire (0.24; 95% CI, −3.20 to 3.69), and the Visual Analogue Scale (VAS) for overall asthma symptoms (0.11; 95% CI, −0.58 to 0.80). 

The mean difference for FEV1 in favor of prednisolone was 105 mL (95% CI, −4 to 213 mL); forced expiratory flow at 25% and 75% 484 mL/s (95% CI, 151 to 816 mL/s). In addition, prednisolone was associated with a 41% reduction in fractional exhaled nitric oxide (95% CI, 25% to 54%), a 49% reduction in blood eosinophil count (95% CI, 31% to 62%), and a 71% reduction in sputum eosinophil percentage (95% CI, 26% to 89%). Among patients with SEA who were treated with mepolizumab, OCS alleviated small-airway blockage and decreased biomarkers of type 2 inflammation, but it had no appreciable impact on symptoms or quality of life.