Evaluation of the Clinical Features and Laboratory Data of Patients with Severe Eosinophilic Asthma Classified as Super-Responders, Partial Responders, or Nonresponders to Mepolizumab Treatment: A Real-Life Study

Introduction: Mepolizumab is a treatment option in patients with severe eosinophilic asthma, which inhibits interleukin-5. The aim of this study was to evaluate the clinical features and laboratory data of patients with severe eosinophilic asthma who were classified as super-responders, partial responders, or nonresponders to mepolizumab treatment. Methods: In this retrospective real-life study, the clinical features and laboratory data were compared between groups of patients with severe eosinophilic asthma who were classified as super-responders, partial responders, or nonresponders to mepolizumab treatment. Results: Evaluation was made of a total of 55 patients, comprising 17 (30.9%) males and 38 (69.1%) females with a mean age of 51.28 +/- 14.32 years. All the patients were receiving mepolizumab treatment for severe eosinophilic asthma, with 17 (30.9%) patients evaluated as super-responders, 26 (47.3%) as partial responders, and 12 (21.8%) as nonresponders. After mepolizumab treatment, there was a statistically significant decrease in asthma exacerbations, the number of oral corticosteroids (OCSs) used, the rate of hospitalization due to asthma attacks, and the eosinophil count (cells/mu L) (p < 0.001, p < 0.001, p < 0.001, and <0.001, respectively). A statistically significant increase was determined in the forced expiratory volume in 1 s (FEV1) value (p = 0.010) and asthma control test (ACT) score (p < 0.001) after mepolizumab treatment. The baseline eosinophil count, eosinophil/lymphocyte ratio and FEV1 (%) values were significantly higher in the super-responder and partial responder groups (p < 0.001, p = 0.002, and p = 0.002, respectively). The baseline ACT score and the rate of chronic sinusitis with nasal polyps were significantly higher in the partial responder group (p = 0.004, p = 0.015, respectively). The rate of regular OCS use before mepolizumab treatment was significantly higher in the nonresponder group (p = 0.049). As a result of the receiver operating characteristics curve analysis, the blood eosinophil count (area under the curve [AUC]: 0.967, p < 0.001), eosinophil/lymphocyte ratio (AUC: 0.921, p < 0.001), and FEV1 (%) (AUC: 0.828, p = 0.002) were found to have diagnostic value in predicting the response to mepolizumab treatment in patients with severe eosinophilic asthma. Conclusion: Baseline eosinophil count, eosinophil/lymphocyte ratio, and FEV1 (%) were found to be important predictors of response to mepolizumab treatment. Further studies are needed to define the characterization of mepolizumab responders in the real world.

Automated summary

This study aimed to evaluate the clinical features and laboratory data of patients with severe eosinophilic asthma who were classified as super-responders, partial responders, or nonresponders to mepolizumab treatment. The results showed that the baseline eosinophil count, eosinophil/lymphocyte ratio, and FEV1 (%) were important predictors of response to mepolizumab treatment.