Anti-Interleukin-5 (IL5) Monoclonal Antibody (MAb) in Prednisone-dependent Eosinophilic Asthma

The steroid sparing effect of anti interleukin (IL-5) monoclonal antibody has been proven, but the effectiveness of subcutaneous (SC) compared to intravenous (IV) administration of these drugs to suppress airway eosinophilia is still under debate. As part of a previous study, 100mg of mepolizumab were administered subcutaneously to a group of subjects with prednisone-dependent eosinophilic asthma. Despite this intervention, 50% of the subjects (15 patients participated in this study) had persistently elevated sputum eosinophil counts. The same 15 patients will be invited to participate in the current study, and if they provide their informed consent, will receive 2 monthly doses of placebo, followed by 4 monthly doses of IV reslizumab. The primary outcomes are blood and sputum eosinophils, and the secondary outcomes include sputum and blood Innate lymphoid cell-2 (ILC2) cells, cluster of differentiation 4 (CD4+) cells, cluster of differentiation-8 (CD8+) cells, cluster of differentiation-34 (CD34+), Eosinophil-Basophil cluster cells (Eo/B progenitor cells), forced expired volume in 1 second (FEV1), asthma control questionnaire (ACQ) and number of eosinophilic exacerbations. Measurements of the outcomes will be done before placebo, after placebo and after IV reslizumab. This study design will determine whether IV reslizumab is effective in suppressing airway eosinophilia in prednisone-dependent patients.