Treating severe paediatric asthma with mepolizumab or omalizumab: The TREAT randomised non-inferiority trial study protocol

A minority of school-aged children with asthma have persistent poor control and experience frequent asthma attacks despite maximal prescribed maintenance therapy. These children have higher morbidity and risk of death. The first add-on biologic therapy, omalizumab, a monoclonal antibody that blocks immunoglobulin (Ig)E, was licensed for children with severe asthma in 2005. While omalizumab is an effective treatment, non-response is common. A second biologic, mepolizumab which blocks interleukin (IL)-5 and targets eosinophilic inflammation, was licensed in 2018, but the license was granted by extrapolation of adult clinical trial data to children. This non-inferiority trial will determine whether mepolizumab is as efficacious as omalizumab in reducing asthma attacks in children with severe therapy resistant asthma (STRA) and refractory difficult asthma (DA).