A prospective multi-centre, non-interventional observational study, that will be conducted in several centers in Greece for a 2-year time period (completion date December 2020), to describe patient characteristics, medical history, and the clinical benefit of mepolizumab in patients with severe eosinophilic asthma newly initiated to the drug.

Inclusion Criteria:

• Patients with uncontrolled severe eosinophilic asthma placed under treatment with mepolizumab, i.e. in patients with peripheral blood eosinophils ≥300 cells/μL at any measurement in the previous year or ≥150 cells/μL in a recent measurement, with poor symptom control and increased number of exacerbations (2 or more) despite optimal treatment with high doses of inhaled corticosteroids and β2 stimulants

Exclusion Criteria:

• Patient refusal to participate in the study

Patients with uncontrolled severe eosinophilic asthma