Efficacy of Mepolizumab in Polish Patients With Severe Eosinophilic Asthma

This study is aimed at evaluation of the efficacy of mepolizumab 100 mg subcutaneously (SC) every 4 weeks in patients with severe eosinophilic asthma who have been treated for at least 12 months in several Polish allergy/asthma centres under the same protocol. Target population to be recruited has been set at 130 subjects from at least 6 asthma centers throughout the country. Data on demographics and asthma status will be collected using questionnaires at 3 time-points: pre-mepolizumab (pre-MEPO), after 24 weeks of mepolizumab (MEPO) and after 1 year of MEPO administration (some of the outcomes will be observed every 4 weeks). Primary endpoints will include: * Asthma exacerbations measured at qualification for the treatment (in the period of previous 52 weeks) and at the 24th and 52nd week of the treatment. * Oral Corticosteroids use dose (documented at qualification for the treatment and at the 24th and 52nd week of the treatment).