Introduction: Benralizumab is a humanized monoclonal antibody targeting the interleukin-5 receptor (IL-5a) that is expressed on eosinophils and inhibits eosinophilic inflammation. It is approved for the treatment of severe eosinophilic asthma.

Aim: To evaluate the clinical experience, effectiveness and safety of benralizumab treatment to patients with severe eosinophilic asthma in Greece.

Methods: A multicenter prospective observational study which was conducted in 19 different Pulmonary Centers in Greece. The recruitment period lasted 18 months and the follow-up period is 2 years.

Preliminary results: 122 patients were eligible (70 women), with an average age of 56 years (min 30, max 82). 76 patients completed the 12month follow up. Significant improvement in ACT score (22±3.5 vs 15.9±4.4, p<0,01) and in FEV1 %pred (81.2±20 vs 72.4±22.2, p<0,01) was observed. There was 77,8% (p<0,001) reduction in annual exacerbation rate, while 50% of patients experienced no exacerbations during 12 months of treatment. OCS mean dosage was reduced from 10.4±6 to 5.2±2.1 mg (p<0,01) prednisolone equivalent and 70% of those treated with OCS at baseline discontinued OCS. Adverse events were experienced by 12 patients (9.8%), most commonly headache, while 4 patients withdrew from the study voluntarily and 5 discontinued the drug (2 due to urticaria, 1 due to pregnancy, 2 due to personal reasons). No serious adverse events were observed.

Conclusions: Benralizumab was associated with improvement in asthma control and lung function and significant reduction in the annual rate of exacerbations and OCS use after one year of treatment.