Introduction
Recently many studies have supported the use of biological treatment in Severe Eosinophilic Asthma(SEA) and Eosinophilic Granulomatosis with Polyangiitis(EGPA).Mepolizumab, an anti-interleukin 5, or Benralizumab, an anti-interleukin 5 receptor, can change the natural course of these diseases.

Aims and objective
The aim of the study was to evaluate the efficacy of Mepolizumab and Benralizumab in patients with SEA and EGPA, analyzing the improvement in respiratory function and systemic clinical manifestations.

Methods
We enrolled 10patients with SEA and EGPA, 7 treated with Benralizumab and 3 with Mepolizumab. Before and after 12months of treatment, we evaluated pulmonary function, blood eosinophils count, Asthma Control Test(ACT), Birmingham Vasculitis Activity Score(BVAS), inhaled(ICS) and oral corticosteroids(OCS) consumption and immunosuppressive therapy.

Results
After 12months of treatment, there was an improvement of respiratory function, ACT score and BVAS(p=0.002). The number of circulating eosinophils decreased from 1843±2075.8cells/?L to 30±37cells/?L(p=0.002).ICS were reduced from high to medium dose and OCS from 10.1±8.2 mg/day to 4.5±5.9 mg/day (p=0.008). 3patients discontinued OCS therapy and 3patients discontinued immunosuppressive therapy. Negative autoantibody titre occurred in 1 of two p-ANCA positive patients.

Conclusions
Pulmonologists have to identify precociously patients with severe asthma and EGPA. Biological treatment has proven to be a powerful tool to control respiratory and systemic clinical manifestations, avoiding severe forms of disease and adverse effects of oral corticosteroids and immunosuppressive therapy.