Predictive Signature of Benralizumab Response

Inclusion Criteria: * Patients between 18 and 75 years old. * Patients diagnosed with severe asthma (Chung and al, Eur Respir J 2014), i.e.: * asthma requiring high doses of ICS (\>1000 microgram per day of Beclomethasone or equivalent) associated with LABA and/or systemic corticosteroids to be controlled over one year, * and/or uncontrolled asthma despite the later medications, * and/or a controlled asthma worsening after decreasing medications, * Documented historical reversibility of FEV1 ≥12% and FEV1 gain ≥ 200 milliliter * ACQ-7 score ≥ 1,5 at M0. * ≥ 3 exacerbations in the 12 months prior to screening visit M-1. * Eosinophil blood count ≥ 0,3 G/L at inclusion visit or in the 12 months prior to the inclusion visit. If eosinophil blood count is ≥ 0,15 G/L and \< 0,3 G/L, an eosinophilic phenotype defined by at least 1 of the following criteria will be required: * Fractional Exhaled Nitric Oxide (FeNO) \> 25 ppm at inclusion visit or in the 12 months prior to the inclusion visit. * Sputum eosinophils ≥ 3% at inclusion visit or in the 12 months prior to the inclusion visit. * Patients who provide written informed consent prior to participation in the study Exclusion Criteria: * Patients diagnosed with difficult-to-treat asthma and/or with uncontrolled asthma differential diagnosis according to the judgment of the investigator (e.g., vocal cord dysfunction, gastroesophageal reflux disease, granulomatous eosinophilic vasculitis, obstructive sleep apnea syndrom…