Primary Objectives:

1. To describe the demographic and baseline characteristics in patients with severe eosinophilic asthma in Spain who received at least one dose of Benralizumab, after its marketing authorization
2. To describe background treatment patterns of severe eosinophilic asthma patients at baseline and after the index date (benralizumab initiation)

This is a descriptive, observational, multi-centre, longitudinal, retrospective cohort study in adults patients (≥18 years) with severe asthma (maintenance treatment with high dose inhaled corticosteroids combined with long-acting agonist β2) and eosinophilic phenotype, who, at the discretion of the physician, received benralizumab accordingly to the clinical practice, in the period after the marketing authorization of benralizumab in Spain, on January 1st 2019.

Inclusion Criteria:

• Adult patients (age ≥18 years)
• Diagnosis of severe eosinophilic asthma requiring stable treatment of high doses of inhaled corticosteroids and a long-acting agonist β2 ± additional asthma controller.
• Patients with at least 12-month data available before index date (starting benralizumab treatment)
• Patients with at least 3-month electronic medical records data available from first benralizumab dose ("index date")
• Informed consent signed.

Exclusion Criteria:

• Patients who received benralizumab in a clinicaltrial, during the observation period.

The target population will be all patients with severe eosinophilic asthma (those requiring stable treatment with high doses of inhaled corticosteroids and a long-acting agonist β2 ± additional asthma controller), who received at least one dose of benralizumab according to routine clinical practice, after marketing approval on January 1st, 2019. The targeted patients need to have available medical record of 12 months prior to index date.