Real Life Experience Survey of Dupilumab in the Netherlands

Rationale: Dupilumab has proven to be effective and safe in several large randomized controlled trials. However, study populations in RCT's represent only a small proportion of severe asthma patients treated in real life circumstances. Therefore, real-life studies provide data complementary to RCT's derived from a more diverse and heterogeneous group of patients. This study is unique in that it represents a large population of European patients that are not represented in the Global Registry. Objective: To collect and analyse efficacy and safety data in severe asthma patients treated with dupilumab in a real-life setting. Study design: Single center, retrospective cohort analysis of severe asthma patients treated with dupilumab, as decided by the treating physician. Setting: Severe Asthma Expert Center Franciscus Gasthuis \& Vlietland, Rotterdam Study population: All patients that started with dupilumab from jan 2019 (early access program) until June 2020 are eligible for the study. They should be 18 years or older, with severe T2 high asthma and treated with at least one dose of dupilumab. Main study parameters/endpoints: * Primary endpoint: To assess changes in annual exacerbation rate between baseline and after 12 months treatment in severe asthma patients treated with dupilumab. * Secondary endpoints: To collect data on ACQ, OCS use, FEV1, treatment response rate, influence of co-morbidities and safety. Methods: Exacerbation history and patient characterization will be done at baseline. We aim to include patients in the analysis that had at least one administration of dupilumab (intention-to-treat). Treatment response evaluation is done at 12 months. Final evaluation of efficacy and safety is done at 12 months of treatment. We aim to enroll at least 120 patients in the study. Data collection will be done in Castor Electronic Data Capture. Of the 120 patients scheduled for inclusion, all have already started treatment and data will be collected retrospecti