Inclusion Criteria:  Physician-diagnosed/managed severe asthma patients that are clinically eligible for dupilumab Current treatment with a medium-to-high-dose inhaled glucocorticoid (fluticasone propionate at a total daily dose of greater or equal (≥) 440 μg or equipotent equivalent) plus up to at least one additional controller (e.g., a long-acting β2-agonist or leukotriene receptor antagonist) Eosinophilic asthma phenotype (blood eosinophil level >300) or asthma requiring daily oral corticosteroids Asthma that is uncontrolled, as defined by a score on the Asthma Control Test of 19 or lower, or a worsening of asthma in the past year that led to an asthma hospitalization, Emergency Department visit, or 3 days of oral corticosteroids Severity of asthma that, in the opinion of the subject's asthma care specialist, requires dupilumab for control For women of childbearing age: agree to use birth control or remain abstinent during the duration of the study.  Exclusion Criteria:  Patients with diagnosis of other chronic lung diseases (e.g. Chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis, Churg-Strauss syndrome, Allergic bronchopulmonary aspergillosis, etc.) Current smoker or reported smoking within 1 month of the screening visit (tobacco or any inhaled recreational product) Greater than 10 total pack-year of cigarette smoking history Treatment with oral corticosteroids for an asthma exacerbation 1 month prior to screening or during the screening period Use of any biologic therapy for asthma within the past 3 months Respiratory or Gastrointestinal illness within 1 month prior to screening or during the screening period Treatment with antibiotics for acute infections within six weeks prior to screening or during the screening period. Pregnancy at enrollment or during the study Known hypersensitivity to dupilumab or its excipients