Measuring the Effect of Dupilumab Treatment on Mucociliary Clearance (MCC) in Subjects With Moderate to Severe Asthma

Inclusion Criteria: * Moderate - Severe Th2 (Type 2) High asthma, as defined by Forced Expiratory Volume in one second (FEV1) \<90% predicted, on medium to high dose inhaled corticosteroids (ICS) with or without a second controller * Age \> 18 * Inhaled steroid doses of 500micrograms (mcg) per day or more (Fluticasone equivalent) * Reversibility \>/= 12% at screening or within the past 2 years, or a positive methacholine challenge test within the past 2 years, or a positive methacholine challenge during screening * FEV1/Forced Vital Capacity (FVC)\<75% * Blood Eosinophils (EOS) \>300 cells per mm3 * Exhaled Nitric Oxide (FeNO) \>25 parts per billion (ppb) * Asthma Control Test (ACT) score \<20 Exclusion Criteria: * Pregnant, nursing, or unwilling to test for pregnancy * Current smoker or \>10 pack year smoking history * Body Mass Index (BMI)\>37 * Respiratory infection in the last 30 days * Use of antibiotics or oral prednisone in the last 30 days * Current or previous use of dupilumab * Current or recent use of anti-IL-5 therapies * Any other criteria that place the subject at unnecessary risk * Diagnosis of other lung diseases including Chronic Obstructive Pulmonary Disease (COPD) * History of non-skin cell cancer in the last 5 years * Drug or alcohol addiction in the last 5 years * Any other uncontrolled disease