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