Azithromycin Treatment for the Airway Microbiome in Asthma

Inclusion criteria (All participants):

1. Age 18 - 55 years

2. Able to provide informed consent

3. Smoking history < 10 pack-years

Inclusion Criteria for subjects with poorly controlled asthma

1. Methacholine PC20 < 16 mg/ml or

2. Albuterol response > 12% on FEV1 after 4 puffs of albuterol

3. Ability to use combination ICS + LABA

4. Meet definition for Th2-low asthma: peripheral blood eosinophil count < 300 and
exhaled nitric oxide level < 30 ppb.

Exclusion Criteria (All participants)

1. History of allergy or intolerance to any medications used in this study

2. Medication exclusions:

1. Current use of medications that prolong QTc interval

2. Current use of omalizumab or other ant-IgE therapies

3. Current use of anti IL 5 therapies

4. Current use of anticoagulants

5. Prednisone or other oral steroids within past 3 months 3. Pregnancy or lactation 4.
Other respiratory or inflammatory disorders (e.g., sarcoidosis, emphysema) 5. Pre-existing
liver disease (AST or ALT >10% above the upper limit of normal) 6. Smoking within the last
6 months 7. Exacerbation of asthma in past 3 months 8. Affected by a hearing disorder 9.
Clinically significant medical condition (e.g., heart failure, seizure disorder) which may
in-crease risk as determined by study investigator 10. Corrected QT interval > 450 msec.
Patients with known cardiac history or prolonged QT interval on a screening EKG are
excluded given the small but real potential for macrolide-related side effects.