A Prospective Observational Study of Biopredictors of Bronchial Thermoplasty Response in Patients With Severe Refractory Asthma (BTR Study)

Primary Aim To assess the relationship between baseline clinical, physiologic, biologic and
imaging markers and response to bronchial thermoplasty, defined by improvement in asthma
quality of life, in patients with severe refractory asthma.

Secondary Aims

1. To assess the relationship between baseline clinical, physiologic, biologic and imaging
markers and response to bronchial thermoplasty, defined by reduction in severe
exacerbations or healthcare utilization, in patients with severe refractory asthma.

2. To evaluate if baseline clinical, physiologic, biologic and imaging markers are related
to safety of bronchial thermoplasty in patients with severe refractory asthma.

3. To evaluate and validate statistical models that predict response to bronchial
thermoplasty in patients with severe refractory asthma.

Inclusion Criteria:

1. Males or females age 18 or greater and less than 65

2. Subject has asthma and is taking regular maintenance medication for past 12 months
that includes:

- Inhaled corticosteroid (ICS) at a dosage greater than 1000μg beclomethasone per
day or equivalent, AND long acting ß2-agonist (LABA) at a dosage of ≥100μg per
day Salmeterol or equivalent.

- Other asthma medications such as leukotriene modifiers, or anti-IgE, are
acceptable (Subjects on Xolair® must have been on Xolair for greater than 1
year).

3. Asthma confirmed by: (a) b-agonist reversibility of FEV1 ≥ 12 % following 360mcg
albuterol OR (b) methacholine FEV1 PC20 ≤ 8 mg/ml if not receiving an ICS or ≤ 16
mg/ml if receiving an ICS.

4. FEV1 ≥ 50% predicted pre-bronchodilator.

5. Asthma symptoms on at least two days or one night per week over the last 2 weeks.

6. Subject is a non-smoker for 1 year or greater (if former smoker, less than 10 pack
years total smoking history).

7. Ability to undergo bronchoscopy in the opinion of the investigator.

8. Ability and willingness to provide informed consent.

Exclusion Criteria:

1. Asthma exacerbation (ED visit, hospitalization, course of increased systemic steroids,
or urgent health care visit for asthma) during the prior four weeks.

2. Subject has 3 or more hospitalizations for exacerbations of asthma in the previous
year or 1 or more ICU admission for asthma in the previous year.

3. Chronic oral steroid therapy greater than 30 mg per day

4. Subject has other respiratory diseases including interstitial lung disease, emphysema,
cystic fibrosis, vocal cord dysfunction, mechanical upper airway obstruction,
untreated obstructive sleep apnea, Churg-Strauss syndrome, cardiac dysfunction, and
allergic bronchopulmonary aspergillosis (total IgE of >1000 Units/mL with positive
specific IgE to aspergillus and evidence of central bronchiectasis) that in the
opinion of the investigator would prevent participation in the trial or put the
participant at risk by participation.

5. Subject has segmental atelectasis, lobar consolidation, significant or unstable
pulmonary infiltrate, or pneumothorax, confirmed on x-ray.

6. Subject has clinically significant cardiovascular disease, including myocardial
infarction, angina, cardiac dysrhythmia, conduction defect, cardiomyopathy, aortic
aneurysm, or stroke.

7. Subject has uncontrolled hypertension (>200mm Hg systolic or >100mm Hg diastolic
pressure).

8. Subject uses an internal or external pacemaker or cardiac defibrillator.

9. Chronic diseases (other than asthma) that in the opinion of the investigator would
prevent participation in the trial or put the participant at risk by participation,
e.g. chronic diseases of the lung (other than asthma), heart, liver, kidney, or
nervous system, or immunodeficiency

10. History of cigarette smoking with > 10 pack years total

11. Use of investigative drugs or intervention trials in the 30 days prior to enrollment
or during the duration of the study

12. Any condition or compliance issue which in the opinion of the investigator might
interfere with participation in the study