Table 1 Inclusion and exclusion criteria

1) Life expectancy < 6 months at the time of enrollment as judged by the enrolling investigator

1) Subjects able to sign the Informed Consent

2) The need for chronic oxygen therapy

2) 18 years of age or older

3) Baseline %FEV1 ≤ 20%

3) Diagnosis of post-HSCT-BOS according to NIH 2014 criteria

4) History of thoracic air leak syndrome

4) Baseline %FEV1 < 70%

5) Documented respiratory infection

5) Must be symptomatic, defined as NIH Lung Score 1–3, and no other contributing etiology (including cardiac diseases, infection, anemia, or extrinsic thoracic compression) is present for respiratory symptoms

6) Active malignancy

6) Stable disease defined as less than 10% change in %FEV1 during the past 3 months while having no change in immunosuppressive and topical respiratory medications in the past 3 months

7) Graft failure

7) Must have received a combination of inhaled corticosteroid and inhaled long-acting beta-2 agonist during the past 3 months

8) Known history of asthma or chronic obstructive lung disease (COPD)

8) No new or supplemental immunosuppressive therapy for extra-thoracic GVHD during the past 3 months

9) Active smoking during the past 12 months

9) Patients with prior exposure to short-acting or long-acting inhaled anti-cholinergic drugs are eligible unless they have been received within the past 3 months

10) Substance abuse or uncontrolled psychiatric disorder

10) Ability to use Revolizer

11) Pregnant or nursing women

12) Daily corticosteroid of more than 1 mg/kg prednisone equivalent

13) Known intolerance or allergy to anticholinergic drugs

14) History of urinary retention, angle-closure glaucoma, CrCl ≤ 30 ml/min

15) History of arrhythmia in past years, MI in past 6 months, or hospital admission due to heart failure in past year

16) Ongoing participation in any other clinical trial (more typical would be using an investigational agent within 28 days of enrollment)

17) Any condition that, in the opinion of the enrolling investigator, would interfere with the subject's ability to comply with the study requirements

18) Inability to perform pulmonary function tests (PFT) reliably, as determined by the enrolling investigator or PFT lab

19) No compliance