A Study Of ¹²⁹XE MRI To Assess Disease Progression In Patients With COPD Treated With Or Without Azithromycin And Standard-of-Care Medications

Inclusion Criteria: * Current or former smokers with years ≥ 10 pack years * mMRC dyspnea score \> 1 * Post-bronchodilator FEV-1/forced vital capacity (FVC) \<0.70 at Visit 1 or Visit 2 * Cohort A: GOLD Stage 2-4 COPD with a history of ≥ 2 moderate/severe exacerbations within a 12-month period in the 24 months prior to screening * Cohort B: GOLD Stage 1 COPD with a history of ≥1 moderate/severe exacerbations within a 12-month period in the 24 months prior to screening * Receiving SOC background drug therapy as per GOLD or British Thoracic Society (BTS) guidance for COPD for 12 weeks prior to screening Visit 1 * On an eligible bronchodilator medication (LABA ± LAMA) ± ICS therapy for ≥12 weeks prior to Visit 1 * Chest X-ray or CT scan within 6 months prior to Visit 1, or during the screening period (prior to Visit 2), that confirms the absence of clinically significant lung disease besides COPD * Use of contraceptive measures Exclusion Criteria: * Diagnosis of significant respiratory disease other than COPD * Comorbid conditions that may interfere with the evaluation of an investigational medical product * Known sensitivity or allergy to azithromycin * A COPD exacerbation and or pneumonia within 4 weeks prior to Visit 1 * Use of systemic corticosteroids within 4 weeks (oral or intravenous) or within 12 weeks (intramuscular IM) prior to screening Visit 1 * MRI is contraindicated * Any known arrhythmia, bradycardia or severe cardiac insufficiency * Participant can not hold breath for 15 seconds * Participant does not fit in the ¹²⁹XE vest coil used for MRI * Pregnant, lactating, or intending to become pregnant during the study or within 4 weeks after the last dose of the investigational medical product * History or evidence of substance abuse that would pose a risk to participants safety, interfere with the conduct of the study, or have an impact on the study results * For participants in Cohort A: Known significant hearing impairment as indicated by a score of ≥ 26 on the Hearing Handicap Inventory in the Elderly-Screening Questionnaire or as determined by the investigator * History of Clostridium difficile (C. difficile) diarrhea Clinically significant ECG changes, which in the opinion of investigator warrants further investigation or with a QTc interval \> 450 ms