Inclusion Criteria:

• Participant must be ≥40 years of age at the time of signing the informed consent.
• Documented primary diagnosis of COPD for at least 12 months prior to enrolment.
• Pre-BD FEV1/FVC < 0.7 at Visit 1 and pre- and post-BD FEV1/FVC < 0.7, and post-BD FEV1 ≥ 25% to < 80% of predicted normal at Visit 2.
• Documented history of ≥ 2 moderate or ≥ 1 severe COPD exacerbations in the 12 months prior to screening.
• Documented stable regimen of inhaled triple maintenance therapy or inhaled dual maintenance therapy for ≥ 3 months prior to screening.
• CAT score ≥ 10 at Visit 1.
• Current or ex-smokers with a cigarette smoking history of ≥ 10 pack-years.
• Participants who are clinically stable and free from an exacerbation of COPD for 4 weeks prior to Visit 1 and are also exacerbation free for at least 4 weeks (28 days) prior to Visit 3 (randomisation).
• Negative pregnancy test at Visit 1 and Visit 3 for Women Of Child-Bearing Potential (WOCBP).

Exclusion Criteria:

• Clinically important pulmonary disease other than COPD (eg, asthma [current diagnosis per GINA or other accepted guidelines], active pulmonary infection, clinically significant bronchiectasis when bronchiectasis is the predominant diagnosis, pulmonary fibrosis, cystic fibrosis, hypoventilation syndrome associated with obesity, lung cancer, alpha-1 antitrypsin deficiency or primary ciliary dyskinesia).
• Radiological findings suggestive of a respiratory disease other than COPD that is significantly contributing to the participant's respiratory symptoms.
• Any unstable disorder, including, but not limited to, CV, gastrointestinal, hepatic, renal, neurological, musculoskeletal, infectious, endocrine, metabolic, haematological, psychiatric disorder, major physical and/or cognitive impairment.
• Significant left heart failure.
• Unstable angina, acute coronary syndrome/acute myocardial infarction or coronary intervention with percutaneous coronary intervention/coronary artery bypass graft within 6 months of randomisation, uncontrolled arrhythmia, or cardiomyopathy, clinically significant aortic stenosis, or signs of pulmonary oedema or volume overload.
• Pulmonary arterial hypertension, either idiopathic or due to connective tissue or thromboembolic disease.
• History of another underlying condition that predisposes the participant to infections.
• History of ulcerative colitis, Crohn's disease, or microscopic colitis diagnosed by either a gastroenterologist or by histopathology.
• Abnormal laboratory findings.
• Participants with evidence of active liver disease and/or evidence of chronic liver disease.
• Participants with history of HIV infection or who test positive for HIV.
• History of lung volume reduction surgery.
• Current or history of malignancy within 5 years before the screening visit.