An Efficacy and Safety Study of Mitiperstat (AZD4831) (MPO Inhibitor) vs Placebo in the Treatment of Moderate to Severe COPD.

Inclusion Criteria:

• Provision of informed consent.

• Participants must be deemed as high risk of exacerbations as defined by: >= 1moderate or severe exacerbation in the previous 24 months; or frequent productivecough; or post-bronchodilator (BD) forced expiratory volume in the first second (FEV1) < 50% predicted.

• Participants must be 40-80 years of age inclusive, at the time of signing informedconsent form (ICF).

• Participants who have a confirmed primary diagnosis of moderate to severe COPD.

• Participants who are current or ex-smokers with a tobacco history of ≥ 10pack-years.

• Participants who have a documented stable regimen of triple therapy or dual therapyfor

≥ 3 months prior to enrolment.

• Body mass index within the range 18 to 40 kg/m2 (inclusive).

Exclusion Criteria:

• As judged by the investigator, any evidence of any active medical or psychiatriccondition or other reason (at SV1 [screening] and SV3 [pre-dose]) which in theinvestigator's opinion makes it undesirable for the participant to participate inthe study.

• Current diagnosis of asthma or past diagnosis of asthma which persisted beyond theage of 25 years.

• Clinically important pulmonary disease other than COPD.

• Any other clinically relevant abnormal findings on physical examination, laboratorytesting including haematology, coagulation, serum chemistry, or urinalysis; or chestCT scan at screening or randomisation, which in the opinion of the investigator ormedical monitor may compromise the safety of the participant in the study orinterfere with evaluation of the study intervention or reduce the participant'sability to participate in the study.

• History of a clinically significant infection (viral, bacterial, or fungal; definedas requiring systemic antibiotics, antiviral, or antifungal medication for > 7 days)within 4 weeks prior to SV3 (Day 1) (including unexplained diarrhoea) or clinicalsuspicion of infection at time of dosing.