Rademikibart Add-on Treatment of an Acute COPD Exacerbation (Seabreeze STAT COPD)

Inclusion Criteria: * Physician-diagnosed COPD with duration of ≥12 months. * Must have experienced at least 1 COPD exacerbation requiring the use of systemic corticosteroids. * Participants in a stable condition must have a documented historical peripheral blood eosinophil count of ≥250 cells/μL and/or FeNO ≥ 25 ppb. * Current or former smoker with a history of smoking of ≥10 pack-years. * Current acute COPD exacerbation requiring an urgent healthcare visit for treatment. * Peripheral blood eosinophil count of ≥300 cells/μL as part of the assessment of the index acute COPD exacerbation. * Requires systemic corticosteroids as standard of care treatment in the urgent healthcare setting for the current acute COPD exacerbation. Exclusion Criteria: * Regular use of immunosuppressive medication 12 weeks or 5 half-lives prior to randomization, whichever is longer. * Current diagnosis or a history of asthma, according to the Global Initiative for Asthma; or participants with a current diagnosis or history of Asthma COPD Overlap Syndrome. * Other respiratory disorders that might compromise the safety of the participant or affect the interpretation of the results. * Unstable ischemic heart disease, cardiomyopathy, heart failure (New York Heart Association Class III or IV), uncontrolled hypertension. Cardiac arrhythmias including paroxysmal atrial fibrillation. * Transient ischemic attack or stroke \<6 months from Screening Visit; hospitalization for any cardiovascular or cerebrovas…