Mechanistic Study of the Effect of Itepekimab on Airway Inflammation in Patients With COPD

Inclusion Criteria: * Participant must be 40 to 70 years of age inclusive * Physician diagnosis of COPD for at least 1 year (based on the Global Initiative for Chronic Obstructive Lung Disease \[GOLD\] definition). * Smoking history of ≥10 pack-years * For former smokers: Participants who reported that they were not currently smoking, and smoking cessation must had occurred ≥6 months prior to Screening (Visit 1) with an intention to quit permanently. * For current smokers (not eligible for Part A): Participants who reported that they are currently smoking tobacco (participant smoked at least 5 cigarettes per day on average during the past 7 days) at Screening (Visit 1) and at Baseline, and who were not currently participating in, or planning to initiate, a smoking cessation intervention at Screening (Visit 1) or during the screening period. * Participant-reported history of signs and symptoms of chronic bronchitis (chronic productive cough for at least 3 months in the year before screening in a participant in whom other causes of chronic cough \[eg, inadequately treated gastroesophageal reflux or chronic rhinosinusitis; or clinical diagnosis of bronchiectasis\] had been excluded). * Documented or self-reported history of exacerbation having had ≥1 moderate or severe exacerbation within the 5 years prior to Screening (Visit 1), with at least 1 exacerbation treated with systemic corticosteroids: * Moderate exacerbations were defined as an acute worsening of respiratory symptoms that required either systemic corticosteroids (intramuscular \[IM\], intravenous \[IV\], or oral) and/or antibiotics. * Severe exacerbations were defined as AECOPD that required hospitalization or observation for \>24 hours in emergency department/urgent care facility. * Participants treated with SoC controller therapy for ≥3 months before Screening (Visit 1) and at a stable dose and regimen of controller therapy for at least 1 month before the screening visit AND during the screening period, including either: triple therapy with LAMA + LABA + ICS or double therapy with ICS + LABA or LABA + LAMA or ICS + LAMA, or monotherapy with LABA or LAMA. * Participants who had received appropriate vaccination according to local recommendations against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), administered a minimum of 1 week prior to Screening (Visit 1). * Body mass index (BMI) ≥18 kg/m2 * A female participant was eligible to participate if she was not pregnant, not breastfed, and at least one of the following conditions applies: * Not a women of child-bearing potential (WOCBP) or * A WOCBP who agreed to follow the contraceptive guidance during the intervention period and for at least 20 weeks after the last dose of study intervention. Exclusion Criteria: * Current diagnosis or previously confirmed diagnosis of asthma according to the Global Initiative for Asthma (GINA) guidelines unless asthma resolved before 18 years of age and has not recurred. * For former smokers (Parts A): Active smoking or vaping of any products (eg, nicotine, tetrahydrocannabinol \[THC\]) within 6 months prior to Screening (Visit 1) or during the screening period. For current smokers (Part B): vaping of any products (eg, nicotine, THC) within 6 months prior to Screening (Visit 1) or during the screening period. * Participants who were expected to be regularly exposed to environmental (ie, 'second hand') tobacco smoke in an indoor setting during the screening or treatment periods (former smokers only). * Clinically significant new abnormal electrocardiogram (ECG) within 6 months before or at Screening (Visit 1) that might affect the participant's participation in the study. * Clinically significant and current pulmonary disease other than COPD, eg, sarcoidosis, interstitial lung disease, bronchiectasis (clinical diagnosis), diagnosis of α1 anti-trypsin deficiency, or another diagnosed pulmonary disease. * Diagnosis of cor pulmonale, evidence of right cardiac failure, or moderate-to-severe pulmonary hypertension. * Participants who required more than 2 L/min of long-term treatment with oxygen at rest. Participants who used up to 4L/min of supplemental oxygen during exercise might enroll. Oxygen during sleep was allowed. * Hypercapnia that required bi-level positive airway pressure (BiPAP). * Moderate or severe exacerbation of COPD (AECOPD) within 8 weeks prior to Screening (Visit 1) or during the screening period. * Prior history of pneumonectomy, lobectomy, segmentectomy, or therapeutic bronchoscopy procedure (including bronchoscopic volume reduction). Note: Prior history of surgical lung biopsy or wedge resection were not exclusion criteria. * Any surgery or major procedures (including those requiring conscious sedation) planned to occur during the study. Minor skin procedures were allowed. * Unstable ischemic heart disease, including acute myocardial infarction within 1 year before Screening (Visit 1), or unstable angina within 6 months before Screening (Visit 1) or during the screening period. * Cardiac arrhythmias, including paroxysmal (eg, intermittent) atrial fibrillation. Participants with isolated premature ventricular contractions (PVCs) or premature atrial contractions (PACs) might be considered for inclusion. * Cardiomyopathy, as defined by Stage III-IV (New York Heart Association) cardiac failure, or other relevant cardiovascular disorder that that might affect the participant's participation in the study. * Any underlying disease required the use of prophylaxis for endocarditis. * Uncontrolled hypertension (ie, systolic blood pressure \[BP\] \>180 mm Hg or diastolic BP \>110 mm Hg with or without use of antihypertensive therapy). * Participants with active tuberculosis (TB), latent TB, a history of incompletely treated TB, suspected extrapulmonary TB infection (TBI), or who were at high risk of contracting TB (such as close contact with individuals with active or latent TB) or received Bacillus Calmette Guérin (BCG)-vaccination within 12 weeks before Screening (Visit 1). * History of human immunodeficiency virus (HIV) infection or positive HIV 1/2 serology at Screening (Visit 1). * Suspicion of, or confirmed, coronavirus disease 2019 (COVID-19) infection or contact with known exposure to COVID19 at Screening (Visit 1) or during the screening period; known history of COVID19 infection within 6 weeks before Screening (Visit 1); history of requiring mechanical ventilation or extracorporeal membrane oxygenation (ECMO) secondary to COVID-19 within 12 months before Screening (Visit 1); participants who had a COVID-19 infection before Screening (Visit 1) who had not yet sufficiently recovered to participate in the procedures of a clinical trial. * Evidence of acute or chronic infection requiring systemic treatment with antibacterial, antiviral, antifungal, antiparasitic, or antiprotozoal medications within 6 weeks before Screening (Visit 1) or during the screening period, significant viral infections within 6 weeks before Screening (Visit 1) or during the screening period that might not have been treated with antiviral treatment (eg, influenza receiving only symptomatic treatment). * Participants with active autoimmune disease or participants taking immunosuppressive therapy for autoimmune disease (eg, rheumato arthritis, inflammatory bowel disease, primary biliary cirrhosis, systemic lupus erythematosus, multiple sclerosis). * History of malignancy within 5 years before Screening (Visit 1), or during the screening period, except completely treated in situ carcinoma of the cervix, completely treated and resolved nonmetastatic squamous or basal cell carcinoma of the skin. * Symptomatic herpes zoster within 3 months prior to screening. * Previous use of Itepekimab. The above information was not intended to contain all considerations relevant to a participant's potential participation in a clinical trial.