Effect of Switching From Cigarette Smoking to THS on Disease Progression in Mild to Moderate COPD Subjects With Chronic Bronchitis Symptoms.

Main Inclusion Criteria: * Subjects have read, understood, and signed the written informed consent form (ICF) * Diagnosis of COPD GOLD Stage 1 or 2 (FEV1/FVC \<0.70 \& FEV1 ≥60% predicted \[post-BD\]) * Current symptoms of chronic bronchitis (sputum and cough) based on CAT questionnaire scores for CAT1 (cough) item ≥ 3 and CAT2 (sputum) item ≥ 3 * Body mass index (BMI) 17.6-40.0 kg/m2 and body weight \> 50 kg (male) or 40 kg (female). * Subject has a smoking history of at least 10 years. * Subject has been smoking ≥ 10 commercially available cigarettes/day on average (no brand restriction) for at least 1 year prior to V1 (based on self-reporting). * Subject has not used other tobacco and nicotine products apart from cigarettes on a daily basis over the past year prior to V1. * For subjects not willing to quit smoking only: have been advised to quit smoking, informed of smoking risks and of cessation programs and is still not willing to quit during the study duration. * Subjects willing to quit smoking only: willing to set a target quit date (TQD) within the next 28 days at V1 as assessed by self-reported questions. Main Exclusion Criteria: * Subjects with any (mild, moderate or severe) COPD exacerbation that has not resolved at least four weeks prior to V1 * Subjects with active cancer or history of any cancer * Subjects with pneumonia or other lower respiratory tract infections that have not resolved at least four weeks prior to V1 * Subjects with other active systemic infections that have not resolved at least 4 weeks prior to V1 * Subjects with other active respiratory disorders such as, but not limited to, tuberculosis, bronchiectasis, sarcoidosis, asthma2, pulmonary hypertension, interstitial lung diseases (e.g., idiopathic pulmonary fibrosis \[IPF\]). No new examination is required if the subject can present at V1, at a minimum, a Chest XRay (CXR) (or Computed Tomography (CT) of the chest, if available) not older than 6 months with anterior-posterior and left lateral views * The subject is confirmed or suspected with active SARS-CoV-2 infection (as per site and per country recommendation) * Clinically significant ECG alterations that will not allow subject to participate in the study, per Investigator's discretion * Any concomitant disease that in the opinion of the investigator would interfere with the study procedures * Subjects with diagnosed alpha-1 antitrypsin deficiency (AATD) * History of alcohol and/or drug abuse which as per judgment of the Investigator would jeopardize either the participation in an investigational study or safety of the subject * Positive serology test (HIV 1/2, hepatitis B or C). * Inability to cooperate with the study procedures * Previous participation in this study, or participation in an investigational study (drug or medical device) within 4 weeks before V1 (participation in observational studies/registries allowed) * Close affiliation with the investigational site: a close relative of the investigator, a person dependent on the investigational site (e.g., employee or student of the investigational site) * Subject is a current or former employee of the tobacco industry or their first-degree relatives (parent, child, spouse) * Subjects have re-initiated smoking in the six months prior to V1 * Subjects have used in the past 3 months, or are currently daily using THS * Any oral/injectable corticosteroids (acute or chronic treatments) or oxygen therapy in the last 2 months excluding short term use for a COPD exacerbation * Female subject is pregnant or breastfeeding, (a urine pregnancy test will be performed at V1 and V2) * For women of childbearing potential, female subject who does not agree to using an acceptable method of effective contraception during the entire study.