A Study of RO7830698 in Healthy Participants and Participants With Chronic Obstructive Pulmonary Disease

Inclusion Criteria: All participants: * Body mass index (BMI) between 18 and 32 kilograms per meter square (kg/m2) * Agreement to adhere to the contraception requirements Part 1: * Absence of evidence of any active or chronic disease Part 2: * Confirmed diagnosis of COPD for \> 6 months, as defined by the Global Initiative for Chronic obstructive Lung Disease (GOLD) guidelines * Using maintenance inhaled therapy that may include inhaled corticosteroids (ICS) and/or long-acting β-agonist (LABA) and/or long-acting muscarinic antagonist (LAMA) as separate inhaler(s) or in combination preparation(s) * Current smoker or ex-smoker with a tobacco history of \>= 10 pack years Exclusion Criteria: * Pregnant or breastfeeding, or planning to become pregnant during the study or within the timeframe in which contraception is required * Current or chronic history of clinically significant liver disease or known hepatic or biliary abnormalities (with the exception of Gilbert syndrome or asymptomatic gallstones) or cirrhosis * Known history of allergy to drugs or other substances, or clinically significant, acute, and/or uncontrolled allergic disease * Known or suspected history of immunosuppression * History of recurrent severe infections and underlying conditions predisposing participant to infections * History of disseminated herpes simplex infection, or recurrent (\> 1 episode) or disseminated herpes zoster * Autoimmune disease requiring systemic immunosuppressive therapy * History of or presence of any clinically significant unstable cardiovascular disease * Treatment with medications targeting the same pathways as RO7830698, immunomodulatory/ immunosuppressive therapy, or licensed biologics for COPD and asthma within protocol-defined periods * Positive results for hepatitis B infection, human immunodeficiency virus infection, or hepatitis C infection at the Screening visit * Evidence of tuberculosis infection or disease * Participation in any clinical study of a drug or medical device within protocol-defined periods * Any other conditions that may affect providing informed consent or study protocol adherence, or if study participation may affect study results or participant safety