A Study to Evaluate the Respiratory Safety of Lemborexant in Adult and Elderly Participants With Moderate to Severe Obstructive Sleep Apnea, and in Adult and Elderly Participants With Moderate to Severe Chronic Obstructive Pulmonary Disease

Inclusion Criteria

• Male or female, age >=45 and =30 per hour)
• SpO2 >=94% assessed as part of vital signs at Screening Visit 1

Additional Inclusion Criteria (COPD Cohort)

• Screening spirometry performed as per the Global Initiative for Obstructive Lung Disease (GOLD) recommendations
• On screening spirometry, based on post-bronchodilator Forced Expiratory Volume in 1 second (FEV1):
• FEV1/Forced Vital Capacity (FVC) 90% (both supine and sitting)
• SpO2 during sleep >=80% for at least 75% of the recording period with no more than five continuous minutes =10
• Age >65 years: PLMAI >15
• A prolonged QT interval by Fredericia (QTcF) (QTcF >450 milliseconds [ms]) as demonstrated by a repeated electrocardiogram (ECG) at Screening
• Any suicidal ideation with intent with or without a plan at Screening or within 6 months of Screening (that is, answering "Yes" to questions 4 or 5 on the Suicidal Ideation section of the Columbia-Suicide Severity Rating Scale [C-SSRS])
• Any lifetime suicidal behavior (per the Suicidal Behavior section of the C-SSRS) within 10 years of Screening
• Evidence of clinically significant disease (example, cardiac, respiratory, gastrointestinal, renal disease) that in the opinion of the investigator(s) could affect the participant's safety or interfere with the study assessments
• Hypersensitivity to the study drug or any of the excipients
• Used any prohibited prescription or over-the-counter medications within 1 week or 5 half-lives, whichever is longer, before the screening PSG
• Any history of or concomitant medical condition that in the opinion of the investigator(s) would compromise the participant's ability to safely complete the study
• Scheduled for surgery during the study that requires general anesthesia or administration of prohibited medications
• Psychotic disorder(s) or unstable recurrent affective disorder(s) evident by use of antipsychotics or prior suicide attempt(s) within approximately the last 2 years
• History of drug or alcohol dependency or abuse within approximately the last 2 years
• Use of illegal recreational drugs (includes marijuana, regardless of whether prescribed for medicinal use)
• Currently enrolled in another clinical study or used any investigational drug or device within 28 days or 5*the half-life, whichever is longer preceding informed consent
• Previously participated in other clinical trial of lemborexant
• Exposure within the last 14 days to an individual with confirmed or probable corona virus disease 2019 (COVID-19) or symptoms within the last 14 days that are on the most recent Centers for Disease Control and Prevention (CDC) list of COVID symptoms or any other reason to consider the participant at potential risk for an acute COVID-19 infection

Additional Exclusion Criteria (OSA Cohort)

• SpO2 =5% of TST during the screening PSG
• Use of a continuous positive airway pressure (CPAP) device or dental appliance within 2 weeks of the screening PSG, and does not agree to abstain from the use of a CPAP device or dental appliance from the
• Current evidence of a clinically significant, active respiratory disorder other than OSA. This includes bronchiectasis, emphysema, asthma, COPD or any other pulmonary disorder identified by review of medical history, physical examination, and which in the opinion of the investigator, could compromise the participant's safety or interfere with study assessments
• Current evidence of other clinically significant disease (example, psychiatric disorders, disorders of the gastrointestinal tract, liver, kidney, respiratory system, endocrine system, hematological system, neurological system, cardiovascular system, or a congenital abnormality), malignancy within the past 5 years (other than adequately treated basal cell carcinoma or in situ carcinoma of the cervix), or chronic pain that in the opinion of the investigator could affect the participant's safety or interfere with the study assessments