Study to Evaluate the Pharmacokinetics of Lemborexant (E2006) and Its Metabolites in Subjects With Mild and Moderate Hepatic Impairment Compared to Healthy Subjects

Inclusion Criteria

Inclusion Criteria for All Participants:

• Male or female participants, ages 18 to 79, inclusive, at the time of informed consent
• Body Mass Index (BMI) between 18 and 40 kilograms per meters squared, inclusive, at Screening
• Voluntary agreement to provide written informed consent, and the willingness and ability to comply with all aspects of the protocol
• Nonsmokers or smokers who smoke 20 cigarettes or less per day
• For Cohorts A and B: stable (without any change in disease status for at least 60 days prior to study Screening) hepatic impairment conforming to Child-Pugh classification A or B, respectively, and documented by medical history and a physical examination
• For Cohort C: healthy participants matched to participants with hepatic impairment with regard to age (±10 years), sex, and BMI (±20%), and as determined by no clinically significant deviation from normal in medical history, physical examination, electrocardiogram (ECG), and clinical laboratory determinations

Exclusion Criteria

Exclusion Criteria for All Participants:

• Females who are breastfeeding or pregnant at Screening or Baseline
• Females of childbearing potential who did not use a highly effective method of contraception within 28 days before study entry, or who did not agree to use an approved method of contraception from 28 days before study entry, throughout the entire study period, and for 28 days after study drug discontinuation. Approved (highly effective) methods of contraception for this study included at least one of the following: 1. Total abstinence (if it was their preferred and usual lifestyle); 2. An intrauterine device or intrauterine hormone-releasing system (IUS); 3. A double-barrier method of contraception such as condom plus diaphragm with spermicide; 4. A contraceptive implant; 5. An oral contraceptive (with additional barrier method). Participant must have been on a stable dose of the same oral contraceptive product for at least 28 days before dosing, throughout the study, and for 28 days after study drug discontinuation; 6. Have a vasectomized partner with confirmed azoospermia. (Note: All females will be considered to be of childbearing potential unless they are postmenopausal (amenorrheic for at least 12 consecutive months, in the appropriate age group, and without other known or suspected cause) or have been sterilized surgically (i.e., bilateral tubal ligation, total hysterectomy, or bilateral oophorectomy, all with surgery at least 1 month before dosing).
• Known to be positive for human immunodeficiency virus
• Currently enrolled in another clinical study or used any investigational drug or device within 4 weeks, or 5 times the half-life of the investigational drug (whichever is longer), preceding informed consent
• Receipt of blood products within 4 weeks, or donation of blood within 8 weeks, or donation of plasma within 1 week of dosing until study discharge
• Intake of herbal preparations containing St. John's Wort within 4 weeks prior to dosing until study discharge
• Intake of nutritional supplements (including herbal preparations), foods or beverages that may affect cytochrome P3A enzyme (e.g., alcohol, grapefruit, grapefruit juice, grapefruit-containing beverages, apple or orange juice, vegetables from the mustard green family [e.g., kale, broccoli, watercress, collard greens, kohlrabi, Brussels sprouts, mustard] and charbroiled meats) within 1 week before dosing until study discharge
• Intake of beverages, food, or other products that contain caffeine from 24 hours before until 48 hours after dosing with lemborexant
• Engagement in strenuous exercise (e.g., moving large bulky items, bodybuilding) within 2 weeks prior to check-in until study discharge
• History of clinically significant drug or food allergies, or is presently experiencing significant seasonal allergies
• A prolonged QT/corrected QT (QTc) interval (QTc >480 milliseconds) demonstrated on ECG at Screening or Baseline (Day -1)