Main Inclusion Criteria:  Parts 1, 2 and 3: Healthy Volunteers  Male or female between 18 and 55 years old (inclusive) at the time of screening. In good general health at screening, free from clinically significant unstable medical, surgical or psychiatric illness, at the discretion of the Investigator.  Main Exclusion Criteria:  Parts 1, 2 and 3: Healthy Volunteers  Evidence or history of any condition or situation that adversely impacts a normal sleep-wake cycle. Confirmed COVID-19 infection within 6 months of screening, known exposure to another person with COVID-19 within 14 days of screening History of illness with fever within 28 days prior to the first dose. A history of, or current evidence for, serious mental illness