Inclusion Criteria:
- Subjects who are Japanese male or female aged 65 years or older at the time of obtaining informed consent
- Subjects with a body Mass Index (BMI) from 18.5 to less than 25.0 and a body weight of 40.0 kg or over at the screening test
- Subjects who are judged by the principal investigators or subinvestigators as an eligible for the clinical trial participation based on the results of tests conducted in the screening, VISIT 1 and prior to the administration of the investigational drug.
Other protocol defined inclusion criteria could apply.
Exclusion Criteria:
- Subjects who are judged to have any disease by the principal investigator or sub-investigator and are not considered healthy
- Subjects who have any unsuitable medical histories for participation in this clinical trial, including respiratory, cardiovascular, gastrointestinal, hepatic, renal, urological, endocrinological, metabolic, hematologic, immunologic, dermatological, neurological, or psychiatric diseases
- Subjects who have any medical histories including sleep-associated symptoms, narcolepsy-like symptoms, suicidal ideation, or suicidal attempts.
Other protocol defined exclusion criteria could apply.