A study to evaluate the respiratory safety of TS-142 in patients with mild obstructive sleep apnea hypopnea.

Inclusion Criteria:

• Japanese male and female, age 20 years or older at the time of informed consent
• Patients who meet the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) criteria for obstructive sleep apnea hypopnea
• Other protocol defined inclusion criteria could apply

Exclusion Criteria:

Subjects who meet any of the following criteria will be excluded from this study:

• Patients who meet the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) criteria excepting obstructive sleep apnea hypopnea and insomnia disorder
• Patients who have clinically significant respiratory dysfunction (bronchiectasis, emphysema, asthma, etc.) other than obstructive sleep apnea hypopnea
• Patients with percutaneous arterial oxygen saturation (SpO2) <94% by pulse oximetry at visit 1
• Other protocol defined exclusion criteria could apply