Phase IIB 2-Period Crossover Polysomnography Study in Participants With Primary Insomnia (MK-4305-006)

A Phase IIb, Multicenter, Randomized, Double-Blind Placebo-Controlled, 2-period Adaptive Crossover Polysomnography Study to Evaluate Safety and Efficacy of MK-4305 in Patients With Primary Insomnia

A cross-over, polysomnography study to test the safety, tolerability and effectiveness of different doses of suvorexant (MK-4305) in the treatment of patients with primary insomnia.

Inclusion Criteria:

• Has a diagnosis of Primary Insomnia based on sleep history and the investigator's judgment
• Must be willing to stay overnight at a sleep laboratory
• Must be willing to stay in bed for at least 8 hours each night while at the sleep laboratory
• Regular bedtime is between 9 PM and 12 AM (midnight)

Exclusion Criteria:

• Breast feeding, pregnant or planning to become pregnant during the study
• Within the past 6 months before starting the study you have a history of significant cardiovascular disorder such as unstable angina, congestive heart - failure or acute coronary syndrome
• Currently participating or have participated in a study with an investigational compound or device within the last 30 days
• Has traveled across 3 or more time zones in the last 2 weeks or plans on traveling across 3 or more time zones at any time during the study
• Has done shift work within the past 2 weeks
• Has donated blood products within the last 8 weeks
• Has difficulty sleeping due to a medical condition