Safety and Efficacy Study of Suvorexant in Participants With Primary Insomnia - Study A (MK-4305-028)
Condition: Primary Insomnia
MeSH terms: Sleep Initiation and Maintenance Disorders
Intervention: Suvorexant High Dose (HD); Suvorexant Low Dose (LD); Comparator: Placebo
Intervention description: Suvorexant 40 mg + placebo matching suvorexant 20 mg for participants <65 years old; Suvorexant 30 mg + placebo matching suvorexant 15 mg for participants ≥65 years old; all study drug is tablet for oral administration, taken once daily at bedtime. Participants receive this dose during the 3-month TRT Phase and, if applicable, the optional 3-month EXT Phase. During the 1-week double-blind (DB) Run-out (RO) following the TRT/EXT phase, participants in this study arm receive the noted suvorexant dose or placebo, in a 1:1 ratio. During the 2-week single-blind Run-in period prior to randomization all participants receive placebo to suvorexant once daily at bedtime.; Suvorexant 20 mg + placebo matching suvorexant 40 mg for participants <65 years old; Suvorexant 15 mg + placebo matching suvorexant 30 mg for participants ≥65 years old; all study drug is tablet for oral administration, taken once daily at bedtime. Participants receive this dose during the 3-month TRT Phase and, if applicable, the optional 3-month EXT Phase. During the 1-week DB RO following the TRT/EXT phase, participants in this study arm receive the noted suvorexant dose or placebo, in a 1:1 ratio. During the 2-week single-blind Run-in period prior to randomization all participants receive placebo to suvorexant once daily at bedtime.; Matching placebos to suvorexant 40 mg and 20 mg for participants <65 years old; matching placebos to suvorexant 30 mg and 15 mg for participants ≥65 years old; all study drug is tablet for oral administration, taken once daily at bedtime. Placebo is a third treatment arm for comparison to the two active (suvorexant) treatment arms during the 3-month TRT Phase and, if applicable, the optional 3-month EXT Phase. During the 1-week DB RO following the TRT/EXT phase, participants in this study arm continue to receive placebo. During the 2-week single-blind Run-in period prior to randomization all participants receive placebo to suvorexant once daily at bedtime.
Intervention MeSH terms: Suvorexant
Phase: Phase 3
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Enrollment: 1023.0
Sex: All
Minimum age: 18 Years
Healthy volunteers: No

Summary:

      This is a multicenter study to test the hypothesis that suvorexant (MK-4305) is superior to
      placebo in improving insomnia as measured by change from baseline in: subjective total sleep
      time and time to sleep onset, wake time after persistent sleep onset, and latency to onset of
      persistent sleep. Participants who complete the initial 3-month Treatment (TRT) Phase may
      participate in an optional 3-month Extension (EXT) Phase.
    

Eligibility criteria:

        Inclusion Criteria:

          -  Must be ≥18 yrs old on the day of signing informed consent

          -  Diagnosed with Primary Insomnia

          -  Good physical and mental health

          -  Participant ≥65 yrs old score at least 25 on the Mini Mental State Examination

          -  A female participant who is of reproductive potential has a negative serum pregnancy
             test and agrees to use contraception

          -  Reports difficulty with initiating and maintaining sleep during the 4 weeks prior to
             Visit 1 (accordingly to specific protocol criteria)

          -  Reports spending 6.5 to 9 hours nightly in bed on at least 3 out of 7 nights prior to
             Visit 1

          -  Regular bedtime is between 9 pm-1 am

          -  Willing to refrain from napping while in study

          -  Able to read, understand and complete questionnaires and all diaries

          -  Willing to limit alcohol, caffeine, and nicotine consumption while in the study

          -  For a portion of participants: Must be willing to stay overnight in a sleep laboratory
             and must be willing to stay in bed for at least 8 hours each night while at the sleep
             laboratory

        Exclusion Criteria:

          -  Female participant is pregnant and/or breastfeeding at Prestudy visit, or expecting to
             conceive while in study

          -  History or diagnosis of another sleep disorder

          -  Difficulty sleeping due to a medical condition

          -  History of a neurological disorder

          -  History of bipolar disorder, psychotic disorder, or posttraumatic stress disorder, or
             current psychiatric disorder that requires a prohibited medication

          -  Ongoing depression

          -  History of substance abuse or dependence

          -  History or current evidence of a clinically significant cardiovascular disorder or
             clinically significant electrocardiogram (ECG) at Prestudy Visit

          -  Taking certain prohibited medications

          -  Consumption of the equivalent of >15 cigarettes a day

          -  History of malignancy ≤5 years prior to signing informed consent, except for
             adequately treated basal cell or squamous cell skin cancer or in situ cervical cancer

          -  Participant is considered morbidly obese

          -  Previously randomized in another investigational study of suvorexant