Conditions: Insomnia
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 781
Healthy volunteers: no

Brief summary:
This study will establish the safety and tolerability of suvorexant (MK-4305) when administered for up to 14 months. Participants will be randomized to receive suvorexant or placebo for a 12-month double-blind (DB) Treatment Phase. Participants who complete the 12-month DB Treatment Phase will enter a 2-month DB Randomized Discontinuation Phase. At the time of initial randomization, participants assigned to receive suvorexant during the initial 12-month Treatment Phase will be simultaneously randomized, in a 1:1 ratio, to receive either suvorexant or placebo during the 2-month Randomized Discontinuation Phase. Participants randomized to receive placebo in the initial 12-month Treatment Phase will continue to receive placebo during the 2-month Randomized Discontinuation Phase.

The first 3 nights of the Randomized Discontinuation Phase are referred to as the Run-Out Phase, and will assess rebound and withdrawal.

Detailed description:

Arms:
arm 1: After a 1-week single-blind placebo run-in, participants received suvorexant (40 mg for participants aged 18 to \<65 years; and 30 mg for participants aged ≥65 years) daily before bedtime for 12 months during the Treatment Phase. arm 2: After a 1-week single-blind placebo run-in, participants received dose-matched placebo to suvorexant (administered according to age) daily before bedtime for 12 months during the Treatment Phase.

Interventions: intervention 1: Suvorexant intervention 2: Dose-matched Placebo to Suvorexant
Intervention descriptions: intervention 1: Oral tablet (30 mg and 10 mg), administered daily before bedtime intervention 2: Oral tablet, administered daily before bedtime

Protocol document: