Recruiting
Phase 3

Suvorexant

Sponsor:

Merck Sharp & Dohme LLC

Code:

NCT06655883

Conditions

Insomnia

Eligibility Criteria

Sex: All

Age: 18 - 70

Healthy Volunteers: Not accepted

Interventions

Suvorexant

Placebo

Study Details

Brief summary:

People with opioid use disorder (OUD) can have trouble falling or staying asleep. Researchers want to know if suvorexant will help people with OUD fall asleep and stay asleep. The goal of this study is to learn about the safety of suvorexant and how well people tolerate it. Researchers also want to learn if suvorexant helps people sleep longer compared to people who take placebo. A placebo looks like the study medicine but has no actual study medicine in it.

Conditions

Insomnia

Study ID

NCT06655883

Start date

Oct 9, 2025

Status verified date

Aug, 2026

Completion date

Jun 24, 2027

Anticipated

Primary completion date

Jun 24, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 70

Healthy Volunteers: Not accepted

Inclusion Criteria:

The main inclusion criteria include but are not limited to the following:

  • Has a primary diagnosis of OUD according to Diagnostic and Statistical Manual of Mental Disorder, 5th Edition (DSM-5), and confirmed through the Mini International Neuropsychiatric Interview (MINI).
  • Is on a verified, stable dose of medications for opioid use disorder (MOUD) treatment.
  • Meets DSM-5 criteria for the diagnosis of Insomnia Disorder
  • Has a regular bedtime between 8 PM (20:00) and 1 AM (01:00) and is willing to maintain it for the duration of the study.
  • Has not used opioids for a period of at least 4 weeks before entering the study.

Exclusion Criteria:

The main exclusion criteria include but are not limited to the following:

  • Has current uncontrolled major co-morbid psychiatric illness including major depressive disorder, bipolar disorder, schizophrenia, or any psychiatric condition with psychotic features.
  • Has current diagnosis or history within 5 years of any of the following: narcolepsy, sleep paralysis, severe periodic limb movement disorder, restless leg syndrome, cataplexy, circadian rhythm sleep disorder, parasomnia including nightmare disorder, sleep terror disorder, sleepwalking disorder, rapid eye movement (REM) behavior disorder, significant degree of sleep-related breathing disorder, excessive daytime sleepiness (EDS), or primary hypersomnia.
  • Is at imminent risk of self-harm.
  • Has a known history of stroke that may confound the diagnosis of insomnia.
  • Has a clinically significant movement disorder such as akinesia.
  • Has a history of hepatitis or live disease.
  • Has habitual use of central nervous system (CNS)-depressants or stimulants that may be responsible for the participant's disturbed sleep.
  • Has a history of malignancy, ≤3 years prior to start of study, with the exception of nonmelanoma skin cancer, prostate cancer or localized carcinoma in situ of the cervix.
  • Has a history of hypersensitivity to more than 3 chemical classes of drugs, including prescription and over-the-counter medications.
  • Has donated blood products or had phlebotomy within 8 weeks prior to start of study.
  • Has a history of transmeridian travel within 2 weeks prior to start of study.

Study Design

Enrollment

300 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Suvorexant

Participants receive 10 mg of suvorexant for the first three nights, increased to 20 mg of suvorexant nightly thereafter at the investigator's discretion, for up to approximately 8 weeks.

placebo comparator: Placebo

Participants receive suvorexant-matching placebo for up to approximately 8 weeks.

Interventions

Suvorexant

Oral Tablet

Placebo

Oral Tablet

Primary outcome measure

  • Change from Baseline in Total Sleep Time at Week 8 [ Time Frame: Baseline and Week 8 ]
  • Number of Participants Who Experience One or More Adverse Events (AEs) [ Time Frame: Up to approximately 10 weeks ]
  • Number of Participants Who Experience One or More Serious Adverse Events (SAEs) [ Time Frame: Up to approximately 10 weeks ]
  • Number of Participants Who Discontinue Study Treatment Due to an AE [ Time Frame: Up to approximately 8 weeks ]

Central Contacts and Locations

Central contacts

Toll Free Number

1-888-577-8839Trialsites@msd.com

Locations

Cenexel CNS ( Site 2012)

Recruiting

Garden Grove, California, United States, 92845

Contacts

Study Coordinator

866-787-4257

Yale University School of Medicine ( Site 1003)

Recruiting

New Haven, Connecticut, United States, 06520

Contacts

Study Coordinator

203-785-3627

Bradenton Research Center ( Site 2021)

Recruiting

Bradenton, Florida, United States, 34205

Contacts

Study Coordinator

941-708-0005

CenExel iResearch, LLC ( Site 2010)

Recruiting

Savannah, Georgia, United States, 31405

Contacts

Study Coordinator

912-744-0800

Johns Hopkins University ( Site 1001)

Recruiting

Baltimore, Maryland, United States, 21224

Contacts

Study Coordinator

443-216-9237

Hassman Research Institute Marlton Site ( Site 2005)

Recruiting

Marlton, New Jersey, United States, 08053

Contacts

Study Coordinator

856-261-6420

The Rivus Wellness & Research Institute ( Site 2014)

Recruiting

Oklahoma City, Oklahoma, United States, 73112

Contacts

Study Coordinator

405-607-2233

Penn Medicine University of Pennsylvania Health System- Center for Studies of Addiction ( Site 1006)

Recruiting

Philadelphia, Pennsylvania, United States, 19104

Contacts

Study Coordinator

215-222-3200

Butler Hospital ( Site 1002)

Recruiting

Providence, Rhode Island, United States, 02906

Contacts

Study Coordinator

401-455-6440

Medical University of South Carolina ( Site 1005)

Recruiting

Charleston, South Carolina, United States, 29403

Contacts

Study Coordinator

843-792-4636

Adams Clinical Dallas ( Site 2007)

Recruiting

DeSoto, Texas, United States, 75115

Contacts

Study Coordinator

972-283-6286

Memorial Hermann Village ( Site 2001)

Recruiting

Houston, Texas, United States, 77043

Contacts

Study Coordinator

281-369-5765

VCU Institute for Drug and Alcohol Studies ( Site 1004)

Recruiting

Richmond, Virginia, United States, 23219

Contacts

Study Coordinator

804-827-3784

More Information

Sponsor

Merck Sharp & Dohme LLC

Last update posted

Aug 28, 2026

Last verified

Aug, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-20. This information was provided to ClinicalTrials.gov by Merck Sharp & Dohme LLC on 2026-08-28.