A Study of Suvorexant (MK-4305) for the Treatment of Insomnia Disorder in Participants With Opioid Use Disorder (MK-4305-098)

August 27, 2026 updated by: Merck Sharp & Dohme LLC

A Phase 3, Multicenter, Randomized, Double-blind, Placebo-controlled Study to Evaluate the Efficacy and Safety of Suvorexant for the Treatment of Insomnia in Participants With Opioid Use Disorder

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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
300

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United States
    • California
      • Garden Grove, California, United States, 92845
        • Recruiting
        • Cenexel CNS ( Site 2012)
        • Contact:
          • Study Coordinator
          • Phone Number: 866-787-4257
    • Connecticut
      • New Haven, Connecticut, United States, 06520
        • Recruiting
        • Yale University School of Medicine ( Site 1003)
        • Contact:
          • Study Coordinator
          • Phone Number: 203-785-3627
    • Florida
      • Bradenton, Florida, United States, 34205
        • Recruiting
        • Bradenton Research Center ( Site 2021)
        • Contact:
          • Study Coordinator
          • Phone Number: 941-708-0005
    • Georgia
      • Savannah, Georgia, United States, 31405
        • Recruiting
        • CenExel iResearch, LLC ( Site 2010)
        • Contact:
          • Study Coordinator
          • Phone Number: 912-744-0800
    • Maryland
      • Baltimore, Maryland, United States, 21224
        • Recruiting
        • Johns Hopkins University ( Site 1001)
        • Contact:
          • Study Coordinator
          • Phone Number: 443-216-9237
    • New Jersey
      • Marlton, New Jersey, United States, 08053
        • Recruiting
        • Hassman Research Institute Marlton Site ( Site 2005)
        • Contact:
          • Study Coordinator
          • Phone Number: 856-261-6420
    • Oklahoma
      • Oklahoma City, Oklahoma, United States, 73112
        • Recruiting
        • The Rivus Wellness & Research Institute ( Site 2014)
        • Contact:
          • Study Coordinator
          • Phone Number: 405-607-2233
    • Pennsylvania
      • Philadelphia, Pennsylvania, United States, 19104
        • Recruiting
        • Penn Medicine University of Pennsylvania Health System- Center for Studies of Addiction ( Site 1006)
        • Contact:
          • Study Coordinator
          • Phone Number: 215-222-3200
    • Rhode Island
      • Providence, Rhode Island, United States, 02906
        • Recruiting
        • Butler Hospital ( Site 1002)
        • Contact:
          • Study Coordinator
          • Phone Number: 401-455-6440
    • South Carolina
      • Charleston, South Carolina, United States, 29403
        • Recruiting
        • Medical University of South Carolina ( Site 1005)
        • Contact:
          • Study Coordinator
          • Phone Number: 843-792-4636
    • Texas
      • DeSoto, Texas, United States, 75115
        • Recruiting
        • Adams Clinical Dallas ( Site 2007)
        • Contact:
          • Study Coordinator
          • Phone Number: 972-283-6286
      • Houston, Texas, United States, 77043
        • Recruiting
        • Memorial Hermann Village ( Site 2001)
        • Contact:
          • Study Coordinator
          • Phone Number: 281-369-5765
    • Virginia
      • Richmond, Virginia, United States, 23219
        • Recruiting
        • VCU Institute for Drug and Alcohol Studies ( Site 1004)
        • Contact:
          • Study Coordinator
          • Phone Number: 804-827-3784

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

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 Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
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.
Drug: Suvorexant
Oral Tablet
Other Names:
  • MK-4305
Placebo Comparator: Placebo
Participants receive suvorexant-matching placebo for up to approximately 8 weeks.
Drug: Placebo
Oral Tablet

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change from Baseline in Total Sleep Time at Week 8
Time Frame: Baseline and Week 8
Total sleep time will be measured in a sleep laboratory by polysomnography at the participant's habitual bedtime. Change from baseline in total sleep time at Week 8 will be reported.
Baseline and Week 8
Number of Participants Who Experience One or More Adverse Events (AEs)
Time Frame: Up to approximately 10 weeks
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention.
Up to approximately 10 weeks
Number of Participants Who Experience One or More Serious Adverse Events (SAEs)
Time Frame: Up to approximately 10 weeks
An SAE is any untoward medical occurrence that at any dose results in death, is life threatening, requires or prolongs inpatient hospitalization, results in persistent or significant disability or incapacity, is a congenital anomaly or birth defect or is another important medical event deemed such by medical or scientific judgement.
Up to approximately 10 weeks
Number of Participants Who Discontinue Study Treatment Due to an AE
Time Frame: Up to approximately 8 weeks
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention.
Up to approximately 8 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change from Baseline in Wakefulness after Persistent Sleep Onset at Week 8
Time Frame: Baseline and Week 8
Wakefulness after persistent sleep onset will be measured in a sleep laboratory by polysomnography at the participant's habitual bedtime. Change from baseline in wakefulness after persistent sleep onset at Week 8 will be reported.
Baseline and Week 8
Number of Participants Who are Positive for Substance Abuse at Day 1
Time Frame: Day 1
A positive assessment for substance abuse at Day 1 is defined as either a positive urine drug test for opioids and other nonmedical substances including fentanyl, cocaine, amphetamines, benzodiazepines, and cannabis OR a positive response on the Substance Use History (SUH) Since Last Assessment questionnaire. The Substance Use History Questionnaire (SUH) has been developed specifically for this study. This is a self-reported questionnaire used to obtain a variety of quantitative estimates of cannabis, alcohol, and other nonmedical substance use. The SUH Since Last Assessment Questionnaire will be used to assess nonmedical substance and alcohol use since the previous study visit.
Day 1
Number of Participants Who are Positive for Substance Abuse at Day 4
Time Frame: Day 4
A positive assessment for substance abuse at Day 4 is defined as either a positive urine drug test for opioids and other nonmedical substances including fentanyl, cocaine, amphetamines, benzodiazepines, and cannabis OR a positive response on the Substance Use History (SUH) Since Last Assessment questionnaire. The Substance Use History Questionnaire (SUH) has been developed specifically for this study. This is a self-reported questionnaire used to obtain a variety of quantitative estimates of cannabis, alcohol, and other nonmedical substance use. The SUH Since Last Assessment Questionnaire will be used to assess nonmedical substance and alcohol use since the previous study visit.
Day 4
Number of Participants Who are Positive for Substance Abuse at Week 2
Time Frame: Week 2
A positive assessment for substance abuse at Week 2 is defined as either a positive urine drug test for opioids and other nonmedical substances including fentanyl, cocaine, amphetamines, benzodiazepines, and cannabis OR a positive response on the Substance Use History (SUH) Since Last Assessment questionnaire. The Substance Use History Questionnaire (SUH) has been developed specifically for this study. This is a self-reported questionnaire used to obtain a variety of quantitative estimates of cannabis, alcohol, and other nonmedical substance use. The SUH Since Last Assessment Questionnaire will be used to assess nonmedical substance and alcohol use since the previous study visit.
Week 2
Number of Participants Who are Positive for Substance Abuse at Week 4
Time Frame: Week 4
A positive assessment for substance abuse at Week 4 is defined as either a positive urine drug test for opioids and other nonmedical substances including fentanyl, cocaine, amphetamines, benzodiazepines, and cannabis OR a positive response on the Substance Use History (SUH) Since Last Assessment questionnaire. The Substance Use History Questionnaire (SUH) has been developed specifically for this study. This is a self-reported questionnaire used to obtain a variety of quantitative estimates of cannabis, alcohol, and other nonmedical substance use. The SUH Since Last Assessment Questionnaire will be used to assess nonmedical substance and alcohol use since the previous study visit.
Week 4
Number of Participants Who are Positive for Substance Abuse at Week 8
Time Frame: Week 8
A positive assessment for substance abuse at Week 8 is defined as either a positive urine drug test for opioids and other nonmedical substances including fentanyl, cocaine, amphetamines, benzodiazepines, and cannabis OR a positive response on the Substance Use History (SUH) Since Last Assessment questionnaire. The Substance Use History Questionnaire (SUH) has been developed specifically for this study. This is a self-reported questionnaire used to obtain a variety of quantitative estimates of cannabis, alcohol, and other nonmedical substance use. The SUH Since Last Assessment Questionnaire will be used to assess nonmedical substance and alcohol use since the previous study visit.
Week 8
Number of Participants with Positive Urine Drug Screen
Time Frame: Day 1, Day 4, Week 2, Week 4, Week 8
A positive urine drug screen is defined as urine drug test positive for opioids and other nonmedical substances including fentanyl, cocaine, amphetamines, benzodiazepines, and cannabis
Day 1, Day 4, Week 2, Week 4, Week 8

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Merck Sharp & Dohme LLC

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Medical Director, Merck Sharp & Dohme LLC

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
October 9, 2025

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 24, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 24, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 22, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 22, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
October 24, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 28, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 27, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 4305-098
  • MK-4305-098 (Other Identifier: MSD)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings