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Taking people in United StatesPhase 3

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

Key facts

Who runs it
Merck Sharp & Dohme LLC
Where
Baltimore, Bradenton, Charleston, DeSoto, Garden Grove, Houston, Marlton, New Haven, Oklahoma City, Philadelphia, Providence, Richmond, and Savannah, United StatesSee the 13 sites
Trial code
Status
Recruiting
Phase
Phase 3
People taking part
300 people, planned
Started
9 Oct 2025
Expected to end
24 Jun 2027
Type of study
Interventional, 2 groupsOne group gets a placebo (a dummy treatment), for comparison.
Treatments tested
  • Suvorexant
  • Placebo
Record updated
21 September 2026

Who can take part

Age
18 years to 70 years
Sex
Women and men
Healthy volunteers
Cannot take part

The registry criteria, word for word

Show all 18 criteriaShow less

Who can take part

  • 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

Who cannot take part

  • 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
  • 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
  • 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 a history of hypersensitivity to more than 3 chemical classes of drugs, including prescription and over-the-counter medications
  • 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
  • The main exclusion criteria include but are not limited to the following:
  • Is at imminent risk of self-harm
  • Has habitual use of central nervous system (CNS)-depressants or stimulants that may be responsible for the participant's disturbed sleep

Check if you might fit

Answer for yourself. This is not a decision: only the study team can say whether you can take part.

  • Are you between 18 and 70 years old?

Where in United States

  • Johns Hopkins University (Site 1001)Baltimore, United StatesContact: Study CoordinatorTaking people
  • Bradenton Research Center (Site 2021)Bradenton, United StatesContact: Study CoordinatorTaking people
  • Medical University of South Carolina (Site 1005)Charleston, United StatesContact: Study CoordinatorTaking people
  • Adams Clinical Dallas (Site 2007)DeSoto, United StatesContact: Study CoordinatorTaking people
  • Cenexel CNS (Site 2012)Garden Grove, United StatesContact: Study CoordinatorTaking people
  • Memorial Hermann Village (Site 2001)Houston, United StatesContact: Study CoordinatorTaking people
  • Hassman Research Institute Marlton Site (Site 2005)Marlton, United StatesContact: Study CoordinatorTaking people
  • Yale University School of Medicine (Site 1003)New Haven, United StatesContact: Study CoordinatorTaking people
  • The Rivus Wellness & Research Institute (Site 2014)Oklahoma City, United StatesContact: Study CoordinatorTaking people
  • Penn Medicine University of Pennsylvania Health System- Center for Studies of Addiction (Site 1006)Philadelphia, United StatesContact: Study CoordinatorTaking people
  • Butler Hospital (Site 1002)Providence, United StatesContact: Study CoordinatorTaking people
  • VCU Institute for Drug and Alcohol Studies (Site 1004)Richmond, United StatesContact: Study CoordinatorTaking people
  • CenExel iResearch, LLC (Site 2010)Savannah, United StatesContact: Study CoordinatorTaking people

About the trial

What the trial wants to find out

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.

The 2 groups in the trial

  • SuvorexantTreatment being tested

    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.

  • PlaceboPlacebo, for comparison

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

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Data and sources

Registry record
Listed on ClinicalTrials.gov.
Official title
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
Fit questions
Built from NCT06655883, who can take part
Record updated
21 September 2026