Not Yet RecruitingPhase 1

A Study of Ulonivirine (MK-8507) and Methadone in Healthy Volunteers (MK-8507-019)

14 participantsStarted 2026-08-17

Plain-language summary

This study is designed to determine the effect of ulonivirine (MK-8507) on methadone in the body. Participants will take methadone alone and then methadone with ulonivirine to see if ulonivirine changes how the body processes methadone.

Who can participate

Age range

18 Years – 65 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria The main Inclusion Criteria include but are not limited to: * Is in good health * Has a body mass index (BMI) between \>18 and ≤40 kg/m\^2 * Is reliably participating in a methadone maintenance program for at least 2 months prior to Day 1 and is on a documented stable dose of methadone for at least 14 days prior to Day 1 Exclusion Criteria The main Exclusion Criteria include but are not limited to: * Has a history of cancer (malignancy) * Has a history of significant multiple and/or severe allergies, or has had an anaphylactic reaction or significant intolerability to prescription or nonprescription drugs or food * Has tested positive human immunodeficiency virus (HIV) or for a sexually transmitted infection at screening * Is under the age of legal consent

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Dose-Normalized Area Under the Plasma Concentration Time Curve From 0-24 Hours Postdose (AUC0-24) of R-Methadone

Timeframe: Up to 24 hours post-dose

Dose-Normalized AUC0-24 of S-Methadone

Timeframe: Up to 24 hours post-dose

Trial details

NCT IDNCT07595263

SponsorMerck Sharp & Dohme LLC

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2027-01-15

View on ClinicalTrials.gov More Healthy trials

Who can participate

Age range

18 Years – 65 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.