HealthyPhase 1NCT07595263
A Study of Ulonivirine (MK-8507) and Methadone in Healthy Volunteers (MK-8507-019)
A Phase 1 study testing Ulonivirine and Methadone in people with Healthy, run by Merck Sharp & Dohme LLC at 1 site in United States.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- Ulonivirine and Methadone
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 14 participants
- Where
- 1 siteUnited States
- Study dates
- 17 Aug 2026to 15 Jan 2027
- Phase
- Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 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
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Pinnacle Research Group ( Site 0002)
Anniston, Alabama, 36207
Study Coordinator, 256-236-0055
About this study
Official title: A Clinical Trial to Study the Effect of a Single Dose of Ulonivirine on the Pharmacokinetics of Methadone
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.
- Conditions
- Healthy
- Being tested
- Ulonivirine, Methadone
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
UlonivirineDrug
Also called MK-8507
Oral Tablet
MethadoneDrug
Oral (per local guidelines)
| Study group | Role | What they receive |
|---|---|---|
| Methadone + Ulonivirine | Experimental | Participants receive a stable dose of methadone orally from Day -14 through Day 16. Methadone is co-administered with one dose of oral ulonivirine on Day 2. Receives: Drug: Ulonivirine; Drug: Methadone |
What is being measured
The primary outcome is the main question the study is designed to answer.
Dose-Normalized Area Under the Plasma Concentration Time Curve From 0-24 Hours Postdose (AUC0-24) of R-Methadone
The AUC0-24 of R-methadone will be determined on Day 1 (methadone) and Day 2 (methadone + ulonivirine).
Measured: Up to 24 hours post-dose
Dose-Normalized AUC0-24 of S-Methadone
The AUC0-24 of S-methadone will be determined on Day 1 (methadone) and Day 2 (methadone + ulonivirine).
Measured: Up to 24 hours post-dose
Secondary outcomes (12)
Dose-Normalized Maximum Plasma Concentration (Cmax) of R-Methadone
The Cmax of R-methadone will be determined on Day 1 (methadone) and Day 2 (methadone + ulonivirine).
Measured: Up to 24 hours post-dose
Dose-Normalized Plasma Concentration 24 Hours Postdose (C24) of R-Methadone
The C24 of R-methadone will be determined on Day 1 (methadone) and Day 2 (methadone + ulonivirine).
Measured: 24 hours post-dose
Time to Maximum Plasma Concentration (Tmax) of R-Methadone
The Tmax of R-methadone will be determined on Day 1 (methadone) and Day 2 (methadone + ulonivirine).
Measured: Up to 24 hours post-dose
Dose-Normalized Cmax of S-Methadone
The Cmax of S-methadone will be determined on Day 1 (methadone) and Day 2 (methadone + ulonivirine).
Measured: Up to 24 hours post-dose
Dose-Normalized C24 of S-Methadone
The C24 of S-methadone will be determined on Day 1 (methadone) and Day 2 (methadone + ulonivirine).
Measured: 24 hours post-dose
Tmax of S-Methadone
The Tmax of S-methadone will be determined on Day 1 (methadone) and Day 2 (methadone + ulonivirine).
Measured: Up to 24 hours post-dose
Dose-Normalized AUC0-24 of Total Methadone
The AUC0-24 of total methadone will be determined on Day 1 (methadone) and Day 2 (methadone + ulonivirine).
Measured: Up to 24 hours post-dose
Dose-Normalized Cmax of Total Methadone
The Cmax of total methadone will be determined on Day 1 (methadone) and Day 2 (methadone + ulonivirine).
Measured: Up to 24 hours post-dose
Dose-Normalized C24 of Total Methadone
The C24 of total methadone will be determined on Day 1 (methadone) and Day 2 (methadone + ulonivirine).
Measured: 24 hours post-dose
Tmax of Total Methadone
The Tmax of total methadone will be determined on Day 1 (methadone) and Day 2 (methadone + ulonivirine).
Measured: Up to 24 hours post-dose
Number of Participants With Adverse Events (AEs) Following Methadone + Ulonivirine Coadministration
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. The number of participants experiencing an AE following coadministration of methadone and ulonivirine will be presented.
Measured: Up to 16 Days
Number of Participants Discontinuing Study Therapy Due to AEs Following Coadministration of Methadone and Ulonivirine
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. The number of participants discontinuing study therapy due to an AE following coadministration of methadone and ulonivirine will be presented.
Measured: Up to 16 Days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 May 2026
- Study start17 Aug 2026
- Primary completion15 Jan 2027 (estimated)
- Study completion15 Jan 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HealthyStudies of the same condition, open and under way.
- More trials run by Merck Sharp & Dohme LLCThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 14 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Merck Sharp & Dohme LLC
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Medical Director, Study director, Merck Sharp & Dohme LLC
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07595263
- Sponsor's protocol ID
- 8507-019
- Other IDs
- MK-8507-019
- Status last verified
- Sep 2026
- First submitted
- 12 May 2026
- Last updated
- 23 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf
Study at a glance
From the registry record, last updated by the sponsor on 23 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Clinical Trial to Study the Effect of a Single Dose of Ulonivirine on the Pharmacokinetics of Methadone
- ClinicalTrials.gov ID
- NCT07595263
- Acronym / sponsor ID
- 8507-019
- Conditions
- Healthy
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 14 participants (estimated)
- Lead sponsor
- Merck Sharp & Dohme LLCIndustry (pharma, biotech, devices)
- Study start
- 17 Aug 2026 (actual)
- Primary completion
- 15 Jan 2027 (estimated)
- Study completion
- 15 Jan 2027 (estimated)
- First posted
- 19 May 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Methadone + Ulonivirine | Experimental | Drug: Ulonivirine, Drug: MethadoneParticipants receive a stable dose of methadone orally from Day -14 through Day 16. Methadone is co-administered with one dose of oral ulonivirine on Day 2. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- 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
Key exclusion criteria (5 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| UlonivirineAlso: MK-8507Oral Tablet | Drug | Methadone + Ulonivirine |
| MethadoneOral (per local guidelines) | Drug | Methadone + Ulonivirine |
Primary outcome
Dose-Normalized Area Under the Plasma Concentration Time Curve From 0-24 Hours Postdose (AUC0-24) of R-Methadone
Time frame: Up to 24 hours post-dose
The AUC0-24 of R-methadone will be determined on Day 1 (methadone) and Day 2 (methadone + ulonivirine).
Dose-Normalized AUC0-24 of S-Methadone
Time frame: Up to 24 hours post-dose
The AUC0-24 of S-methadone will be determined on Day 1 (methadone) and Day 2 (methadone + ulonivirine).
12 secondary outcomes
Dose-Normalized Maximum Plasma Concentration (Cmax) of R-Methadone
Time frame: Up to 24 hours post-dose
Dose-Normalized Plasma Concentration 24 Hours Postdose (C24) of R-Methadone
Time frame: 24 hours post-dose
Time to Maximum Plasma Concentration (Tmax) of R-Methadone
Time frame: Up to 24 hours post-dose
Dose-Normalized Cmax of S-Methadone
Time frame: Up to 24 hours post-dose
Dose-Normalized C24 of S-Methadone
Time frame: 24 hours post-dose
Tmax of S-Methadone
Time frame: Up to 24 hours post-dose
Dose-Normalized AUC0-24 of Total Methadone
Time frame: Up to 24 hours post-dose
Dose-Normalized Cmax of Total Methadone
Time frame: Up to 24 hours post-dose
Dose-Normalized C24 of Total Methadone
Time frame: 24 hours post-dose
Tmax of Total Methadone
Time frame: Up to 24 hours post-dose
Number of Participants With Adverse Events (AEs) Following Methadone + Ulonivirine Coadministration
Time frame: Up to 16 Days
Number of Participants Discontinuing Study Therapy Due to AEs Following Coadministration of Methadone and Ulonivirine
Time frame: Up to 16 Days
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Sep 2026.
- Merck Clinical Trials InformationLink provided by the sponsor.
- Individual participant dataSharing planned: Yes. https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Medical Director study director
Merck Sharp & Dohme LLC
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Ulonivirine and Methadone in people with Healthy, run by Merck Sharp & Dohme LLC at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 23 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Toll Free Number (1-888-577-8839, Trialsites@msd.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Dose-Normalized Area Under the Plasma Concentration Time Curve From 0-24 Hours Postdose (AUC0-24) of R-Methadone (time frame: Up to 24 hours post-dose). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Sep 2026.