A Clinical Trial to Evaluate the Effect of Ulonivirine (MK-8507) on Heart Rhythm in Healthy Adults (MK-8507-012)

April 20, 2026 updated by: Merck Sharp & Dohme LLC

A Double-Blind, Placebo-Controlled Trial to Evaluate the Effect of MK-8507 on the QTc Interval in Healthy Adult Participants

Researchers are looking for new treatments for HIV-1 (human immunodeficiency virus type 1) that are safe, well-tolerated, and can be taken less often. HIV-1 is the most common type of HIV, which is a virus that attacks cells of the immune system.

Ulonivirine (MK-8507) is a study medicine designed to treat HIV-1

The goal of this study is to learn if ulonivirine does not increase the QT interval (a measure of heart rhythm on an electrocardiogram) above a certain amount. Researchers also want to learn what happens to the amount of ulonivirine in a healthy person's body over time.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

62

Phase

  • Phase 1

Contacts and Locations

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

Study Locations

  • United States
    • Texas
      • San Antonio, Texas, United States, 78209
        • ICON Early Phase Services (0001)

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

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Is in good health before randomization
  • Has body Mass Index (BMI) between 18 and 32 kg/m2, inclusive

Exclusion Criteria:

  • Has a history of clinically significant endocrine, gastrointestinal (GI), cardiovascular, hematological, hepatic, immunological, renal, respiratory, genitourinary, or major neurological (including stroke and chronic seizures) abnormalities or diseases
  • Has history of cancer (malignancy)
  • Has positive test(s) for hepatitis B surface antigen (HBsAg), hepatitis C antibodies or human immunodeficiency virus (HIV)

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: Crossover Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Moxifloxacin 400 mg + Placebo (Arm 1)
Participants will receive ulonivirine dose matched placebo + moxifloxacin dose matched placebo OR ulonivirine dose matched placebo + moxifloxacin 400 mg.
Drug: Moxifloxacin
Oral tablet
Drug: Ulonivirine Placebo
Oral tablet
Drug: Moxifloxacin Placebo
Oral tablet
Experimental: Ulonivirine Dose 1 + Placebo (Arm 2)
Participants will receive ulonivirine dose matched placebo + moxifloxacin dose matched placebo OR moxifloxacin dose matched placebo + ulonivirine Dose 1.
Drug: Ulonivirine Placebo
Oral tablet
Drug: Moxifloxacin Placebo
Oral tablet
Drug: Ulonivirine
Oral tablet
Other Names:
  • MK-8507
  • ULO

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change From Baseline in QT Interval Corrected for Heart Rate (QTc) Following Ulonivirine Administration
Time Frame: Baseline and up to approximately 24 hours
Change from baseline in QTc following ulonivirine administration will be reported.
Baseline and up to approximately 24 hours
Plasma Concentration of Ulonivirine at QTc Intervals (Cqtc)
Time Frame: At designated timepoints (up to approximately 24 hours)
Blood samples will be collected to determine the Cqtc of ulonivirine.
At designated timepoints (up to approximately 24 hours)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change From Baseline in QT Interval Corrected for Heart Rate (QTc) Following Moxifloxacin Administration
Time Frame: Baseline to up to approximately 24 hours
Change from baseline in QTc following moxifloxacin administration will be reported.
Baseline to up to approximately 24 hours
Plasma concentration of Moxifloxacin at QTc intervals (Cqtc)
Time Frame: At designated timepoints (up to approximately 24 hours)
Blood samples will be collected to determine the Cqtc of moxifloxacin.
At designated timepoints (up to approximately 24 hours)
Maximum Plasma Concentration (Cmax) of Moxifloxacin
Time Frame: At designated timepoints (up to approximately 168 hours)
Blood samples will be collected to determine the Cmax of moxifloxacin.
At designated timepoints (up to approximately 168 hours)
Area Under the Plasma Concentration-Time Curve From Time 0 to 24 Hours (AUC0-24) of Ulonivirine
Time Frame: At designated timepoints (up to 168 hours)
Blood samples will be collected to determine the AUC0-24 of ulonivirine.
At designated timepoints (up to 168 hours)
Maximum Plasma Concentration (Cmax) of Ulonivirine
Time Frame: At designated timepoints (up to 168 hours)
Blood samples will be collected to determine the Cmax of ulonivirine.
At designated timepoints (up to 168 hours)
Time to Maximum Plasma Concentration (Tmax) of Ulonivirine
Time Frame: At designated timepoints (up to 168 hours)
Blood samples will be collected to determine the Tmax of ulonivirine.
At designated timepoints (up to 168 hours)

Collaborators and Investigators

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

Sponsor

Merck Sharp & Dohme LLC

Investigators

  • 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)

January 22, 2026

Primary Completion (Actual)

April 9, 2026

Study Completion (Actual)

April 9, 2026

Study Registration Dates

First Submitted

December 12, 2025

First Submitted That Met QC Criteria

December 12, 2025

First Posted (Actual)

December 26, 2025

Study Record Updates

Last Update Posted (Actual)

April 21, 2026

Last Update Submitted That Met QC Criteria

April 20, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 8507-012
  • MK-8507-012 (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.

Subscribe