A Clinical Trial of MK-4646 With Bictegravir/Emtricitabine/Tenofovir Alafenamide and Dolutegravir in Healthy Adult Participants (MK-4646)

August 21, 2026 updated by: Merck Sharp & Dohme LLC

A Drug-Drug Interaction Study of MK-4646 With Bictegravir/Emtricitabine/Tenofovir Alafenamide and Dolutegravir

Researchers are looking for new treatments for people living with HIV-1(Human Immunodeficiency Virus Type 1). HIV-1 is the most common type of HIV, which is a virus that attacks cells of the immune system.

HIV-1 treatments, called ART (antiretroviral therapy), involve taking medicines to lower the amount of HIV-1 virus in the body. Standard ART may include Bictegravir/Emtricitabine/Tenofovir Alafenamide (BIC/FTC/TAF) and Dolutegravir (DTG).

MK-4646 is a trial medicine designed to treat HIV-1. Before giving a trial medicine to people with a health condition, researchers first do trials in healthy people.

The goals of this study are to learn:

  • If taking MK 4646 together with BIC/FTC/TAF or DTG changes the amount of these ARTs in the blood over time.
  • About the safety of MK-4646 and if people tolerate it. Tolerate means participants will receive treatment in the trial unless they need to stop it due to health problems.

Study Overview

Status

Status

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

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 (Actual)

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.
16

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 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 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
    • Alabama
      • Anniston, Alabama, United States, 36207
        • Pinnacle Research Group ( Site 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

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

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Is in good health before randomization
  • Has a body mass index (BMI) between 18 and 32 kg/m^2, 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 a history of cancer (malignancy)

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: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

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: Treatment A: bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF)
Participants will receive a single oral dose of bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF).
Drug: Bictegravir/emtricitabine/tenofovir alafenamide
Single oral tablet
Experimental: Treatment B: dolutegravir (DTG)
Participants will receive a single oral dose of dolutegravir (DTG).
Drug: Dolutegravir
Oral tablet
Experimental: Treatment C: MK-4646 + bictegravir/ emtricitabine/tenofovir alafenamide (BIC/FTC/TAF)
Participants will receive a single oral dose of MK-4646 coadministered with bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF).
Drug: Bictegravir/emtricitabine/tenofovir alafenamide
Single oral tablet
Drug: MK4646
Oral capsule
Experimental: Treatment D: MK-4646 + dolutegravir (DTG)
Participants will receive a single oral dose of MK-4646 coadministered with dolutegravir (DTG).
Drug: Dolutegravir
Oral tablet
Drug: MK4646
Oral capsule

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
Area Under the Concentration-Time Curve from Time 0 to Infinity (AUC0-∞) of Bictegravir
Time Frame: At designated timepoints (up to approximately 72 hours post dose)
Blood samples will be collected to determine the AUC0-∞ of bictegravir.
At designated timepoints (up to approximately 72 hours post dose)
Area Under the Concentration-Time Curve from Time 0 to Infinity (AUC0-∞) of Emtricitabine
Time Frame: At designated timepoints (up to approximately 72 hours post dose)
Blood samples will be collected to determine the AUC0-∞ of emtricitabine.
At designated timepoints (up to approximately 72 hours post dose)
Area Under the Concentration-Time Curve from Time 0 to Infinity (AUC0-∞) of Tenofovir Alafenamide
Time Frame: At designated timepoints (up to approximately 72 hours post dose)
Blood samples will be collected to determine the AUC0-∞ of tenofovir alafenamide.
At designated timepoints (up to approximately 72 hours post dose)
Area Under the Concentration-Time Curve from Time 0 to Infinity (AUC0-∞) of Tenofovir
Time Frame: At designated timepoints (up to approximately 72 hours post dose)
Blood samples will be collected to determine the AUC0-∞ of tenofovir.
At designated timepoints (up to approximately 72 hours post dose)
Area Under the Concentration-Time Curve from Time 0 to Infinity (AUC0-∞) of Dolutegravir
Time Frame: At designated timepoints (up to approximately 72 hours post dose)
Blood samples will be collected to determine the AUC0-∞ of dolutegravir.
At designated timepoints (up to approximately 72 hours post dose)

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
Number of Participants Who Experience an Adverse Event (AE)
Time Frame: Up to approximately 44 days
An AE is any untoward medical occurrence in a participant, temporally associated with the use of study treatment, whether or not considered related to the study treatment. The number of participants who experience an AE will be reported.
Up to approximately 44 days
Number of Participants Who Discontinue Study Treatment Due to an AE
Time Frame: Up to approximately 31 Days
An AE is any untoward medical occurrence in a participant, temporally associated with the use of study treatment, whether or not considered related to the study treatment. The number of participants who discontinue study treatment due to an AE will be reported.
Up to approximately 31 Days
Maximum Plasma Concentration (Cmax) of Bictegravir
Time Frame: At designated timepoints (up to approximately 72 hours post dose)
Blood samples will be collected to determine the Cmax of bictegravir.
At designated timepoints (up to approximately 72 hours post dose)
Time to Maximum Plasma Concentration (Tmax) of Bictegravir
Time Frame: At designated timepoints (up to approximately 72 hours post dose)
Blood samples will be collected to determine the Tmax of bictegravir.
At designated timepoints (up to approximately 72 hours post dose)
Apparent Terminal Half-life (t½) of Bictegravir
Time Frame: At designated timepoints (up to approximately 72 hours post dose)
Blood samples will be collected to determine the t½ of bictegravir.
At designated timepoints (up to approximately 72 hours post dose)
Maximum Plasma Concentration (Cmax) of Emtricitabine
Time Frame: At designated timepoints (up to approximately 72 hours post dose)
Blood samples will be collected to determine the Cmax of emtricitabine.
At designated timepoints (up to approximately 72 hours post dose)
Time to Maximum Plasma Concentration (Tmax) of Emtricitabine
Time Frame: At designated time points (up to approximately 72 hours post dose)
Blood samples will be collected to determine the Tmax of emtricitabine.
At designated time points (up to approximately 72 hours post dose)
Apparent Terminal Half-life (t½) of Emtricitabine
Time Frame: At designated timepoints (up to approximately 72 hours post dose)
Blood samples will be collected to determine the t½ of emtricitabine.
At designated timepoints (up to approximately 72 hours post dose)
Maximum Plasma Concentration (Cmax) of Tenofovir
Time Frame: At designated timepoints (up to approximately 72 hours post dose)
Blood samples will be collected to determine the Cmax of tenofovir.
At designated timepoints (up to approximately 72 hours post dose)
Time to Maximum Plasma Concentration (Tmax) of Tenofovir
Time Frame: At designated timepoints (up to approximately 72 hours post dose)
Blood samples will be collected to determine the Tmax of tenofovir.
At designated timepoints (up to approximately 72 hours post dose)
Apparent Terminal Half-life (t½) of Tenofovir
Time Frame: At designated timepoints (up to approximately 72 hours post dose)
Blood samples will be collected to determine the t½ of tenofovir.
At designated timepoints (up to approximately 72 hours post dose)
Maximum Plasma Concentration (Cmax) of Dolutegravir
Time Frame: At designated timepoints (up to approximately 72 hours post dose)
Blood samples will be collected to determine the Cmax of dolutegravir.
At designated timepoints (up to approximately 72 hours post dose)
Time to Maximum Plasma Concentration (Tmax) of Dolutegravir
Time Frame: At designated timepoints (up to approximately 72 hours post dose)
Blood samples will be collected to determine the Tmax of dolutegravir.
At designated timepoints (up to approximately 72 hours post dose)
Apparent Terminal Half-life (t½) of Dolutegravir
Time Frame: At designated timepoints (up to approximately 72 hours post dose)
Blood samples will be collected to determine the t½ of dolutegravir.
At designated timepoints (up to approximately 72 hours post dose)
Plasma Concentration at 24 Hours (C24) of Bictegravir
Time Frame: 24 hours post dose
Blood samples will be collected to determine the C24 of bictegravir.
24 hours post dose
Plasma Concentration at 24 Hours (C24) of Emtricitabine
Time Frame: 24 hours post dose
Blood samples will be collected to determine the C24 of emtricitabine.
24 hours post dose
Maximum Plasma Concentration (Cmax) of Tenofovir Alafenamide
Time Frame: At designated timepoints (up to approximately 72 hours post dose)
Blood samples will be collected to determine the Cmax of tenofovir alafenamide.
At designated timepoints (up to approximately 72 hours post dose)
Plasma Concentration at 24 Hours (C24) of Tenofovir Alafenamide
Time Frame: At designated time points (up to approximately 24 hours post dose)
Blood samples will be collected to determine the C24 of tenofovir alafenamide.
At designated time points (up to approximately 24 hours post dose)
Time to Maximum Plasma Concentration (Tmax) of Tenofovir Alafenamide
Time Frame: At designated time points (up to approximately 72 hours post dose)
Blood samples will be collected to determine the Tmax of tenofovir alafenamide.
At designated time points (up to approximately 72 hours post dose)
Apparent Terminal Half-life (t½) of Tenofovir Alafenamide
Time Frame: At designated timepoints (up to approximately 72 hours post dose)
Blood samples will be collected to determine the t½ of tenofovir alafenamide.
At designated timepoints (up to approximately 72 hours post dose)
Plasma Concentration at (C24) of Tenofovir
Time Frame: 24 hours post dose
Blood samples will be collected to determine the C24 of tenofovir.
24 hours post dose
Plasma Concentration at (C24) of Dolutegravir
Time Frame: 24 hours post dose
Blood samples will be collected to determine the C24 of dolutegravir.
24 hours post dose

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.
May 11, 2026

Primary Completion (Actual)

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.
July 23, 2026

Study Completion (Actual)

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.
July 23, 2026

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).
April 8, 2026

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.
April 8, 2026

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.
April 15, 2026

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 25, 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 21, 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.
  • 4646-006
  • MK-4646-006 (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.

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