Skip to main content
OpenTrials
Completed

NCT Number: NCT07199452

A Study of Rifabutin and MK-4646 in Healthy Participants (MK-4646-004)

Researchers have designed a new study medicine called MK-4646 as a new way to treat human immunodeficiency virus (HIV). Rifabutin is a medication used to treat tuberculosis (TB).

Researchers want to learn about MK-4646 when taken at the same time as Rifabutin.

They want to:

Measure a person's blood to find out if the amount of MK-4646 in the blood is the same when MK-4646 is taken alone or with Rifabutin Learn about the safety of MK-4646 when taken alone or with Rifabutin and if people tolerate it

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Healthy

Age range

18 year–55 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 1

Primary location

Fortea CRU Madison ( Site 0001)

Madison, Wisconsin, 53704, United States

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

The main inclusion criteria include but are not limited to:

  • Is in good health
  • Has a body-mass index (BMI) between 18 and 32 kg/m2

The main exclusion criteria include but are not limited to:

  • Has a history of clinically significant endocrine, gastrointestinal, cardiovascular, hematological, hepatic, immunological, renal, respiratory, genitourinary, or major neurological (including stroke and chronic seizures) abnormalities or diseases
  • Has a history of cancer (malignancy)

Treatment and study plan

MK-4646

Drug

Oral Capsule

rifabutin

Drug

Oral Capsule

Primary outcomes

  1. Area Under the Concentration-time Curve from Time 0 Extrapolated to Infinity (AUC0-inf) of MK-4646 in Plasma

    Time frame: At designated timepoints (up to approximately 3 days post dose)

    Blood samples will be collected to determine the AUC0-inf of MK-4646 in plasma.

Secondary outcomes

  1. Number of Participants Who Experience an Adverse Event (AE)

    Time frame: Up to approximately 5 weeks

    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. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention. The number of participants who experience an AE will be reported.

  2. Number of Participants Who Discontinue Study Treatment Due to an AE

    Time frame: Up to approximately 3 weeks

    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. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention. The number of participants who discontinue study treatment due to an AE will be reported.

Sponsors and collaborators

Lead sponsor

Merck Sharp & Dohme LLC

Industry

Registry information

Official study title

An Open-Label Clinical Study to Evaluate the Effects of Multiple Oral Doses of Rifabutin on the Single-Dose Pharmacokinetics of MK-4646 in Healthy Participants

Important dates

Study start
2025
Primary completion
2025
Study completion
2026
First posted
Sep 30, 2025
Registry last updated
Jan 29, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.