MK-4646 Multiple Dose Trial in Participants With Human Immunodeficiency Virus Type 1 (HIV-1) (MK-4646-003)

NCT07042945 | Recruiting Phase 1 FDA Drug

• 4 other identifiers: 4646-003MK-4646-0032025-521102-17-00U1111-1318-7985
• Study Type: interventional
• Target: 28
• Locations: 2 countries
• Sites: 2

Brief Summary

This study will examine if at least one dose level of MK-4646 can lower HIV-1 viral load in a person's blood by a certain amount. The goals of this study are to learn about the safety of MK-4646 and if people tolerate it; and how HIV-1 viral load may decrease after starting to take MK-4646.

Conditions

HIV Infection

Outcome Measures

Primary Outcomes (3)

• Participants with averse events (AEs)

  Percentage of participants with one or more AEs

  14 days post last dose (Up to Day 23)

• Participants who discontinued study medication due to an AE

  Percentage of participants who discontinued study medication due to an AE

  Up to Day 7

• Viral load decline of plasma HIV-1 ribonucleic acid (RNA)

  Time course of plasma HIV-1 RNA viral load decline.

  Predose, 1,2, 3, 4 and 5 days postdose

Secondary Outcomes (5)

• Area under the curve from time 0 to 24 hours (AUC0-24) of MK-4646

  Predose, 0.5, 1, 2, 3, 4, 5, 6, 8, 12, 24 hours postdose

• Maximum plasma concentration (Cmax) of MK-4646

  Predose, 0.5, 1, 2, 3, 4, 5, 6, 8, 12, 24 hours postdose

• Concentration at 24 hours (C24) of MK-4646

  24 hours postdose

• Time to maximum concentration (Tmax) of MK-4646

  Predose, 0.5, 1, 2, 3, 4, 5, 6, 8, 12, 24 hours postdose

• Half life (t1/2) of MK-4646

  Predose, 0.5, 1, 2, 3, 4, 5, 6, 8, 12, 24 hours postdose

Study Arms (4)

MK-4646 Panel A

EXPERIMENTAL

MK-4646 160 mg every 24 hours (q24h) for 7 days

Drug: MK-4646

MK-4646 Panel B

EXPERIMENTAL

MK-4646 ≤460 mg q24h for 7 days

Drug: MK-4646

MK-4646 Panel C

EXPERIMENTAL

MK-4646 ≤460 mg q24h for 7 days

Drug: MK-4646

MK-4646 Panel D

EXPERIMENTAL

MK-4646 ≤460 mg every 12 hours (q12h) for 7 days

Drug: MK-4646

Interventions

MK-4646 DRUG

MK-4646 in capsular form administered orally

MK-4646 Panel A; MK-4646 Panel B; MK-4646 Panel C; MK-4646 Panel D

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Other than having HIV-1, is in good health
• Is antiretroviral therapy (ART)-naïve
• If ART-experienced has not received any antiretroviral therapy within 60 days (or 5 half-lives, whichever is longer) prior to screening
• Is willing to receive no other ART prior to Day 8 post-dose of the trial
• If capable of producing sperm agrees to use contraception
• If assigned female sex at birth is not breastfeeding
• A participant of childbearing potential (POCBP) is not pregnant and has a negative highly sensitive pregnancy test (urine or serum), and uses a contraceptive method that is highly effective

You may not qualify if:

• Has acute (primary) HIV-1 infection
• Has 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
• Is mentally or legally incapacitated, has significant emotional problems at the time of prestudy (screening) visit or expected during the conduct of the study or has a history of clinically significant psychiatric disorder of the last 5 years.
• Has history of cancer (malignancy)
• Has history of significant multiple and/or severe allergies
• Tests positive for hepatitis B surface antigen (HBsAg), hepatitis C antibodies
• Has had a major surgery and/or donated or lost 1 unit of blood (approximately 500 mL) within 4 weeks prior to the prestudy (screening) visit
• Has received any vaccine starting from 30 days prior to study intervention or is scheduled to receive any vaccine through 14 days following study intervention
• Is unable to refrain from using protocol specified prohibited medications
• Is an excessive smoker, or consumes excessive amounts of alcoholic or caffeinated beverages
• Is a regular user of any illicit drugs or has a history of drug (including alcohol) abuse

Sponsors & Collaborators

• Merck Sharp & Dohme LLC: lead

Study Sites (2)

PMSI Republican Clinical Hospital "T.Mosneaga" ( Site 0002)

Chisinau, 2025, Moldova

RECRUITING

ARENSIA Exploratory Medicine ( Site 0001)

Bucharest, Bucharest, 021105, Romania

RECRUITING

Related Links

• Merck Clinical Trials Information
• Plain Language Summary

MeSH Terms

Conditions

HIV Infections

Condition Hierarchy (Ancestors)

Blood-Borne Infections; Communicable Diseases; Infections; Sexually Transmitted Diseases, Viral; Sexually Transmitted Diseases; Lentivirus Infections; Retroviridae Infections; RNA Virus Infections; Virus Diseases; Genital Diseases; Urogenital Diseases; Immunologic Deficiency Syndromes; Immune System Diseases

Study Officials

• Medical Director

  Merck Sharp & Dohme LLC

  STUDY DIRECTOR

Central Study Contacts

Toll Free Number

CONTACT

1-888-577-8839; Trialsites@msd.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SEQUENTIAL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 9, 2025
• First Posted: June 29, 2025
• Study Start: July 9, 2025
• Primary Completion (Estimated): July 8, 2026
• Study Completion (Estimated): August 17, 2026
• Last Updated: May 26, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will share

Locations

RO (1); MO (1)