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

Multiple Dose Clinical Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Antiretroviral Activity of MK-4646 Monotherapy in Antiretroviral Therapy-Naïve Participants With HIV-1

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.

Inclusion Criteria:

• 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

Exclusion Criteria:

• 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