Purpose

This study will evaluate whether oral islatravir (ISL) is effective in preventing Human Immunodeficiency Virus Type 1 (HIV-1) infection in women at high-risk for HIV-1 infection. The study will compare oral ISL taken once a month with standard-of-care medication for prevention of HIV-1 infection, emtricitabine/tenofovir disoproxil (FTC/TDF), taken once per day. The primary hypothesis is that oral ISL is more effective than FTC/TDF at reducing the incidence rate per year of confirmed HIV-1 infections.

Conditions

Eligibility

Eligible Ages
Between 16 Years and 45 Years
Eligible Genders
Female
Accepts Healthy Volunteers
Yes

Inclusion Criteria

  • Confirmed HIV-uninfected based on negative HIV-1/HIV-2 test results before randomization. - Sexually active (vaginal and/or anal sex) with a male sexual partner in the 30 days prior to screening. - High risk for HIV-1 infection. - Not pregnant or breastfeeding, and one of the following conditions applies: Not a woman of childbearing potential (WOCBP) or is a WOCBP and is using an acceptable contraceptive method during the intervention period and for at least 42 days after the last dose. - A WOCBP must have a negative pregnancy test within 24 hours prior to the first dose of study intervention.

Exclusion Criteria

  • Hypersensitivity or other contraindication to any of the components of the study interventions as determined by the investigator. - Findings of chronic hepatitis B virus (HBV) infection or past HBV. - Current or chronic history of liver disease. - History of malignancy within 5 years of screening except for adequately-treated basal cell or squamous cell skin cancer, or in situ cervical cancer. - Past or current use of cabotegravir, lenacapavir, or any other long-acting HIV prevention product. - Currently participating in or has participated in an interventional clinical study with an investigational compound or device, within 30 days prior to Day 1. - Expecting to conceive or donate eggs at any time during the study.

Study Design

Phase
Phase 3
Study Type
Interventional
Allocation
Randomized
Intervention Model
Parallel Assignment
Primary Purpose
Prevention
Masking
Triple (Participant, Care Provider, Investigator)
Masking Description
In Study Part 1, a double-blinding technique with in-house blinding will be used. ISL and FTC/TDF and FTC/TAF will be packaged identically relative to their matching placebos so that blind is maintained. The participant, the investigator, and Sponsor personnel or delegate(s) who are involved in the study intervention administration or clinical evaluation of the participants are unaware of the intervention assignments. In Study Part 2, sponsor personnel not directly involved with blinded safety monitoring will be unblinded to participants' randomized study intervention in Part 1. In Study Part 3, participants, investigators, and all Sponsor personnel will be unblinded to the participants' original randomized study intervention group.

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
ISL QM
ISL (islatravir) once monthly AND placebo to FTC/TDF (emtricitabine/tenofovir disoproxil) once daily during Part 1.
  • Drug: Islatravir
    Oral 60 mg tablet administered once monthly during Part 1.
    Other names:
    • MK-8591
  • Drug: Placebo to FTC/TDF
    0 mg tablet administered once daily during Part 1.
Active Comparator
FTC/TDF QD
FTC/TDF (TRUVADA™ or generic product emtricitabine/tenofovir disoproxil) administered once daily in Parts 1, 2, and 3. Placebo to ISL (islatravir) also administered once monthly during Part 1.
  • Drug: FTC/TDF
    Each tablet contains 200 mg emtricitabine and 245 mg of tenofovir disoproxil (equivalent to 300 mg tenofovir disoproxil fumarate or 201.22 mg tenofovir disproxil phosphate), administered orally once daily in Parts 1, 2, and 3.
    Other names:
    • TRUVADA™
    • Emtricitabine/Tenofovir disoproxil
    • Emtricitabine/Tenofovir disoproxil fumarate
  • Drug: Placebo to ISL
    0 mg tablet administered orally once monthly in Part 1.

More Details

Status
Active, not recruiting
Sponsor
Merck Sharp & Dohme LLC

Study Contact

Detailed Description

Based on laboratory findings of decreased lymphocyte and CD4+ T-cell counts across the islatravir program, dosing of blinded study intervention was halted on 13-Dec-2021 and screening and randomization of new participants was ended. Blinded assessments conducted prior to this date are designated as Study Part 1. During Study Part 2, participants from Part 1 have the option to receive daily FTC/TDF while continuing in the study. Study Part 3 was added to unblind each participant's Part 1 study intervention assignment, continue participants on FTC/TDF, and monitor safety.

Notice

Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.