NCT04644029

Oral ISL QM as PrEP in Cisgender Women at High Risk for HIV-1 Infection (MK-8591-022)

A Phase 3, Randomized, Active-Controlled, Double-blind Clinical Study to Evaluate the Efficacy and Safety of Oral Islatravir Once-Monthly as Preexposure Prophylaxis in Cisgender Women at High Risk for HIV-1 Infection

• Status: Terminated
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 730 (actual)
• Sponsor: Merck Sharp & Dohme LLC · Industry
• Sex: Female
• Age: 16 Years – 45 Years
• Healthy volunteers: Accepted

Summary

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.

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 open-label FTC/TDF while continuing in the study for safety monitoring. Study Part 3 was added to unblind each participant's Part 1 study intervention assignment, continue participants on FTC/TDF, and monitor safety.

Conditions

• HIV-I
• Human Immunodeficiency Virus Type 1
• Prophylaxis

Interventions

Type	Name	Description
DRUG	Islatravir	Oral 60 mg tablet administered once monthly during Part 1.
DRUG	Placebo to FTC/TDF	0 mg tablet administered once daily 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.
DRUG	Placebo to ISL	0 mg tablet administered orally once monthly in Part 1.

Timeline

• Start date: 2021-02-24
• Primary completion: 2023-07-18
• Completion: 2024-06-11
• First posted: 2020-11-25
• Last updated: 2026-02-04
• Results posted: 2024-08-09

Locations

24 sites across 3 countries: United States, South Africa, Uganda

Regulatory

• FDA-regulated drug study