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Taking people in FrancePhase 2/3

Tests a once-weekly HIV pill combination in adults not yet treated

Tests islatravir and ulonivirine, taken weekly, against a daily standard HIV treatment.

Key facts

Who runs it
Merck Sharp & Dohme LLC
Where
Bobigny Cedex, Bordeaux, Creteil, Lyon Cedex 04, Montpellier Cedex 5, Nantes, Nice, Nîmes, Paris, Paris Cedex 18, Toulouse, and Tourcoing Cedex, FranceSee the 12 sitesAlso in 8 other countries, 56 sites
Trial code
Registry title
A Clinical Study of Islatravir and Ulonivirine for People With HIV-1 Who Have Not Been Treated Before (MK-8591B-062)
Status
Recruiting
Phase
Phase 2/3
People taking part
570 people, planned
Started
18 Dec 2025
Expected to end
18 Dec 2031
Type of study
Interventional, 4 groupsOne group gets an existing treatment, for comparison.
Treatments tested
  • ISL
  • ULO
  • BIC/FTC/TAF
  • Placebo for BIC/FTC/TAF
  • Placebo to ISL/ULO
  • ISL/ULO
Record updated
4 November 2026

Who can take part

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for adults with HIV-1 who have never taken HIV medicines. It compares a once-weekly two-medicine treatment with a once-daily standard treatment.

Age
18 years or older
Sex
All sexes can join.
Disease stage
HIV-1 infection with plasma HIV-1 RNA ≥500 and ≤100,000 copies/mL in Phase 2, or ≥500 and ≤1,000,000 copies/mL in Phase 3. In Phase 2, CD4+ T-cell count must be ≥200 cells/mm^3.
Earlier treatment
People must never have taken any HIV medicine (antiretroviral therapy) since their HIV-1 diagnosis. They must not have taken islatravir (ISL) or ulonivirine (ULO) before.
Biomarker or test result
HIV-1 positive, with plasma HIV-1 RNA in the range given above.

Main reasons for not taking part

  • HIV-2 infection
  • Active AIDS-defining opportunistic infection
  • Active hepatitis C or hepatitis B infection
  • Cancer within the 5 years before consent (some skin, cervical and anal cancers and cutaneous Kaposi's sarcoma are allowed)
  • Earlier use of islatravir (ISL) or ulonivirine (ULO)

The registry criteria, word for word

Show all 9 criteriaShow less

Who can take part

  • Phase 2: Is human immunodeficiency virus type 1 (HIV-1) positive with Plasma HIV-1 ribonucleic acid (RNA) ≥500 and ≤100,000 copies/mL
  • Phase 3: Is HIV-1 positive with Plasma HIV-1 RNA ≥500 and ≤1,000,000 copies/mL
  • Phase 2: Has cluster of differentiation 4-positive (CD4+) T-cell count ≥200 cells/mm\^3
  • Is naïve to antiretroviral therapy (ART), defined as having received no prior therapy with any antiretroviral agent following a diagnosis of HIV 1 infection

Who cannot take part

  • Has prior exposure to islatravir (ISL) or ulonivirine (ULO) for any duration any time prior to Day 1
  • Has human immunodeficiency virus type 2 (HIV-2) infection
  • Has a diagnosis of an active acquired immune deficiency syndrome (AIDS)-defining opportunistic infection
  • Has active hepatitis C virus (HCV) or active hepatitis B virus (HBV) infection
  • Has a history of malignancy ≤5 years prior to providing documented informed consent except for adequately treated basal cell or squamous cell skin cancer, in situ cervical or in situ anal cancer, or cutaneous Kaposi's sarcoma

Where in France

Also in 8 other countries, 56 sites

  • Assistance Publique Hopitaux De ParisBobigny Cedex, FranceTaking people
  • Pellegrin HospitalBordeaux, FranceTaking people
  • Assistance Publique Hopitaux De ParisCreteil, FranceTaking people
  • Hospital La Croix Rousse HclLyon Cedex 04, FranceTaking people
  • Centre Hospitalier Universitaire De MontpellierMontpellier Cedex 5, FranceTaking people
  • Hospital Hotel DieuNantes, FranceTaking people
  • Centre Hospitalier Universitaire de NiceNice, FranceTaking people
  • Centre Hospitalier Universitaire de NîmesNîmes, FranceTaking people
  • Hopital Saint LouisParis, FranceTaking people
  • Assistance Publique Hopitaux De ParisParis Cedex 18, FranceTaking people
  • Centre Hospitalier Universitaire de ToulouseToulouse, FranceTaking people
  • Centre Hospitalier De TourcoingTourcoing Cedex, FranceTaking people

About the trial

What the trial wants to find out

Researchers are looking for new ways to treat HIV-1 (Human Immunodeficiency Virus Type 1). The usual (standard) treatment for HIV-1 is antiretroviral therapy (ART), which includes taking medicines to lower the amount of HIV-1 in the body. Standard ART helps people live longer, but people must take up to 3 medicines up to twice a day. Standard ART may also cause other health problems. Researchers want to know if a study ART works as well as a standard ART to treat HIV-1. The study ART combines 2 medicines, islatravir and ulonivirine, and is taken once a week. The goals of this study are to learn: 1) If the study ART works as well as a standard ART to treat HIV-1, and 2) About the safety of the study ART and if people tolerate it compared to a standard ART.

The 4 groups in the trial

  • Phase 2: ISL + ULOTreatment being tested

    Islatravir (ISL) 2mg and Ulonivirine (ULO) 200mg administered orally once weekly (qw) for 96 weeks

    Treatment: ISL and ULO

  • Phase 2: BIC/FTC/TAFExisting treatment, for comparison

    Bictegravir/Emtricitabine/Tenofovir Alafenamide (BIC/FTC/TAF) 50/200/25 mg, administered orally once daily (qd) for 96 weeks

    Treatment: BIC/FTC/TAF

  • Phase 3: ISL/ULO and Placebo to BIC/FTC/TAFTreatment being tested

    ISL/ULO fixed dose combination (2/200 mg), administered orally qw, and matching placebo to BIC/FTC/TAF administered orally qd for 96 weeks

    Treatment: Placebo for BIC/FTC/TAF and ISL/ULO

  • Phase 3: BIC/FTC/TAF and Placebo to ISL/ULOExisting treatment, for comparison

    BIC/FTC/TAF 50/200/25 mg, administered orally qd, and matching placebo to ISL/ULO administered orally qw for 96 weeks

    Treatment: BIC/FTC/TAF and Placebo to ISL/ULO

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Data and sources

Registry record
Listed on ClinicalTrials.gov and on the EU's official list of trials (CTIS).
Official title
A Phase 2/3, Randomized, Active-Controlled, Open-Label (Phase 2) and Double-Blind (Phase 3) Study to Evaluate the Antiretroviral Activity, Safety, and Tolerability of Islatravir (ISL) and Ulonivirine (ULO) Once Weekly Compared With Bictegravir/Emtricitabine/Tenofovir Alafenamide (BIC/FTC/TAF) Once Daily in Treatment-Naïve Adult Participants Living With HIV-1
Plain-language title
Tests a once-weekly HIV pill combination in adults not yet treatedGenerated from the registry record. The registry title is the official one.
AI summary
From the trial's eligibility criteria. Read by machine on 12 November 2026.
Record updated
4 November 2026