AzTrials
AzTrials

Human Immunodeficiency Virus Type 1 (HIV-1) InfectionPhase 2/3NCT07266831

A Clinical Study of Islatravir and Ulonivirine for People With HIV-1 Who Have Not Been Treated Before (MK-8591B-062)

A Phase 2/3 study testing ISL, ULO and BIC/FTC/TAF in people with Human Immunodeficiency Virus Type 1 (HIV-1) Infection, run by Merck Sharp & Dohme LLC at 56 sites in 9 countries.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

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. Read more about this study

Who is it for?
Ages 18 years and older
What is being tested?
ISL, ULO and BIC/FTC/TAF
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
570 participants
Where
56 sitesin 9 countries
Study dates
18 Dec 2025to 18 Dec 2031
Phase
Phase 2/3
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • 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 join

  • 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.
  • Has prior exposure to islatravir (ISL) or ulonivirine (ULO) for any duration any time prior to Day 1.

Trial locations and contacts

56 sites in 9 countries. Contact the study team or a site near you to ask about taking part.

Toll Free Number contact

1-888-577-8839

Trialsites@msd.com

56 sites in 9 countries

United States24 sites, 23 recruiting

  • Saint Hope Foundation, Inc. ( Site 1504)

    Bellaire, Texas, 77401

    Study Coordinator, 713-839-7111

    Recruiting

  • Atrium Health Infectious Disease Kenilworth - Charlotte ( Site 1533)

    Charlotte, North Carolina, 28204

    Study Coordinator, 704-468-3510

    Recruiting

  • Rush University Medical Center-Infectious Disease ( Site 1522)

    Chicago, Illinois, 60612

    Study Coordinator, 312-942-5865

    Recruiting

  • The Ohio State University ( Site 1536)

    Columbus, Ohio, 43210

    Study Coordinator, 614-293-8112

    Recruiting

  • Prism Health North Texas, Oak Cliff Health Center ( Site 1514)

    Dallas, Texas, 75208

    Study Coordinator, 214-521-5191

    Recruiting

  • North Texas Infectious Diseases Consultants ( Site 1500)

    Dallas, Texas, 75246

    Active, not recruiting

  • Metro Infectious Diseases Consultants L.L.C. ( Site 1509)

    Decatur, Georgia, 30033

    Study Coordinator, 404-297-9755

    Recruiting

  • Vivent Health ( Site 1519)

    Denver, Colorado, 80246

    Study Coordinator, 303-393-8050

    Recruiting

  • Henry Ford Hospital ( Site 1535)

    Detroit, Michigan, 48202

    Study Coordinator, 313-916-2600

    Recruiting

  • Texas Center for Infectious Disease Associates ( Site 1502)

    Fort Worth, Texas, 76104

    Study Coordinator, 817-348-0042

    Recruiting

  • Midway Immunology and Research Center ( Site 1503)

    Ft. Pierce, Florida, 34982

    Study Coordinator, 772-595-9830

    Recruiting

  • Regional Center for Infectious Diseases ( Site 1516)

    Greensboro, North Carolina, 27401

    Study Coordinator, 336-832-3275

    Recruiting

  • ID Care ( Site 1507)

    Hillsborough, New Jersey, 08844

    Study Coordinator, 908-281-0221

    Recruiting

  • KC CARE Health Center ( Site 1506)

    Kansas City, Missouri, 64111

    Study Coordinator, 816-753-5144

    Recruiting

  • DCOL Center for Clinical Research ( Site 1511)

    Longview, Texas, 75605

    Study Coordinator, 903-238-8854

    Recruiting

  • Ruane Clinical Research Group, Inc. ( Site 1513)

    Los Angeles, California, 90036

    Study Coordinator, 323-954-0400

    Recruiting

  • Mercer university, Department of internal medicine-Clinical Research ( Site 1512)

    Macon, Georgia, 31201

    Study Coordinator, 478-301-5846

    Recruiting

  • CAN Community Health- Miami Gardens ( Site 1549)

    Miami Gardens, Florida, 33055

    Study Coordinator, 954-955-0023

    Recruiting

  • Orlando Immunology Center ( Site 1501)

    Orlando, Florida, 32803

    Study Coordinator, 407-374-0220

    Recruiting

  • University of Pennsylvania Perelman School of Medicine ( Site 1508)

    Philadelphia, Pennsylvania, 19104

    Study Coordinator, 215-349-8092

    Recruiting

  • CAN Community Health ( Site 1510)

    Sarasota, Florida, 34237

    Study Coordinator, 941-366-0134

    Recruiting

  • Harborview Medical Center ( Site 1526)

    Seattle, Washington, 98104

    Study Coordinator, 206-744-8886

    Recruiting

  • Whitman-Walker Institute ( Site 1538)

    Washington D.C., District of Columbia, 20032

    Study Coordinator, 202-207-2510

    Recruiting

  • Triple O Research Institute ( Site 1505)

    West Palm Beach, Florida, 33407

    Study Coordinator, 561-855-7871

    Recruiting

Other trials in United States

France7 sites, 7 recruiting

  • Hôpital Avicenne ( Site 3602)

    Bobigny, Île-de-France Region, 93000

    Study Coordinator, +33148955421

    Recruiting

  • Bordeaux University Hospital - Pellegrin ( Site 3605)

    Bordeaux, Gironde, 33076

    Study Coordinator, +33556795536

    Recruiting

  • HOPITAL DE LA CROIX ROUSSE ( Site 3613)

    Lyon, Rhone, 69317

    Study Coordinator, +33472071107

    Recruiting

  • Centre Hospitalier Universitaire de Nantes - L' Hopital l'hôtel-Dieu-Infectious Disease ( Site 3606)

    Nantes, Pays de la Loire Region, 44093

    Study Coordinator, +33240083109

    Recruiting

  • Hôpital Saint-Louis ( Site 3600)

    Paris, Île-de-France Region, 75010

    Study Coordinator, +33142494852

    Recruiting

  • Hôpital Bichat - Claude-Bernard ( Site 3601)

    Paris, Île-de-France Region, 75018

    Study Coordinator, +33140257803

    Recruiting

  • Centre Hospitalier Universitaire de Toulouse - Hôpital Purpan ( Site 3608)

    Toulouse, Haute-Garonne, 31059

    Study Coordinator, +33561776800

    Recruiting

Other trials in France

Argentina6 sites, 6 recruiting

  • Fundación IDEAA ( Site 3101)

    Buenos Aires, Buenos Aires F.D., C1405CKC

    Study Coordinator, +5491161835390

    Recruiting

  • Centro Medico Dra. Laura Maffei- Investigacion Clinica Aplicada ( Site 3102)

    Caba, Buenos Aires, C1425AGC

    Study Coordinator, +5491141639539

    Recruiting

  • Fundación Huesped ( Site 3100)

    CABA, Buenos Aires, C1427CEA

    Study Coordinator, +541121209999

    Recruiting

  • Instituto de Investigaciones Clinicas Mar del Plata ( Site 3103)

    Mar del Plata, Buenos Aires, B7600FZN

    Study Coordinator, +5492234365218

    Recruiting

  • Instituto CAICI SRL ( Site 3106)

    Rosario, Santa Fe Province, S2000PBJ

    Study Coordinator, +543414248045

    Recruiting

  • Clínica Mayo de Urgencias Médicas Cruz Blanca S.R.L ( Site 3105)

    San Miguel de Tucumán, Tucumán Province, T4000IHE

    Study Coordinator, +5403814502600

    Recruiting

Other trials in Argentina

Spain6 sites, 6 recruiting

  • Hospital Universitari Vall d'Hebron ( Site 3402)

    Barcelona, 08035

    Study Coordinator, +34934894377

    Recruiting

  • HOSPITAL CLÍNIC DE BARCELONA ( Site 3400)

    Barcelona, 08036

    Study Coordinator, +34932275574

    Recruiting

  • Hospital Universitario La Paz ( Site 3404)

    Madrid, Madrid, Comunidad de, 28029

    Study Coordinator, +34915383515

    Recruiting

  • Hospital Universitario 12 de Octubre ( Site 3405)

    Madrid, 28041

    Study Coordinator, +34917792853

    Recruiting

  • Complejo Hospitalario Virgen De La Victoria ( Site 3409)

    Málaga, 29010

    Study Coordinator, +34 951032594

    Recruiting

  • Consorcio Hospital General Universitario de Valencia ( Site 3406)

    Valencia, Valenciana, Comunitat, 46014

    Study Coordinator, +34 963131800x437834

    Recruiting

Other trials in Spain

Chile3 sites, 2 recruiting

  • Biomedica Research Group ( Site 4201)

    Santiago, Region M. de Santiago, 7500710

    Study Coordinator, 56222045686

    Recruiting

  • Clínica Universidad de Los Andes ( Site 4207)

    Santiago, Region M. de Santiago, 7620157

    Study Coordinator, 56226183123

    Recruiting

  • Espacio Eme ( Site 4202)

    Santiago, Region M. de Santiago, 7770086

    Active, not recruiting

Other trials in Chile

Guatemala3 sites, 3 recruiting

  • Clínica Médica Especializada en Pediatría e Infectología Pediátrica - Dr. Mario Melgar ( Site 3801)

    Guatemala City, 01009

    Study Coordinator, +50223196600

    Recruiting

  • MEDI-K ( Site 3803)

    Guatemala City, 01009

    Study Coordinator, +50222912323

    Recruiting

  • CELAN,S.A ( Site 3802)

    Guatemala City, 01010

    Study Coordinator, +50222968018

    Recruiting

Other trials in Guatemala

South Africa3 sites, 3 recruiting

  • Josha Research ( Site 4302)

    Bloemfontein, Free State, 9301

    Study Coordinator, +27 51 412 8160

    Recruiting

  • Wentworth Hospital ( Site 4303)

    Durban, KwaZulu-Natal, 4052

    Study Coordinator, +27837471149

    Recruiting

  • Be Part Yoluntu Centre ( Site 4300)

    Mbekweni, Paarl, Western Cape, 7646

    Study Coordinator, +27 21 8683990/1/2

    Recruiting

Other trials in South Africa

Canada2 sites, 1 recruiting

  • Gestion clinique médicale l'Actuel ( Site 3303)

    Montreal, Quebec, H2L 4P9

    Study Coordinator, 5145243642x2271

    Recruiting

  • Spectrum Health ( Site 3307)

    Vancouver, British Columbia, V6Z 2T1

    Completed

Other trials in Canada

Mexico2 sites, 2 recruiting

  • Morales Vargas Centro de Investigacion, S.C. ( Site 4502)

    León, Guanajuato, 37000

    Study Coordinator, 4777160714

    Recruiting

  • Arké SMO S.A de C.V ( Site 4505)

    Veracruz, 91910

    Study Coordinator, +522299314102

    Recruiting

Other trials in Mexico

About this study

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

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.

Being tested
ISL, ULO, BIC/FTC/TAF, Placebo for BIC/FTC/TAF, Placebo to ISL/ULO
Medical subject headings
Acquired Immunodeficiency Syndrome, Infections

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • ISLDrug

    Also called islatravir, MK-8591

    ISL 2 x 1 mg oral capsules administered qw for 96 weeks

  • ULODrug

    Also called ulonivirine, MK-8507

    ULO 2 x 100 mg oral tablets administered qw for 96 weeks

  • BIC/FTC/TAFDrug

    Also called bictegravir/emtricitabine/tenofovir alafenamide, BIKTARVY®

    BIC/FTC/TAF 50/200/25 mg oral tablet administered qd for 96 weeks

  • Placebo for BIC/FTC/TAFDrug

    BIC/FTC/TAF-matching placebo oral tablet administered qd for 96 weeks

  • Placebo to ISL/ULODrug

    ISL/ULO-matching placebo oral tablets administered qw for 96 weeks

  • ISL/ULODrug

    Also called MK-8591B

    ISL/ULO fixed-dose combination 2 mg/200 mg oral tablet administered qw for 96 weeks

Study groups in NCT07266831
Study groupRoleWhat they receive
Phase 2: ISL + ULOExperimentalIslatravir (ISL) 2mg and Ulonivirine (ULO) 200mg administered orally once weekly (qw) for 96 weeks
Receives: Drug: ISL; Drug: ULO
Phase 2: BIC/FTC/TAFActive comparatorBictegravir/Emtricitabine/Tenofovir Alafenamide (BIC/FTC/TAF) 50/200/25 mg, administered orally once daily (qd) for 96 weeks
Receives: Drug: BIC/FTC/TAF
Phase 3: ISL/ULO and Placebo to BIC/FTC/TAFExperimentalISL/ULO fixed dose combination (2/200 mg), administered orally qw, and matching placebo to BIC/FTC/TAF administered orally qd for 96 weeks
Receives: Drug: Placebo for BIC/FTC/TAF; Drug: ISL/ULO
Phase 3: BIC/FTC/TAF and Placebo to ISL/ULOActive comparatorBIC/FTC/TAF 50/200/25 mg, administered orally qd, and matching placebo to ISL/ULO administered orally qw for 96 weeks
Receives: Drug: BIC/FTC/TAF; Drug: Placebo to ISL/ULO

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Phase 2: Percentage of Participants With Human Immunodeficiency Virus Type 1 (HIV-1) Ribonucleic Acid (RNA) <50 Copies/mL at Week 24

    Plasma HIV-1 ribonucleic acid (RNA) quantification will be performed at the central laboratory using a polymerase chain reaction (PCR) assay. Percentage of participants with HIV-1 RNA <50 copies/mL will be reported at week 24.

    Measured: Week 24

  2. Phase 2: Percentage of Participants Who Experience an Adverse Event (AE) at Week 24

    An AE is defined as any unfavorable and unintended sign, symptom, disease, or worsening of preexisting condition temporally associated with study treatment and irrespective of causality to study treatment.

    Measured: Week 24

  3. Phase 2: Percentage of Participants Who Discontinue Study Intervention Due to an AE at Week 24

    An AE is defined as any unfavorable and unintended sign, symptom, disease, or worsening of preexisting condition temporally associated with study treatment and irrespective of causality to study treatment.

    Measured: Week 24

  4. Phase 3: Percentage of Participants With HIV-1 RNA <50 Copies/mL at Week 48

    Plasma HIV-1 RNA quantification will be performed at the central laboratory using a PCR assay. Percentage of participants with HIV-1 RNA <50 copies/mL will be reported at week 48.

    Measured: Week 48

  5. Phase 3: Percentage of Participants Who Experience an AE at Week 48

    An AE is defined as any unfavorable and unintended sign, symptom, disease, or worsening of preexisting condition temporally associated with study treatment and irrespective of causality to study treatment.

    Measured: Week 48

  6. Phase 3: Percentage of Participants Who Discontinue Study Intervention Due to an AE at Week 48

    An AE is defined as any unfavorable and unintended sign, symptom, disease, or worsening of preexisting condition temporally associated with study treatment and irrespective of causality to study treatment.

    Measured: Week 48

Secondary outcomes (24)

  1. Phase 2: Percentage of Participants With HIV-1 RNA <50 Copies/mL at Week 48

    Plasma HIV-1 RNA quantification will be performed at the central laboratory using a PCR assay. Percentage of participants with HIV-1 RNA <50 copies/mL will be reported at week 48.

    Measured: Week 48

  2. Phase 2: Percentage of Participants With HIV-1 RNA <50 Copies/mL at Week 96

    Plasma HIV-1 RNA quantification will be performed at the central laboratory using a PCR assay. Percentage of participants with HIV-1 RNA <50 copies/mL will be reported at week 96.

    Measured: Week 96

  3. Phase 2: Percentage of Participants With HIV-1 RNA <200 Copies/mL at Week 24

    Plasma HIV-1 RNA quantification will be performed at the central laboratory using a PCR assay. Percentage of participants with HIV-1 RNA <200 copies/mL will be reported at week 24.

    Measured: Week 24

  4. Phase 2: Percentage of Participants With HIV-1 RNA <200 Copies/mL at Week 48

    Plasma HIV-1 RNA quantification will be performed at the central laboratory using a PCR assay. Percentage of participants with HIV-1 RNA <200 copies/mL will be reported at week 48.

    Measured: Week 48

  5. Phase 2: Percentage of Participants With HIV-1 RNA <200 Copies/mL at Week 96

    Plasma HIV-1 RNA quantification will be performed at the central laboratory using a PCR assay. Percentage of participants with HIV-1 RNA <200 copies/mL will be reported at week 96.

    Measured: Week 96

  6. Phase 2: Mean Change From Baseline in Cluster of Differentiation 4-Positive (CD4+) T-Cell Count at Week 24

    Blood samples will be collected to measure CD4+ T-cell count. The mean change from baseline in CD4+ T-cell count will be calculated at 24 weeks.

    Measured: Baseline (Day 1) and Week 24

  7. Phase 2: Mean Change From Baseline in CD4+ T-Cell Count at Week 48

    Blood samples will be collected to measure CD4+ T-cell count. The mean change from baseline in CD4+ T-cell count will be calculated at 48 weeks.

    Measured: Baseline (Day 1) and Week 48

  8. Phase 2: Mean Change From Baseline in CD4+ T-Cell Count at Week 96

    Blood samples will be collected to measure CD4+ T-cell count. The mean change from baseline in CD4+ T-cell count will be calculated at 96 weeks.

    Measured: Baseline (Day 1) and Week 96

  9. Phase 2: Percentage of Participants Who Experience an AE

    An AE is defined as any unfavorable and unintended sign, symptom, disease, or worsening of preexisting condition temporally associated with study treatment and irrespective of causality to study treatment.

    Measured: Up to approximately 102 weeks

  10. Phase 2: Percentage of Participants Who Discontinue Study Intervention Due to an AE

    An AE is defined as any unfavorable and unintended sign, symptom, disease, or worsening of preexisting condition temporally associated with study treatment and irrespective of causality to study treatment.

    Measured: Up to approximately 96 weeks

  11. Phase 2: Number of Participants With Evidence of Viral Drug Resistance-Associated Substitutions at Week 24

    Participants who meet the definition of clinically significant confirmed viremia (CSCV) or who discontinue study intervention for another reason and have HIV-1 RNA ≥200 copies/mL at the time of discontinuation, will be assessed for development of viral drug resistance. Among such participants, those with confirmed HIV-1 RNA ≥400 copies/mL will be included in the resistance analyses set. In addition, anyone for whom available genotypic and/or phenotypic data show evidence of resistance, irrespective of viral load, will also be included in the resistance analyses set. The number of participants in each treatment group who have evidence of resistance-associated substitutions at week 24 will be presented.

    Measured: Week 24

  12. Phase 2: Number of Participants With Evidence of Viral Drug Resistance-Associated Substitutions at Week 48

    Participants who meet the definition of clinically significant confirmed viremia (CSCV) or who discontinue study intervention for another reason and have HIV-1 RNA ≥200 copies/mL at the time of discontinuation, will be assessed for development of viral drug resistance. Among such participants, those with confirmed HIV-1 RNA ≥400 copies/mL will be included in the resistance analyses set. In addition, anyone for whom available genotypic and/or phenotypic data show evidence of resistance, irrespective of viral load, will also be included in the resistance analyses set. The number of participants in each treatment group who have evidence of resistance-associated substitutions at week 48 will be presented.

    Measured: Week 48

  13. Phase 2: Number of Participants With Evidence of Viral Drug Resistance-Associated Substitutions at Week 96

    Participants who meet the definition of clinically significant confirmed viremia (CSCV) or who discontinue study intervention for another reason and have HIV-1 RNA ≥200 copies/mL at the time of discontinuation, will be assessed for development of viral drug resistance. Among such participants, those with confirmed HIV-1 RNA ≥400 copies/mL will be included in the resistance analyses set. In addition, anyone for whom available genotypic and/or phenotypic data show evidence of resistance, irrespective of viral load, will also be included in the resistance analyses set. The number of participants in each treatment group who have evidence of resistance-associated substitutions at week 96 will be presented.

    Measured: Week 96

  14. Phase 3: Percentage of Participants With HIV-1 RNA <50 Copies/mL at Week 96

    Plasma HIV-1 RNA quantification will be performed at the central laboratory using a PCR assay. Percentage of participants with HIV-1 RNA <50 copies/mL will be reported at week 96.

    Measured: Week 96

  15. Phase 3: Percentage of Participants With HIV-1 RNA <200 Copies/mL at Week 48

    Plasma HIV-1 RNA quantification will be performed at the central laboratory using a PCR assay. Percentage of participants with HIV-1 RNA <200 copies/mL will be reported at week 48.

    Measured: Week 48

  16. Phase 3: Percentage of Participants With HIV-1 RNA <200 Copies/mL at Week 96

    Plasma HIV-1 RNA quantification will be performed at the central laboratory using a PCR assay. Percentage of participants with HIV-1 RNA <200 copies/mL will be reported at week 96.

    Measured: Week 96

  17. Phase 3: Mean Change From Baseline in Cluster of Differentiation 4-Positive (CD4+) T-Cell Count at Week 48

    Blood samples will be collected to measure CD4+ T-cell count. The mean change from baseline in CD4+ T-cell count will be calculated at 48 weeks.

    Measured: Baseline (Day 1) and Week 48

  18. Phase 3: Mean Change From Baseline in Cluster of Differentiation 4-Positive (CD4+) T-Cell Count at Week 96

    Blood samples will be collected to measure CD4+ T-cell count. The mean change from baseline in CD4+ T-cell count will be calculated at 96 weeks.

    Measured: Baseline (Day 1) and Week 96

  19. Phase 3: Percentage of Participants Who Experience an AE

    An AE is defined as any unfavorable and unintended sign, symptom, disease, or worsening of preexisting condition temporally associated with study treatment and irrespective of causality to study treatment.

    Measured: Up to approximately 102 weeks

  20. Phase 3: Percentage of Participants Who Discontinue Study Intervention Due to an AE

    An AE is defined as any unfavorable and unintended sign, symptom, disease, or worsening of preexisting condition temporally associated with study treatment and irrespective of causality to study treatment.

    Measured: Up to approximately 96 weeks

  21. Phase 3: Number of Participants With Evidence of Viral Drug Resistance-Associated Substitutions at Week 48

    Participants who meet the definition of clinically significant confirmed viremia (CSCV) or who discontinue study intervention for another reason and have HIV-1 RNA ≥200 copies/mL at the time of discontinuation, will be assessed for development of viral drug resistance. Among such participants, those with confirmed HIV-1 RNA ≥400 copies/mL will be included in the resistance analyses set. In addition, anyone for whom available genotypic and/or phenotypic data show evidence of resistance, irrespective of viral load, will also be included in the resistance analyses set. The number of participants in each treatment group who have evidence of resistance-associated substitutions at week 48 will be presented.

    Measured: Week 48

  22. Phase 3: Number of Participants With Evidence of Viral Drug Resistance-Associated Substitutions at Week 96

    Participants who meet the definition of clinically significant confirmed viremia (CSCV) or who discontinue study intervention for another reason and have HIV-1 RNA ≥200 copies/mL at the time of discontinuation, will be assessed for development of viral drug resistance. Among such participants, those with confirmed HIV-1 RNA ≥400 copies/mL will be included in the resistance analyses set. In addition, anyone for whom available genotypic and/or phenotypic data show evidence of resistance, irrespective of viral load, will also be included in the resistance analyses set. The number of participants in each treatment group who have evidence of resistance-associated substitutions at week 96 will be presented.

    Measured: Week 96

  23. Phase 3: Mean Change From Baseline in Body Weight at Week 48

    Body weight will be collected throughout the study.

    Measured: Baseline (Day 1) and Week 48

  24. Phase 3: Mean Change From Baseline in Body Weight at Week 96

    Body weight will be collected throughout the study.

    Measured: Baseline (Day 1) and Week 96

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted5 Dec 2025
  2. Study start18 Dec 2025
  3. Primary completion1 Feb 2029 (estimated)
  4. Study completion18 Dec 2031 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2/3
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Double blind
Who is masked
Participant, Investigator
Enrolment
570 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07266831
Sponsor's protocol ID
8591B-062
Other IDs
U1111-1323-4689, 2025-522519-40, MK-8591B-062, 2025
Status last verified
Nov 2026
First submitted
1 Dec 2025
Last updated
4 Nov 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Yes: https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf

Questions about this trial

What is this clinical trial studying?

A Phase 2/3 study testing ISL, ULO and BIC/FTC/TAF in people with Human Immunodeficiency Virus Type 1 (HIV-1) Infection, run by Merck Sharp & Dohme LLC at 56 sites in 9 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 4 Nov 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 56 sites in United States, France, Argentina, Spain, Chile and 4 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this combined phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Toll Free Number (1-888-577-8839, Trialsites@msd.com), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Phase 2: Percentage of Participants With Human Immunodeficiency Virus Type 1 (HIV-1) Ribonucleic Acid (RNA) <50 Copies/mL at Week 24 (time frame: Week 24). The study lists 6 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07266831.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Nov 2026.

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