A Study of Islatravir (ISL) and Ulonivirine (ULO) Once Weekly (QW) in Virologically Suppressed Adults With Human Immunodeficiency Virus Type 1 (HIV-1) (MK-8591B-060)

NCT06891066 | Active Not Recruiting Phase 2 DMC FDA Drug

• 2 other identifiers: 8591B-060MK-8591B-060
• Study Type: interventional
• Target: 150
• Locations: 4 countries
• Sites: 23

Brief Summary

Investigators are trying to find better treatments for people with HIV-1. In this clinical study, investigators want to see how well a new treatment called ISL+ULO, taken once a week, works compared to an existing treatment called BIC/FTC/TAF, which is taken every day. Investigators will check how many people still have a high level of the virus in their blood after 24 weeks. The investigators also want to understand if the new treatment, MK-8591B, is safe and how well people can handle it.

Conditions

Human Immunodeficiency Virus Type 1 (HIV-1) Infection

Keywords

HIV-1

Outcome Measures

Primary Outcomes (3)

• Percentage of Participants With HIV-1 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.

  Week 24

• Percentage of Participants who Experience an Adverse Event (AE)

  An AE is any untoward medical occurrence in a participant, temporally associated with the use of study treatment, whether or not considered related to the study treatment. The percentage of participants who experience an AE will be reported.

  Up to ~ 96 weeks

• Percentage of Participants Discontinuing Study Treatment due to AEs

  An AE is any untoward medical occurrence in a participant, temporally associated with the use of study treatment, whether or not considered related to the study treatment. The percentage of participants who discontinue study treatment due to an AE will be reported.

  Up to ~ 96 weeks

Secondary Outcomes (14)

• Percentage of Participants With HIV-1 RNA ≥50 copies/mL at Week 48

  Week 48

• Percentage of Participants With HIV-1 RNA <50 copies/mL at Week 24

  Week 24

• Percentage of Participants With HIV-1 RNA <50 copies/mL at Week 48

  Week 48

• Percentage of Participants With HIV-1 RNA <200 copies/mL at Week 24

  Week 24

• Percentage of Participants With HIV-1 RNA <200 copies/mL at Week 48

  Week 48

Study Arms (3)

ISL + ULO in Group 1

EXPERIMENTAL

In part 1 of the study, participants will receive ISL 2mg + ULO 200mg orally once a week (QW) for 48 weeks. In part 2 (2nd 48 weeks), participants will continue to receive ISL 2mg + ULO 200mg once a week till week 96.

Drug: ISL; Drug: ULO

BIC/FTC/TAF in Group 2

ACTIVE COMPARATOR

In part 1 of the study, participants will receive BIC 50mg/FTC 200mg/TAF 25mg orally once daily (QD) for 48 weeks.

Drug: BIC/FTC/TAF

ISL + ULO in Group 2

EXPERIMENTAL

In part 2 of the study, participants previously on BIC/FTC/TAF (for the 1st 48 weeks, or part 1) will switch to ISL + ULO, to week 96.

Drug: ISL; Drug: ULO

Interventions

ISL DRUG

ISL 1mg oral capsule will be administered as 2mg orally (each capsule 1mg) as part of ISL and ULO combination to group 1 participants for 96 weeks and for group 2 participants in part 2 of the study from 49 to 96 weeks.

Also known as: MK-8591, Islatravir

ISL + ULO in Group 1; ISL + ULO in Group 2

ULO DRUG

ULO 100mg oral tablet will be administered as 200mg (2 tablets) orally as part of ISL and ULO combination to group 1 participants for 96 weeks and for group 2 participants in part 2 of the study from 49 to 96 weeks.

Also known as: MK-8507, Ulonivirine.

ISL + ULO in Group 1; ISL + ULO in Group 2

BIC/FTC/TAF DRUG

BIC 50mg oral tablet/FTC 200mg oral tablet/TAF 25 mg oral tablet administered orally to group 2 participants for 48 weeks in part 1 of the study.

Also known as: BIKTARVY®

BIC/FTC/TAF in Group 2

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• \- Has been receiving Bictegravir/Emtricitabine/Tenofovir alafenamide (BIC/FTC/TAF) therapy with documented viral suppression \[Human immunodeficiency virus type 1 (HIV-1) ribonucleic acid (RNA) \<50 copies/mL\] for ≥6 months prior to providing documented informed consent and has no history of prior virologic treatment failure on any past or current regimen.

You may not qualify if:

• 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) coinfection.
• Has hepatitis B virus (HBV) coinfection.
• 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.

Sponsors & Collaborators

• Merck Sharp & Dohme LLC: lead

Study Sites (23)

Zuckerberg San Francisco General Hospital and Trauma Center ( Site 4107)

San Francisco, California, 94110, United States

Location

Mills Clinical Research ( Site 4109)

West Hollywood, California, 90046, United States

Location

Georgetown University Medical Center ( Site 4106)

Washington D.C., District of Columbia, 20007, United States

Location

Orlando Immunology Center ( Site 4103)

Orlando, Florida, 32803, United States

Location

Triple O Research Institute ( Site 4111)

West Palm Beach, Florida, 33407, United States

Location

Chatham County Health Department - Chatham CARE Center ( Site 4116)

Savannah, Georgia, 31401, United States

Location

KC CARE Health Center ( Site 4101)

Kansas City, Missouri, 64111, United States

Location

Regional Center for Infectious Diseases ( Site 4115)

Greensboro, North Carolina, 27401, United States

Location

Central Texas Clinical Research ( Site 4100)

Austin, Texas, 78705, United States

Location

Prism Health North Texas, Oak Cliff Health Center ( Site 4114)

Dallas, Texas, 75208, United States

Location

DCOL Center for Clinical Research ( Site 4112)

Longview, Texas, 75605, United States

Location

Momentum Clinical Research - Darlinghurst ( Site 4260)

Darlinghurst, New South Wales, 2010, Australia

Location

St. Vincent's Hospital ( Site 4263)

Darlinghurst, New South Wales, 2010, Australia

Location

Momentum Clinical Research Fortitude Valley ( Site 4261)

Fortitude Valley, Queensland, 4006, Australia

Location

The Alfred Hospital ( Site 4264)

Melbourne, Victoria, 3004, Australia

Location

Prahran Market Clinic ( Site 4262)

Prahran, Victoria, 3181, Australia

Location

Ponce Medical School Foundation Inc./CAIMED Center ( Site 4301)

Ponce, 00716, Puerto Rico

Location

Clinical Research Puerto Rico ( Site 4300)

San Juan, 00909, Puerto Rico

Location

HOPE Clinical Research ( Site 4303)

San Juan, 00909, Puerto Rico

Location

University Hospital Basel-Infectiology ( Site 4402)

Basel, Canton of Basel-City, 4031, Switzerland

Location

Inselspital Bern-Inselspital Infektiologie ( Site 4403)

Bern, Canton of Bern, 3010, Switzerland

Location

Hôpitaux Universitaires de Genève (HUG)-Infectious Disease Department ( Site 4404)

Geneva, Canton of Geneva, 1205, Switzerland

Location

Ospedale Regionale di Lugano, Sede Civico-Servizio Malattie Infettive ( Site 4405)

Lugano, Canton Ticino, 6900, Switzerland

Location

Related Links

• Merck Clinical Trials Information

MeSH Terms

Conditions

Acquired Immunodeficiency Syndrome; Infections

Interventions

islatravir; ulonivirine; bictegravir, emtricitabine, tenofovir alafenamide, drug combination

Condition Hierarchy (Ancestors)

HIV Infections; Blood-Borne Infections; Communicable Diseases; Sexually Transmitted Diseases, Viral; Sexually Transmitted Diseases; Lentivirus Infections; Retroviridae Infections; RNA Virus Infections; Virus Diseases; Slow Virus Diseases; Genital Diseases; Urogenital Diseases; Immunologic Deficiency Syndromes; Immune System Diseases

Study Officials

• Medical Director

  Merck Sharp & Dohme LLC

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: March 17, 2025
• First Posted: March 24, 2025
• Study Start: April 14, 2025
• Primary Completion (Estimated): August 10, 2027
• Study Completion (Estimated): September 30, 2031
• Last Updated: October 16, 2025

Record last verified: 2025-10

Data Sharing

• IPD Sharing: Will share

Locations

US (11); AU (5); PR (3); CH (4)