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Study on Doravirine and Islatravir for People with HIV-1 Previously Treated with the Same Drug Combination

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying the treatment of HIV-1 infection, a virus that attacks the immune system and can lead to acquired immunodeficiency syndrome (AIDS) if not treated. The study involves a medication that combines two active substances: doravirine and islatravir. These substances are provided in a film-coated tablet form, known by the code name MK-8591A, and are taken orally once a day.

The purpose of this study is to evaluate the safety and tolerability of the doravirine/islatravir combination in participants who have previously received this treatment in earlier studies. Participants will continue to take the medication for a period of time, and researchers will monitor them to gather information about any side effects or adverse events that may occur. The study aims to collect data over a period of up to 96 weeks.

Throughout the study, researchers will also assess the effectiveness of the treatment by measuring the levels of HIV-1 in the blood. This will help determine how well the medication is working to control the virus. The study will provide valuable information on the long-term use of this treatment combination for managing HIV-1 infection.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Beginning of the trial

    Upon joining the study, participants will start taking a medication called doravirine/islatravir.

    This medication is provided in the form of a film-coated tablet and is taken orally.

  2. Step 2

    Medication regimen

    Participants will take the doravirine/islatravir tablet once daily.

    The dosage for this study is 100 mg of doravirine and 0.25 mg of islatravir.

  3. Step 3

    Duration of treatment

    The treatment will continue for a period of up to 96 weeks.

    Participants are expected to adhere to the daily medication schedule throughout this period.

  4. Step 4

    Monitoring and assessments

    Participants will be monitored for any adverse events or side effects during the study.

    Regular assessments will be conducted to evaluate the HIV-1 RNA levels in the blood, aiming for levels below 50 copies/mL at Week 96.

  5. Step 5

    Completion of the trial

    At the end of the study period, participants will undergo a final evaluation.

    The study aims to assess the overall safety and tolerability of the medication regimen.

Who can join the trial?

5 criteria

  • The patient must have HIV-1 infection.
  • The patient is currently taking a specific combination tablet called doravirine/islatravir (DOR/ISL) in certain clinical studies sponsored by Merck Sharp & Dohme (MSD).
  • The patient can be of any gender, both male and female are eligible.
  • The patient must be within the age range of 18 to 65 years old.
  • The study includes individuals who may be considered part of a vulnerable population, which means they might need extra protection or care.

Who cannot join the trial?

6 criteria

  • Patients who do not have an HIV-1 infection cannot participate.
  • Patients who are not within the specified age range cannot participate. The age range includes both adults and adolescents.
  • Patients who are not part of the specified clinical trial groups cannot participate.
  • Patients who are not willing to follow the study procedures cannot participate.
  • Patients who are pregnant or breastfeeding cannot participate.
  • Patients who have any other medical condition that the study doctors think might make it unsafe for them to participate cannot participate.
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Investigated drugs

  • Doravirine

    is a medication used to treat HIV-1 infection. It works by blocking a specific enzyme that the virus needs to multiply, helping to lower the amount of virus in the body. This can improve the immune system and reduce the risk of developing HIV-related illnesses.

  • Islatravir

    is another medication used in the treatment of HIV-1 infection. It helps to prevent the virus from multiplying by interfering with its ability to replicate. This can help to control the infection and improve the patient's overall health by maintaining a stronger immune system.

What is already known about the treatment

Doravirine/Islatravir – This medication is taken orally in the form of a pill and is used to treat HIV-1 infection. It is currently being studied in a Phase 3 clinical trial to assess its safety and tolerability over a 96-week period. Doravirine/Islatravir works by interfering with the virus's ability to replicate, helping to control the infection. It belongs to a class of drugs known as antiretrovirals, which are used to manage HIV infections.

Investigated diseases

HIV-1 infection – Human Immunodeficiency Virus Type 1 (HIV-1) infection is a viral condition that targets the immune system, specifically the CD4 cells, which are crucial for immune response. As the virus replicates, it gradually depletes these cells, weakening the body's ability to fight off infections and diseases. The progression of the infection can lead to a significant reduction in immune function, making the individual more susceptible to opportunistic infections and certain cancers. Over time, if untreated, the infection can advance to Acquired Immunodeficiency Syndrome (AIDS), characterized by a severely compromised immune system. The virus is primarily transmitted through contact with infected bodily fluids, such as blood, semen, vaginal fluids, and breast milk. The progression of the disease can vary greatly among individuals, influenced by factors such as viral load, genetic factors, and overall health.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2022-502126-40-00Protocol codeMK-8591A-054Estimated enrolment1 312 patientsSponsorMerck Sharp & Dohme LLC

sourced from the EU Clinical Trials Register and site verification

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On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

This service is not affiliated with the European Commission, the EMA, or the official CTIS system. Most information comes from publicly available international clinical-trial registries, supplemented by data from academic sites, national regulators and commercial sponsors. On this site, “treatment” and “therapy” mean a medicine being tested in a clinical trial. Its safety and effectiveness in the use being studied are not yet confirmed, some participants may receive a placebo or a comparator, and taking part does not guarantee a health benefit. The doctor at the research site decides who can take part. This site provides information, not medical advice. Certain content and visual elements on this website have been generated or enhanced using artificial intelligence (AI).