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Study of Fostemsavir in Adults with HIV Transitioning from Prior ViiV Clinical Trials for Continued Treatment Access

Registered drugNo placebo
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What is this trial about?

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

The study involves people living with HIV infection who have previously taken the investigational medication fostemsavir in the form of Rukobia 600 mg prolonged-release tablets. This medication is taken by mouth and is designed to be released slowly over time to keep a steady level of the drug in the body.

The purpose of the study is to provide continued access to the treatment for participants who are still benefiting from it and to observe its safety over a longer period.

Participants who move into the study will continue to take the same tablets as before and will attend regular clinic visits where basic health checks and safety assessments are performed. The study follows them for an extended time to record any health problems or side effects that may occur while they remain on the medication.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Transition Into the Study

    After completing a ViiV Healthcare‑sponsored parent study, you will be offered the chance to continue receiving the same treatment in this continued‑access study.

    You will sign a new consent form that explains the purpose of the study, which is to keep providing the medication you have been using and to monitor its safety over time.

  2. Step 2

    Baseline Assessments

    Before the first dose, study staff will perform a brief health check that includes a blood test to confirm your HIV infection status and to record any existing health conditions.

    The results will be used to establish a starting point for future comparisons.

  3. Step 3

    Start of Study Medication

    You will begin taking Rukobia tablets, which contain the active substance fostemsavir.

    The prescribed dose is 1200 mg per day, taken as two 600 mg prolonged‑release tablets taken orally once daily.

    The tablets are designed to release the medicine slowly over time, so you should swallow them whole with water and not crush or chew them.

  4. Step 4

    Regular Study Visits

    You will attend scheduled clinic visits approximately every 12 weeks (about every three months).

    During each visit, staff will check your overall health, perform blood tests to monitor HIV levels and any possible side effects, and record any adverse events you may have experienced.

    These visits continue for the entire duration of the study, which may last until the study end date of 31 December 2030 unless you discontinue earlier.

  5. Step 5

    Ongoing Safety Monitoring

    If you notice any new symptoms or health problems, you should report them to the study team as soon as possible.

    The study will track serious adverse events (SAEs) and adverse events of special interest (AESIs) to ensure your safety.

  6. Step 6

    Study Completion or Discontinuation

    The study will end for you either when the overall study concludes on 31 December 2030, or earlier if you choose to stop, if you no longer receive clinical benefit, or if safety concerns arise.

    At the final visit, you will undergo a last set of assessments and will be given information about any further treatment options.

Who can join the trial?

5 criteria

  • The doctor must confirm that you are still receiving a health improvement called clinical benefit from the medication you used in the earlier parent study, and that you have finished the treatment period required by that earlier study. You also need to still meet the earlier study’s eligibility (you have not been removed for any reason).
  • You (or your legally authorized representative, called a LAR) must be willing and able to attend all scheduled visits, follow the treatment plan, and complete any other study procedures.
  • You (or your LAR) must be able to sign an informed consent form, which means you understand the study, agree to follow its rules, and, if you are a minor, also provide written assent (your agreement).
  • Both males and females are eligible to participate.
  • You must be in the age groups allowed by the study, which include children and adolescents (generally ages 4 years and older).

Who cannot join the trial?

1 criterion

  • If the study Investigator (the doctor in charge of the trial) or the Sponsor (the organization funding the trial) believes there is any reason that would preclude (prevent) you from joining, you cannot take part in the study.
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Investigated drugs

Rukobia is an oral tablet taken by mouth that contains the medicine fostemsavir. It works by blocking a step that HIV needs to enter and infect healthy cells, helping to keep the virus under control. In this study, participants who were already benefiting from Rukobia in earlier trials continued to receive the same medication to see how safe it remains over a longer period and to maintain its health benefits.

What is already known about the treatment

Rukobia 600 mg prolonged-release tablets - This medication is taken by mouth as a prolonged‑release tablet that is swallowed with water. It is an approved prescription drug that is listed in medical literature for use in adults with HIV infection who have limited treatment options. It works by attaching to a part of the HIV virus called gp120, which blocks the virus from connecting to and entering immune cells. Rukobia belongs to the class of antiretroviral drugs known as HIV attachment inhibitors.

Investigated diseases

HIV infection - HIV infection is a viral condition that attacks the immune system, specifically targeting certain white blood cells. Over time, the virus reduces the body's ability to fight infections and diseases. If untreated, the condition can progress from an early stage with few symptoms to a later stage where the immune system is weakened. The virus replicates continuously, and the amount of virus in the blood can rise and fall. Persistent infection leads to gradual loss of immune function.
Trial detailsLast updated 12 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2025-522910-21-00Protocol code300269Estimated enrolment8 patientsSponsorViiv Healthcare UK Limited

sourced from the EU Clinical Trials Register and site verification

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