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Study on the Safety and Tolerability of VGL101 for Adults with Adult-Onset Leukoencephalopathy

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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 a rare brain disease called Adult-Onset Leukoencephalopathy with Axonal Spheroids and Pigmented Glia (ALSP). This condition affects the brain's white matter, which is crucial for transmitting signals in the brain. The study will use a treatment called VGL101, which is given as a solution for injection through a method known as intravenous infusion, meaning it is delivered directly into the bloodstream.

The purpose of the study is to evaluate how safe and tolerable the treatment is for patients with ALSP. Participants in the study will receive either the treatment or a placebo. The study will last for about a year, during which participants will have regular check-ups to monitor their health and any changes in their condition. These check-ups will include various tests, such as blood tests and MRI scans, to observe any effects of the treatment on the brain and overall health.

Throughout the study, researchers will pay close attention to any side effects or adverse reactions to the treatment. The goal is to gather information that could help in understanding how well VGL101 works and how it might be used to help people with ALSP in the future. Participants will be closely monitored to ensure their safety and well-being during the trial period.

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

    Initial visit

    Upon joining the study, you will attend an initial visit. During this visit, you will undergo a series of assessments to confirm your eligibility for the trial. These assessments may include a review of your medical history, a physical examination, and various tests such as blood tests and an MRI scan to evaluate your condition.

  2. Step 2

    Baseline visit

    At the baseline visit, you will receive your first dose of the study medication, VGL101. This medication is administered as a solution for injection through an intravenous infusion. The healthcare team will monitor you closely during and after the infusion to ensure your safety and to observe any immediate effects.

  3. Step 3

    Regular follow-up visits

    You will attend regular follow-up visits throughout the study. These visits are scheduled to monitor your health and the effects of the medication. During these visits, you may undergo various assessments, including blood tests, MRI scans, and other evaluations to track your progress and any changes in your condition.

  4. Step 4

    Medication administration

    The study medication, VGL101, will be administered at specified intervals as determined by the study protocol. The dosage and frequency of administration will be explained to you by the healthcare team. It is important to adhere to the schedule provided to ensure the effectiveness of the treatment.

  5. Step 5

    Safety and tolerability assessments

    Throughout the study, your safety and the tolerability of the medication will be closely monitored. This includes tracking any side effects or adverse reactions you may experience. Regular assessments will be conducted to ensure your well-being and to address any concerns that may arise.

  6. Step 6

    End of study visit

    At the end of the study, you will attend a final visit. This visit will include a comprehensive evaluation of your health and the overall effects of the treatment. The healthcare team will discuss the results with you and provide guidance on any further steps or follow-up care that may be necessary.

Who can join the trial?

17 criteria

  • The person must be at least 18 years old.
  • The person can walk on their own or with help, like using a cane or crutches. If they use a wheelchair, they should be able to move it themselves, get in and out of it, and walk a short distance with or without help. People who cannot walk might still join after talking with the study doctor.
  • If the person has trouble with thinking or memory, they need a study partner (like a caregiver, family member, or friend) who can help them follow the study rules and provide information during visits.
  • The study partner must have regular contact with the person and be willing to sign a consent form.
  • If the person is a woman who can have children or a man who can father children, they must agree to use effective birth control during the study and for at least 3 months after the last dose of the study drug.
  • The person must sign a consent form to join the study. If they cannot sign themselves, their study partner or legal guardian can sign for them.
  • If the person is a woman who can have children, she must have a negative pregnancy test before starting the study drug.
  • The person must have a body mass index (BMI) between 17.5 and 38.0. BMI is a measure of body fat based on height and weight.
  • The person must follow local rules for COVID-19 testing before joining the study.
  • The person must be able to understand the study and follow its rules, or have a study partner or legal guardian who can help them do so.
  • The person must agree not to use any medications or treatments that are not allowed by the study.
  • The person must have approval from the study's medical team to join.
  • The person must have a documented gene mutation in the CSF1R gene. This can be from past records, but a blood test will be done to confirm it.
  • The person must have at least two of the following: trouble with thinking or mental health, certain signs found in a neurological exam, stiffness or movement problems, or epilepsy. They must also have specific MRI findings that match the study's criteria.
  • The person must have shown signs of their condition getting worse in the past year, according to the study doctor.
  • The person must score at least 14 on the Montreal Cognitive Assessment (MoCA), a test that checks thinking abilities.
  • The person must be in a stable condition, as judged by the study doctor.

Who cannot join the trial?

3 criteria

  • Patients with a history of leukoencephalopathy cannot participate. Leukoencephalopathy is a condition that affects the white matter of the brain.
  • Patients who are not within the specified age range for the study cannot participate. The study is for adults only.
  • Patients who are part of a vulnerable population, such as those who may not be able to give informed consent, cannot participate.
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Investigated drugs

  • VGL101

    is a medication being studied to see if it can help people with a condition called adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP). This condition affects the brain and can cause problems with thinking and movement. The study is looking at how safe and tolerable VGL101 is for patients with this condition.

  • Iluzanebart

    is another medication being tested in the study. It is being evaluated to see if it can be a safe and effective treatment for people with ALSP. The goal is to understand how well patients can tolerate this medication and if it can help manage the symptoms of the condition.

What is already known about the treatment

VGL101 – VGL101 is administered as an intravenous infusion, meaning it is delivered directly into the bloodstream through a vein. Currently, it is being studied in clinical trials and is not yet widely available in medical practice. The main therapeutic indication for VGL101 is adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP), a rare neurological condition. At the molecular level, VGL101 is believed to work by targeting specific pathways involved in the disease process, although the exact mechanism is still under investigation. It is classified pharmacologically as an investigational drug, meaning it is still being tested for its safety and effectiveness.

Investigated diseases

Adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) – This is a rare neurological disorder that affects the brain's white matter. It is characterized by the degeneration of myelin, the protective covering of nerve fibers, leading to a range of neurological symptoms. The disease progresses with the formation of axonal spheroids, which are swollen nerve fibers, and the presence of pigmented glial cells, which are supportive cells in the brain. As the condition advances, individuals may experience cognitive decline, motor dysfunction, and behavioral changes. The progression of symptoms can vary widely among individuals, with some experiencing rapid changes and others having a more gradual onset. The underlying cause is often linked to genetic mutations affecting the brain's normal functioning.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IVTrial ID2022-502505-15-00Protocol codeVGL101-01.201Estimated enrolment18 patientsSponsorVigil Neuroscience Inc.

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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).