A Study of VGL101 in Patients With Adult-Onset Leukoencephalopathy With Axonal Spheroids and Pigmented Glia

June 5, 2025 updated by: Vigil Neuroscience, Inc.

A Phase 2 Safety, Tolerability, and Proof-of-Concept Study of VGL101 in Patients With Adult-Onset Leukoencephalopathy With Axonal Spheroids and Pigmented Glia (ALSP) (The Ignite Study)

This is a multicenter, open-label study to assess the safety and tolerability of iluzanebart (also referred to as VGL101) in subjects with documentation of a gene mutation in the CSF1R gene for the treatment of adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) and to evaluate the effects of iluzanebart on imaging and biomarkers of disease progression in subjects with ALSP. Participants will receive infusions of iluzanebart approximately every 4 weeks for 1 year. The study includes a 52-week, open-label Core Study, followed by a Long-Term Extension (LTE), which provides subjects who complete the original 52-week study (Core Study) with the option to continue treatment for up to an additional 2 years.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Terminated

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
20

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • France
      • Paris, France
        • Investigative Site 10
  • Germany
      • Leipzig, Germany
        • Investigative Site 7
      • Tübingen, Germany
        • Investigative Site 9
  • Netherlands
      • Amsterdam, Netherlands
        • Investigative Site 8
  • United Kingdom
      • London, United Kingdom
        • Investigative Site 4
  • United States
    • California
      • San Francisco, California, United States, 94158
        • Investigative Site 3
    • Colorado
      • Englewood, Colorado, United States, 80113
        • Investigative Site 2
    • Florida
      • Jacksonville, Florida, United States, 32224
        • Investigative Site 1
    • Massachusetts
      • Boston, Massachusetts, United States, 02114
        • Investigative Site 5
    • Pennsylvania
      • Philadelphia, Pennsylvania, United States, 19104
        • Investigative Site 6

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Key Inclusion Criteria:

  • Participants who have documentation of a gene mutation in the CSF1R gene

  • Participants fulfill both (Parts A and B) of the following criteria:

    1. The participant has more than 2 findings of clinical signs or symptoms in the following categories:

      1. Cognitive impairment or psychiatric problem
      2. Pyramidal signs on neurological examination
      3. Extrapyramidal signs, such as rigidity.
      4. Epilepsy
    2. MRI findings consistent with ALSP, specifically, bilateral cerebral white matter lesions with or without thinning of the corpus callosum, on the Screening MRI.
  • The participant must have a study partner (i.e., caregiver, family member, friend, etc.) who, in the investigator's judgment, has frequent and sufficient contact with the subject so as to be able to provide accurate information about the participant's health and cognitive and functional abilities. The study partner must be willing to sign a study partner ICF.

Key Exclusion Criteria:

  • The participant has any neurological disease that poses a risk to the participant or can produce cognitive, motor, or behavioral impairment similar to ALSP, including, but not limited to, brain tumor, hydrocephalus, Alzheimer's disease, frontotemporal dementia (FTD), ALS, stroke, Huntington disease, multiple sclerosis, Parkinson's disease, and Down syndrome.
  • Participant with any condition or situation that, in the opinion of the investigator or sponsor medical personnel, may place the subject at significant risk, confound the study results, or interfere significantly with the participant's participation in the study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: VGL101
Solution administered via Intravenous Infusion (IV)
Drug: VGL101
Solution administered via Intravenous Infusion (IV)

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Core Study Adverse Events
Time Frame: Through Week 52
To evaluate the safety and tolerability of iluzanebart for the treatment of adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) by adverse events in the Core Study
Through Week 52
Long-Term Extension Adverse Events
Time Frame: Week 52 through Week 148
To evaluate the safety and tolerability of iluzanebart for the treatment of ALSP by adverse events in the Long-Term Extension
Week 52 through Week 148

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
To evaluate the effects of iluzanebart on brain volume loss on MRI in subjects with ALSP in the Core Study
Time Frame: Baseline and Week 52
Percentage of subjects with minimal radiological progression from Baseline to Week 52
Baseline and Week 52
To assess the correlation between brain volume loss on MRI and clinical measures of disease progression in subjects with ALSP in the Core Study
Time Frame: Baseline and Week 52
  • Correlation between brain volume loss and Montreal Cognitive Assessment (MoCA) changes from Baseline to Week 52
  • Correlation between brain volume loss and Cortical basal ganglia functional scale (CBFS) changes from Baseline to Week 52
Baseline and Week 52
To evaluate the effects of iluzanebart on clinical measures of disease progression in subjects with ALSP in the Core Study
Time Frame: Baseline and Week 52
  • Percentage of subjects with minimal progression in the MoCA scale, from Baseline to Week 52
  • Percentage of subjects with minimal progression in CBFS from Baseline to Week 52
  • Percentage of subjects who did not worsen in the Clinical Global Impression - Change (CGI-C) scale at Week 52
Baseline and Week 52
To evaluate the effects of iluzanebart on fluid biomarkers of neurodegeneration in subjects with ALSP in the Core Study
Time Frame: Baseline and Week 52
Change from Baseline to Week 52 in neurofilament light chain (NfL) in and blood
Baseline and Week 52
To evaluate the pharmacokinetics of iluzanebart in subjects with ALSP in the Core Study
Time Frame: Through Week 52
Serum and cerebrospinal fluid (CSF) concentrations of iluzanebart
Through Week 52
To evaluate the effects of iluzanebart on brain volume loss on MRI in subjects with ALSP in the Long-Term Extension
Time Frame: Baseline and Weeks 76, 100, 124, and 148
Change from Baseline to Weeks 76, 100, 124, and 148 in brain volume loss
Baseline and Weeks 76, 100, 124, and 148
To assess the correlation between brain volume loss on MRI and clinical measures of disease progression in subjects with ALSP in the Long-Term Extension
Time Frame: Baseline and Weeks 76, 100, 124, and 148
  • Correlation between brain volume loss and MoCA changes from Baseline to Weeks 76, 100, 124, and 148
  • Correlation between brain volume loss and CBFS changes from Baseline to Weeks 76, 100, 124, and 148
Baseline and Weeks 76, 100, 124, and 148
To evaluate the effects of iluzanebart on clinical measures of disease progression in subjects with ALSP in the Long-Term Extension
Time Frame: Baseline and Weeks 64, 76, 88, 100, 112, 124, 136, and 148
  • Change from baseline to Weeks 64, 76, 88, 100, 112, 124, 136, and 148 in the MoCA and CBFS
  • Mean CGI-C score at Weeks 64, 76, 88, 100, 112, 124, 136, and 148
Baseline and Weeks 64, 76, 88, 100, 112, 124, 136, and 148
To evaluate the effects of iluzanebart on fluid biomarkers of neurodegeneration in subjects with ALSP in the Long-Term Extension
Time Frame: Baseline and Weeks 76, 100, 124, and 148
Change from Baseline to Weeks 76, 100, 124, and 148 in NfL in blood
Baseline and Weeks 76, 100, 124, and 148
To evaluate the pharmacokinetics of iluzanebart in subjects with ALSP in the Long-Term Extension
Time Frame: Week 52 through Week 148
Serum and CSF concentrations of iluzanebart
Week 52 through Week 148

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Vigil Neuroscience, Inc.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
December 14, 2022

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
February 14, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 4, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 30, 2022

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 22, 2022

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
January 10, 2023

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 11, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 5, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • VGL101-01.201

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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