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

NCT05677659 | Terminated Phase 2 FDA Drug

• 1 other identifier: VGL101-01.201
• Study Type: interventional
• Target: 20
• Locations: 5 countries
• Sites: 10

Brief Summary

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.

Conditions

ALSP

Keywords

ALSP; CSF1R; leukoencephalopathy; Hereditary Diffuse Leukoencephalopathy with Spheroids; HDLS; CSF1R-related Leukoencephalopathy; Adult-Onset Leukoencephalopathy with Axonal Spheroids and Pigmented Glia; CSF1R gene mutation; IGNITE

Outcome Measures

Primary Outcomes (2)

• Core Study Adverse Events

  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

  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 Outcomes (10)

• To evaluate the effects of iluzanebart on brain volume loss on MRI in subjects with ALSP in the Core Study

  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

  Baseline and Week 52

• To evaluate the effects of iluzanebart on clinical measures of disease progression in subjects with ALSP in the Core Study

  Baseline and Week 52

• To evaluate the effects of iluzanebart on fluid biomarkers of neurodegeneration in subjects with ALSP in the Core Study

  Baseline and Week 52

• To evaluate the pharmacokinetics of iluzanebart in subjects with ALSP in the Core Study

  Through Week 52

Study Arms (1)

VGL101

EXPERIMENTAL

Solution administered via Intravenous Infusion (IV)

Drug: VGL101

Interventions

VGL101 DRUG

Solution administered via Intravenous Infusion (IV)

VGL101

Eligibility Criteria

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

You may qualify if:

• Participants who have documentation of a gene mutation in the CSF1R gene
• Participants fulfill both (Parts A and B) of the following criteria:
• The participant has more than 2 findings of clinical signs or symptoms in the following categories:
• Cognitive impairment or psychiatric problem
• Pyramidal signs on neurological examination
• Extrapyramidal signs, such as rigidity.
• Epilepsy
• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• Vigil Neuroscience, Inc.: lead

Study Sites (10)

Investigative Site 3

San Francisco, California, 94158, United States

Location

Investigative Site 2

Englewood, Colorado, 80113, United States

Location

Investigative Site 1

Jacksonville, Florida, 32224, United States

Location

Investigative Site 5

Boston, Massachusetts, 02114, United States

Location

Investigative Site 6

Philadelphia, Pennsylvania, 19104, United States

Location

Investigative Site 10

Paris, France

Location

Investigative Site 7

Leipzig, Germany

Location

Investigative Site 9

Tübingen, Germany

Location

Investigative Site 8

Amsterdam, Netherlands

Location

Investigative Site 4

London, United Kingdom

Location

MeSH Terms

Conditions

Leukoencephalopathies; Hereditary Diffuse Leukoencephalopathy with Spheroids

Condition Hierarchy (Ancestors)

Brain Diseases; Central Nervous System Diseases; Nervous System Diseases

Study Design

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

Study Record Dates

• First Submitted: November 30, 2022
• First Posted: January 10, 2023
• Study Start: December 14, 2022
• Primary Completion: February 14, 2025
• Study Completion: June 4, 2025
• Last Updated: June 11, 2025

Record last verified: 2025-06

Data Sharing

• IPD Sharing: Will not share

Locations

NL (1); GB (1); US (5); DE (2); FR (1)