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Safety and early effectiveness study of VG801 subretinal injection in patients with ABCA4 mutation-associated retinal dystrophy

Verified siteInvestigationalNo placebo
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What is this trial about?

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

This study focuses on patients with ABCA4 Mutation-Associated Retinal Dystrophy, which is an inherited eye disease that causes progressive vision loss due to damage to the light-sensing cells in the retina. The study will test a new experimental treatment called VG801, which is given as a single injection underneath the retina (through subretinal injection).

The purpose of this research is to evaluate the safety of VG801 and to see if it might help improve vision in people with this genetic eye condition. The treatment being studied is a sterile solution that contains two active components: VG801-1 and VG801-2. During the study, participants will receive the treatment in one eye and will be monitored through various eye examinations and tests.

Throughout the study, doctors will perform regular eye examinations using special imaging techniques such as optical coherence tomography to look at the retina in detail. They will also test vision using standard eye charts and measure how well participants can see in different lighting conditions. Additionally, participants will complete a special test using virtual reality to assess their ability to move around in their environment.

The research process

The trial runs in 4 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial eye examination and preparation

    Your eye will be examined to ensure clear ocular media and proper pupil dilation

    You will receive guidance on protecting your eyes from sunlight using a hat, UV-absorbing sunglasses, and sunscreen (SPF 30 minimum)

    Basic health tests including blood work, urine analysis, and pregnancy test will be conducted

  2. Step 2

    Treatment administration

    You will receive VG801 medication as a single injection under the retina (subretinal injection)

    The procedure will be performed on one eye only (study eye)

    The eye chosen for treatment must have vision not better than 20/60

  3. Step 3

    Post-treatment monitoring

    Regular eye examinations will be conducted using specialized equipment

    Tests will include: visual acuity measurements, eye pressure checks, and detailed pictures of your retina

    Samples of blood, tears, and saliva will be collected to monitor treatment effects

    Your ability to see contrast and move in different lighting conditions will be evaluated

    A special virtual reality test will assess your mobility function

  4. Step 4

    Long-term follow-up

    The study continues until December 31, 2026

    Regular monitoring of eye health and vision changes will continue throughout the study period

    Testing will track any changes in retinal structure and function

    Your immune system response to the treatment will be monitored

Who can join the trial?

14 criteria

  • Must provide written consent to participate in the study
  • Must be 6 years of age or older
  • Must have confirmed ABCA4 genetic mutations (tested in a certified laboratory)
  • Must have visible changes in the macula (the central part of the retina) that match with retinal disease
  • Vision in the study eye must be worse than 20/60 (meaning you must see at 20 feet what a person with normal vision sees at 60 feet)
  • Must have detectable outer nuclear layer (a specific layer of the retina) thickness in the macula, measured by special eye imaging called OCT (Optical Coherence Tomography)
  • The study eye must have:
    • Clear eye tissue that light can pass through
    • Ability to dilate properly
    • No allergies to eye dilation drops
    • Ability to focus steadily for eye imaging
    • Must have a negative pregnancy test if applicable
    • Must be willing to protect against sun exposure by using:
      • Hat
      • UV-protective sunglasses
      • Sunscreen (SPF 30 or higher)

Who cannot join the trial?

14 criteria

  • Currently participating in another clinical trial or received an investigational drug within 30 days before this study
  • History of any eye surgery in the study eye within 3 months before the trial
  • Presence of active eye inflammation (swelling or infection in the eye)
  • Uncontrolled glaucoma (high pressure inside the eye)
  • Presence of cataracts (clouding of the natural lens) that could interfere with vision testing
  • History of retinal detachment (separation of the light-sensitive layer of the eye)
  • Pregnant or breastfeeding women
  • Known allergies to the study medication or its components
  • Serious medical conditions that could interfere with study participation
  • Unable to comply with study visits and procedures
  • History of drug or alcohol abuse within the past year
  • Mental conditions that could affect ability to provide informed consent
  • Blood clotting disorders or use of blood thinners that cannot be safely stopped
  • Active eye infection or inflammation
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Investigated drugs

VG801 is a gene therapy product that is administered through subretinal injection (injection under the retina of the eye). This experimental treatment is designed for patients who have retinal dystrophy caused by mutations in both copies of the ABCA4 gene. The therapy aims to treat this inherited eye condition that causes progressive vision loss. The treatment is given directly into the eye to potentially help improve or stabilize vision in affected patients.

What is already known about the treatment

VG801 - An investigational gene therapy medication administered through subretinal injection for the treatment of Biallelic ABCA4 Mutation-Associated Retinal Dystrophy, a genetic eye condition affecting the retina. The drug is currently being evaluated in Phase 1/2 clinical trials to assess its safety profile and preliminary effectiveness in treating retinal dystrophy caused by mutations in the ABCA4 gene. The therapy aims to improve visual acuity and retinal function in affected patients, with its mechanism of action likely involving the delivery of functional copies of the ABCA4 gene to retinal cells, though specific molecular details are still under investigation in the ongoing clinical trials.

Investigated diseases

Biallelic ABCA4 Mutation-Associated Retinal Dystrophy - A genetic eye disorder caused by mutations in both copies of the ABCA4 gene. This condition leads to progressive degeneration of the retina, particularly affecting the light-sensitive cells in the macula area of the eye. The disease typically begins in childhood or young adulthood, causing gradual deterioration of central vision and color perception. People with this condition may experience increasing difficulty with detailed tasks like reading or recognizing faces. The disorder also causes sensitivity to light and delayed adjustment to changes in lighting conditions.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase I/IITrial ID2024-520425-37-00Protocol codeVG801-2022A-EU-37-00Estimated enrolment18 patientsSponsorVeonGen Therapeutics GmbH

sourced from the EU Clinical Trials Register and site verification

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