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Study of ultevursen treatment in patients with retinitis pigmentosa caused by mutations in USH2A gene exon 13

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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 people with Retinitis Pigmentosa, a genetic eye disease that causes progressive vision loss. The condition being studied specifically affects people who have mutations in a part of the USH2A gene called exon 13. The study will test a medication called ultevursen (also known as QR-421a), which is given as an injection into the eye. The purpose is to evaluate how well this treatment works and how safe it is over a period of 24 months.

During the study, participants will receive either ultevursen injections or undergo a sham procedure (which mimics the injection but without actually inserting anything into the eye). The medication will be given as a solution that is injected directly into the eye through a procedure called intravitreal injection. Some participants will receive higher doses of the medication while others will receive lower doses.

The study will track changes in participants' vision and eye structure using various tests that measure the health of the retina (the light-sensitive layer at the back of the eye). Researchers will particularly focus on measuring a specific layer of the retina called the ellipsoid zone, which is typically affected in people with this condition. They will also monitor participants' vision in different lighting conditions and their ability to see details and colors.

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 treatment phase

    You will be assigned to receive either ultevursen injections or a sham procedure (a procedure that mimics the injection without actual medication).

    The treatment will be administered through intravitreal injection (an injection into the eye).

    The study is double-masked, which means neither you nor your doctor will know which treatment you are receiving.

  2. Step 2

    Treatment period

    The treatment will continue for 24 months (2 years).

    During this time, your eyes will be regularly monitored to assess how well the treatment is working.

    The study will measure changes in your vision using several tests:

    - Examination of the retina using special imaging (SD-OCT)

    - Tests of your visual field and retinal sensitivity

    - Vision tests under normal and low light conditions

    - Tests of your ability to see in dark conditions

  3. Step 3

    Monitoring and assessments

    Regular eye examinations will check for any changes in your vision or eye health.

    Blood samples will be taken to measure the levels of ultevursen in your body.

    Your body will be checked for any immune response to the medication.

    If you are 13 years or older, you will complete questionnaires about your vision-related experiences.

  4. Step 4

    Safety monitoring

    Throughout the study, you will be monitored for any side effects or adverse reactions.

    Both eye-related and general health effects will be recorded and evaluated.

    The study team will regularly assess your overall health and safety.

Who can join the trial?

13 criteria

  • Age requirement: Must be either an adult (18 years or older) who can give informed consent, or a minor (12-17 years) with parent/guardian permission
  • Vision requirements:
    • Must have similar vision quality in both eyes (vision test scores between eyes must not differ by more than 10 letters)
    • Must have minimum vision of 55 letters on vision test in both eyes
    • Must have clear eye media (the transparent parts of the eye) and ability to dilate pupils adequately
    • Must have specific measurable retinal characteristics as determined by special eye imaging
    • Genetic requirements:
      • Must have confirmed genetic changes in the USH2A gene
      • Must have either Usher syndrome type 2 or non-syndromic Retinitis Pigmentosa (types of inherited eye conditions)
      • For women who can become pregnant and fertile men:
        • Must use effective birth control methods during the study
        • Women must not be pregnant or breastfeeding
        • Compliance requirements:
          • Must be willing to follow study instructions
          • Must be able to attend all required study visits
          • Must be able to complete all study assessments
          • Must be able to undergo eye imaging tests with reliable results

Who cannot join the trial?

13 criteria

  • Age below 18 years or above 75 years
  • Pregnancy or breastfeeding women
  • Previous participation in gene therapy clinical trials
  • Active eye infections or inflammation
  • History of other significant eye diseases besides Retinitis Pigmentosa
  • Major surgery in the past 3 months
  • Participation in other clinical trials within the last 30 days
  • Severe systemic diseases (serious conditions affecting the whole body)
  • Known allergies to medications used in the study
  • Unable to provide informed consent
  • Mental conditions that could interfere with study compliance
  • Drug or alcohol dependency
  • Contraindications to required study procedures
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Investigated drugs

Ultevursen is an investigational medication designed to treat retinitis pigmentosa, a genetic eye condition caused by mutations in the USH2A gene. The medication is being studied for its potential to help patients with specific genetic mutations in exon 13 of this gene. This treatment aims to slow down or stop the progression of vision loss in affected individuals. The trial also includes a sham (placebo) control, which is not an active treatment but is used to compare the effectiveness of Ultevursen.

What is already known about the treatment

Ultevursen - An investigational antisense oligonucleotide medication administered through intravitreal injection directly into the eye, specifically developed for treating Retinitis Pigmentosa caused by mutations in the USH2A gene's exon 13. This targeted therapy works at the molecular level by modifying RNA processing to potentially restore the function of the USH2A protein, which is essential for proper retinal cell function. Currently undergoing clinical trials to evaluate its efficacy and safety, Ultevursen represents a novel approach in the treatment of inherited retinal diseases and belongs to the class of RNA-targeting therapeutics.

Investigated diseases

Retinitis Pigmentosa - A genetic eye disease that gradually destroys the retina, which is the light-sensitive tissue at the back of the eye. The condition typically begins with decreased night vision and loss of peripheral (side) vision. Over time, it causes the breakdown of photoreceptor cells called rods and cones in the retina. The disease usually progresses symmetrically, affecting both eyes similarly. People with this condition first notice difficulty seeing in dim light and gradually lose their peripheral vision, developing "tunnel vision." The loss of vision is usually gradual, occurring over several years or decades.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IITrial ID2024-515199-10-01Protocol codeSB-421a-006Estimated enrolment81 patientsSponsorLaboratoires Thea

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