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Safety and Efficacy of Sodium Phenylbutyrate Eye Drops in Children with Myopia

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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 studying paediatric myopia, which means short-sightedness in children, a condition that makes distant objects look blurry. The study is testing T10430, an eye drop treatment made with sodium phenylbutyrate, and comparing it with placebo. The purpose of the study is to see whether the eye drops are safe for the eyes and whether they may help slow the worsening of myopia over time.

Children in the study receive eye drops in a single-dose container and are followed over several months. During the study, eye health, vision, eye comfort, and possible side effects are checked at different visits and by phone calls. The study also looks at changes in the length of the eye, which can increase as myopia gets worse, as well as other eye findings such as redness, eye surface irritation, eye pressure, and the condition of the cornea, which is the clear front part of the eye.

The trial compares T10430 with placebo to learn more about safety and possible benefit. The treatment is given to both eyes, and the study follows participants for about one year.

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

    <b>study treatment begins</b>

    You start the trial by using t10430 eye drops or placebo eye drops. The placebo is a preservative-free eye solution that does not contain the active medicine.

    The active medicine is sodium phenylbutyrate, given as eye drops in a single-dose container. The source data does not state the exact dose, so the amount is listed as not specified.

    The drops are used in the eyes. The source data does not state the exact frequency or the exact daily schedule, so these details are not specified.

    The treatment period continues through the trial, which is planned to run from july 2026 to november 2027.

  2. Step 2

    <b>1-month visit</b>

    At about 1 month after starting treatment, you have follow-up checks in both eyes.

    Your eye health is checked for eye-related side effects, including any serious problems, any problems linked to the study medicine, and any side effects that lead to stopping the study medicine early.

    Your vision is measured, including best-corrected visual acuity, which means the clearest vision you can achieve with glasses or contact lenses.

    Your eyes are examined for redness, surface staining of the eye, and tear film breakup time, which is the time it takes for tears to dry on the eye surface.

    Your eye pressure is measured.

    The thickness of your cornea, which is the clear front part of the eye, is measured.

    The number and shape of cells on the back surface of the cornea are checked.

    Your eye symptoms are recorded during the day and immediately after putting in the eye drops.

    Your eye comfort and how well you tolerate the treatment are assessed.

    You or your parent or legal guardian gives a rating of overall satisfaction with the single-dose container.

  3. Step 3

    <b>6-month visit</b>

    At about 6 months after starting treatment, you return for another full set of checks in both eyes.

    Your eye health is checked for eye-related side effects, including serious problems, problems linked to the study medicine, and problems that lead to stopping the study medicine early.

    The study measures changes in axial length, which is the length of the eye, and cycloplegic spherical equivalent refractive error, which is a measure of how much the eye needs correction for clear distance vision after the focusing muscles are relaxed with eye drops.

    Your best-corrected visual acuity is measured again.

    Your eyes are checked for redness, corneal fluorescein staining, conjunctival fluorescein staining, and tear film breakup time. Fluorescein is a dye used to show small areas of damage on the eye surface.

    Your eye pressure is measured again.

    The thickness of your cornea is measured again.

    Further eye measurements are taken, including corneal shape, front chamber depth of the eye, and lens thickness.

    The number and shape of cells on the back surface of the cornea are checked again.

    Your eye symptoms are recorded during the day and immediately after putting in the eye drops.

    Your eye comfort and how well you tolerate the treatment are assessed.

    You or your parent or legal guardian again rates overall satisfaction with the single-dose container.

  4. Step 4

    <b>12-month visit</b>

    At about 12 months after starting treatment, you have the final planned checks in both eyes.

    Your eye health is checked for eye-related side effects, including serious problems, problems linked to the study medicine, and problems that lead to stopping the study medicine early.

    The study measures changes in axial length and cycloplegic spherical equivalent refractive error again.

    Your best-corrected visual acuity is measured again.

    Your eyes are checked for redness, corneal fluorescein staining, conjunctival fluorescein staining, and tear film breakup time.

    Your eye pressure is measured again.

    The thickness of your cornea is measured again.

    Further eye measurements are taken, including corneal shape, front chamber depth, and lens thickness.

    The number and shape of cells on the back surface of the cornea are checked again.

    Your eye symptoms are recorded during the day and immediately after putting in the eye drops.

    Your eye comfort and how well you tolerate the treatment are assessed.

    You or your parent or legal guardian again rates overall satisfaction with the single-dose container.

Who can join the trial?

6 criteria

  • Informed consent must be signed and dated. This means the parent or legal guardian must agree in writing for the child to take part.
  • The participant must be a boy or girl who is at least 6 years old but younger than 12 years old.
  • Each eye must have a spherical equivalent refractive error between -1.00 diopter and -6.00 diopters. This is a measure of how nearsighted the eye is; a more negative number means more nearsightedness.
  • This eye measurement must be checked with cycloplegic autorefraction. This means a special eye test is done after drops are used to temporarily relax the focusing muscles of the eyes.
  • The eye pressure must be less than 21 mmHg in each eye. mmHg is a unit used to measure pressure inside the eye.
  • The child must be able to see distant objects with vision of at least 0.1 LogMAR or better in each eye, which is the same as about 20/25 vision or better on a standard eye chart.

Who cannot join the trial?

22 criteria

  • Known intolerance to eye drops, meaning the child cannot tolerate eye drop treatment.
  • Myopia caused by something other than eye shape, such as refractive myopia or secondary myopia. Refractive myopia means short-sightedness caused by how the eye focuses light, and secondary myopia means short-sightedness caused by another condition or factor.
  • Abnormal eye shape or structure, such as keratoconus, keratoglobus, lenticonus, or spherophakia. These are conditions where parts of the eye have an unusual shape.
  • Known or suspected hypersensitivity to T10430 or to study eye tests or medicines, such as fluorescein or a cycloplegic agent. Hypersensitivity means an allergic-type reaction.
  • A current or past body-wide condition, such as a connective tissue disease or allergy, that could make the study unsafe or affect the results, based on the investigator’s judgment.
  • Pregnancy in a participant who has started menstruation, confirmed by a positive urine pregnancy test.
  • A sexually active adolescent who can become pregnant and is not willing to use preventive measures, meaning methods used to avoid pregnancy.
  • The participant or legal guardian cannot understand the study steps or cannot give informed consent, meaning permission after understanding the study.
  • The participant or legal guardian is unlikely to follow the study plan, such as not wanting to attend visits, answer phone calls, or complete the diary, or having daily life circumstances that would make participation difficult.
  • Taking part in another clinical study at the same time.
  • Taking part in this study within 4 weeks after finishing another clinical study not related to myopia, or within 5 half-lives of the previous product if that is longer. A half-life is the time it takes for half of a medicine to leave the body.
  • Astigmatism greater than 1.50 diopters in either eye, measured after using eye drops that relax focusing. Astigmatism means the eye does not focus light evenly.
  • Already being randomly assigned to this study before.
  • Being a family member of the study site staff or of the company running the study.
  • Using, having used, or planning to use a treatment that is not allowed in the study, or changing an allowed treatment in a way that is not allowed.
  • Anisometropia of 1.50 diopters or more, meaning the two eyes have a large difference in focusing power.
  • Current or past amblyopia, also called “lazy eye,” or manifest strabismus, including intermittent tropia. Strabismus means the eyes do not line up properly.
  • Current or past glaucoma.
  • Current or past significant or severe damage to the cornea, the clear front surface of the eye.
  • Problems in the front part of the eye, such as an iris malformation or cataract. An iris malformation means the colored part of the eye did not form normally, and a cataract means clouding of the eye’s natural lens.
  • Problems in the back part of the eye or the retina, such as dystrophies. Dystrophies are inherited conditions that cause body tissue to weaken or change over time.
  • A past or current disease or syndrome that can lead to severe myopia, such as Marfan syndrome, Stickler syndrome, or retinopathy of prematurity. A syndrome is a group of medical problems that happen together.
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Investigated drugs

Sodium phenylbutyrate is being studied as eye drops. In this trial, it is given directly into the eyes to see if it is safe and if it may help slow the worsening of near-sightedness in children. The study is mainly looking at whether the eye drops are well tolerated and whether they can help control myopia progression.

What is already known about the treatment

Sodium phenylbutyrate - Sodium phenylbutyrate is given as eye drops in a single-dose container and is placed directly into the eye. It is an established medicine in medical literature, mainly known for other uses, but in this trial it is being studied for eye care and safety. Its main known medical use is in the treatment of certain inherited problems of the body’s waste removal system, and it belongs to the class of ammonia-lowering agents and small-molecule chemical chaperones. At the molecular level, it can help cells handle stress better and may affect how certain genes are turned on or off, which is why it is being explored for possible benefits in slowing myopia progression.

Investigated diseases

Paediatric myopia - Paediatric myopia is a condition in which a child’s eye focuses light in front of the retina, making distant objects look blurry. It usually develops during childhood and often becomes more noticeable as the eye grows. The condition can progress over time as the eyeball lengthens, which increases the degree of nearsightedness. Vision for distant objects may gradually worsen while near vision is often less affected.
Trial detailsLast updated 7 Oct 2026
Age0-17PhasePhase IITrial ID2025-521563-13-01Protocol codeLT10430-201Estimated enrolment206 patientsSponsorLaboratoires Thea

sourced from the EU Clinical Trials Register and site verification

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