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Study on the Safety and Effectiveness of Timbetasin Acetate Eye Drops for Patients with Neurotrophic Keratopathy

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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 focused on studying a condition called Neurotrophic Keratopathy, which affects the eyes. It is a disease where the cornea, the clear front part of the eye, loses its ability to heal properly due to nerve damage. The study will test a new treatment called RGN-259, which is an eye drop solution containing the active ingredient Timbetasin acetate. This treatment is designed to help the cornea heal by promoting cell growth and repair.

The purpose of the study is to compare the safety and effectiveness of RGN-259 with a placebo, which looks like the real treatment but does not contain the active ingredient. Participants in the study will be randomly assigned to receive either the RGN-259 eye drops or the placebo. The study will last for several weeks, during which participants will use the eye drops and attend regular check-ups to monitor their progress. The main goal is to see if the treatment helps heal the corneal defects associated with Neurotrophic Keratopathy.

Throughout the study, doctors will assess the healing of the cornea using special eye exams and will also check for any side effects. Participants will be asked to report any changes in their symptoms, such as discomfort or vision changes. The study aims to provide valuable information on whether RGN-259 can be a safe and effective treatment option for people with Neurotrophic Keratopathy.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial visit and screening

    The initial visit involves a screening process to confirm eligibility for the study. This includes a review of medical history and a physical examination.

    Documentation or observation of a persistent epithelial defect (PED) in one or both eyes is required. This defect must not have resolved after one week of conventional treatment.

    The study eye must have stage 2 or 3 neurotrophic keratopathy with a defect measuring at least 1 mm in length or width.

    Corneal sensitivity is measured using a Cochet-Bonnet aesthesiometer, and a BCVA score is determined using the ETDRS chart.

  2. Step 2

    Randomization and treatment initiation

    Participants are randomly assigned to receive either the RGN-259 ophthalmic solution or a placebo.

    The solution is administered as eye drops, with a concentration of 0.1%.

    The drops are applied to the affected eye(s) as directed by the study protocol.

  3. Step 3

    Treatment period

    The treatment period involves regular application of the assigned eye drops.

    Participants attend scheduled visits for monitoring and assessment of the eye condition.

    The primary goal is to achieve complete healing of the PED, defined as a 0 mm lesion size, by Day 29.

  4. Step 4

    Follow-up visits

    Follow-up visits occur at specified intervals to assess healing progress and monitor any side effects.

    Corneal fluorescein staining is used to measure lesion size and healing status.

    Visual acuity and corneal sensitivity are evaluated at each visit.

  5. Step 5

    Final assessment

    The final assessment occurs at the end of the study period.

    The primary endpoint is the percentage of participants achieving complete healing of the PED by Day 29.

    Secondary endpoints include changes in lesion size, visual acuity, and symptom severity.

Who can join the trial?

13 criteria

  • Be a male or female of any race, at least 18 years old.
  • Male participants must meet one of the following:
    • If their partner is a woman who can become pregnant, they must use a male condom from the time they sign the consent form until 12 weeks after the last dose of the study product. It's advised that their partner also uses a highly effective birth control method.
    • If their partner cannot become pregnant, no birth control is needed.
    • If the male participant is not fertile, no birth control is needed.
    • Provide written informed consent, which means agreeing in writing to participate in the study after understanding all the details.
    • Be able and willing to follow instructions, including attending all study assessments and visits.
    • At the first visit, have a **Persistent Epithelial Defect (PED)** in one or both eyes. This is a type of eye condition where the surface of the eye has not healed after 1 week of standard treatments like eye drops, antibiotics, or other methods.
    • Have stage 2 or 3 **neurotrophic keratopathy** in at least one eye. This is a condition affecting the cornea, the clear front part of the eye. The defect in the eye must be at least 1 mm in size and confirmed by the study doctor not to be a simple superficial eye issue.
    • Show evidence of decreased corneal sensitivity, which means the eye is less sensitive to touch. This is measured using a tool called the **Cochet-Bonnet aesthesiometer** at the first visit.
    • Have a **BCVA score** of 75 or fewer letter counts in the study eye. BCVA stands for Best Corrected Visual Acuity, which is a measure of the best vision a person can achieve with glasses or contact lenses, using a specific eye chart.
    • Have at least one eye that meets all the criteria mentioned for the eye conditions and measurements.
    • Female participants must not be pregnant or breastfeeding and must meet one of the following:
      • If they can become pregnant, they must use a highly effective birth control method for at least 4 weeks before the first dose of the study product and until 12 weeks after the last dose. They must also have a negative pregnancy test during screening.
      • If they cannot become pregnant, which means they are permanently unable to have children or are post-menopausal, no birth control is needed.

Who cannot join the trial?

7 criteria

  • Patients who have any other eye condition that could interfere with the study results.
  • Patients who have had eye surgery within the last 3 months.
  • Patients who are currently using any other eye medication that could affect the study.
  • Patients who have a history of allergic reactions to the study medication or similar medications.
  • Patients who are pregnant or breastfeeding.
  • Patients who have participated in another clinical trial within the last 30 days.
  • Patients who have any serious health condition that could affect their participation in the study.
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Investigated drugs

RGN-259 Ophthalmic Solution is an eye drop solution being tested for its ability to treat Neurotrophic Keratopathy, a condition that affects the cornea of the eye. This medication is designed to help heal the cornea by promoting cell growth and reducing inflammation, which may improve vision and comfort for patients with this eye condition.

What is already known about the treatment

RGN-259 – This medication is administered as an ophthalmic solution, meaning it is applied directly to the eyes. It is currently being studied in clinical trials for its safety and effectiveness in treating neurotrophic keratopathy, a condition affecting the cornea. RGN-259 works by promoting healing and regeneration of corneal tissues, potentially through its action on cellular growth factors. It is classified as a therapeutic agent for eye disorders, specifically targeting corneal health.

Investigated diseases

Neurotrophic Keratopathy – This is a rare eye condition characterized by reduced or absent corneal sensitivity, leading to a breakdown of the corneal epithelium. The disease progresses through stages, starting with mild epithelial changes and potentially advancing to persistent epithelial defects and corneal ulcers. As the condition worsens, the cornea may become more vulnerable to injury and infection due to the lack of protective reflexes. The progression can result in significant visual impairment if not managed properly. The condition is often associated with damage to the trigeminal nerve, which affects the cornea's ability to heal and respond to stimuli.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-518969-98-00Protocol codeRGN-NK-302Estimated enrolment70 patientsSponsorRegentree LLC

sourced from the EU Clinical Trials Register and site verification

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