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Study on the Effects of GTX-102 for Children with Angelman Syndrome

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 clinical trial is focused on studying Angelman Syndrome, a rare genetic disorder that affects the nervous system and causes developmental disabilities and neurological problems. The study will investigate the effects of a treatment called GTX-102, which is a solution for injection designed to improve cognitive function in children with Angelman Syndrome. The treatment involves a special type of medication known as an antisense oligonucleotide, which is a small piece of DNA or RNA that can bind to specific molecules in the body to alter their function.

The purpose of the study is to evaluate how well GTX-102 works in improving cognitive abilities in children with Angelman Syndrome. Participants in the study will receive the treatment through an injection into the space around the spinal cord, a method known as intrathecal use. The study will also use a solution called GTX/UX Diluent and Flush Solution to help administer the treatment. This solution contains several common substances, including sodium chloride and potassium chloride, which are often used in medical settings to maintain the balance of fluids and electrolytes in the body.

Throughout the study, participants will be monitored for changes in their cognitive abilities and any potential side effects. The study will last for a period of time, during which participants will have regular visits to assess their progress. The goal is to determine if GTX-102 can provide a meaningful improvement in the lives of children with Angelman Syndrome by enhancing their cognitive function and overall quality of life.

The research process

The trial runs in 7 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial assessment

    The study begins with an initial assessment to confirm eligibility. This includes verifying a diagnosis of Angelman Syndrome and ensuring the participant meets all criteria, such as age and ability to ambulate independently or with assistance.

  2. Step 2

    Consent and preparation

    Informed consent is obtained from the parent(s) or legal guardian(s). Participants must be willing to comply with all study procedures, including scheduled visits and drug administration.

  3. Step 3

    Baseline evaluation

    A baseline evaluation is conducted to assess cognitive function and other relevant health metrics. This serves as a reference point for measuring changes throughout the study.

  4. Step 4

    Treatment administration

    The investigational drug, GTX-102, is administered via intrathecal use, which means it is injected into the space around the spinal cord. The exact dosage and frequency are determined by the study protocol.

  5. Step 5

    Ongoing monitoring

    Participants are monitored regularly to assess the effects of the treatment. This includes measuring changes in cognitive function and other health indicators at specified intervals.

  6. Step 6

    Final assessment

    At the end of the study period, a final assessment is conducted to evaluate the overall impact of the treatment. This includes a comparison of cognitive function and other health metrics to the baseline evaluation.

  7. Step 7

    Follow-up

    Participants are followed up for a specified period after the final dose to monitor any long-term effects of the treatment.

Who can join the trial?

7 criteria

  • Signed informed consent from parent(s) or legal guardian(s).
  • Males and females aged 4 to less than 18 years old at the time of informed consent.
  • Confirmed diagnosis of Angelman Syndrome (AS) with genetic confirmation of full maternal UBE3A gene deletion causing AS in the region of 15q11.2 q13. This means a specific part of the genetic material is missing, which is known to cause AS.
  • Able to walk independently or with help at the Screening Visit. Children who mainly use a wheelchair for moving around are not eligible.
  • Platelet count, prothrombin time / international normalized ratio, and partial thromboplastin time must be within 1.5 times the normal limits at the Screening Visit. These are blood tests to check how well your blood clots.
  • Willing and able to attend scheduled visits, follow the drug administration plan, undergo laboratory tests, and participate in all study procedures, including a procedure called LP (lumbar puncture) and tolerate anesthesia without needing a breathing tube.
  • From the time of informed consent through to at least 6 months after the final dose of GTX-102, females who can have children and are sexually active must use highly effective birth control or abstain from sex. Males must agree to abstain from heterosexual intercourse or use acceptable birth control methods during the study and for at least 3 months after the final dose of GTX-102.

Who cannot join the trial?

8 criteria

  • Participants who do not have a diagnosis of Angelman Syndrome cannot join the study. Angelman Syndrome is a genetic disorder that affects the nervous system.
  • Participants who are not within the specified age range for the study cannot participate. The study is open to certain age groups only.
  • Participants who are not able to follow the study procedures or instructions cannot take part in the study.
  • Participants who have other medical conditions that might interfere with the study results cannot join the study.
  • Participants who are currently taking medications that might affect the study outcomes cannot participate.
  • Participants who have a history of allergic reactions to the study medication or similar medications cannot join the study.
  • Participants who are pregnant or breastfeeding cannot take part in the study.
  • Participants who are involved in another clinical trial at the same time cannot participate in this study.
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Investigated drugs

GTX-102 is a medication being studied for its potential to improve cognitive function in children with Angelman Syndrome. Angelman Syndrome is a genetic disorder that affects the nervous system, leading to developmental delays and neurological problems. The trial aims to determine how effective and safe GTX-102 is for these patients.

What is already known about the treatment

GTX-102 – GTX-102 is administered as an intrathecal injection, meaning it is delivered directly into the spinal canal. It is currently being studied in clinical trials, specifically a Phase 3 trial, to assess its safety and effectiveness in treating Angelman Syndrome, a rare genetic disorder. The main therapeutic indication for GTX-102 is to improve cognitive function in individuals with Angelman Syndrome. At the molecular level, GTX-102 works by targeting specific genetic pathways to enhance neurological function. It is classified pharmacologically as a gene therapy agent.

Investigated diseases

Angelman Syndrome – Angelman Syndrome is a rare genetic disorder that primarily affects the nervous system. It is characterized by developmental delays, lack of speech, seizures, and problems with movement and balance. Individuals with this condition often exhibit a happy demeanor, frequent smiling, and laughter. The syndrome is caused by a loss of function of the UBE3A gene on chromosome 15. Symptoms typically become noticeable in early childhood, and while they can vary, they generally include severe intellectual disability and motor coordination issues. The progression of the syndrome involves persistent challenges in communication and mobility throughout life.
Trial detailsLast updated 7 Oct 2026
Age0-17PhasePhase IIITrial ID2024-512600-19-00Protocol codeGTX-102-CL301Estimated enrolment120 patientsSponsorUltragenyx Pharmaceutical Inc.

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