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Study on the Long-Term Safety of GTX-102 for Patients 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 the long-term safety and effectiveness of a treatment called GTX-102 for individuals with Angelman Syndrome. Angelman Syndrome is a genetic disorder that affects the nervous system and can cause developmental delays, speech difficulties, and balance issues. The treatment being tested, GTX-102, is a special type of medication known as an antisense oligonucleotide, which is designed to target specific genetic material in the body. It is administered as a solution for injection directly into the spinal fluid, a method known as intrathecal use.

The purpose of this study is to evaluate how safe GTX-102 is for patients over a long period. Participants in the trial will receive the treatment and be monitored for any side effects or changes in their condition. The study will also involve the use of Elliotts B Solution, a buffered intrathecal electrolyte/dextrose injection, which contains substances like calcium chloride, glucose, and sodium chloride. This solution is used to help deliver the treatment safely.

Throughout the study, participants will undergo regular assessments to track their progress and any changes in their symptoms. These assessments will include evaluations of cognitive abilities, communication skills, and motor functions. The study aims to provide valuable information on the long-term use of GTX-102 in managing Angelman Syndrome, helping to determine its potential benefits and any risks associated with its use.

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

    Joining the study

    Participation begins after prior involvement in a clinical trial with GTX-102. Completion of the loading phase in the previous study is required.

    The screening visit must occur within 6 months of the last visit in the prior GTX-102 study.

  2. Step 2

    Medication administration

    The medication used in this trial is GTX-102, also known as ELLIOTTS B SOLUTION, which is a buffered intrathecal electrolyte/dextrose injection.

    The medication is administered as a solution for injection through intrathecal use, which means it is injected into the space around the spinal cord.

  3. Step 3

    Safety monitoring

    The main objective is to evaluate the long-term safety profile of GTX-102 in patients with Angelman Syndrome.

    Monitoring includes tracking any treatment-emergent adverse events (AEs) and serious adverse events (SAEs), their frequency, severity, and relationship to the investigational product throughout the study.

  4. Step 4

    Efficacy assessment

    Secondary assessments involve measuring changes from the start of the long-term extension (LTE) phase and pretreatment in various developmental scores.

    These scores include Bayley-4 Cognition, Receptive Communication, Expressive Communication, Gross Motor, and Fine Motor raw scores.

  5. Step 5

    Trial duration

    The estimated end date for the trial is October 2, 2029.

    The estimated start date for recruitment is October 2, 2024.

Who can join the trial?

3 criteria

  • The patient must have a signed informed consent from their parent(s) or legal guardian(s). This means that the parent or guardian agrees to let the patient participate in the study after understanding all the details.
  • The patient must have previously participated in a clinical trial with **GTX-102** and completed a specific part of that trial called the Loading phase. The patient must also have approval from the Ultragenyx Medical Monitor. The first visit for this study must happen within 6 months after the last visit in the previous GTX-102 study.
  • Females who can have children and are sexually active must use highly effective birth control methods or choose not to have sexual intercourse from the time they agree to join the study until at least 6 months after the last dose of **GTX-102**. Males can participate if they agree to not have sexual intercourse or use acceptable birth control methods during the study and for at least 3 months after the last dose of **GTX-102**.

Who cannot join the trial?

10 criteria

  • Patients who have a history of severe allergic reactions to the study medication.
  • Patients who are currently participating in another clinical trial.
  • Patients who have a medical condition that the study doctors believe would make it unsafe for them to participate.
  • Patients who are unable to follow the study procedures or instructions.
  • Patients who are pregnant or breastfeeding.
  • Patients who have a history of substance abuse that could interfere with the study.
  • Patients who have a serious mental health condition that could affect their ability to participate.
  • Patients who have had a major surgery within the last 3 months.
  • Patients who have an infection that requires treatment with antibiotics.
  • Patients who have a history of certain heart conditions.
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Investigated drugs

GTX-102 is a medication being studied for its safety and effectiveness in patients with Angelman Syndrome. This trial aims to understand how well patients tolerate the medication over a long period and to gather information on any potential side effects. Angelman Syndrome is a genetic disorder that affects the nervous system, and this medication is being tested to see if it can help manage symptoms associated with the condition.

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 under investigation in clinical trials for its safety and efficacy in treating Angelman Syndrome, a rare genetic disorder. The medication is designed to target the underlying genetic cause of the syndrome by modulating gene expression at the molecular level. GTX-102 is classified as a gene therapy, aiming to improve neurological function and quality of life for affected individuals.

Investigated diseases

Angelman Syndrome – Angelman Syndrome is a rare genetic disorder that primarily affects the nervous system. It is characterized by developmental delays, intellectual disability, severe speech impairment, 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 seizures and sleep disturbances. The progression of the disorder involves persistent developmental challenges and requires ongoing support.
Trial detailsLast updated 7 Oct 2026
Age0-17PhasePhase IIITrial ID2024-510917-14-00Protocol codeGTX-102-CL302Estimated enrolment98 patientsSponsorUltragenyx Pharmaceutical Inc.

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