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Study on Soticlestat for Children and Adults with Dravet or Lennox-Gastaut Syndrome Previously Treated with Fenfluramine

Investigational
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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 effects of a medication called soticlestat in individuals with Dravet Syndrome or Lennox-Gastaut Syndrome. These are both rare forms of epilepsy that begin in childhood and are characterized by frequent seizures. The study is designed to evaluate whether soticlestat can help reduce seizures in patients who have previously been treated with another medication called fenfluramine.

The purpose of the study is to assess the effectiveness and safety of soticlestat. Participants in the study will take soticlestat in the form of a tablet, which is taken orally. The study will last for up to 52 weeks, during which time participants will be monitored to see how their seizure frequency changes. Some participants may receive a placebo, which is a tablet that looks like the medication but does not contain the active substance.

Throughout the study, participants will have regular check-ups to monitor their health and any changes in their condition. The goal is to determine if soticlestat can provide a beneficial treatment option for those living with Dravet Syndrome or Lennox-Gastaut Syndrome, especially for those who have already tried fenfluramine. This study is an important step in finding new ways to manage these challenging conditions.

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

    Upon joining the study, eligibility is confirmed based on age (2 years or older) and a documented diagnosis of Dravet Syndrome or Lennox-Gastaut Syndrome. Previous exposure to the medication fenfluramine is also required.

  2. Step 2

    Initial assessment

    An initial assessment is conducted to establish a baseline for seizure frequency. This involves monitoring the number of convulsive seizures for Dravet Syndrome or major motor drop seizures for Lennox-Gastaut Syndrome over a 28-day period.

  3. Step 3

    Medication administration

    The medication soticlestat is administered orally in tablet form. The specific dosage and frequency are determined by the study protocol and the healthcare provider overseeing the trial.

  4. Step 4

    Maintenance period

    During the maintenance period, which lasts for 12 weeks, the primary focus is on observing any changes in seizure frequency compared to the baseline established during the initial assessment.

  5. Step 5

    Evaluation of results

    The primary endpoint of the study is to measure the percent change in seizure frequency over the 12-week maintenance period. This helps determine the efficacy of soticlestat in reducing seizures.

Who can join the trial?

3 criteria

  • The participant can be of any sex and must be at least 2 years old at the time of giving consent to join the study.
  • The participant must have a documented clinical diagnosis of Dravet Syndrome (DS) or Lennox-Gastaut Syndrome (LGS). This means they have been diagnosed with one of these conditions based on typical symptoms and as determined by the doctor in charge.
  • The participant must have been exposed to fenfluramine, which means they are either currently taking it or have used it in the past.

Who cannot join the trial?

6 criteria

  • Patients who have not been diagnosed with Dravet Syndrome or Lennox-Gastaut Syndrome cannot participate. These are specific types of epilepsy.
  • Patients who have not been exposed to fenfluramine cannot participate. Fenfluramine is a medication that may have been used to treat seizures.
  • Patients who are not within the specified age range cannot participate. The age range includes children and young adults.
  • Patients who are not part of the specified clinical trial group cannot participate. This refers to a specific group of patients selected for the study.
  • Patients who are not male or female cannot participate. The study includes both genders.
  • Patients who are not considered part of a vulnerable population cannot participate. Vulnerable populations may include groups like children or those with certain health conditions.
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Investigated drugs

  • Soticlestat

    is a medication being studied for its effectiveness and safety in treating individuals with Dravet Syndrome or Lennox-Gastaut Syndrome. These are types of epilepsy that cause severe seizures. Soticlestat works by targeting specific pathways in the brain to help reduce the frequency and severity of seizures in patients with these conditions.

  • Fenfluramine

    is another medication that participants in the study have been exposed to. It is used to treat seizures associated with Dravet Syndrome. Fenfluramine helps to control seizures by affecting certain chemicals in the brain, which can help improve the quality of life for patients with this condition.

What is already known about the treatment

Soticlestat – Soticlestat is administered orally in the form of tablets. It is currently being studied in clinical trials for its effectiveness in treating Dravet Syndrome and Lennox-Gastaut Syndrome, particularly in patients who have previously been treated with fenfluramine. The medication works by inhibiting an enzyme involved in the production of certain neurotransmitters, which helps to reduce seizure frequency. Soticlestat is classified as an antiepileptic drug, focusing on managing severe forms of epilepsy.

Investigated diseases

  • Dravet Syndrome

    Dravet Syndrome is a rare, severe form of epilepsy that begins in infancy. It is characterized by prolonged seizures that are often triggered by fever or hot temperatures. As the child grows, other types of seizures may develop, including myoclonic and absence seizures. The condition can also lead to developmental delays and behavioral challenges. Over time, individuals may experience difficulties with balance and coordination. The frequency and severity of seizures can vary widely among those affected.

  • Lennox-Gastaut Syndrome

    Lennox-Gastaut Syndrome is a complex, rare form of epilepsy that typically appears in early childhood. It is marked by multiple types of seizures, including tonic and atonic seizures, which can cause sudden falls. Children with this syndrome often experience developmental delays and learning difficulties. The condition is known for its resistance to many standard epilepsy treatments. Seizures can occur frequently and may be difficult to control. Over time, the syndrome can impact cognitive and motor skills.

Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-504104-29-00Protocol codeTAK-935-3004Estimated enrolment15 patientsSponsorTakeda Development Center Americas Inc.

sourced from the EU Clinical Trials Register and site verification

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On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

This service is not affiliated with the European Commission, the EMA, or the official CTIS system. Most information comes from publicly available international clinical-trial registries, supplemented by data from academic sites, national regulators and commercial sponsors. On this site, “treatment” and “therapy” mean a medicine being tested in a clinical trial. Its safety and effectiveness in the use being studied are not yet confirmed, some participants may receive a placebo or a comparator, and taking part does not guarantee a health benefit. The doctor at the research site decides who can take part. This site provides information, not medical advice. Certain content and visual elements on this website have been generated or enhanced using artificial intelligence (AI).