In short
There are currently 2 clinical trials investigating new treatments for CDKL5 deficiency disorder, a rare genetic condition that causes seizures and developmental delays. These studies are taking place across several European countries and are testing medications that may help reduce seizure frequency when used alongside existing treatments. Both trials focus on the long-term safety and effectiveness of investigational drugs that aim to improve quality of life for children and adults living with this condition.
Clinical trial locations
- Austria
- Belgium
- Germany
- Ireland
- Italy
- Netherlands
- Poland
- Portugal
- Spain
Study on Long-Term Safety of Soticlestat for Adults and Children with Developmental Epileptic Encephalopathies
This trial is studying the long-term safety of a medication called soticlestat (also known as TAK-935) for people with developmental epileptic encephalopathies, including CDKL5 deficiency disorder. The study follows patients who have already participated in earlier studies of this medication.
Who can participate: Patients who have previously taken part in a soticlestat study and either completed it or received at least 10 weeks of treatment are eligible. They must not have experienced serious side effects that would make continuing the medication unsafe. The study doctor must believe the patient could benefit from taking soticlestat. The trial is open to people of any gender and includes individuals who might need extra care or protection.
Who cannot participate: People with other types of epilepsy beyond the specific developmental epileptic encephalopathies being studied cannot join. Patients must be using at least one anti-seizure therapy, which could be medication, a vagal nerve stimulator, or special diets like the ketogenic or modified Atkins diet. Those who are unwilling or unable to follow study procedures, or who have medical conditions that would make participation unsafe, are excluded.
What the trial involves: Participants will take soticlestat as an oral tablet alongside their current seizure treatments. The maximum daily dose is 600 milligrams, and the treatment period can last up to 96 weeks. Throughout the study, researchers will monitor patients for any side effects, changes in behavior, seizure frequency, and other health indicators. Regular assessments will include checking vital signs, body weight, and laboratory tests. The study aims to gather information about how well soticlestat can be tolerated when used over a longer period.
Study medication: Soticlestat works by targeting specific enzymes in the brain to help reduce seizure frequency. It is being tested as an additional treatment to be used alongside other therapies patients are already taking for their epilepsy. The medication is still investigational, meaning it is being researched and is not yet widely available.
Study on the Effectiveness and Safety of Fenfluramine Hydrochloride for Patients with CDKL5 Deficiency Disorder
This trial is testing a treatment called fenfluramine hydrochloride (also known as ZX008) specifically for people with CDKL5 deficiency disorder. The study aims to see if this medication can help reduce seizures and improve overall condition in both children and adults.
Who can participate: Patients must have a confirmed mutation in the CDKL5 gene and a clinical diagnosis that includes epilepsy starting in the first year of life, along with motor and developmental delays. Participants can be between 1 and 35 years old, though younger children can only join after a safety review for older patients is completed. They must have tried at least two different seizure treatments without achieving full control, and currently be using at least one treatment such as medication, the ketogenic diet, or devices like vagus nerve stimulation. All treatments must be stable before starting the study. At the beginning of the trial, patients must experience at least four countable motor seizures per week that last about 3 seconds or longer. Both patient and caregiver must be able to follow study requirements, including keeping a diary and attending visits.
Who cannot participate: Those without a confirmed CDKL5 deficiency disorder diagnosis, people outside the specified age range, or anyone unable to follow study procedures are excluded. Patients with other medical conditions that might interfere with the study, those currently in another clinical trial, or those who have recently changed their medication cannot join. Pregnant or breastfeeding women, people with a history of drug or alcohol abuse, those allergic to the study medication, and individuals with serious heart conditions are also excluded.
What the trial involves: The study has two parts. In the first phase, participants are randomly assigned to receive either ZX008 or a placebo in a double-blind design, meaning neither participants nor researchers know who receives the actual medication. After completing this phase, all participants can enter an open-label extension where everyone receives ZX008. The study lasts 74 weeks in total. During a titration period, the medication dosage is adjusted to reach a target of 0.8 mg/kg per day given as an oral solution. Once the target dose is reached, patients continue at this fixed dose during the maintenance period. Throughout the trial, seizure frequency and overall health are closely monitored through regular follow-up visits.
Study medication: Fenfluramine hydrochloride is being evaluated as an additional therapy used alongside other treatments. It works by modulating neurotransmitter activity in the brain, which may help reduce seizures and improve neurological function. The medication is classified as an anticonvulsant and is being tested to confirm its benefits and safety profile for long-term use in this specific disorder.
Summary
Two clinical trials are currently recruiting patients with CDKL5 deficiency disorder across multiple European countries. The fenfluramine hydrochloride study has a broader geographic reach, taking place in eight countries including Germany, Belgium, Ireland, Italy, Portugal, Spain, Netherlands, and Austria. The soticlestat study is being conducted in Spain, Poland, and Portugal.
Both trials share a common approach of testing investigational drugs as add-on treatments to existing seizure therapies rather than as standalone treatments. They focus on long-term safety monitoring and require patients to maintain stable baseline treatments before joining. The fenfluramine study is designed to measure effectiveness against a placebo, while the soticlestat study is an extension trial for patients who have already participated in earlier research.
These studies offer hope for families affected by this rare genetic condition by investigating new treatment options that may help reduce seizure frequency and improve quality of life. The trials demonstrate ongoing commitment to finding better therapies for developmental epileptic encephalopathies, with both medications working through different mechanisms to target brain activity and seizure control.
