ClinicalTrials.gov record NCT05249556

Double-blind, Randomized, Placebo-controlled Trial of Ganaxolone in CDKL5 Deficiency Patients 6 Months to Less Than 2 Years Old

Record copied from ClinicalTrials.gov: Oct 10, 2026AI summaries generated: Aug 22, 2026

Double-blind, Randomized, Placebo-controlled Trial of Adjunctive Ganaxolone in the Treatment of Seizures Associated With Genetically Confirmed Cyclin-dependent Kinase-like 5 (CDKL5) Deficiency Disorder (CDD) in Pediatric Patients From 6 Months to Less Than 2 Years of Age.

StatusNot yet recruitingThe study has been registered but has not started enrolling. Sites and contacts may not be listed yet.
Study typeInterventionalA study in which researchers assign participants to one or more interventions, such as a drug, procedure, device, behavioural programme or other approach, to measure their effects.
PhasePhase 3A later-stage study, usually with more participants, designed to give stronger evidence about how well a treatment works and how safe it is. It often compares the treatment with standard care or a placebo, and results may support an application for approval.
Age6 months old to 2 years old
SexAll
AI summaryWhat this study is about, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

This randomized, triple-masked, placebo-controlled Phase 3 trial evaluates ganaxolone added to standard anti-seizure medication in infants aged 6 months to less than 2 years with genetically confirmed CDKL5 deficiency disorder and refractory seizures. The main comparison is a 12-week double-blind phase of ganaxolone versus placebo. An optional long-term open-label phase follows, during which all participants receive ganaxolone; safety, tolerability, efficacy, and pharmacokinetics are assessed.

What it is studying. The study tests whether adding ganaxolone to a child’s existing anti-seizure medication affects seizure frequency, and it collects safety, tolerability, and pharmacokinetic (drug levels) information compared with placebo.

What the researchers hope to learn. To measure changes in 28-day seizure frequency and seizure-free days; to determine the percentage of participants with ≥50% seizure reduction; to assess seizure changes by type and caregiver-reported improvement; and to collect safety, tolerability, and pharmacokinetic data for ganaxolone in this age group.

What this study is about

The study's own summary, as published on ClinicalTrials.gov. Underlined terms have a short explanation.

This study will assess the efficacy, safety, and tolerability of ganaxolone (GNX) compared with placebo (PBO) as adjunctive therapy to the participant's standard anti-epileptic medication for the treatment of seizures in pediatric patients from 6 months to less than 2 years old with genetically confirmed CDD during a 12-week, DB phase. Pharmacokinetic (PK) assessments and population PK analyses will also be performed during this time. The DB phase will be followed by an optional long-term OL phase at which time all participants will receive GNX as an adjunct to their standard anti-seizure medication. Efficacy, safety and tolerability, and PK assessments will continue to be performed.

Interventions being studied

Being studied in this trial does not mean the treatment or procedure is approved or available for this condition.

Drug
  • Ganaxolone
  • Placebo

Eligibility

The criteria exactly as listed on ClinicalTrials.gov. Only the study team can say whether they apply to you.

Inclusion criteria

  • A diagnosis of CDD, including molecular confirmation of a pathogenic or likely pathogenic CDKL5 variant and refractory seizures (see Inclusion criterion 5).
  • The principal investigator (PI) must review the results of the genetic analysis and confirm that gene mutation is likely to be the cause of the epilepsy syndrome.
  • If the participant has a de novo variant of unknown significance (VUS) in the kinase domain of the CDKL5 gene, parental testing is negative and meets all other inclusion criteria, then the participant can be included.
  • Genetic mutations will be confirmed by the sponsor's chosen central laboratory. In France, genetic mutations may be confirmed by an approved French organization, in compliance with French legislation prior to Screening/Visit 1.
  • Male or female participants aged 6 months to less than 2 years.
  • Parent(s) or LAR willing to give written informed consent, after being properly informed of the nature and risks of the study and prior to engaging in any study-related procedures.
  • Failure to control seizures despite appropriate trial of 1 or more anti-seizure medications at therapeutic doses.
  • Have a history of at least 8 countable seizures during the 28 days prior to screening. Countable seizures will be defined by the following:
  • Seizures with or without impairment of consciousness with a clear motor component, including generalized tonic-clonic, focal to bilateral tonic-clonic, atonic, bilateral clonic, bilateral tonic, focal motor seizures with or without impaired awareness, or infantile spasms. Clusters of infantile spasms/tonic seizures will be counted as a single seizure.
  • Excludes myoclonic, absence or focal aware seizures without a clear motor component.
  • Participants should be on a stable regimen of anti-seizure medications for ≥ 2 weeks prior to the screening visit, without a foreseeable change in dosing for the duration of the DB phase.
  • Concurrent use of adrenocorticotropic hormone (ACTH), prednisone or other glucocorticoids or vigabatrin are permitted.
  • Vagus nerve stimulator (VNS) settings, ketogenic diet, or a modified Atkins diet should be unchanged for 1 month prior to screening and throughout the study (until the end of the DB phase).
  • Use of dietary supplements or herbal preparations is permitted if the participant has been using them consistently for more than 1 month prior to screening and there is no plan on changing the dose for the duration of the DB phase.
  • Parent/caregiver is able and willing to maintain an accurate and complete daily seizure eDiary for the duration of the study.
  • Able and willing to administer IP with food 3 times daily.

Exclusion criteria

  • Have an active CNS infection, demyelinating disease, degenerative neurological disease, or CNS disease deemed progressive as evaluated by brain imaging (magnetic resonance imaging [MRI]).
  • Have any disease or condition (medical or surgical; other than CDKL5 deficiency) at screening that might compromise the hematologic, cardiovascular, pulmonary, renal, gastrointestinal, or hepatic systems; or other conditions that might interfere with the absorption, distribution, metabolism, or excretion of the IP, or would place the participant at increased risk.
  • Has a positive result for tetrahydrocannabinol (THC) test (via urine or plasma drug screen) at the screening visit. Concomitant Epidiolex/Epidyolex (cannabidiol derivative [CBD]) use will be allowed in the DB phase provided the participant has been on a stable dose for at least 1 month prior to screening and is expected to remain on a stable dose without a foreseeable change for the duration of the DB phase.
  • Use of a CBD preparation other than Epidiolex/Epidyolex for 1 month prior to screening.
  • An AST (aspartate aminotransferase/serum glutamic-oxaloacetic transaminase [SGOT]) or ALT (alanine aminotransferase/serum glutamic-pyruvic transaminase [SGPT]) > 3 times the upper limit of normal (ULN) at study entry. If AST or ALT increases > 3 X ULN during the study, the participant should be followed with weekly laboratory repeat testing and continue in study if levels trending down. The participant will be discontinued if levels do not decline to < 3 X ULN.
  • Total bilirubin levels greater than the ULN at study entry. In cases of a documented, stable medical condition (ie, Gilbert's Syndrome) resulting in levels of total bilirubin greater than the ULN, the medical monitor can determine if a protocol exception can be made. If total bilirubin increases to 1.5 x the ULN or more during study, the participant will be discontinued.
  • Participants with significant renal insufficiency, with an estimated glomerular filtration rate (eGFR) < 30 mL/min (calculated using the Cockcroft-Gault formula or Pediatric GFR calculator or Bedside Schwartz).
  • Using St. John's Wort.
  • Have been exposed to any other investigational drug within 30 days or less than 5 half-lives prior to screening.
  • Known allergic reaction or sensitivity to GNX or its excipients.
  • Participating in any other study involving administration of an investigational medication or device.

Study description and what participation involves

The registry record has no detailed description beyond the summary above.

AI summaryWhat participation may involve, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

Participants join a 12‑week, double‑blind randomized phase adding either ganaxolone or placebo to their usual anti‑seizure medicines. Caregivers give the medicine with food three times daily, keep a daily seizure eDiary, and attend clinic visits for efficacy, safety and pharmacokinetic (PK) assessments during the double‑blind phase. Safety monitoring includes laboratory testing and drug screening as required. After the double‑blind phase there is an optional open‑label long‑term phase in which all participants may receive ganaxolone and continue efficacy, safety and PK assessments.

How the study is structured. Phase 3 interventional trial. Participants are randomly assigned to receive either ganaxolone suspension or a matching placebo in a parallel group format, with participants, caregivers, and study staff triple-masked during a 12-week double-blind period. Pharmacokinetic assessments are performed. After the double-blind phase there is an optional long-term open-label phase in which all participants receive ganaxolone as an adjunct to their standard medication.

Questions you could ask

These questions are suggestions for a conversation with the study team or your own clinician, not advice.

  • Some participants receive a placebo. How is that decided, and what happens for placebo-group participants when the study ends?
  • The registry says recruitment has not started. When is it expected to open, and can I register interest now?
  • No sites are listed on the registry yet. Where will the study take place?
  • Which of the eligibility criteria would need to be checked with tests before I could join?

More on CDKL5 deficiency disorder

This trial is also listed on this site under Dravet syndrome.

Clinical trials22 trials listed for CDKL5 deficiency disorderEvery trial the registry lists for CDKL5 deficiency disorder, with recruitment status, phase and sites, updated from ClinicalTrials.gov.See all trials →Research updatesWhat changed in CDKL5 deficiency disorder researchLatest monthly update: September 2026. Includes: EEG background changes. New research summarized each month in plain language, with links to every source paper.Read the latest update →

Important dates

Study start
March 2027 (estimated)
Primary completion
December 2029 (estimated)
Study completion
December 2029 (estimated)
Target enrollment
20 participants (estimated)
Last updated on registry
Aug 5, 2026
Data verified
Oct 10, 2026

Sponsor and research team

The lead sponsor funds and oversees the trial. A pharmaceutical or biotech company sponsor typically means the study is testing that company's drug or device; a hospital, university, or government agency usually indicates investigator-initiated or publicly funded research.

Lead sponsor
Immedica Pharma AB

Central study contact

If you're interested in participating, the central contact can answer general questions about the study — including eligibility requirements and how to find a recruiting site near you. Actual eligibility is determined by the site's medical team.

Participating sites

Study locations have not been posted on ClinicalTrials.gov yet. This study is not yet recruiting, so sites may be added when recruitment begins. The central study contact above may be able to tell you about planned sites.

Terms used on this page · explanations by MedicalUpdates.ai

placebo
A treatment that looks like the study treatment but contains no active ingredient. Some participants receive it instead of the study treatment, usually without knowing which they got.
Pharmacokinetic
How the body absorbs, distributes, breaks down and removes a drug. It is studied by measuring drug levels or related substances at set times after a dose.
refractory
A condition that has not responded to a treatment. 'Relapsed' means it responded and then came back; 'refractory' means it did not respond in the first place.
principal investigator
The doctor or scientist responsible for running the study at a site or overall.
inclusion criteria
The conditions a person must meet to be considered for the study, for example a confirmed diagnosis, an age range or a test result.
sponsor
The organisation or person that initiates the study and has authority over it. The sponsor may be a company, hospital, university, government agency or individual, and is not necessarily the organisation that funds the study.
prior to Screening
The checks done before enrolment to see whether a person qualifies, such as tests, scans or a review of medical history.
LAR
A person who is legally allowed to make decisions, including consent to research, on behalf of someone who cannot consent for themselves.
written informed consent
The process of explaining a study, including its risks and what participation involves, so that a person can decide freely whether to take part. Consent is usually documented in writing, and a participant can choose to leave the study later.
stable regimen
A dose that has not changed for a defined period before the study starts. Studies may require this so that background treatment is relatively stable when study measurements begin.
prednisone
Steroid medicines, such as prednisone, that reduce inflammation. Studies often require a stable dose at entry or measure whether the study treatment allows the dose to be reduced.
magnetic resonance imaging
A scan that uses magnets and radio waves, not X-rays, to make detailed pictures of the inside of the body. Some implants and metal objects mean a person cannot have one.
upper limit of normal
The highest value of a blood test that a laboratory considers normal. Criteria such as '≤ 3 × ULN' mean the result must be no more than three times that value.
estimated glomerular filtration rate
A blood-test estimate of how well the kidneys are filtering. Lower numbers mean reduced kidney function; many studies set a minimum value.
Cockcroft-Gault
A measure of kidney function, calculated from a blood creatinine level together with age, weight and sex.
investigational drug
A treatment that is being tested and has not been approved for this use. It may be approved for a different condition. Being studied does not mean it works or is available outside the study.
5 half-lives
The time it takes for the amount of a drug in the body to fall by half. 'Five half-lives' is often used as the point at which a previous drug has essentially left the body.
Exclusion Criteria
The conditions that rule a person out even if they meet the inclusion criteria, for example other illnesses, certain medicines or pregnancy.

The study record on this page is reproduced from ClinicalTrials.gov, a database of the U.S. National Library of Medicine, where it was submitted by the study sponsor. MedicalUpdates.ai does not own this content, is not affiliated with or endorsed by ClinicalTrials.gov, NIH, or the U.S. Government, and does not verify the record. Plain-language notes, the glossary and the questions above are added by this site; text in the boxes marked "AI summary" was written by an AI model and may contain errors. Registry records change over time. Check the original record for the current version and discuss eligibility or participation with a qualified healthcare professional.

← Back to clinical trials