Clinical Trial Evaluating the Effects of Ganaxolone in Children With Autism

June 3, 2026 updated by: Antonio Hardan, Stanford University

A Randomized Controlled Trial of Ganaxolone for Children With Autism Spectrum Disorder

The goal of this study is to conduct a randomized, placebo-controlled trial (RCT) of ganaxolone, a neuroactive steroid (NAS), in autistic children and adolescents aged 5 to 17 years old. Ganaxolone is approved and effective for treating seizures in children as young as 2 years old who have CDKL5 deficiency disorder (CDD), a neurogenetic condition associated with developmental delays, seizure disorder, hypotonia, visual impairments, and autistic features. The primary outcome of interest for this trial is irritability on the Aberrant Behavior Checklist (ABC) because it is a common symptom of emotion dysregulation in ASD that impacts quality of life, including mental health, independence, educational opportunities, and integration into the community. The secondary domains of interest for this trial are restricted and repetitive behaviors (RRB), specifically insistence on sameness (IS), a subdomain of RRB characterized by inflexibility and a strong preference for predictable routines and familiar environments. Secondary outcome measures include the IS subscale from the Dimensional Assessment of Repetitive Behaviors (DARB) and subscales of the Clinical Global Impressions Scale for irritability (CGI-IR) and IS (CGI-IS). For participants living within 150 miles of Stanford University, we require participants to attend site visits and attempt EEG and MRI procedures before and after the trial, though we are recruiting nationally and the study can be completed without site vists.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
66

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • California
      • Stanford, California, United States, 94305
        • Stanford University
        • Contact:
        • Contact:
        • Principal Investigator:
          • Antonio Hardan, M.D.

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Child

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. children between the ages of 5 years and 17 years old at enrollment
  2. diagnosis of autism spectrum disorder based on DSM-5 criteria and confirmed with the Autism Diagnostic Inventory - Revised (ADI-R) and Autism Diagnostic Observation Schedule 2nd edition (ADOS-2), or Childhood Autism Rating Scales (CARS)
  3. medical stability based on clinical interview
  4. stable medication regimens (2 weeks, with the exception of fluoxetine for 4 weeks)
  5. stable psychosocial therapies (4 weeks) prior to randomization and no plans to change treatments or intensity during the trial
  6. high rates of irritability defined as the Aberrant Behavior Checklist irritability subscale score > 18
  7. for participants who are sexually active, use of an effective contraceptive (e.g., birth control medications for female participants and condoms for male participants) and no plans for pregnancy throughout the trial
  8. for females, negative urine pregnancy test at baseline
  9. no planned changes in school placement
  10. for participants living within 150 miles of Stanford University, have the ability to attend site visits and attempt EEG and MRI procedures before and after the trial
  11. availability of a reliable informant who interacts with the participant regularly and can reliably complete assessments in English regarding their behaviors throughout the trial
  12. ability to participate in the testing administered in English to the extent that valid standard scores and biological samples can be obtained.

Exclusion Criteria:

  1. any unstable medical condition, such as unstable seizure disorder or heart disease
  2. any lifetime diagnosis of severe psychiatric (e.g., schizophrenia) or neurodegenerative conditions
  3. concomitant use of any neuroactive steroids or corticosteroids.
  4. history of substance abuse or active/planned use of alcohol, opioids, or cannabinoids
  5. recent history or current suicidal ideation assessed with the Columbia-Suicide Severity Rating Scale (C-SSRS) and by clinical interview with the study physician
  6. pregnancy and mothers who are breastfeeding
  7. prior participation in any clinical trial in the 30 days prior to study entry
  8. known intolerance or hypersensitivity to ganaxolone or similar analogs
  9. Concomitant use of medications that are inducers of CYP450 3A4/5, such as rifampin, carbamazepine, phenytoin, phenobarbital, and St. John's wort

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Ganaxolone Arm
Participants receives up to 20 weeks of Ganaxolone treatment
Drug: Ganaxolone (Ztalmy)

Liquid oral suspension of ganaxolone will be administered orally with food three times daily. Dosage will be increased based on tolerability, no more frequently than every 7 days. Dosing will be flexible and occur between 4 to 8 weeks, depending on tolerability and response across each individual patient. Once the maximum tolerated dose is identified, it will be held stable for the remaining 4-8 weeks of the study, for a total of 12 weeks in the randomized, controlled phase.

The titration schedule for patients weighing 28 kg or less is:

Days 1-7: 2 mg/kg x 3 per day Days 8-14: 4 mg/kg x 3 per day Days 15-21: 8 mg/kg x 3 per day Days 22-28: 14 mg/kg x 3 per day Day 29 and thereafter: 21 mg/kg x 3 per day

The titration schedule for patients weighing more than 28 kg is:

Days 1-7: 50 mg/kg x 3 per day Days 8-14: 100 mg/kg x 3 per day Days 15-21: 200 mg/kg x 3 per day Days 22-28: 400 mg/kg x 3 per day Day 29 and thereafter: 600 mg/kg x 3 per day
Placebo Comparator: Placebo Arm
Participants receives up to 20 weeks of placebo treatment
Drug: Placebo
The placebo suspension will contain the same components as the active compound, except for ganaxolone.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
The score on irritability subscale on the Aberrant Behavior Checklist (ABC)
Time Frame: The measures will be completed at screening, baseline, week 2, week 4, week 6, week 8, week 10, week 12, week 14, and week 16.
It is a common symptom of emotion dysregulation in ASD that impacts quality of life, including mental health, independence, educational opportunities, and integration into the community, and ganaxolone may provide more direct benefits or increased tolerability compared to atypical antipsychotics.
The measures will be completed at screening, baseline, week 2, week 4, week 6, week 8, week 10, week 12, week 14, and week 16.

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
The score of Insistence on Sameness subscale of the Dimensional Assessment of Repetitive Behaviors (DARB)
Time Frame: The measures will be completed at screening, baseline, week 2, week 4, week 6, week 8, week 10, week 12, week 14, and week 16.
The DARB is an informant report measure developed and validated following methods outlined by the NIH Patient-Reported Outcome Measurement Information System (PROMIS) framework. Comprehensive, multi-trait, multi-method factor analyses across existing RRB instruments and meta-analysis of factor analyses identified the following eight RRB subdomains: repetitive motor behaviors, insistence on sameness, restricted interests, unusual interests, self-injurious behaviors, sensory sensitivity, obsessions and compulsions, and repetitive language.
The measures will be completed at screening, baseline, week 2, week 4, week 6, week 8, week 10, week 12, week 14, and week 16.
The score on irritability subscale on the Clinical Global Impressions Scale (CGI-IR)
Time Frame: The measures will be completed at screening, baseline, week 2, week 4, week 6, week 8, week 10, week 12, week 14, and week 16.
The study physician will also administer the CGI scale, which includes clinical judgment of the severity of illness and global improvement. The CGI is widely used in psychopharmacological studies and has high sensitivity to measure medication effects.
The measures will be completed at screening, baseline, week 2, week 4, week 6, week 8, week 10, week 12, week 14, and week 16.
The score on Insistence on Sameness subscale on the Clinical Global Impressions Scale(CGI-IS)
Time Frame: These measures will be completed at screening, baseline, week 2, week 4, week 6, week 8, week 10, week 12, week 14, and week 16.
The study physician will also administer the CGI scale, which includes clinical judgment of the severity of illness and global improvement. The CGI is widely used in psychopharmacological studies and has high sensitivity to measure medication effects.
These measures will be completed at screening, baseline, week 2, week 4, week 6, week 8, week 10, week 12, week 14, and week 16.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Stanford University

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
SPARK NS

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Antonio Y. Hardan, M.D., Stanford University School of Medicine-Psychiatry and Behavioral Sciences - Child and Adolescent Psychiatry and Child Development

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 1, 2027

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
January 1, 2030

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
January 1, 2030

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 3, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 3, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 9, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 9, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 3, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • IRB-84478

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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