Safety and Efficacy of TSHA-102 in Pediatric Females With Rett Syndrome (REVEAL Pediatric Study)

October 10, 2025 updated by: Taysha Gene Therapies, Inc.

A Multicenter, Open Label, Randomized, Dose-Escalation and Dose-Expansion Study of the Safety, Tolerability, and Efficacy of a Single Intrathecal Administration of TSHA-102, an AAV9-Delivered Gene Therapy, for the Treatment of Pediatric Females With Rett Syndrome

The REVEAL Pediatric Study is a multi-center, Phase 1/2 open-label, dose-escalation and dose-expansion study of TSHA-102, an investigational gene therapy, in pediatric females with Rett Syndrome.

The safety, tolerability, and preliminary efficacy of two dose levels will be evaluated. The study duration is up to 6 years.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not 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 (Actual)

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.
6

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
  • Phase 1

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.
  • Name: Taysha Gene Therapies Medical Information
  • Phone Number: 1-833-489-8742
  • Email: medinfo@tayshagtx.com

Study Locations

  • Canada
    • Quebec
      • Montreal, Quebec, Canada, H3T 1C5
        • CHU Ste-Justine
  • United Kingdom
      • London, United Kingdom
        • Children's Neurosciences, Evelina London Children's Hospital, Guy's and St Thomas' NHS Foundation Trust
  • United States
    • Illinois
      • Chicago, Illinois, United States, 60612
        • Rush University Medical Center & Children's Hospital
    • Minnesota
      • Saint Paul, Minnesota, United States, 55101
        • Gillette Children's Specialty Healthcare
    • Missouri
      • St Louis, Missouri, United States, 63110
        • Washington University, St. Louis

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:

  • Participant has a confirmed diagnosis of classical/typical Rett Syndrome with a documented mutation of the MECP2 gene that results in loss of function.
  • Participant is between ≥5 to ≤8 years of age at the time of consent.
  • Participant must be up to date with all relevant local vaccination requirements, with last vaccination dose received at least 42 days prior to the start of the immunosuppression regimen.
  • Participant's parent/caregiver must be willing to allow participant to receive blood or blood products for the treatment of an AE if medically needed.

Exclusion Criteria:

  • Participant has another neurodevelopmental disorder independent of the MECP2 gene loss of function mutation, or any other genetic syndrome with a progressive course.
  • Participant has a history of brain injury that causes neurological problems.
  • Participant had grossly abnormal psychomotor development in the first 6 months of life.
  • Participant has a diagnosis of atypical Rett syndrome.
  • Participant has an MECP2 mutation that does not cause Rett syndrome.
  • Participant requires non-invasive and invasive ventilatory support.
  • Participant has contraindications for IT administration of TSHA-102 or lumbar puncture procedure, other medical conditions, or contraindications to any medications required for IT administration.
  • Participant has acute or chronic hepatitis B or C infections.

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: Sequential Assignment
  • Masking: None (Open Label)

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.
Experimental: Cohort 1
Dose Level 1
Genetic: TSHA-102
TSHA-102 is a recombinant, non-replicating, self-complementary AAV9 (scAAV9) vector encoding for the miniMECP2 gene. TSHA-102 is a one-time intrathecal (IT) administration.
Experimental: Cohort 2
Dose Level 2
Genetic: TSHA-102
TSHA-102 is a recombinant, non-replicating, self-complementary AAV9 (scAAV9) vector encoding for the miniMECP2 gene. TSHA-102 is a one-time intrathecal (IT) administration.

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
Primary Safety
Time Frame: Baseline through week 52
The incidence of participants experiencing any treatment-emergent adverse events (AEs) and serious adverse events (SAEs)
Baseline through week 52

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
Exploratory Efficacy
Time Frame: Baseline through week 52
Change from baseline in participant's status after TSHA-102 administration as assessed by Clinical Global Impressions Improvement (CGI-I). This 7-point scale (1 = very much improved, 7 = very much worse, etc.) is used by the clinician to assess the participant's overall performance status; higher scores indicate increased severity.
Baseline through week 52
Exploratory Efficacy
Time Frame: Baseline through week 52
Change from baseline in participant's status after TSHA-102 administration as assessed by Revised Motor Behavior Assessment (R-MBA). This 34-item questionnaire with scores of 0-4 will be administered by a cliniciant to indicate frequency of daily activities (behavioral/social, respiratory, motor/physical, etc.) in participants with Rett Syndrome. Higher scores correlate with greater clinical severity of disease.
Baseline through week 52
Exploratory Efficacy
Time Frame: Baseline through week 52
Change from baseline in participant's status after TSHA-102 administration as assessed by Rett Syndrome Behavior Questionnaire (RSBQ). The RSBQ is a 45-item questionnaire and is completed by the participant's Caregiver. Scores (0 = not true, 1 = somewhat/sometimes true, or 2 = very true) are applied to subscales including General Mood, Breathing Problems, Fear/Anxiety, Walking/Standing, etc.; higher scores indicate greater severity.
Baseline through week 52
Exploratory Efficacy
Time Frame: Baseline through week 52
Change from baseline in participant's status after TSHA-102 administration as assessed by Clinical Global Impressions-Severity (CGI-S). This 7-point scale (1 = normal - not I'll all all, 7 = extremely ill, etc.) will be administered by a clinician, based on their experience with patients with the same diagnosis. A higher score indicates greater severity of illness.
Baseline through week 52
Exploratory Efficacy
Time Frame: Baseline through week 52
Change from baseline in quantitative EEG findings with auditory evoked potential and visual evoked potentials (AEP and VEP). This testing will provide a measure of the electrophysiologic responses of the brain to visual and auditory stimuli.
Baseline through week 52
Exploratory Efficacy
Time Frame: Baseline through week 52
The percent change from the steroid-free baseline period in monthly countable seizure frequency (MCSF). This testing will provide a measure of participants with seizure freedom following administration of TSHA-102.
Baseline through week 52

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.
Taysha Gene Therapies, Inc.

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.
  • Study Director: Laura Pisani, M.D., Taysha Gene Therapies

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 (Actual)

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.
December 12, 2023

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.
November 2, 2028

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.
November 2, 2031

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).
November 21, 2023

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.
November 21, 2023

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.
November 30, 2023

Study Record Updates

Last Update Posted (Estimated)

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.
October 15, 2025

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.
October 10, 2025

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.
October 1, 2025

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.
  • TSHA-102-CL-102

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

product manufactured in and exported from the U.S.

Yes

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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