Investigating a gene therapy for Rett syndrome in adult females

An Open-label Phase 1/2/3 Study Consisting of a Phase 1/2 Safety and Dose-escalation and Phase 3 Dose-expansion Study to Evaluate Safety and Efficacy of a Single Intrathecal Administration of TSHA-102, an AAV9-Delivered Gene Therapy in Females With Rett Syndrome

Phase 3 Interventional Taysha Gene Therapies, Inc. · NCT05606614

This study is testing a new gene therapy to see if it can help adult women with Rett syndrome feel better and improve their symptoms.

Quick facts

PhasePhase 3
Study typeInterventional
Enrollment15 (estimated)
Ages6 Years to 21 Years
SexFemale
SponsorTaysha Gene Therapies, Inc. Industry-sponsored
Locations6 sites (La Jolla, California and 5 other locations)
Trial IDNCT05606614 on ClinicalTrials.gov

What this trial studies

The REVEAL Adult Study is a multi-center, Phase 1/2 open-label, dose-escalation investigation of TSHA-102, an experimental gene therapy aimed at treating adult females diagnosed with Rett syndrome. This study will assess the safety, tolerability, and preliminary efficacy of two different dose levels of TSHA-102 over an estimated duration of up to 63 months. Participants will receive the treatment and undergo monitoring to evaluate their response and any adverse effects.

Who should consider this trial

Good fit: Ideal candidates for this study are adult females with a clinical diagnosis of classical Rett syndrome and a documented pathogenic mutation in the MECP2 gene.

Not a fit: Patients with other neurodevelopmental disorders or atypical Rett syndrome may not benefit from this study.

Why it matters

Potential benefit: If successful, this gene therapy could significantly improve the quality of life for patients with Rett syndrome by addressing the underlying genetic cause.

How similar studies have performed: While gene therapy for Rett syndrome is a novel approach, similar studies targeting genetic causes of neurodevelopmental disorders have shown promise.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Females between the ages of 12 and \<22 in Part A (closed) and females between the ages of 6 and \<22 in Part B (pivotal cohort).
* Participant has a clinical diagnosis of classic/typical Rett syndrome with a documented pathogenic mutation of the methyl-CpG-binding protein 2 (MECP2) gene that results in loss of gene function.
* Participants must be willing to receive blood or blood products for the treatment of an AE if medically needed.
* Participants and parent/caregiver must agree to reside within easy access to the study site prior to the baseline visit and at least 3 months after TSHA-102 treatment

Exclusion Criteria:

* Participant has another neurodevelopmental disorder independent of the MECP2 loss-of-function mutation, or any other genetic syndrome with a progressive course.
* Participant has a history of brain injury that causes neurological problems or had grossly abnormal psychomotor development in the first 6 months of life.
* Participant has a diagnosis of atypical Rett syndrome or a MECP2 gene mutation that does not cause Rett syndrome.
* Participant requires invasive ventilatory support.

Note: Other protocol defined inclusion/exclusion criteria may apply

Where this trial is running

La Jolla, California and 5 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Rett SyndromeNeurodevelopmental disorderRettMECP2AAV9Typical Rett SyndromeClassic Rett SyndromeRTT
Last reviewed 2026-06-10 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.