Safety and Preliminary Efficacy of TSHA-102 Gene Therapy in Pediatric Females Aged >2 to <4 Years With Rett Syndrome

NCT07480564 | Recruiting Phase 3 DMC FDA Drug

• 1 other identifier: TSHA-102-CL-201
• Study Type: interventional
• Target: 3
• Locations: 1 country
• Sites: 1

Brief Summary

The primary objectives of this study are to evaluate the safety, tolerability and preliminary efficacy of a single intrathecal (IT) dose of TSHA-102 in pediatric females with typical Rett syndrome.

Conditions

Rett Syndrome

Keywords

Neurodevelopmental Disorders; Rett; MECP2; AAV9; Typical Rett Syndrome; Classic Rett Syndrome; RTT; Rett Disorder; Retts; MECP2-Related Disorder; Gene Therapy; Intrathecal Administration; Genetic Diseases, X-Linked; Nervous System Diseases; Developmental Regression; TSHA-102; miRARE; Self-complementary Vector; Neurologic Manifestations; Intellectual Disability; Pathologic Process; X-Linked Intellectual Disability; Congenital, Hereditary, and Neonatal Diseases and Abnormalities

Outcome Measures

Primary Outcomes (1)

• Primary Safety

  Safety and Tolerability of TSHA-102 Proportions of participants experiencing any treatment-emergent adverse events (AEs) and serious adverse events (SAEs)

  Baseline through Week 25

Study Arms (1)

Treatment

EXPERIMENTAL

Participants receive a single intrathecal (IT) administration of TSHA-102 at 1.0 × 10¹⁵ total vector genomes (vg) adjusted for the participant's brain volume.

Genetic: TSHA-102

Interventions

TSHA-102 GENETIC

TSHA-102 is a recombinant, non-replicating, self-complementary adeno-associated virus serotype 9 (scAAV9) vector encoding for the miniMECP2 gene. TSHA-102 is a one-time intrathecal (IT) administration.

Treatment

Eligibility Criteria

• Age: 2 Years - 3 Years
• Sex: female
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• Pediatric females between the ages of 2 and less than 4 years old.
• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• Taysha Gene Therapies, Inc.: lead

Study Sites (1)

Boston Children's Hospital

Boston, Massachusetts, 02115, United States

RECRUITING

MeSH Terms

Conditions

Rett Syndrome; Neurodevelopmental Disorders; Genetic Diseases, X-Linked; Nervous System Diseases; Neurologic Manifestations; Intellectual Disability; Pathologic Processes; X-Linked Intellectual Disability; Congenital, Hereditary, and Neonatal Diseases and Abnormalities

Condition Hierarchy (Ancestors)

Neurobehavioral Manifestations; Genetic Diseases, Inborn; Heredodegenerative Disorders, Nervous System; Mental Disorders; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Medical Monitor, M.D.

  Taysha Gene Therapies

  STUDY DIRECTOR

Central Study Contacts

Taysha Gene Therapies Medical Information

CONTACT

833-489-8742; medinfo@tayshagtx.com

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: NA
• Masking: NONE
• Masking Details: Blinded central raters
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: Participants will receive a single dose of TSHA-102 at a dose level of 1.0×10¹⁵ total vector genomes (vg) adjusted for the participant's brain volume. TSHA-102 will be administered via lumbar puncture (LP). The study comprises a screening period, TSHA-102 administration, a primary safety analysis period through 25 weeks post TSHA-102 administration, and an extended follow-up observation period through 5 years post TSHA-102 administration.

Study Record Dates

• First Submitted: March 13, 2026
• First Posted: March 18, 2026
• Study Start: May 8, 2026
• Primary Completion (Estimated): June 1, 2031
• Study Completion (Estimated): June 1, 2031
• Last Updated: May 22, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)