Taysha Gene Therapies Achieves Milestones in TSHA-102 Pivotal Gene Therapy Program for Rett Syndrome
DALLAS, January 6, 2026 — Taysha Gene Therapies, Inc. (Nasdaq: TSHA), a biotechnology company dedicated to developing gene therapies for serious central nervous system diseases, has made significant advancements in its TSHA-102 program for Rett syndrome. The company recently dosed its first patient in the REVEAL pivotal trial and reached a pivotal alignment with the FDA regarding the inclusion of safety data in its forthcoming Biologics License Application (BLA).
Key Developments in the TSHA-102 Program
- First patient dosed in the REVEAL pivotal trial in Q4 2025.
- Enrollment is ongoing across multiple clinical trial sites.
- The trial involves 15 females, aged 6 to <22 years, receiving a single high-dose administration of TSHA-102 (1x1015 total vector genomes).
- FDA alignment has been reached for including ≥3 months of safety data from the ASPIRE trial in the BLA submission.
- Completion of dosing in both the REVEAL and ASPIRE trials expected by Q2 2026.
FDA Collaboration and Trial Structure
According to Sean P. Nolan, Chairman and CEO of Taysha, "Dosing the first patient in our REVEAL pivotal trial last quarter represents a significant milestone. Our collaboration with the FDA continues to be constructive, ensuring that we can streamline the BLA submission process." The FDA's recent approval confirms that data from three patients aged 2 to <4 years from the ASPIRE trial will support a broad label for patients ≥2 years with Rett syndrome.
The REVEAL trial is structured as a single-arm, open-label study aimed at assessing response rates through the achievement of developmental milestones in patients.
Anticipated Milestones and Market Opportunity
Completion of dosing across the REVEAL pivotal trial is slated for the second quarter of 2026, with longer-term safety and efficacy data updates expected in the first half of the same year. Taysha estimates that Rett syndrome affects approximately 15,000 to 20,000 individuals across the U.S., EU, and U.K., highlighting a significant market opportunity.
“With compelling clinical data from the REVEAL trial, we are poised to redefine treatment for this high-need condition,” added Nolan.
About TSHA-102
TSHA-102 is an innovative intrathecally delivered AAV9 gene therapy designed as a one-time treatment for Rett syndrome. By addressing the underlying genetic cause of the disorder, TSHA-102 seeks to deliver functional MECP2 protein to neurons while avoiding overexpression risks through advanced miRNA-Responsive Auto-Regulatory Element (miRARE) technology.
This investigational therapy has received several FDA designations including Breakthrough Therapy and Orphan Drug status, showcasing its potential in a field with limited treatment options.
Understanding Rett Syndrome
Rett syndrome is a rare neurodevelopmental disorder primarily affecting females and caused by mutations in the MECP2 gene. It is characterized by severe developmental delays and loss of motor skills, among other debilitating symptoms. Without approved therapies that specifically target its genetic cause, Rett syndrome remains a condition with high unmet medical needs.
Company Overview: Taysha Gene Therapies
Taysha Gene Therapies (Nasdaq: TSHA) is at the forefront of developing AAV-based gene therapies. With a strong emphasis on clinical development, Taysha aims to introduce transformative treatments for severe monogenic diseases. The company's dedicated team possesses extensive experience in gene therapy, aiming to ensure rapid translation of innovative therapies from the laboratory to patient care.
For more information, visit www.tayshagtx.com.
Forward-Looking Statements: This article contains forward-looking statements that may involve risks and uncertainties. Actual results may differ from those projected, including, but not limited to, the timing and results of clinical trials involving TSHA-102 and other product candidates from Taysha.