Taysha Gene Therapies Inc

Taysha Gene Therapies is a clinical-stage biotechnology company that develops adeno-associated virus (AAV)-based gene therapies for severe monogenic diseases of the central nervous system. It has no product revenue.

Its lead program, TSHA-102, is a self-complementary, intrathecally delivered AAV9 gene transfer therapy for Rett syndrome. It is designed as a one-time treatment that delivers a functional form of the MECP2 gene. It uses Taysha's miRNA-Responsive Auto-Regulatory Element (miRARE) technology to regulate MECP2 expression cell by cell without risk of overexpression.

TSHA-102 holds several regulatory designations:
- FDA: Breakthrough Therapy, Regenerative Medicine Advanced Therapy, Fast Track, Orphan Drug and Rare Pediatric Disease.
- European Commission: Orphan Drug.
- UK MHRA: Innovative Licensing and Access Pathway.

The therapy is being evaluated in the REVEAL Phase 1/2 trial, the REVEAL pivotal trial and the ASPIRE trial. The company has completed a BLA-enabling commercial-scale manufacturing (PPQ) campaign and is preparing for a potential BLA submission. Rett syndrome caused by MECP2 mutations is estimated to affect 15,000 to 20,000 patients in the U.S., EU and U.K., and there are no approved disease-modifying therapies that address its genetic root cause.

Taysha plans to nominate a second CNS gene therapy candidate in the first half of 2027 to broaden its CNS genetic medicine portfolio. Updated Nov 12, 2026