---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-227505"
form_type: "8-K"
ticker: "TSHA"
cik: "0001806310"
company_name: "Taysha Gene Therapies, Inc."
filed_at: "2025-10-02T23:59:59+00:00"
generated_at: "2026-05-17T04:57:20.300049+00:00"
event_type: "regulatory"
sentiment: "positive"
materiality_score: 0.85
calibrated_materiality_score: 0.85
confidence: "high"
source: SEC EDGAR
---

# FDA grants Breakthrough Therapy designation for TSHA-102 in Rett syndrome; pivotal trial protocol finalized

## Summary
- FDA Breakthrough Therapy designation for TSHA-102 based on Part A data from 12 patients showing 100% response rate on milestone gain.
- FDA alignment finalized on REVEAL pivotal trial protocol and SAP; 6-month interim analysis could expedite BLA by at least two quarters.
- Pivotal trial to enroll 15 females aged 6-22 with primary endpoint of milestone gain; enrollment on track for Q4 2025.
- Clinical data also showed dose-dependent improvements on R-MBA and CGI-I; safety generally well-tolerated.

## SEC filing metadata
- accession: 0001193125-25-227505
- form_type: 8-K
- ticker: TSHA
- cik: 0001806310
- company_name: Taysha Gene Therapies, Inc.
- filed_at: 2025-10-02T23:59:59+00:00
- event_type: regulatory
- sentiment: positive
- materiality_score: 0.85
- calibrated_materiality_score: 0.85
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1806310/000119312525227505/0001193125-25-227505-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1806310/000119312525227505/d61846d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-227505
- JSON: https://secwatch.observer/filing/0001193125-25-227505.json
- Plain text: https://secwatch.observer/filing/0001193125-25-227505.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.