---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-129849"
form_type: "8-K/A"
ticker: "TSHA"
cik: "0001806310"
company_name: "Taysha Gene Therapies, Inc."
filed_at: "2025-05-29T23:59:59+00:00"
generated_at: "2026-05-20T06:15:02.275417+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.8
calibrated_materiality_score: 0.8
confidence: "high"
source: SEC EDGAR
---

# Taysha reports FDA-aligned pivotal trial for TSHA-102; 100% of Part A patients gained milestones

## Summary
- FDA aligned on single-arm pivotal Part B trial (N=15) for TSHA-102 in Rett syndrome patients ≥6 years; primary endpoint: developmental milestone gain/regain.
- Part A: 100% (10/10) of patients aged 6-21 gained ≥1 milestone; high dose showed faster and deeper effects vs low dose.
- Natural history data (~1,100 patients) showed ~0% likelihood of milestone gain/regain after age 6, supporting trial design.
- No treatment-related SAEs or DLTs; all related AEs mild-to-moderate across 12 patients.
- Company suspended $100M ATM prospectus; Sales Agreement remains in effect; new prospectus required for future sales.

## SEC filing metadata
- accession: 0001193125-25-129849
- form_type: 8-K/A
- ticker: TSHA
- cik: 0001806310
- company_name: Taysha Gene Therapies, Inc.
- filed_at: 2025-05-29T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.8
- calibrated_materiality_score: 0.8
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1806310/000119312525129849/0001193125-25-129849-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1806310/000119312525129849/d907074d8ka.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-129849
- JSON: https://secwatch.observer/filing/0001193125-25-129849.json
- Plain text: https://secwatch.observer/filing/0001193125-25-129849.txt

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