---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-141739"
form_type: "8-K"
ticker: "DYN"
cik: "0001818794"
company_name: "Dyne Therapeutics, Inc."
filed_at: "2025-06-17T23:59:59+00:00"
generated_at: "2026-05-19T05:01:39.646110+00:00"
event_type: "regulatory"
sentiment: "positive"
materiality_score: 0.85
calibrated_materiality_score: 0.85
confidence: "high"
source: SEC EDGAR
---

# FDA Breakthrough Therapy Designation for DYNE-101 in DM1; revised Accelerated Approval path

## Summary
- FDA granted Breakthrough Therapy Designation to DYNE-101 for myotonic dystrophy type 1 (DM1).
- Revised ACHIEVE trial protocol submitted with vHOT as primary endpoint (60 patients, 3:1 randomization).
- Enrollment in Registrational Expansion Cohort expected to complete Q4 2025; data mid-2026, submission late 2026.
- New 12-month data: sustained vHOT improvement of 3.3 sec at 6 months; QMT strength improved 10% at 6 mo, 20% at 12 mo.
- Cash $677.5M as of March 31, 2025; runway extended into Q4 2026.

## SEC filing metadata
- accession: 0001193125-25-141739
- form_type: 8-K
- ticker: DYN
- cik: 0001818794
- company_name: Dyne Therapeutics, Inc.
- filed_at: 2025-06-17T23:59:59+00:00
- event_type: regulatory
- sentiment: positive
- materiality_score: 0.85
- calibrated_materiality_score: 0.85
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1818794/000119312525141739/0001193125-25-141739-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1818794/000119312525141739/d47489d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-141739
- JSON: https://secwatch.observer/filing/0001193125-25-141739.json
- Plain text: https://secwatch.observer/filing/0001193125-25-141739.txt

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