---
schema_version: "secwatch.filing_event.v1"
accession: "0001818794-26-000009"
form_type: "8-K"
ticker: "DYN"
cik: "0001818794"
company_name: "Dyne Therapeutics, Inc."
filed_at: "2026-09-29T20:10:18+00:00"
generated_at: "2026-10-12T13:48:54.142763+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.6
calibrated_materiality_score: 0.6
confidence: "high"
source: SEC EDGAR
---

# Dyne ACHIEVE 1-year data: vHOT fell 3.2 sec vs placebo's 0.4 sec rise; REC topline due Q1 2027

## Summary
- Pooled dose group (N=25-26) drawn from 3.4 mg/kg Q4W, 5.4 mg/kg Q8W and 6.8 mg/kg Q8W MAD cohorts; mean baseline vHOT 8.2 sec fell 3.2 sec at 6 months vs a 0.4 sec rise on placebo (N=14).
- At 12 months the pooled group improved 5xSTS by 1.2 sec and 10MWR by 0.3 sec; QMT total and hand grip each rose 4.8% predicted, diverging from the matched natural history cohort on 10MWR and QMT.
- MDHI patient-reported total score improved 25.2% from baseline at 12 months vs an unmatched END-DM1 cohort (N=410); safety data as of April 20, 2026 showed no related serious TEAEs.
- ACHIEVE REC (71 participants) mean baseline vHOT is 8.3 sec and remains blinded; topline expected Q1 2027 to support a BLA for U.S. Accelerated Approval in Q3 2027.
- Phase 3 HARMONIA, with 12-month change in 5xSTS as the primary confirmatory endpoint, is recruiting at over 35 active global sites.

## SEC filing metadata
- accession: 0001818794-26-000009
- form_type: 8-K
- ticker: DYN
- cik: 0001818794
- company_name: Dyne Therapeutics, Inc.
- filed_at: 2026-09-29T20:10:18+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.6
- calibrated_materiality_score: 0.6
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1818794/000181879426000009/0001818794-26-000009-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1818794/000181879426000009/dyn-20260929.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001818794-26-000009
- JSON: https://secwatch.observer/filing/0001818794-26-000009.json
- Plain text: https://secwatch.observer/filing/0001818794-26-000009.txt

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