---
schema_version: "secwatch.filing_event.v1"
accession: "0001599901-25-000091"
form_type: "8-K"
ticker: null
cik: "0001599901"
company_name: "Avidity Biosciences, Inc."
filed_at: "2025-04-29T23:59:59+00:00"
generated_at: "2026-05-23T03:49:56.171166+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.3
calibrated_materiality_score: 0.3
confidence: "high"
source: SEC EDGAR
---

# Avidity Biosciences appoints Deloitte as auditor; dismisses BDO effective after Q1 2025 filing

## Summary
- Deloitte & Touche appointed as independent registered public accounting firm for FY2025, effective after Q1 2025 10-Q filing.
- BDO dismissed on April 25, 2025; its 2023-2024 audit opinions were unqualified with no disagreements.
- 2023 material weakness in ITGC segregation of duties was fully remediated and BDO issued unqualified opinion on 2024 ICFR.
- Company did not consult Deloitte on any accounting or audit matters prior to appointment.

## SEC filing metadata
- accession: 0001599901-25-000091
- form_type: 8-K
- cik: 0001599901
- company_name: Avidity Biosciences, Inc.
- filed_at: 2025-04-29T23:59:59+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.3
- calibrated_materiality_score: 0.3
- confidence: high
- sec_items: 4.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1599901/000159990125000091/0001599901-25-000091-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1599901/000159990125000091/rna-20250425.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001599901-25-000091
- JSON: https://secwatch.observer/filing/0001599901-25-000091.json
- Plain text: https://secwatch.observer/filing/0001599901-25-000091.txt

## Key facts
- Auditor Changes
  Avidity Biosciences, Inc. dismissed BDO USA, P.C. as its auditor.
  - Action: dismissal
  - Auditor: BDO USA, P.C.
  - Successor: Deloitte & Touche LLP
  source text: the Audit Committee approved the dismissal of BDO USA, P.C. ("BDO") on April 25, 2025 as the Company's independent registered public accounting firm
  evidence_url: https://www.sec.gov/Archives/edgar/data/1599901/000159990125000091/0001599901-25-000091-index.htm
- Auditor Changes
  Avidity Biosciences, Inc. engaged Deloitte & Touche LLP as its auditor.
  - Action: engagement
  - Auditor: Deloitte & Touche LLP
  source text: the Audit Committee approved the appointment of Deloitte & Touche LLP ("Deloitte") as the Company's independent registered public accounting firm for the year ending December 31, 2025
  evidence_url: https://www.sec.gov/Archives/edgar/data/1599901/000159990125000091/0001599901-25-000091-index.htm

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