---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-087390"
form_type: "8-K"
ticker: "APTOF"
cik: "0000882361"
company_name: "Aptose Biosciences Inc."
filed_at: "2025-04-21T23:59:59+00:00"
generated_at: "2026-05-23T10:48:49.193633+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.65
calibrated_materiality_score: 0.65
confidence: "high"
source: SEC EDGAR
---

# KPMG notifies Aptose it will not stand for re-appointment as auditor; material weakness disclosed

## Summary
- KPMG informed Aptose on Apr 15, 2025 it will not seek reappointment for the 2025 annual audit.
- KPMG will continue reviewing interim financials through first two fiscal quarters of 2025.
- No disagreements between Aptose and KPMG on accounting principles or audit scope.
- A previously disclosed material weakness in internal control over financial reporting (warrants) was noted.
- Aptose has initiated a process to select a new independent registered public accounting firm.

## SEC filing metadata
- accession: 0001193125-25-087390
- form_type: 8-K
- ticker: APTOF
- cik: 0000882361
- company_name: Aptose Biosciences Inc.
- filed_at: 2025-04-21T23:59:59+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.65
- calibrated_materiality_score: 0.65
- confidence: high
- sec_items: 4.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/882361/000119312525087390/0001193125-25-087390-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/882361/000119312525087390/d198638d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-087390
- JSON: https://secwatch.observer/filing/0001193125-25-087390.json
- Plain text: https://secwatch.observer/filing/0001193125-25-087390.txt

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