---
schema_version: "secwatch.filing_event.v1"
accession: "0001171843-25-002427"
form_type: "8-K"
ticker: "APTOF"
cik: "0000882361"
company_name: "Aptose Biosciences Inc."
filed_at: "2025-04-23T23:59:59+00:00"
generated_at: "2026-05-23T08:45:07.842343+00:00"
event_type: "other_material"
sentiment: "negative"
materiality_score: 0.55
calibrated_materiality_score: 0.55
confidence: "high"
source: SEC EDGAR
---

# KPMG not standing for re-appointment as Aptose auditor; material weakness disclosed

## Summary
- KPMG informed Aptose on April 15, 2025 it will not stand for re-appointment for the 2025 annual audit.
- No disagreements on accounting principles or practices between KPMG and Aptose during fiscal years 2024/2023 and through April 15, 2025.
- KPMG identified a material weakness in internal control over financial reporting for complex financial instruments (warrants) as per 2024 10-K.
- Company has initiated process to appoint a new independent registered public accounting firm; KPMG authorized to respond to successor.
- KPMG issued unqualified reports on 2024 and 2023 financial statements; no internal control report due to smaller reporting company status.

## SEC filing metadata
- accession: 0001171843-25-002427
- form_type: 8-K
- ticker: APTOF
- cik: 0000882361
- company_name: Aptose Biosciences Inc.
- filed_at: 2025-04-23T23:59:59+00:00
- event_type: other_material
- sentiment: negative
- materiality_score: 0.55
- calibrated_materiality_score: 0.55
- confidence: high
- sec_items: 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/882361/000117184325002427/0001171843-25-002427-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/882361/000117184325002427/f8k_042325.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001171843-25-002427
- JSON: https://secwatch.observer/filing/0001171843-25-002427.json
- Plain text: https://secwatch.observer/filing/0001171843-25-002427.txt

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