---
schema_version: "secwatch.filing_event.v1"
accession: "0001171843-25-005463"
form_type: "8-K"
ticker: "APTOF"
cik: "0000882361"
company_name: "Aptose Biosciences Inc."
filed_at: "2025-08-18T23:59:59+00:00"
generated_at: "2026-05-17T12:15:17.026617+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "high"
source: SEC EDGAR
---

# Aptose reports tuspetinib triplet achieves 90% CR/CRh in newly diagnosed AML Phase 1/2 trial

## Summary
- 100% CR/CRh at 80 mg and 120 mg TUS doses in combination with VEN+AZA (9/10 subjects).
- 78% MRD-negativity among responders (7/9); 100% MRD-negativity in TP53, RAS, FLT3-ITD subgroups.
- No dose-limiting toxicities or prolonged myelosuppression; enrollment advancing to 160 mg cohort.
- Single non-responder was at 40 mg dose with subtherapeutic TUS exposure; all other patients remain on study.

## SEC filing metadata
- accession: 0001171843-25-005463
- form_type: 8-K
- ticker: APTOF
- cik: 0000882361
- company_name: Aptose Biosciences Inc.
- filed_at: 2025-08-18T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: high
- sec_items: 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/882361/000117184325005463/0001171843-25-005463-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/882361/000117184325005463/f8k_081825.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001171843-25-005463
- JSON: https://secwatch.observer/filing/0001171843-25-005463.json
- Plain text: https://secwatch.observer/filing/0001171843-25-005463.txt

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