---
schema_version: "secwatch.filing_event.v1"
accession: "0001171843-25-002741"
form_type: "8-K"
ticker: "APTOF"
cik: "0000882361"
company_name: "Aptose Biosciences Inc."
filed_at: "2025-05-05T23:59:59+00:00"
generated_at: "2026-05-22T21:42:48.253569+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Aptose TUSCANY trial: TUS+VEN+AZA triplet shows CRs, MRD negativity in high-risk AML

## Summary
- Four patients at 40 mg TUS+VEN+AZA: three achieved CR/CRi and MRD-negative, including a TP53-mutated/CK AML patient.
- Three patients at 80 mg TUS+VEN+AZA: all had blast reductions meeting CR/CRi criteria in Cycle 1; no DLTs reported.
- No dose-limiting toxicities across both cohorts; safety profile favorable for the triplet combination.
- Enrollment target of 18–24 patients by mid-late 2025; additional data releases expected.

## SEC filing metadata
- accession: 0001171843-25-002741
- form_type: 8-K
- ticker: APTOF
- cik: 0000882361
- company_name: Aptose Biosciences Inc.
- filed_at: 2025-05-05T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/882361/000117184325002741/0001171843-25-002741-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/882361/000117184325002741/f8k_050225.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001171843-25-002741
- JSON: https://secwatch.observer/filing/0001171843-25-002741.json
- Plain text: https://secwatch.observer/filing/0001171843-25-002741.txt

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