secwatch.observer — SEC 8-K summary
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Issuer:     Aptose Biosciences Inc. (APTOF)
CIK:        0000882361
Form:       8-K
Filed at:   2026-06-15T12:00:25+00:00
Accession:  0001171843-26-004119
Event type: other_material
Sentiment:  positive
Materiality: 0.85
Item codes: 7.01, 9.01
LLM model:  deepseek-v4-flash:cloud@v2

Aptose TUSCANY trial shows 86.2% CRc in newly diagnosed AML; all TP53-mut respond
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- Composite complete response (CRc) rate 86.2% in evaluable patients across all TUS+VEN+AZA dose groups.
- MRD negativity rate 86.4% in patients achieving CR/CRh; 62.5% overall MRD negative among all dosed.
- 160mg cohort: 100% CR in 4 TP53-mutated patients with complex karyotype; 76.9% CRc across 13 patients.
- No treatment-related deaths, QT prolongation, CPK elevations, or differentiation syndrome observed.
- 19 patients remain on treatment; 6 proceeded to stem cell transplantation.

Source:
  EDGAR index:    https://www.sec.gov/Archives/edgar/data/882361/000117184326004119/0001171843-26-004119-index.htm
  Primary doc:    https://www.sec.gov/Archives/edgar/data/882361/000117184326004119/f8k_061326.htm
  HTML page:      https://secwatch.observer/filing/0001171843-26-004119

License: Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer