Aptose Clinical and Preclinical Data to be Presented at European School of Haematology (ESH) 6th International Conference

Company to Hold Clinical Update Webcast; Details Forthcoming

SAN DIEGO and TORONTO, Oct. 16, 2023 (GLOBE NEWSWIRE) -- Aptose Biosciences Inc. (“Aptose” or the “Company”) (NASDAQ: APTO, TSX: APS), a clinical-stage precision oncology company developing highly differentiated oral kinase inhibitors to treat hematologic malignancies, today announced that two abstracts on tuspetinib, Aptose’s Phase 1/2 myeloid kinase inhibitor in development for acute myeloid leukemia (AML), have been accepted for poster presentations at the European School of Haematology (ESH) 6th International Conference: Acute Myeloid Leukemia "Molecular and Translational": Advances in Biology and Treatment, being held October 29-31, 2023, in Estoril, Portugal.

Aptose is planning to hold a clinical update webcast on October 30, 2023, to provide additional up-to-date data on tuspetinib. Details will be forthcoming.

The posters accepted for presentation are listed below and can be viewed beginning October 29, 2023, on site at the ESH poster exhibit hall and online on the Aptose website here.

Poster Presentations

Tuspetinib Myeloid Kinase Inhibitor Safety and Efficacy as Monotherapy and Combined with Venetoclax in Phase 1/2 Trial of Patients with Relapsed or Refractory (R/R) Acute Myeloid Leukemia (AML)

• Abstract Summary: Tuspetinib (TUS) is a potent once daily oral myeloid kinase inhibitor of SYK, mutated and unmutated forms of FLT3, JAK1/2, RSK, mutant forms of KIT, and TAK1-TAB1 kinases that mediate dysregulated cellular proliferation in acute myeloid leukemia (AML). As a single agent, TUS was well-tolerated and highly active across four dose levels among diverse AML genotypes and delivered a 42% CR/CRh across evaluable venetoclax (VEN) naïve patients at the 80mg daily RP2D. In the ongoing APTIVATE clinical study, tuspetinib is being evaluated clinically as monotherapy (TUS) and in combination with venetoclax (TUS/VEN) in a global Phase 1/2 trial of patients with R/R AML. The TUS/VEN doublet also has been well tolerated and has achieved multiple responses to date in patients who previously failed VEN (Prior-VEN failure AML), including Prior-VEN failure patients who also previously failed FLT3 inhibitors, all of whom represent emerging populations of high unmet medical need. Notably, TUS targets VEN resistance mechanisms and appears to re-sensitize Prior-VEN failure patients to VEN.