Aptose Biosciences Inc. announced that the Company will provide a clinical update on Monday, October 30, 2023 at 8:30 AM Eastern Time, in conjunction with 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. The webcast event will include a comprehensive review of up-to-date clinical data for Aptose's lead compound tuspetinib and will feature Naval Daver, MD, Professor, Director Leukemia Research Alliance Program, Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX. Dr. Daver is the lead investigator on Aptose's APTIVATE trial and is recognized for significant achievements in the development of novel AML treatments, including several combination therapies.

Tuspetinib (TUS), a once-daily oral tablet, is a precision targeted myeloid kinase inhibitor that suppresses a select handful of kinases known to drive the proliferation of acute myeloid leukemia (AML) but avoids other kinases that can compromise safety. Tuspetinib as a single agent was well-tolerated and highly active among relapsed or refractory (R/R) AML patients with a diversity of adverse genotypes and delivered a 42% CR/CRh across evaluable venetoclax (VEN) naïve patients at the 80mg daily RP2D. Tuspetinib also is being studied in combination with venetoclax (VEN) in the APTIVATE international Phase 1/2 expansion trial in R/R AML patients.

The TUS/VEN doublet has been well tolerated and achieved multiple responses in patients who previously failed venetoclax (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, tuspetinib targets venetoclax resistance mechanisms that may re-sensitize Prior-VEN failure patients to venetoclax.