Aptose to Hold KOL Event and Corporate Update Thursday, June 2nd

Clinical Updates for HM43239 and Luxeptinib

Poster Presentation for HM43239 is Scheduled for June 10th at
EHA2022 Hybrid Congress

SAN DIEGO and TORONTO, May 12, 2022 (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 the company management team, along with guest key opinion leaders (KOLs), will provide an update for the investment community on Thursday, June 2^nd at 4:30 PM. The event will include an up-to-date review of clinical data available for Aptose’s two investigational products under development for hematologic malignancies: HM43239, an oral, myeloid kinome inhibitor in an international Phase 1/2 trial in patients with relapsed or refractory acute myeloid leukemia (AML); and luxeptinib, an oral, dual lymphoid and myeloid kinome inhibitor in a Phase 1 a/b trial in patients with relapsed or refractory B-cell malignancies, and in a separate Phase 1 a/b trial in patients with relapsed or refractory AML or high risk myelodysplastic syndrome (MDS).

Aptose Corporate Update Details

Date & Time: Thursday, June 2nd, 4:30 PM ET

Participant Webcast Link: here

The slides will be available on Aptose’s website here and a recording of the presentation will be archived shortly after the conclusion of the event.

Separately, preclinical data for HM43239 also will be presented in a poster at the EHA2022 Hybrid Congress, to be held in Vienna, Austria June 9 - 17, 2022 and virtually. The accepted abstract is being published today, Thursday, May 12^th at 16:00 CEST / 10:00 AM ET.

About Aptose

Aptose Biosciences is a clinical-stage biotechnology company committed to developing personalized therapies addressing unmet medical needs in oncology, with an initial focus on hematology. The Company's small molecule cancer therapeutics pipeline includes products designed to provide single agent efficacy and to enhance the efficacy of other anti-cancer therapies and regimens without overlapping toxicities. The Company has two clinical-stage investigational products under development for hematologic malignancies: HM43239, an oral, myeloid kinome inhibitor in an international Phase 1/2 trial in patients with relapsed or refractory acute myeloid leukemia (AML); and luxeptinib, an oral, dual lymphoid and myeloid kinome inhibitor in a Phase 1 a/b trial in patients with relapsed or refractory B-cell malignancies who have failed or are intolerant to standard therapies, and in a separate Phase 1 a/b trial in patients with relapsed or refractory AML or high risk myelodysplastic syndrome (MDS). For more information, please visit www.aptose.com.

Released May 12, 2022