Ms. Susan Pietropaolo reports

APTOSE TO REPORT FOURTH QUARTER AND YEAR END 2023 FINANCIAL RESULTS AND PROVIDE CORPORATE UPDATE ON TUESDAY, MARCH 26, 2024

Aptose Biosciences Inc. will release financial results for the fourth quarter and year ended Dec. 31, 2023, on Tuesday, March 26, 2024, after the close of the market, and provide a corporate update.

Conference call and webcast

Date:  Tuesday, March 26, 2024

Time:  5 p.m. ET

The webcast will be audio only.

You may register to participate in the question-and-answer session*.

* Analysts interested in participating in the question-and-answer session will preregister for the event to receive the dial-in numbers and a unique PIN, which are required to listen to the conference call. They also will have the option to take advantage of a call-me button, and the system will automatically dial out to connect to the Q&A session.

The audio webcast will also be available in the investor relations section of Aptose's website. A replay of the webcast will be available on the company's website for 30 days.

The press release, the financial statements, and the management's discussion and analysis for the quarter ended Sept. 30, 2023, will be available on SEDAR+ and EDGAR.

About Aptose Biosciences Inc.

Aptose is a clinical-stage biotechnology company committed to developing precision medicines addressing unmet medical needs in oncology, with an initial focus on hematology. The company's small molecule cancer therapeutic 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 oral kinase inhibitors under development for hematologic malignancies: tuspetinib (HM43239), an oral, myeloid kinase inhibitor being studied as monotherapy and in combination therapy in the Aptivate international phase 1/2 expansion trial in patients with relapsed or refractory acute myeloid leukemia; and luxeptinib (CG-806), an oral, dual lymphoid and myeloid kinase inhibitor in phase 1 a/b stage development for the treatment of patients with relapsed or refractory hematologic malignancies.