Ms. Susan Pietropaolo reports

APTOSE TO REPORT THIRD QUARTER 2023 FINANCIAL RESULTS AND HOLD CONFERENCE CALL ON THURSDAY, NOVEMBER 9, 2023

Aptose Biosciences Inc. will release its financial results for the third quarter ended Sept. 30, 2023, on Thursday, Nov. 9, 2023, after the close of the market, and provide a corporate update.

Conference call and webcast

Date:  Thursday, Nov. 9, 2023

Time:  5 p.m. ET

Audio webcast only:  access at the company's website

Question-and-answer participant registration:  register on the Vevent website

Note: Analysts interested in participating in the question-and-answer (Q&A) session will preregister for the event from the participant registration link to receive the dial-in numbers and a unique PIN, which are required to access 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 also can be accessed through a link on 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 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 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 (AML); and luxeptinib (CG-806), an oral, dual lymphoid and myeloid kinase inhibitor in phase 1 a/b development for the treatment of patients with relapsed or refractory hematologic malignancies.