Ms. Susan Pietropaolo reports

APTOSE BIOSCIENCES ANNOUNCES RESCHEDULING OF SPECIAL MEETING OF SHAREHOLDERS TO APPROVE THE ACQUISITION BY HANMI PENDING FINAL CLEARANCE FROM SEC

Aptose Biosciences Inc. will be rescheduling its coming special meeting of shareholders, originally scheduled to be held on Jan. 16, 2026, to a later date to be announced. Aptose will hold the rescheduled meeting as soon as practicable in January, 2026. No changes are expected to be made to the record date of the meeting, being the close of business on Dec. 12, 2025, or to the matters to be put before shareholders at the meeting, including the previously announced continuance of Aptose from the Canada Business Corporations Act to the Business Corporations Act (Alberta) (ABCA) and the subsequent acquisition by HS North America Ltd., a wholly owned subsidiary of Hanmi Pharmaceutical Co. Ltd., by way of a statutory plan of arrangement under the ABCA.

Aptose has determined to reschedule the meeting after it receives final clearance of the proxy statement from the U.S. Securities and Exchange Commission (SEC). Following the clearance from the SEC, Aptose will announce the new date, time and virtual details for the meeting. Aptose intends to mail to all shareholders and to make available, under its profile on SEDAR+ and EDGAR, the proxy statement, form of proxy and letter of transmittal, along with any additional required disclosure in connection with the meeting.

On Dec. 12, 2025, Aptose obtained an interim order from the Court of King's Bench of Alberta authorizing the holding of the meeting and matters relating to the conduct of the meeting.

The company's board of directors unanimously recommends that the holders of Aptose common shares vote for the special resolutions approving the continuance and the arrangement at the meeting.

About Aptose Biosciences Inc. i

Aptose Biosciences 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's lead clinical-stage compound, tuspetinib (TUS), is an oral kinase inhibitor that has demonstrated activity as a monotherapy and in combination therapy in patients with relapsed or refractory acute myeloid leukemia (AML) and is being developed as a front-line triplet therapy in newly diagnosed AML.

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