UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

SCHEDULE 14A

INFORMATION REQUIRED IN PROXY STATEMENT

SCHEDULE 14A INFORMATION

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

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☐ Definitive Proxy Statement

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Aptose Biosciences Inc.

(Name of Registrant as Specified in Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

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VOTING INSTRUCTION FROM APTOSE BIOSCIENCES INC. Meeting Type: special meeting meeting date: monday january 27, 2025 at 7:00 am pst scord date: for holders as of december 24, 2024 proxy deposit date: January 23, 2025 cuid: account No: cusip: 03835t309 control No.: step 2 appoint a proxy (optional ) step 3 complete your ovting directions setp 4 this document must be signed and dated signature(s) invalid if not signed

Voting instruction form special meeting aptose biosciences inc when: monday, january 27, 2025 at 7:00 a.m. pst where: by live Review your voting options step 1 we need to receive your voting instructions at least one business day before the proxy deposit date. control No. proxy deposit date january 23, 2025