POWER OF ATTORNEY
Know all by these presents, that the undersigned hereby constitutes and appoints
Janet Clennett as the undersigned's true and lawful attorney-in-fact to:
(1)	execute for and on behalf of the undersigned, in the undersigned's capacity
as an officer, director and/or 10% shareholder of Aptose Biosciences Inc. (the "Company"),
Forms 3, 4 and 5 (including amendments thereto) in accordance with Section 16(a) of
the Securities Exchange Act of 1934 and the rules and regulations thereunder
and any Form ID, Uniform Application for Access Codes to File on Edgar, or
Update Passphrase Form;
(2)	do and perform any and all acts for and on behalf of the undersigned which may be
necessary or desirable to complete and execute any such Forms 3, 4 or 5, Form ID or
Update Passphrase Form and timely file any such forms (including amendments thereto)
and application with the United States Securites and Exchange Commmission and any
stock exchange or similar authority; and
(3) 	take any other action of any type whatsoever in connection with the foregoing which,
in the opinion of such attorney-in-fact, may be of benefit to, in the best interest of, or
legally required by, the undersigned, it being understood that the documents executed by such
attorney-in-fact on behalf of the undersigned pursuant to this Power of Attorney shall be in
such form and shall contain such terms and conditions as such attorney-in-fact may approve in
such attorney-in-fact's discretion.
The undersigned hereby grants to such attorney-in-fact full power and authority to do and
perform any and every act and thing whatsoever requisite, necessary or proper to be done in
the exercise of any of the rights and powers herein granted, as fully to all intents and
purposes as the undersigned might or could do if personally present, with full power of
substitution or revocation, hereby ratifying and confirming all that such attorney-in-fact,
or such attorney-in-fact's substitute or substitutes, shall lawfully do or cause to be done
by virtue of this power of attorney and the rights and powers herein granted.
The undersigned acknowledges that the foregoing attorneys-in-fact, in serving in such capacity
at the request of the undersigned, is are not assuming, nor is the Company assuming, any of the
undersigned's responsiblities to comply with Section 16 of the Securities Exchange Act of 1934.
The undersigned agrees that such attorney-in-fact herein may rely entirely on information
furnished orally or in writing by the undersigned to such attorney-in-fact. The undersigned
also agrees to indemnify and hold harmless the Company and such attorney-in-fact against
any losses, claims, damages or liabilities (or actions in these respects) that arise out of
or are based upon any untrue statements or omission of necessary facts in the information
provided by the undersigned to such attorney-in-fact for purposes of executing,
acknowledging, delivering or filing Forms 3, 4 or 5 (including amendments thereto), Form ID
or Update Passphrase Form and agrees to reimburse the Company and such attorney-in-fact
for any legal or other expenses reasonably incurred in connection with investigating or
defending against any such loss, claim, damage, liability or action.
This Power of Attorney supersedes any power of attorney previously executed by the undersigned
regarding the purposes outlined in the first paragraph hereof ("Prior Powers of Attorney"),
and the authority of the attorney-in-fact named in any Prior Powers of Attorney is hereby
revoked.
This Power of Attorney shall remain in full force and effect until the undersigned is no
longer required to file Forms 3, 4 or 5 with respect to the undersigned's holdings of and
transactions in securities issued by the Company, unless earlier (a) revoked by the
undersigned in a signed writing delivered to the foregoing attorney-in-fact or (b)
superseded by a new power of attorney regarding the purposes outlined in the first paragraph
hereof dated as of a later date.
IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be executed
as of this 24th day of June, 2022.

/s/ C. Fletcher Payne