UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

_________________

FORM 8-K

_________________

CURRENT REPORT

Pursuant to Section 13 or 15(d)of the Securities Exchange Act of 1934

Date of ~~the~~Report ~~Securities~~(Date ~~Exchange~~of ~~Act~~earliest ofevent ~~1934~~reported): March 31, 2026

~~Date of Report (Date of earliest event reported): March 12, 2026~~_______________________________

Aptose ~~APTOSE~~Biosciences ~~BIOSCIENCES INC~~Inc.

(Exact name of registrant as specified in its charter)

Canada		001-32001		98-1136802
(State or Other Jurisdictionof Incorporation)		(CommissionFile Number)		(I.R.S. EmployerIdentification No.)

_______________________________

Canada	001-32001	98-1136802
(State or Other Jurisdiction of Incorporation)	(Commission File Number)	(I.R.S. Employer Identification No.)

66 Wellington Street West, Suite 5300

TD Bank Tower, Box 48

Toronto, Ontario M5K ~~1E6~~1E6Canada

Canada

(Address of Principal Executive Offices) (Zip Code)

(647) 479-9828

(Registrant’'s telephone number, including area code)

(Former name or former address, if changed since last report)

_______________________________

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class ~~TradingSymbol~~Trading Symbol(s) Name of each ~~exchangeon~~exchange on which registered None N/A N/A

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 17.01. ~~Entry~~Regulation ~~into~~FD ~~a Material Definitive Agreement~~Disclosure.

~~Item~~On ~~5.02~~March ~~Departure~~31, of2026, ~~Directors~~the orRegistrant ~~Certain~~issued ~~Officers;~~a ~~Election~~press ofrelease, ~~Directors;~~a ~~Appointment~~copy of ~~Certain~~which ~~Officers;~~is ~~Compensatory~~attached ~~Arrangements~~hereto ofas ~~Certain~~Exhibit ~~Officers~~99.1 and is incorporated herein by reference.

~~Amended~~In ~~Employment~~accordance ~~Agreement~~with General Instruction B.2 of Form 8-K, the information in the press release attached as Exhibit 99.1 hereto shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), nor shall such information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

OnItem ~~March 12, 2026, Aptose Biosciences Inc~~9. ~~(the “Company”) and Dr~~01. ~~William~~ ~~Rice,~~Financial ~~Chairman,~~Statements ~~President~~ and Chief Executive Officer of the Company, entered into the First Amendment to the Second Amended and Restated Employment Agreement, effective March 12, 2026 (“First Amendment”), which amends Sections 4Exhibits.3 and 15 and Schedule A of the Second Amended and Restated Employment Agreement dated April 29, 2024 (“Original Agreement”). The First Amendment, (i) confirms that no deferred compensation plan was ever created, no deferred compensation was earned, and no deferred compensation benefits are owed to Dr. Rice and (ii) confirms that Dr. Rice is solely responsible for any potential individual taxes, penalties and interest on all benefits paid or payable under the Original Agreement and any prior agreements.

The First Amendment is filed as Exhibit 10.1 herewith and is incorporated herein by reference. The foregoing description of the First Amendment does not purport to be complete and is qualified in its entirety by the full text of such agreement.

Item 9.01. Financial Statements and Exhibits

(d) Exhibits

Exhibit Number		Description
10.1		First Amendment
99.1		Press Release dated March 31, 2026
104		Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	Aptose Biosciences Inc.		~~Aptose Biosciences Inc.~~
Date: March 23, 2026			By:	/s/ William G. Rice, Ph.D.
Date: March 31, 2026	By:	/s/ William G. Rice, Ph.D.
		William G. Rice, Ph.D.		~~William G. Rice, Ph.D.~~
		Chairman, President, and Chief Executive Officer		~~Chairman, President, and Chief Executive Officer~~

Filing Compare · Aptose Biosciences Inc.