Aptose Biosciences (APTOF) clarifies CEO deferred pay and tax responsibility

Rhea-AI Filing Summary

Aptose Biosciences Inc. reported an amendment to the employment agreement of its Chairman, President and Chief Executive Officer, Dr. William Rice. The First Amendment to the Second Amended and Restated Employment Agreement, effective March 12, 2026, clarifies that no deferred compensation plan was ever created, no deferred compensation was earned, and no deferred compensation benefits are owed to Dr. Rice. It also confirms that Dr. Rice is solely responsible for any potential individual taxes, penalties and interest on all benefits paid or payable under his current and prior agreements. The full text of the First Amendment is included as an exhibit.

8-K Event Classification

3 items: 1.01, 5.02, 9.01

3 items

Item 1.01 Entry into a Material Definitive Agreement Business

The company signed a significant contract such as a merger agreement, credit facility, or major partnership.

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers Governance

Key personnel changes including departures, elections, or appointments of directors and executive officers.

Item 9.01 Financial Statements and Exhibits Exhibits

Financial statements, pro forma financial information, and exhibit attachments filed with this report.

Understanding 8-K Material Events →

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

APTOSE BIOSCIENCES INC.

(Exact name of registrant as specified in its charter)

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

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))

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

Title of each class		Trading Symbol(s)		Name of each 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 1.01 Entry into a Material Definitive Agreement

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

Amended Employment Agreement

On March 12, 2026, Aptose Biosciences Inc. (the “Company”) and Dr. William Rice, Chairman, 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 4.3 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
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.
Date: March 23, 2026				By:		/s/ William G. Rice, Ph.D.
						William G. Rice, Ph.D.
						Chairman, President, and Chief Executive Officer

FAQ

What did Aptose Biosciences Inc. (APTOF) change in the CEO’s employment agreement?

Aptose Biosciences amended Dr. William Rice’s employment agreement to clarify there is no deferred compensation plan, no deferred compensation earned, and no deferred compensation benefits owed. It also assigns him responsibility for any individual taxes, penalties, and interest on benefits paid or payable.

Does Aptose Biosciences (APTOF) owe deferred compensation to its CEO under this amendment?

No, the amendment explicitly confirms that no deferred compensation plan was created, no deferred compensation was earned, and no deferred compensation benefits are owed to Dr. William Rice under the current or prior agreements, removing ambiguity around any such potential obligations.

Who is responsible for tax-related amounts under Aptose Biosciences CEO agreement?

The amendment states that Dr. William Rice is solely responsible for any potential individual taxes, penalties, and interest relating to all benefits paid or payable under his original employment agreement and any prior agreements, clarifying the company’s position on these obligations.

When did the amended employment agreement for Aptose Biosciences’ CEO become effective?

The First Amendment to Dr. William Rice’s Second Amended and Restated Employment Agreement became effective on March 12, 2026. This effective date governs the clarifications on deferred compensation status and the allocation of responsibility for related tax, penalty, and interest obligations.

Where can investors find the full text of Aptose’s CEO employment amendment?

The full text of the First Amendment is filed as Exhibit 10.1 to the report and incorporated by reference. Investors can review this exhibit alongside the filing to see the precise contractual language and the specific sections and schedule that were amended.

Filing Exhibits & Attachments

4 documents

Agreements & Contracts

• EX-10.1 EX-10.1 9.0 KB

Other Documents

• EX-101 XBRL TAXONOMY EXTENSION SCHEMA 2.8 KB
• EX-101 XBRL TAXONOMY EXTENSION LABEL LINKBASE 15.6 KB
• EX-101 XBRL TAXONOMY EXTENSION PRESENTATION LINKBASE 9.8 KB