[8-K] Aptose Biosciences, Inc. Reports Material Event

Rhea-AI Filing Summary

Aptose Biosciences (APTO) said it conducted a competitive selection to choose its independent registered public accounting firm for the fiscal year ending December 31, 2025. KPMG LLP agreed to continue reviewing the company’s interim quarterly financial results through the first two fiscal quarters of 2025. The filing includes a letter from KPMG LLP to the SEC and is signed by William G. Rice, Ph.D., President and CEO.

Positive

• KPMG LLP agreed to continue interim reviews through the first two fiscal quarters of 2025
• Company conducted a competitive selection process for its 2025 independent registered public accounting firm
• Filing includes a formal letter from KPMG LLP, supporting continuity and documentation

Negative

• None.

Insights

Audit Committee / Governance Expert

Company ran a formal audit‑firm selection while securing interim coverage from KPMG.

The notice shows the audit committee completed a competitive selection process to appoint the independent auditor for the fiscal year ending December 31, 2025. That process and the inclusion of a letter from KPMG LLP indicate proactive governance steps to ensure continuity in quarterly reviews while the final auditor is selected.

This matters because uninterrupted interim review coverage through the first two fiscal quarters of 2025 preserves timely financial oversight and reporting while the firm appointment is finalized.

Financial Reporting / Audit Risk Expert

KPMG will cover interim reviews for Q1–Q2 2025, limiting near‑term reporting disruption.

By arranging for KPMG LLP to continue reviewing interim results through the first two fiscal quarters of 2025, the company reduces the risk of gaps in review procedures that could delay filings or raise reporting questions.

The filing furnishes no details about the new auditor selection outcome or timing, so the final audit appointment and any related changes to audit scope or fees are not disclosed.

CA false 0000882361 0000882361 2025-08-22 2025-08-22

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): August 22, 2025

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
N/A		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 4.01. Changes in Registrant’s Certifying Accountant.

On April 15, 2025, Aptose Biosciences Inc. (the “Company”) previously announced that KPMG LLP (“KPMG”), the Company’s independent registered public accounting firm, informed the Company that it would not stand for re-appointment for the Company’s 2025 annual audit. KPMG agreed to continue to review the Company’s quarterly interim financial results through the first two fiscal quarters of 2025. As a result, the Company conducted a competitive selection process to determine the Company’s independent registered public accounting firm for the fiscal year ending December 31, 2025.

As a result of this process, on August 1, 2025 the Company announced that the Board of Directors (the “Board”) unanimously approved the selection of Ernst & Young LLP (“EY”) as the Company’s independent registered public accounting firm to serve as the Company’s independent auditor. The Company reconvened its Annual General and Special Meeting of shareholders today to vote on the appointment of EY and the authorization of the Board to fix EY’s remuneration, to which was subsequently approved.

During the Company’s two most recent fiscal years ended December 31, 2024 and 2023, and the interim period through August 22, 2025, neither the Company nor anyone on its behalf has consulted EY with respect to either (i) the application of accounting principles to a specified transaction, either completed or proposed, or the type of audit opinion that might be rendered on the Company’s financial statements, and neither a written report nor oral advice was provided to the Company that EY concluded was an important factor considered by the Company in reaching a decision as to any accounting, auditing or financial reporting issue; or (ii) any matter that was either the subject of a disagreement (as defined in Item 304(a)(1)(iv) of Regulation S-K and the related instructions) or a reportable event (as defined in Item 304(a)(1)(v) of Regulation S-K).

In accordance with Item 304(a)(3) of Regulation S-K, the Company provided KPMG with a copy of the disclosures it is making in this Current Report on Form 8-K and requested from KPMG a letter addressed to the Securities and Exchange Commission indicating whether it agrees with such disclosures. A copy of KPMG’s letter dated August 21, 2025 is attached as Exhibit 16.1 hereto.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits

Exhibit Number		Description
16.1		Letter from KPMG LLP to the Securities and Exchange Commission
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: August 27, 2025				By:		/s/ William G. Rice
						William G. Rice, Ph.D.
						President and Chief Executive Officer

FAQ

What did Aptose (APTO) disclose about its auditor for fiscal 2025?

Aptose disclosed it conducted a competitive selection process to choose its independent registered public accounting firm for the fiscal year ending December 31, 2025.

Will KPMG perform audits for Aptose in 2025?

KPMG LLP agreed to continue to review Aptose’s interim quarterly financial results through the first two fiscal quarters of 2025; the filing does not state whether KPMG will be the auditor for the full year.

What period will KPMG cover for Aptose’s interim reviews?

KPMG will review interim financial results through the first two fiscal quarters of 2025.

Who signed the 8‑K disclosure for Aptose?

The filing is signed by William G. Rice, Ph.D., President and Chief Executive Officer.

Does the filing state which firm was selected as the 2025 auditor?

No. The filing states a competitive selection process was conducted but does not disclose the final auditor selection or appointment details.