APTOF / Aptose Biosciences Inc. - تصريحات هيئة الأوراق المالية والبورصات، التقرير السنوي، بيان الوكيل

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 19, 2025 APTOSE BIOSCIENCE

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 19, 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 F

KPMG LLP

EX-16.1 Exhibit 16.1 KPMG LLP 100 New Park Place, Suite 1400 Vaughan, ON L4K 0J3 Tel 905-265 5900 Fax 905-265 6390 www.kpmg.ca To Securities and Exchange Commission Washington, DC August 21, 2025 Dear Sir/Madam Re: Notice of Change of Auditors of Aptose Biosciences Inc. We have read the statements made by Aptose Biosciences Inc. (the “Company”) set forth in Item 4.01 “Changes in Registrant’s Certi

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 BIOSCIENCE

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 F

Aptose Biosciences Announces Results of Reconvened Annual and Special Shareholders Meeting and Appointment of Ernst & Young LLP as New Auditor Aptose also Receives Additional Advance from Hanmi Pharmaceutical to Continue Development of Tuspetinib in

EXHIBIT 99.1 Aptose Biosciences Announces Results of Reconvened Annual and Special Shareholders Meeting and Appointment of Ernst & Young LLP as New Auditor Aptose also Receives Additional Advance from Hanmi Pharmaceutical to Continue Development of Tuspetinib in Triplet Therapy for AML SAN DIEGO and TORONTO, Aug. 22, 2025 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (TSX:

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 Bioscience

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 F

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 Bioscience

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 F

Aptose Biosciences Announces Results of Reconvened Annual and Special Shareholders Meeting and Appointment of Ernst & Young LLP as New Auditor Aptose also Receives Additional Advance from Hanmi Pharmaceutical to Continue Development of Tuspetinib in

EXHIBIT 99.1 Aptose Biosciences Announces Results of Reconvened Annual and Special Shareholders Meeting and Appointment of Ernst & Young LLP as New Auditor Aptose also Receives Additional Advance from Hanmi Pharmaceutical to Continue Development of Tuspetinib in Triplet Therapy for AML SAN DIEGO and TORONTO, Aug. 22, 2025 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (TSX:

Aptose Reports Early Data Demonstrating Tuspetinib Improves Standard of Care Treatment Across Diverse Populations of Newly Diagnosed AML in Phase 1/2 TUSCANY Trial

EXHIBIT 99.1 Aptose Reports Early Data Demonstrating Tuspetinib Improves Standard of Care Treatment Across Diverse Populations of Newly Diagnosed AML in Phase 1/2 TUSCANY Trial Addition of Tuspetinib (TUS) to Venetoclax (VEN) and Azacitidine (AZA) is being developed as safe and mutation agnostic frontline therapy for AML Addition of TUS to VEN+AZA improves response rates; 100% CR/CRh at 80 mg and

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 18, 2025 Aptose Bioscience

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 18, 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 F

Aptose Reports Second Quarter 2025 Results

EXHIBIT 99.1 Aptose Reports Second Quarter 2025 Results Tuspetinib Continues to Demonstrate Excellent Safety and Complete Responses in the TUSCANY Clinical Trial of Tuspetinib in AML Triple Drug Frontline Therapy at 120 mg Dose Cohort Safety Review Committee (CSRC) Recommends Tuspetinib Dose Escalation to 160 mg Dose Hanmi Continues to Support Development of Tuspetinib SAN DIEGO and TORONTO, Aug.

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 13, 2025 Aptose Bioscience

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 13, 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 F

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

on UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Quarterly Period Ended June 30, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Transition Period from to Commission File Number: 1-32001 APTOSE BIOSCIENCES I

Aptose Enrollment is Open for 160 mg Dosing Cohort of Tuspetinib in Phase 1/2 TUSCANY Trial of Frontline Triple Drug Therapy

EXHIBIT 99.1 Aptose Enrollment is Open for 160 mg Dosing Cohort of Tuspetinib in Phase 1/2 TUSCANY Trial of Frontline Triple Drug Therapy Safety Review Committee endorses escalation to 160 mg TUS dosing Cohorts with 120 mg, 80 mg, 40 mg TUS dosing completed with no dose-limiting toxicities Excellent safety and complete remissions (CRs) in some of the most difficult-to-treat AML populations No dose

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 6, 2025 Aptose Biosciences

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 6, 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 Fi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A (RULE 14a-101) SCHEDULE 14A INFORMATION Proxy Statement Pursuant To Section 14(a) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A (RULE 14a-101) SCHEDULE 14A INFORMATION Proxy Statement Pursuant To Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for use of the Commission Only (as permitted by Ru

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): July 15, 2025 Aptose Biosciences

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): July 15, 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 Fil

Aptose Receives Second Advance under the Loan Agreement with Hanmi Pharmaceutical to Continue Development of Tuspetinib in Triplet Therapy for AML

EXHIBIT 99.1 Aptose Receives Second Advance under the Loan Agreement with Hanmi Pharmaceutical to Continue Development of Tuspetinib in Triplet Therapy for AML SAN DIEGO and TORONTO, July 15, 2025 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. ("Aptose" or the "Company") (TSX: APS; OTC: APTOF), a clinical-stage precision oncology company developing a tuspetinib (TUS) based triple drug frontline therap

Entry into a Material Definitive Agreement, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant

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): June 24, 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 Fil

Interest Deferral Agreement, dated June 24, 2025, between Hanmi and the Company

Exhibit 10.1 Confidental EXECUTION VERSION INTEREST PAYMENT AGREEMENT This Interest Payment Agreement (this “Agreement”), dated June 24, 2025 (the “Effective Date”), is entered into by and between Aptose Biosciences Inc., a corporation incorporated pursuant to the Canada Business Corporations Act (the “Company”), and Hanmi Pharmaceutical Co., Ltd. (the “Lender”), a corporation incorporated under t

Aptose Announces Deferral of Interest Payment

EX-99.1 Exhibit 99.1 For Immediate Release Aptose Announces Deferral of Interest Payment SAN DIEGO and TORONTO, June 30, 2025 — Aptose Biosciences Inc. (“Aptose” or the “Company”) (TSX: APS; OTC: APTOF), a clinical-stage precision oncology company developing a tuspetinib (TUS) based triple drug frontline therapy to treat patients with newly diagnosed acute myeloid leukemia (AML), announced that it

Aptose Upgraded to Trade on OTCQB Market Aptose will trade under the ticker symbol APTOF and begin trading on OTCQB today, July 1st

EXHIBIT 99.1 Aptose Upgraded to Trade on OTCQB Market Aptose will trade under the ticker symbol APTOF and begin trading on OTCQB today, July 1st SAN DIEGO and TORONTO, July 01, 2025 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (TSX: APS; OTC: APTOF), a clinical-stage precision oncology company developing a tuspetinib (TUS) based triple drug frontline therapy to treat pati

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): July 1, 2025 Aptose Biosciences I

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): July 1, 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

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): June 20, 2025 APTOSE BIOSCIENCES

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): June 20, 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 Fil

2025 Loan Agreement, dated June 18, 2025, between Hanmi Pharmaceutical Co., Ltd., the Company, Aptose Biosciences U.S. Inc. and NuChem Pharmaceuticals Inc.

Exhibit 10.1 Execution Version 2025 FACILITY AGREEMENT between Hanmi Pharmaceutical Co., Ltd., as Lender and Aptose Biosciences Inc., as Borrower and Aptose Biosciences U.S. Inc. and NuChem Pharmaceuticals Inc., each as a Guarantor This 2025 facility agreement is dated June 18, 2025. PARTIES Hanmi Pharmaceutical Co., Ltd. incorporated and registered in the Republic of Korea (the “Lender”) and Apto

Regulation FD Disclosure, Financial Statements and Exhibits

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): June 20, 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 Fil

Aptose and Hanmi Enter New Loan Agreement to Advance Development of Tuspetinib in Triplet Therapy for AML

EXHIBIT 99.1 Aptose and Hanmi Enter New Loan Agreement to Advance Development of Tuspetinib in Triplet Therapy for AML SAN DIEGO and TORONTO, June 20, 2025 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. ("Aptose" or the "Company") (TSX: APS; OTC: APTOF), a clinical-stage precision oncology company developing a tuspetinib (TUS) based triple drug frontline therapy to treat patients with newly diagnosed

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): June 16, 2025 APTOSE BIOSCIENCES

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): June 16, 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 Fil

Aptose Provides Corporate Updates

EXHIBIT 99.1 Aptose Provides Corporate Updates Announces short-term cash advance SAN DIEGO and TORONTO, June 17, 2025 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (TSX: APS; OTC: APTOF), a clinical-stage precision oncology company, announced today that the Company has secured a short-term cash advance from Dr. William G. Rice, the Company’s Chairman of the Board, Presiden

Regulation FD Disclosure, Financial Statements and Exhibits

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): June 17, 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 Fil

Aptose Presents Safety, Response, and MRD Clinical Data from TUSCANY Phase 1/2 Clinical Trial of Tuspetinib Triplet Therapy in Newly Diagnosed AML at the 2025 EHA Congress

EXHIBIT 99.1 Aptose Presents Safety, Response, and MRD Clinical Data from TUSCANY Phase 1/2 Clinical Trial of Tuspetinib Triplet Therapy in Newly Diagnosed AML at the 2025 EHA Congress Addition of TUS to standard of care VEN+AZA creates a well-tolerated and mutation agnostic frontline triple drug therapy for newly diagnosed AML AML patients with diverse mutations, including TP53-mutated/CK and FLT

Regulation FD Disclosure, Financial Statements and Exhibits

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): June 12, 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 Fil

Aptose Announces Results from Annual and Special Meeting of Shareholders

EXHIBIT 99.1 Aptose Announces Results from Annual and Special Meeting of Shareholders SAN DIEGO and TORONTO, May 27, 2025 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. ("Aptose" or the "Company") (TSX: APS; OTC: APTOF), a clinical-stage precision oncology company developing a tuspetinib (TUS) based triple drug frontline therapy to treat patients with newly diagnosed acute myeloid leukemia (AML), toda

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): May 27, 2025 Aptose Biosciences I

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): May 27, 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

Regulation FD Disclosure, Financial Statements and Exhibits

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): May 20, 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

Aptose Announces Dosing of First Patient with 120 mg of Tuspetinib in Phase 1/2 Tuscany Trial of Frontline Triple Drug Therapy after Dose Escalation Decision by Safety Review Committee

EXHIBIT 99.1 Aptose Announces Dosing of First Patient with 120 mg of Tuspetinib in Phase 1/2 Tuscany Trial of Frontline Triple Drug Therapy after Dose Escalation Decision by Safety Review Committee TUS+VEN+AZA triplet achieves complete remissions (CRs) and minimal residual disease (MRD)-negativity with favorable safety in newly diagnosed AML patients Completed 40 mg and 80 mg TUS dose cohorts; no

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): May 14, 2025 Aptose Biosciences I

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): May 14, 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

Aptose Selected for Prestigious Oral Presentation of Data from TUSCANY Phase 1/2 Clinical Trial of Tuspetinib Triplet Therapy in Newly Diagnosed AML at the 2025 EHA Congress

EXHIBIT 99.1 Aptose Selected for Prestigious Oral Presentation of Data from TUSCANY Phase 1/2 Clinical Trial of Tuspetinib Triplet Therapy in Newly Diagnosed AML at the 2025 EHA Congress Aptose is developing TUS+VEN+AZA as a one-of-a-kind safe and mutation agnostic frontline triple drug therapy for newly diagnosed AML Oral presentation at EHA will include updated data at the 40 mg and 80 mg dose l

Aptose Reports First Quarter 2025 Results Highlights Progress in TUSCANY Clinical Trial of Tuspetinib in AML Triple Frontline Therapy

EXHIBIT 99.1 Aptose Reports First Quarter 2025 Results Highlights Progress in TUSCANY Clinical Trial of Tuspetinib in AML Triple Frontline Therapy SAN DIEGO and TORONTO, May 08, 2025 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (TSX: APS and OTC: APTOF), a clinical-stage precision oncology company developing a tuspetinib (TUS)-based triple drug frontline therapy to treat

Financial Statements and Exhibits, Results of Operations and Financial Condition

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): May 8, 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

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

on UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Quarterly Period Ended March 31, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Transition Period from to Commission File Number: 1-32001 APTOSE BIOSCIENCES

Aptose Provides Clinical Update for the Tuspetinib-based Triple Drug Frontline Therapy in Newly Diagnosed AML Patients from the Phase 1/2 TUSCANY Trial Aptose is developing TUS+VEN+AZA as a one-of-a-kind safe and mutation agnostic frontline triple dr

EXHIBIT 99.1 Aptose Provides Clinical Update for the Tuspetinib-based Triple Drug Frontline Therapy in Newly Diagnosed AML Patients from the Phase 1/2 TUSCANY Trial Aptose is developing TUS+VEN+AZA as a one-of-a-kind safe and mutation agnostic frontline triple drug therapy for newly diagnosed AML patients First two dose cohorts of TUS+VEN+AZA triplet demonstrate safety, complete remissions, and MR

Regulation FD Disclosure, Financial Statements and Exhibits

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): May 5, 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

Section 1. Purpose Section 2. Definitions Section 3. Administration Section 4. Common Shares Available for Awards Section 5. Eligibility Section 6. Awards Section 7. Amendment and Termination; Corrections Section 8. Income Tax Withholding and Tax Tre

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 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☒ Definitive Proxy Statement ☐ Definitive Additional Materials ☐ Soliciting Material Pursuant to §240.

Aptose Announces Auditor Not Standing for Re-Appointment

EXHIBIT 99.1 Aptose Announces Auditor Not Standing for Re-Appointment SAN DIEGO and TORONTO, April 23, 2025 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (TSX:APS), a clinical-stage precision oncology company developing a tuspetinib (TUS) based triple drug frontline therapy to treat patients with newly diagnosed acute myeloid leukemia (AML), announces that effective on Apr

Regulation FD Disclosure, Financial Statements and Exhibits

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): April 23, 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 Fi

Section 1. Purpose Section 2. Definitions Section 3. Administration Section 4. Common Shares Available for Awards Section 5. Eligibility Section 6. Awards Section 7. Amendment and Termination; Corrections Section 8. Income Tax Withholding and Tax Tre

Table of Contents 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 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☒ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Definitive Proxy Statement ☐ Definitive Additional Materials ☐ Soliciting Material Pursuant to §240.

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): April 15, 2025 APTOSE BIOSCIENCES

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): April 15, 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 Fi

Letter from KPMG LLP to the Securities and Exchange Commission

EX-16.1 Exhibit 16.1 KPMG LLP 100 New Park Place, Suite 1400 Vaughan, ON L4K 0J3 Tel 905-265 5900 Fax 905-265 6390 www.kpmg.ca To: United States Securities and Exchange Commission April 21, 2025 Dear Sir/Madam Re: Notice of Change of Auditors of Aptose Biosciences Inc. We have read the Notice of Aptose Biosciences Inc. in this Form 8-K dated April 21, 2025 and are in agreement with the statements

Section 1. Purpose Section 2. Definitions Section 3. Administration Section 4. Common Shares Available for Awards Section 5. Eligibility Section 6. Awards Section 7. Amendment and Termination; Corrections Section 8. Income Tax Withholding and Tax Tre

Table of Contents 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 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☒ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Definitive Proxy Statement ☐ Definitive Additional Materials ☐ Soliciting Material Pursuant to §240.

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 31, 2025 APTOSE BIOSCIENCES

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 31, 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 Fi

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): April 1, 2025 Aptose Biosciences

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): April 1, 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 Fil

Aptose Common Shares to Delist from Nasdaq as of April 2, 2025

EXHIBIT 99.1 Aptose Common Shares to Delist from Nasdaq as of April 2, 2025 SAN DIEGO and TORONTO, April 01, 2025 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (NASDAQ: APTO, TSX:APS), a clinical-stage precision oncology company developing a tuspetinib (TUS) based triple drug frontline therapy to treat patients with newly diagnosed acute myeloid leukemia (AML), today annou

List of Subsidiaries

Exhibit 21.1 Subsidiaries of the Registrant Name State/Jurisdiction of Incorporation Aptose Biosciences U.S. Inc. Delaware NuChem Pharmaceuticals Inc. Ontario, Canada

Aptose Reports Year End 2024 Results and Corporate Highlights Tuspetinib Triple Drug Frontline Therapy Advancing in TUSCANY Clinical Trial Results to Date Highlight TUS Potential as an Ideal Third Drug to Include in AML Triplet Therapy Aptose Signs D

EXHIBIT 99.1 Aptose Reports Year End 2024 Results and Corporate Highlights Tuspetinib Triple Drug Frontline Therapy Advancing in TUSCANY Clinical Trial Results to Date Highlight TUS Potential as an Ideal Third Drug to Include in AML Triplet Therapy Aptose Signs Debt Conversion Agreement with Hanmi SAN DIEGO and TORONTO, March 28, 2025 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Co

Aptose Bioscience Inc. Clawback Policy

e Exhibit 97.1 APTOSE BIOSCIENCES INC. INCENTIVE COMPENSATION RECOVERY POLICY 1. Introduction. The Board of Directors of Aptose Biosciences Inc. (the “Company”) believes that it is in the best interests of the Company and its shareholders to create and maintain a culture that emphasizes integrity and accountability and that reinforces the Company's compensation philosophy. The Board has therefore

Insider Trading Policy

Exhibit 19.1 AMENDED AND REINSTATED DISCLOSURE AND INSIDER TRADING POLICY APTOSE BIOSCIENCES INC. (the “Company”) As revised and adopted by the Board of Directors (the “Board”) on May 5, 2020 I. OBJECTIVES AND SCOPE 1.1. Objectives The Company is committed to best practices in making timely and accurate disclosure of all material information and providing fair and equal access to material informat

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-32001 Aptose Bioscien

Financial Statements and Exhibits, Results of Operations and Financial Condition

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 28, 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 Fi

Second Amended and Restated Investor’s Rights Agreement, dated March 18, 2025

EX-10.2 Exhibit 10.2 Certain portions of this Exhibit have been redacted pursuant to Item 601(b)(10) of Regulation S-K and, where applicable, have been marked with “[***]” to indicate where redactions have been made. The marked information has been redacted because it is both (i) not material and (ii) is the type of information the Corporation treats as private and confidential. SECOND AMENDED AND

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 18, 2025 APTOSE BIOSCIENCES

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 18, 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 Fi

Debt Conversion and Interest Payment Agreement, dated March 18, 2025

Exhibit 10.1 Certain portions of this Exhibit have been redacted pursuant to Item 601(b)(10) of Regulation S-K and, where applicable, have been marked with “[***]” to indicate where redactions have been made. The marked information has been redacted because it is both (i) not material and (ii) is the type of information the Corporation treats as private and confidential. DEBT CONVERSION AND INTERE

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 17, 2025 Aptose Biosciences

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 17, 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 Fi

Aptose Biosciences Meets Nasdaq Minimum Bid Price Compliance

EXHIBIT 99.1 Aptose Biosciences Meets Nasdaq Minimum Bid Price Compliance SAN DIEGO and TORONTO, March 17, 2025 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (NASDAQ: APTO, TSX: APS), a clinical-stage precision oncology company developing the tuspetinib (TUS)-based triple drug frontline therapy to treat patients with newly diagnosed acute myeloid leukemia (AML), today anno

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 11, 2025 APTOSE BIOSCIENCES

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 11, 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 Fi

Aptose Precision oncology company developing oral targeted agents to treat hematologic malignancies C o r p o r a t e P r e s e n t a t i o n M a r c h 2025 Tuspetinib in Frontline Triple Drug Therapy to Treat Newly Diagnosed AML 1 NASDAQ: APTO TSX:

Exhibit 99.1 Aptose Precision oncology company developing oral targeted agents to treat hematologic malignancies C o r p o r a t e P r e s e n t a t i o n M a r c h 2025 Tuspetinib in Frontline Triple Drug Therapy to Treat Newly Diagnosed AML 1 NASDAQ: APTO TSX: APS AML (Acute Myeloid Leukemia) • Highly aggressive and deadly cancer of the bone marrow and blood Current Frontline (1L) Standard of Ca

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): February 18, 2025 APTOSE BIOSCIEN

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): February 18, 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

Certificate of Amendment

Exhibit 3.1 Innovation, Science and Economic Development Canada Corporations Canada Innovation, Sciences et Développement économique Canada Corporations Canada Certificate of Amendment Certificat de modification Canada Business Corporations Act Loi canadienne sur les sociétés par actions Aptose Biosciences Inc. Corporate name / Dénomination sociale 665030-9 Corporation number / Numéro de société I

Aptose Announces Positive Clinical Safety Review Committee (CSRC) Approval to Dose Escalate in Phase 1/2 Tuscany Trial of Frontline Triple Drug Therapy with Tuspetinib Amid Complete Responses and Favorable Safety in First Cohort

EXHIBIT 99.1 Aptose Announces Positive Clinical Safety Review Committee (CSRC) Approval to Dose Escalate in Phase 1/2 Tuscany Trial of Frontline Triple Drug Therapy with Tuspetinib Amid Complete Responses and Favorable Safety in First Cohort TUS+VEN+AZA triplet achieves complete responses (CRs) in difficult-to-treat TP53-mutated/CK AML and FLT3-wildtype AML patients, including a measurable residua

Regulation FD Disclosure, Financial Statements and Exhibits

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): February 20, 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

Aptose Announces Reverse Share Split

EXHIBIT 99.1 Aptose Announces Reverse Share Split SAN DIEGO and TORONTO, Feb. 18, 2025 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (NASDAQ: APTO, TSX: APS), a clinical-stage precision oncology company developing the tuspetinib (TUS)-based triple drug frontline therapy to treat patients with newly diagnosed AML, today announced that its board of directors (the “Board”) ha

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): February 18, 2025 Aptose Bioscien

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): February 18, 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

Registration Rights Agreement, dated February 7, 2025, between Aptose Biosciences Inc. and Keystone Capital Partners, LLC (incorporated by reference herein to Exhibit 10.2 to the Company’s Current Report filed on Form 8-K on February 12, 2025)

Exhibit 10.28 REGISTRATION RIGHTS AGREEMENT This REGISTRATION RIGHTS AGREEMENT (this “Agreement”), dated as of February 7, 2025, is by and between Keystone Capital Partners, LLC, a Delaware limited liability company (the “Investor”), and Aptose Biosciences Inc., a corporation organized under the laws of Canada (the “Company”). RECITALS A. The Company and the Investor have entered into that certain

Filing Fees

Exhibit 107 Calculation of Filing Fee Table Form S-1 (Form Type) Aptose Biosciences Inc.

As filed with the Securities and Exchange Commission on February 13, 2025

S-1 Table of Contents As filed with the Securities and Exchange Commission on February 13, 2025 Registration No.

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): February 13, 2025 Aptose Bioscien

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): February 13, 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

Common Share Purchase Agreement, dated as of February 7, 2025, by and between the Company and the Investor.

Exhibit 10.1 COMMON SHARE PURCHASE AGREEMENT Dated as of February 7, 2025 by and among APTOSE BIOSCIENCES INC., And KEYSTONE CAPITAL PARTNERS, LLC TABLE OF CONTENTS Page ARTICLE I PURCHASE AND SALE OF COMMON SHARES 1    Section 1.1. Purchase and Sale of Stock 1 Section 1.2. Closing Date; Settlement Dates 1 Section 1.3. Initial Public Announcements and Required Filings 2 ARTICLE II PURCHASE TERMS 3

Exhibit 99.1

Exhibit 99.1 AGREEMENT OF THE REPORTING PERSONS The undersigned acknowledge and agree that the foregoing statement on Schedule 13G is filed on behalf of each of the undersigned and that all subsequent amendments to this statement on Schedule 13G shall be filed on behalf of each of the undersigned without the necessity of filing additional joint filing agreements. The undersigned acknowledge that e

Exhibit 99.2

Exhibit 99.2 The identity and the Item 3 classification of the relevant subsidiary is: Bleichroeder LP, which is an Investment Adviser in accordance with Rule 13d-1(b)(1)(ii)(E).

Aptose Enters into $25 Million Committed Equity Facility and Establishes New At-The-Market Facility

Exhibit 99.1 Not For Immediate Release – confidential for review Aptose Enters into $25 Million Committed Equity Facility and Establishes New At-The-Market Facility SAN DIEGO and TORONTO, February 13, 2025 - Aptose Biosciences Inc. (“Aptose” or the “Company”) (NASDAQ: APTO, TSX: APS), a clinical-stage precision oncology company developing the tuspetinib (TUS)-based triple drug frontline therapy to

Aptose Enters into $25 Million Committed Equity Facility and Establishes New At-The-Market Facility

EXHIBIT 99.1 Aptose Enters into $25 Million Committed Equity Facility and Establishes New At-The-Market Facility SAN DIEGO and TORONTO, Feb. 13, 2025 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (NASDAQ: APTO, TSX: APS), a clinical-stage precision oncology company developing the tuspetinib (TUS)-based triple drug frontline therapy to treat patients with newly diagnosed AM

Registration Rights Agreement, dated as of February 7, 2025, by and between the Company and the Investor.

Exhibit 10.2 REGISTRATION RIGHTS AGREEMENT This REGISTRATION RIGHTS AGREEMENT (this “Agreement”), dated as of February 7, 2025, is by and between Keystone Capital Partners, LLC, a Delaware limited liability company (the “Investor”), and Aptose Biosciences Inc., a corporation organized under the laws of Canada (the “Company”). RECITALS A. The Company and the Investor have entered into that certain

Common Share Purchase Agreement, dated February 7, 2025, between Aptose Biosciences Inc. and Keystone Capital Partners, LLC (incorporated by reference herein to Exhibit 10.1 to the Company’s Current Report filed on Form 8-K on February 12, 2025)

Exhibit 10.27 COMMON SHARE PURCHASE AGREEMENT Dated as of February 7, 2025 by and among APTOSE BIOSCIENCES INC., And KEYSTONE CAPITAL PARTNERS, LLC TABLE OF CONTENTS Page ARTICLE I PURCHASE AND SALE OF COMMON SHARES 1 Section 1.1. Purchase and Sale of Stock 1 Section 1.2. Closing Date; Settlement Dates 1 Section 1.3. Initial Public Announcements and Required Filings 2 ARTICLE II PURCHASE TERMS 3 S

Entry into a Material Definitive Agreement, Unregistered Sales of Equity Securities

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): February 7, 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

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): February 12, 2025 Aptose Bioscien

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): February 12, 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

Aptose’s Frontline Triple Drug Therapy with Tuspetinib Achieves Notable Responses in Newly Diagnosed AML Patients in the Phase 1/2 TUSCANY Trial TUS+VEN+AZA triplet achieves Cycle 1 complete remission (CR) in TP53-mutated/CK AML TUS+VEN+AZA triplet a

EXHIBIT 99.1 Aptose’s Frontline Triple Drug Therapy with Tuspetinib Achieves Notable Responses in Newly Diagnosed AML Patients in the Phase 1/2 TUSCANY Trial TUS+VEN+AZA triplet achieves Cycle 1 complete remission (CR) in TP53-mutated/CK AML TUS+VEN+AZA triplet achieves Cycle 1 complete remissions in FLT3-wildtype AML patients TUS+VEN+AZA triplet shows favorable safety with no alteration of VEN an

Sales Agreement, dated February 3, 2025, among Aptose Biosciences Inc. and A.G.P./Alliance Global Partners

Exhibit 10.1 APTOSE BIOSCIENCES INC. COMMON SHARES SALES AGREEMENT February 3, 2025 A.G.P./Alliance Global Partners 590 Madison Avenue New York, NY 10022 Ladies and Gentlemen: Aptose Biosciences Inc., a company incorporated under the laws of Canada (the “Company”), confirms its agreement (this “Agreement”) with A.G.P./Alliance Global Partners (the “Sales Agent”), as follows: 1. Issuance and Sale o

$1,000,000 Aptose Biosciences Inc. Common Shares

Table of Contents Filed pursuant to 424(b)(5) Registration No. 333-267801 PROSPECTUS SUPPLEMENT (to Prospectus dated October 21, 2022) $1,000,000 Aptose Biosciences Inc. Common Shares On February 3, 2025, we entered into a certain sales agreement (the “Sales Agreement”) with A.G.P./Alliance Global Partners (the “A.G.P”) relating to our common shares offered by this prospectus supplement. In accord

Current Report

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): February 3, 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

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): January 27, 2025 APTOSE BIOSCIENC

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): January 27, 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

Current Report

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 January 14, 2025 (Date of Report - date of earliest event reported) Aptose Biosciences Inc. (Exact Name of Registrant as Specified in Its Charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation or Organizat

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): January 13, 2025 APTOSE BIOSCIENC

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): January 13, 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

Aptose Precision oncology company developing oral targeted agents to treat hematologic malignancies Corporate Presentation January 2025 Tuspetinib in Frontline Triple Drug Therapy to Treat Newly Diagnosed AML 1 NASDAQ: APTO TSX: APS AML (Acute Myeloi

Exhibit 99.1 Aptose Precision oncology company developing oral targeted agents to treat hematologic malignancies Corporate Presentation January 2025 Tuspetinib in Frontline Triple Drug Therapy to Treat Newly Diagnosed AML 1 NASDAQ: APTO TSX: APS AML (Acute Myeloid Leukemia) • Highly aggressive and deadly cancer of the bone marrow and blood Current Standard of Care Therapy • VEN+AZA (Venetoclax + A

Regulation FD Disclosure, Financial Statements and Exhibits

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): January 9, 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 F

Aptose Announces First AML Patients Dosed with Tuspetinib Triplet Frontline Therapy in TUSCANY Trial TUS+VEN+AZA triplet has potential as frontline therapy to treat large, mutationally diverse populations of AML

EXHIBIT 99.1 Aptose Announces First AML Patients Dosed with Tuspetinib Triplet Frontline Therapy in TUSCANY Trial TUS+VEN+AZA triplet has potential as frontline therapy to treat large, mutationally diverse populations of AML SAN DIEGO and TORONTO, Jan. 09, 2025 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (NASDAQ: APTO, TSX: APS), a clinical-stage precision oncology compa

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

Table of Contents 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 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☒ Definitive Proxy Statement ☐ Definitive Additional Materials ☐ Soliciting Material Pursuant to §240.

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

DEFA14A 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 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Definitive Proxy Statement ☒ Definitive Additional Materials ☐ Soliciting Material Pursuant to §240.

Regulation FD Disclosure, Financial Statements and Exhibits

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): December 19, 2024 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission

Aptose Announces Positive Decision by Nasdaq Hearings Panel

EXHIBIT 99.1 Aptose Announces Positive Decision by Nasdaq Hearings Panel SAN DIEGO and TORONTO, Dec. 19, 2024 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (NASDAQ: APTO, TSX: APS), a clinical-stage precision oncology company developing highly differentiated targeted agents to treat hematologic malignancies, today announced that the Nasdaq Hearings Panel (“Panel”) has gran

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

PRE 14A 1 d866874dpre14a.htm PRE 14A Table of Contents 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 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☒ Preliminary Prox

Aptose Announces Publication of Preclinical Data in AACR Journal Demonstrating Tuspetinib’s Unique Mechanism of Action and Synthetic Lethality on AML Cells When Combined with Venetoclax

EXHIBIT 99.1 Aptose Announces Publication of Preclinical Data in AACR Journal Demonstrating Tuspetinib’s Unique Mechanism of Action and Synthetic Lethality on AML Cells When Combined with Venetoclax Peer-reviewed publication details unique TUS mechanism of action TUS+VEN combination synthetic lethality overcomes resistance to VEN Tuspetinib prolongs survival in multiple AML models resistant to oth

Regulation FD Disclosure, Financial Statements and Exhibits

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): December 12, 2024 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission

Regulation FD Disclosure, Financial Statements and Exhibits

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): December 9, 2024 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission

Aptose Clinical Data Featured in Poster Presentation at the 2024 ASH Annual Meeting Support Tuspetinib Triple Drug Therapy for Newly Diagnosed AML

EXHIBIT 99.1 Aptose Clinical Data Featured in Poster Presentation at the 2024 ASH Annual Meeting Support Tuspetinib Triple Drug Therapy for Newly Diagnosed AML TUS+VEN+AZA Triplet Frontline Therapy in Newly Diagnosed AML Patients Now Enrolling at U.S. Sites TUS and TUS+VEN Broadly Active Across AML Populations, with Favorable Safety TUS-based therapies are active in FLT3 wildtype, representing ~70

Aptose Signs CRADA with NCI to Develop Tuspetinib for AML and MDS in Newly Launched MyeloMATCH Precision Medicine Trials

EXHIBIT 99.1 Aptose Signs CRADA with NCI to Develop Tuspetinib for AML and MDS in Newly Launched MyeloMATCH Precision Medicine Trials Tuspetinib selected for a prestigious national clinical research program for ability to target broad spectrum of AML and MDS populations Trials to test tuspetinib in targeted drug combinations for frontline therapy of molecularly defined sub-groups of newly diagnose

Regulation FD Disclosure, Financial Statements and Exhibits

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): December 3, 2024 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission

Form of Common Warrant

EX-4.1 Exhibit 4.1 COMMON SHARE PURCHASE WARRANT APTOSE BIOSCIENCES INC. Warrant Shares:          Issue Date: November [•], 2024 THIS COMMON SHARE PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after the date hereof (

Aptose Biosciences Inc. Announces Closing of $8 Million Public Offering

EX-99.1 Exhibit 99.1 For Immediate Release Aptose Biosciences Inc. Announces Closing of $8 Million Public Offering SAN DIEGO and TORONTO, November 25, 2024 — Aptose Biosciences Inc. (“Aptose” or the “Company”) (NASDAQ: APTO, TSX: APS), a clinical-stage precision oncology company developing highly differentiated oral targeted agents to treat hematologic malignancies, today announced the closing of

Up to 40,000,000 Common Shares Up to 20,000,000 Common Warrants to Purchase 20,000,000 Common Shares Up to 20,000,000 Common Shares Underlying Common Warrants Up to 1,600,000 Common Shares underlying the Placement Agent Warrants

424B4 Table of Contents Filed Pursuant to 424(b)(4) Registration No. (333-281201) PROSPECTUS Up to 40,000,000 Common Shares Up to 20,000,000 Common Warrants to Purchase 20,000,000 Common Shares Up to 20,000,000 Common Shares Underlying Common Warrants Up to 1,600,000 Common Shares underlying the Placement Agent Warrants This prospectus relates to the offering of up to 40,000,000 common shares, no

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): November 21, 2024 APTOSE BIOSCIEN

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): November 21, 2024 APTOSE BIOSCIENCES INC. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or other jurisdiction of incorporation) (Commission

Form of Placement Agent Warrant

EX-4.2 Exhibit 4.2 PLACEMENT AGENT COMMON SHARE PURCHASE WARRANT APTOSE BIOSCIENCES INC. Warrant Shares: Issue Date: November [•], 2024 THIS PLACEMENT AGENT COMMON SHARE PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or

Placement Agency Agreement, dated as of November 21, 2024, by and among Aptose Biosciencs Inc. and A.G.P./Alliance Global Partners, as placement agent.

EX-10.1 Exhibit 10.1 PLACEMENT AGENCY AGREEMENT November 21, 2024 Aptose Biosciences Inc. 251 Consumers Road, Suite 1105 Toronto, Ontario, Canada M2J 4R3 Attention: William G. Rice, Ph.D. Dear Dr. Rice: This letter (the “Agreement”) constitutes the agreement between A.G.P./Alliance Global Partners, as placement agent (the “Placement Agent”), and Aptose Biosciencs Inc., a company incorporated under

Regulation FD Disclosure, Financial Statements and Exhibits

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): November 22, 2024 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission

Aptose Biosciences Inc. Announces Pricing of $8 Million Public Offering

EXHIBIT 99.1 Aptose Biosciences Inc. Announces Pricing of $8 Million Public Offering SAN DIEGO and TORONTO, Nov. 22, 2024 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (NASDAQ: APTO, TSX: APS), a clinical-stage precision oncology company developing highly differentiated oral targeted agents to treat hematologic malignancies, today announced the pricing of its "reasonable b

Regulation FD Disclosure, Financial Statements and Exhibits

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): November 20, 2024 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission

Aptose Initiates TUSCANY Phase 1/2 Study for Newly Diagnosed AML Patients to Receive Tuspetinib-based Triplet Therapy

EXHIBIT 99.1 Aptose Initiates TUSCANY Phase 1/2 Study for Newly Diagnosed AML Patients to Receive Tuspetinib-based Triplet Therapy TUSCANY study is open to enroll patients to receive TUS+VEN+AZA triplet at select US sites Favorable safety and broad clinical activity make tuspetinib an ideal agent to combine with venetoclax and azacitidine to potentially address larger AML populations Study executi

November 19, 2024

November 19, 2024 VIA EDGAR U.S. Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549 Attention: Jimmy McNamara Re: Aptose Biosciences Inc. Registration Statement on Form S-1 File No. 333-281201 Ladies and Gentlemen: In accordance with Rule 461 of the General Rules and Regulations promulgated under the Securities Act of 1933, as amended (the

Aptose Biosciences, Inc. 66 Wellington Street West, Suite 5300 TD Bank Tower Box 48 Toronto, Ontario, Canada

CORRESP Aptose Biosciences, Inc. 66 Wellington Street West, Suite 5300 TD Bank Tower Box 48 Toronto, Ontario, Canada November 19, 2024 VIA EDGAR United States Securities and Exchange Commission Division of Corporation Finance 100 F. Street, N.E. Washington, D.C. 20549 Attention: Jimmy McNamara Re: Aptose Biosciences Inc. – Registration Statement on Form S-1 (File No. 333-281201) Ladies and Gentlem

APTO / Aptose Biosciences Inc. / ARMISTICE CAPITAL, LLC Passive Investment

SC 13G 1 armistice-apto093024.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Aptose Biosciences Inc. (Name of Issuer) Common Shares, no par value (Title of Class of Securities) 03835T309 (CUSIP Number) September 30, 2024 (Date of Event Which Requires Filing of this Statement) Check the appropriate b

Facility Agreement among the Company and Hanmi Pharmaceutical Co., Ltd dated August 27, 2024

Exhibit 10.1 CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE AND CONFIDENTIAL. FACILITY AGREEMENT between Hanmi Pharmaceutical Co., Ltd. and Aptose Biosciences Inc. This agreement (“Agreement”) is dated August 27, 2024. PARTIES (1) Hanmi Pharmaceutical Co., Ltd. incorporated

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

on UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Quarterly Period Ended September 30, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Transition Period from to Commission File Number: 1-32001 APTOSE BIOSCIEN

Aptose Reports Results for the Third Quarter 2024 Aptose and Hanmi Pharmaceutical Co-developing Triplet Therapy of Tuspetinib with Azacitidine and Venetoclax for Newly Diagnosed AML

EXHIBIT 99.1 Aptose Reports Results for the Third Quarter 2024 Aptose and Hanmi Pharmaceutical Co-developing Triplet Therapy of Tuspetinib with Azacitidine and Venetoclax for Newly Diagnosed AML SAN DIEGO and TORONTO, Nov. 08, 2024 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (NASDAQ: APTO, TSX: APS), a clinical-stage precision oncology company developing highly different

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): November 8, 2024 Aptose Bioscienc

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): November 8, 2024 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission

Form of Placement Agency Agreement

Exhibit 10.23 PLACEMENT AGENCY AGREEMENT October [•], 2024 Aptose Biosciences Inc. 251 Consumers Road, Suite 1105 Toronto, Ontario, Canada M2J 4R3 Attention: William G. Rice, Ph.D. Dear Dr. Rice: This letter (the “Agreement”) constitutes the agreement between A.G.P./Alliance Global Partners, as placement agent (the “Placement Agent”), and Aptose Biosciencs Inc., a company incorporated under the la

Form of Securities Purchase Agreement

Exhibit 10.24 SECURITIES PURCHASE AGREEMENT This SECURITIES PURCHASE AGREEMENT (this “Agreement”) is dated as of October [•], 2024, between Aptose Biosciences Inc., a Canadian corporation (the “Company”), and each purchaser identified on the signature pages hereto (each, including its successors and assigns, a “Purchaser” and collectively the “Purchasers”). WHEREAS, subject to the terms and condit

*   *   *

CORRESP DANIEL M. MILLER Partner (604) 630-5199 FAX (604) 687-8504 [email protected] October 30, 2024 Division of Corporation Finance Office of Life Sciences U.S. Securities and Exchange Commission 100 F Street N.E. Washington, D.C. 20549 Attention: Jimmy McNamara and Joe McCann  Re: Aptose Biosciences Inc. Registration Statement on Form S-1 Filed August 2, 2024 File No. 333-281201 Dear Sirs a

Form of Pre-Funded Warrant

Exhibit 4.3 PRE-FUNDED COMMON SHARES PURCHASE WARRANT APTOSE BIOSCIENCES INC. Warrant Shares: Issue Date: October [•], 2024 THIS PRE-FUNDED COMMON SHARES PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after the date h

Filing Fees

Exhibit 107 Calculation of Filing Fee Tables Form S-1 (Form Type) Aptose Biosciences Inc.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 1 FORM S-1 REGISTRATION STATEMENT The Securities Act of 1933 APTOSE BIOSCIENCES INC. (Exact name of Registrant as specified in its charter) Canada 2836 98-1136802 (

S-1/A Table of Contents Registration No. 333-281201 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 1 to FORM S-1 REGISTRATION STATEMENT Under The Securities Act of 1933 APTOSE BIOSCIENCES INC. (Exact name of Registrant as specified in its charter) Canada 2836 98-1136802 (State or other jurisdiction of incorporation or organization) (Primary Standard Industria

Form of Placement Agent Warrant

Exhibit 4.4 PLACEMENT AGENT COMMON SHARE PURCHASE WARRANT APTOSE BIOSCIENCES INC. Warrant Shares:          Issue Date:    October [•], 2024 THIS PLACEMENT AGENT COMMON SHARE PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on

Form of Common Warrant

Exhibit 4.2 COMMON SHARE PURCHASE WARRANT APTOSE BIOSCIENCES INC. Warrant Shares:        Issue Date:  October [•], 2024 THIS COMMON SHARE PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after the date hereof (the “Init

Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing

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): October 1, 2024 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission F

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): September 5, 2024 Aptose Bioscien

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): September 5, 2024 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission

Regulation FD Disclosure, Financial Statements and Exhibits

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): September 5, 2024 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission

Aptose Announces Results from Special Meeting of Shareholders

EXHIBIT 99.1 Aptose Announces Results from Special Meeting of Shareholders SAN DIEGO and TORONTO, Sept. 05, 2024 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (NASDAQ: APTO, TSX: APS), a clinical-stage precision oncology company developing tuspetinib, a highly differentiated oral kinase inhibitor for the treatment of patients with acute myeloid leukemia (AML), announced th

Aptose Receives $10 Million Through a Facility Agreement with Hanmi; Negotiating Future Collaboration Agreement with Hanmi to Jointly Develop Tuspetinib Proceeds to be used for development of lead compound tuspetinib in combination therapy as frontli

EXHIBIT 99.1 Aptose Receives $10 Million Through a Facility Agreement with Hanmi; Negotiating Future Collaboration Agreement with Hanmi to Jointly Develop Tuspetinib Proceeds to be used for development of lead compound tuspetinib in combination therapy as frontline treatment for newly diagnosed AML patients SAN DIEGO and TORONTO, Aug. 30, 2024 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” o

Regulation FD Disclosure, Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant

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 27, 2024 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission F

Aptose Announces Adjournment of its Special Meeting of Shareholders

EXHIBIT 99.1 Aptose Announces Adjournment of its Special Meeting of Shareholders SAN DIEGO and TORONTO, Aug. 15, 2024 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (NASDAQ: APTO, TSX: APS), a clinical-stage precision oncology company developing highly differentiated oral targeted agents to treat hematologic malignancies, today announced that its special meeting of sharehol

Regulation FD Disclosure, Financial Statements and Exhibits

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 15, 2024 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission F

Financial Statements and Exhibits, Results of Operations and Financial Condition

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 8, 2024 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission Fi

Aptose Reports Results for the Second Quarter 2024

EXHIBIT 99.1 Aptose Reports Results for the Second Quarter 2024 TUS+VEN+HMA Triplet Protocol in Frontline Therapy for Newly Diagnosed AML was Reviewed by the FDA and Allowed to Proceed Abstract Supporting Exploration of the TUS+VEN+AZA Triplet in Frontline Therapy for Newly Diagnosed AML has been Submitted to the 2025 Annual Meeting of the American Society of Hematology (ASH) SAN DIEGO and TORONTO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

on UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Quarterly Period Ended June 30, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Transition Period from to Commission File Number: 1-32001 APTOSE BIOSCIENCES I

Filing Fees

EX-FILING FEES Exhibit 107 Calculation of Filing Fee Tables FORM S-1 (Form Type) APTOSE BIOSCIENCES INC.

As filed with the Securities and Exchange Commission on August 1, 2024

S-1 Table of Contents As filed with the Securities and Exchange Commission on August 1, 2024 Registration No.

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): July 26, 2024 APTOSE BIOSCIENCES

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): July 26, 2024 APTOSE BIOSCIENCES INC. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission Fil

Aptose Precision oncology company developing oral targeted agents to treat hematologic malignancies C o r p o r a t e P r e s e n t a t i o n J u l y 26 , 2024 Tuspetinib to Treat Newly Diagnosed AML Aptose Disclosure 2 This presentation does not, an

Exhibit 99.1 Aptose Precision oncology company developing oral targeted agents to treat hematologic malignancies C o r p o r a t e P r e s e n t a t i o n J u l y 26 , 2024 Tuspetinib to Treat Newly Diagnosed AML Aptose Disclosure 2 This presentation does not, and is not intended to, constitute or form part of, and should not be construed as, an offer or invitation for the sale or purchase of, or

Aptose Announces Receipt of Deficiency Notice from Nasdaq

EXHIBIT 99.1 Aptose Announces Receipt of Deficiency Notice from Nasdaq SAN DIEGO and TORONTO, July 19, 2024 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (NASDAQ: APTO, TSX: APS), a clinical-stage precision oncology company developing highly differentiated oral targeted agents to treat hematologic malignancies, today announced that it has received a deficiency letter (the

Regulation FD Disclosure, Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing, Financial Statements and Exhibits

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): July 16, 2024 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission Fil

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

Table of Contents 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 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☒ Definitive Proxy Statement ☐ Definitive Additional Materials ☐ Soliciting Material Pursuant to §240.

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

Table of Contents 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 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☒ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Definitive Proxy Statement ☐ Definitive Additional Materials ☐ Soliciting Material Pursuant to §240.

Regulation FD Disclosure, Financial Statements and Exhibits

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): June 18, 2024 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission Fil

Aptose Announces Results from Annual and Special Meeting of Shareholders

EXHIBIT 99.1 Aptose Announces Results from Annual and Special Meeting of Shareholders SAN DIEGO and TORONTO, June 18, 2024 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (NASDAQ: APTO, TSX: APS), a clinical-stage precision oncology company developing highly differentiated oral kinase inhibitors to treat hematologic malignancies, today announced the voting results from the C

Submission of Matters to a Vote of Security Holders

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): June 18, 2024 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission Fil

Regulation FD Disclosure, Financial Statements and Exhibits

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): June 14, 2024 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission Fil

Aptose Presents Tuspetinib (TUS) Clinical and Preclinical Findings at European Hematology Association (EHA) 2024 Hybrid Congress

EXHIBIT 99.1 Aptose Presents Tuspetinib (TUS) Clinical and Preclinical Findings at European Hematology Association (EHA) 2024 Hybrid Congress TUS Monotherapy and TUS+Venetoclax (VEN) Doublet Therapy Show Broad Clinical Activity and Strong Safety Data in relapsed or refractory (R/R) Acute Myeloid Leukemia (AML) and Differentiate TUS from other Investigational Drugs in AML TUS Monotherapy and TUS+VE

Form of Common Share Purchase Warrant

Exhibit 10.2 [SERIES A/SERIES B] COMMON SHARE PURCHASE WARRANT APTOSE BIOSCIENCES INC. Warrant Shares: Issue Date:, 2024 THIS [SERIES A/SERIES B] COMMON SHARE PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after the S

Aptose Announces Closing of $4.43 Million Registered Direct Offering Priced At-the-Market Under Nasdaq Rules

EXHIBIT 99.1 Aptose Announces Closing of $4.43 Million Registered Direct Offering Priced At-the-Market Under Nasdaq Rules SAN DIEGO and TORONTO, June 03, 2024 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (NASDAQ: APTO, TSX: APS), a clinical-stage precision oncology company developing highly differentiated oral targeted agents to treat hematologic malignancies, today annou

Form of Pre-Funded Common Share Purchase Warrant

Exhibit 10.4 PRE-FUNDED COMMON SHARE PURCHASE WARRANT APTOSE BIOSCIENCES INC. Warrant Shares: Issue Date:, 2024 Initial Exercise Date: , 2024 THIS PRE-FUNDED COMMON SHARE PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or

Form of Placement Agent Common Share Purchase Warrant

Exhibit 10.3 PLACEMENT AGENT COMMON SHARE PURCHASE WARRANT APTOSE BIOSCIENCES INC. Warrant Shares: Issue Date: June 3, 2024 THIS PLACEMENT AGENT COMMON SHARE PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after the Sh

1,800,000 Common Shares 2,055,000 Pre-Funded Warrants to Purchase up to 2,055,000 Common Shares Common Shares Underlying the Pre-Funded Warrants

Table of Contents Filed Pursuant to Rule 424(b)(5) Registration No. 333-267801 Prospectus Supplement (to Prospectus dated October 21, 2022) 1,800,000 Common Shares 2,055,000 Pre-Funded Warrants to Purchase up to 2,055,000 Common Shares Common Shares Underlying the Pre-Funded Warrants We are offering 1,800,000 common shares, no par value (“Common Shares”), and 2,055,000 pre-funded warrants (the “Pr

Form of Securities Purchase Agreement

Exhibit 10.1 SECURITIES PURCHASE AGREEMENT This Securities Purchase Agreement (this “Agreement”) is dated as of May 30, 2024, between Aptose Biosciences Inc., a corporation organized under the laws of Canada (the “Company”), and each purchaser identified on the signature pages hereto (each, including its successors and assigns, a “Purchaser” and collectively the “Purchasers”). WHEREAS, subject to

Entry into a Material Definitive Agreement, Unregistered Sales of Equity Securities

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): May 30, 2024 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

Regulation FD Disclosure, Financial Statements and Exhibits

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): June 3, 2024 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

Regulation FD Disclosure, Termination of a Material Definitive Agreement, Financial Statements and Exhibits

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): May 31, 2024 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

Aptose Announces $4.43 Million Registered Direct Offering Priced At-the-Market Under Nasdaq Rules

EXHIBIT 99.1 Aptose Announces $4.43 Million Registered Direct Offering Priced At-the-Market Under Nasdaq Rules SAN DIEGO and TORONTO, May 31, 2024 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (NASDAQ: APTO, TSX: APS), a clinical-stage precision oncology company developing highly differentiated oral targeted agents to treat hematologic malignancies, today announced that it

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 Filed by the Registra

Table of Contents 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 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☒ Definitive Proxy Statement ☐ Definitive Additional Materials ☐ Soliciting Material Pursuant to §240.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

on UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Quarterly Period Ended March 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Transition Period from to Commission File Number: 1-32001 APTOSE BIOSCIENCES

Financial Statements and Exhibits, Results of Operations and Financial Condition

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): May 14, 2024 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

Aptose Reports Results for the First Quarter 2024

EXHIBIT 99.1 Aptose Reports Results for the First Quarter 2024 TUS+VEN+HMA Triplet Protocol in 1L Therapy for Newly Diagnosed AML was Submitted to the FDA During Q1 and is Now Being Activated at Clinical Sites TUS+VEN+HMA Triplet 1L Therapy for Newly Diagnosed AML is Supported by Extensive TUS and TUS+VEN Data from Completed Trials with R/R AML Conference Call and Webcast at 5:00 pm ET Today SAN D

Aptose to Report First Quarter 2024 Financial Results and Provide Clinical Strategy Update on Tuesday, May 14, 2024

EXHIBIT 99.1 Aptose to Report First Quarter 2024 Financial Results and Provide Clinical Strategy Update on Tuesday, May 14, 2024 SAN DIEGO and TORONTO, May 06, 2024 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (Nasdaq: APTO; TSX: APS), a clinical- stage precision oncology company developing highly differentiated oral targeted agents to treat hematologic malignancies, will report financial results fo

Regulation FD Disclosure, Financial Statements and Exhibits

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): May 6, 2024 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

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Entry into a Material Definitive Agreement

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 April 29, 2024 (Date of Report - date of earliest event reported) Aptose Biosciences Inc. (Exact Name of Registrant as Specified in Its Charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation or Organizatio

Amended and Restated Executive Employment Agreement dated April 29, 2024 between the Company and Dr. Rafael Bejar

Exhibit 10.2 APTOSE BIOSCIENCES INC. AMENDED AND RESTATED EXECUTIVE EMPLOYMENT AGREEMENT This Amended and Restated Executive Employment Agreement (the “Agreement”), made between Aptose Biosciences Inc. (the “Company”) and Rafael Bejar, M.D. Ph.D (“Executive”), and together with the Company, (the “Parties”), is effective as of April 29, 2024 (the “Effective Date”). WHEREAS the Company and the Execu

Amended and Restated Executive Employment Agreement dated April 29, 2024 between the Company and Mr. Fletcher Payne

Exhibit 10.3 APTOSE BIOSCIENCES INC. AMENDED AND RESTATED EXECUTIVE EMPLOYMENT AGREEMENT This Amended and Restated Executive Employment Agreement (the “Agreement”), made between Aptose Biosciences Inc. (the “Company”) and Fletcher Payne (“Executive”), and together with the Company, (the “Parties”), is effective as of April 29, 2024 (the “Effective Date”). WHEREAS the Company and the Executive are

Second Amended and Restated Executive Employment Agreement dated April 29, 2024 between the Company and Dr. William G. Rice

Exhibit 10.1 APTOSE BIOSCIENCES INC. SECOND AMENDED AND RESTATED EXECUTIVE EMPLOYMENT AGREEMENT SECOND AMENDED AND RESTATED EXECUTIVE EMPLOYMENT AGREEMENT THIS SECOND AMENDED AND RESTATED EXECUTIVE EMPLOYMENT AGREEMENT is made as of April 29, 2024 BETWEEN: APTOSE BIOSCIENCES INC. (the “Corporation”) - and - DR. WILLIAM G. RICE (the “Executive”) RECITALS: A. The Corporation is involved in the bioph

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 Filed by the Registra

Table of Contents 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 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☒ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Definitive Proxy Statement ☐ Definitive Additional Materials ☐ Soliciting Material Pursuant to §240.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-32001 Aptose Biosci

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): April 24, 2024 APTOSE BIOSCIENCES

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): April 24, 2024 APTOSE BIOSCIENCES INC. (Exact name of registrant as specified in its charter) Canada (State or Other Jurisdiction of Incorporation) 001-32001 (Commission File Number)

Amended and Restated Warrant to Purchase Common Shares, dated January 31, 2024

EX-99.2 2 ea020476901ex99-2aptose.htm AMENDED AND RESTATED WARRANT TO PURCHASE COMMON SHARES, DATED JANUARY 31, 2024 Exhibit 99.2 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, A

CA:APS / Aptose Biosciences Inc. / Hanmi Pharmaceutical Co., Ltd. - AMENDMENT NO. 2 TO SCHEDULE 13D Activist Investment

SC 13D/A 1 ea0204769-13da2hanmiaptose.htm AMENDMENT NO. 2 TO SCHEDULE 13D UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 2) Aptose Biosciences Inc. (Name of Issuer) Common Shares, no par value (Title of Class of Securities) 03835T200 (CUSIP Number) Tony Koh Hanmi Pharmaceutical Co., Ltd. 14 Wiryeseong-Da

Amended Warrant Agreement

Exhibit 4.1 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing, Financial Statements and Exhibits

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 April 2, 2024 (Date of Report - date of earliest event reported) Aptose Biosciences Inc. (Exact Name of Registrant as Specified in Its Charter) Canada (State or Other Jurisdiction of Incorporation or Organization) 001-32001 (Commissi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-32001 Aptose Bioscien

Aptose Reports Results for the Fourth Quarter and Full Year 2023

EXHIBIT 99.1 Aptose Reports Results for the Fourth Quarter and Full Year 2023 Tuspetinib to Advance to TUS+VEN+HMA Triplet Therapy Pilot Study in 1L AML Tuspetinib Continues Broad Activity Across Mutations with Excellent Safety Profile Luxeptinib G3 Formulation Achieves Desired Levels and Positions for Future Trials Conference Call and Webcast at 5:00 pm ET Today SAN DIEGO and TORONTO, March 26, 2

Financial Statements and Exhibits, Results of Operations and Financial Condition

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 26, 2024 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission Fi

List of Subsidiaries

Exhibit 21.1 Subsidiaries of the Registrant Name State/Jurisdiction of Incorporation Aptose Biosciences U.S. Inc. Delaware NuChem Pharmaceuticals Inc. Ontario, Canada

Aptose Bioscience Inc. Clawback Policy

e Exhibit 97.1 APTOSE BIOSCIENCES INC. INCENTIVE COMPENSATION RECOVERY POLICY 1. Introduction. The Board of Directors of Aptose Biosciences Inc. (the “Company”) believes that it is in the best interests of the Company and its shareholders to create and maintain a culture that emphasizes integrity and accountability and that reinforces the Company's compensation philosophy. The Board has therefore

Aptose to Report Fourth Quarter and Year End 2023 Financial Results and Provide Corporate Update on Tuesday, March 26, 2024

EXHIBIT 99.1 Aptose to Report Fourth Quarter and Year End 2023 Financial Results and Provide Corporate Update on Tuesday, March 26, 2024 SAN DIEGO and TORONTO, March 18, 2024 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (Nasdaq: APTO; TSX: APS), a clinical- stage precision oncology company developing highly differentiated oral targeted agents to treat hematologic malignancies, will report financial

Regulation FD Disclosure, Financial Statements and Exhibits

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 18, 2024 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission Fi

Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing, Financial Statements and Exhibits

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 February 29, 2024 (Date of Report - date of earliest event reported) Aptose Biosciences Inc. (Exact Name of Registrant as Specified in Its Charter) Canada (State or Other Jurisdiction of Incorporation or Organization) 001-32001 (Comm

APTO / Aptose Biosciences Inc. / Nantahala Capital Management, LLC - SC 13G/A Passive Investment

SC 13G/A 1 tm243309d1sc13ga.htm SC 13G/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 4)* Aptose Biosciences Inc. (Name of Issuer) Common Shares, no par value (Title of Class of Securities) 03835T200 (CUSIP Number) December 31, 2023 (Date of Event which Requires Filing of this Statement) Check the appr

Subscription Agreement, dated as of January 25, 2024, by and between the Reporting Person and the Issuer.

EX-99.1 2 ea192731ex99-1aptose.htm SUBSCRIPTION AGREEMENT, DATED AS OF JANUARY 25, 2024, BY AND BETWEEN THE REPORTING PERSON AND THE ISSUER Exhibit 99.1 EXECUTION PAGE - SUBSCRIPTION FOR COMMON SHARES AND WARRANTS TO: Aptose Biosciences Inc. (the “Corporation”) The undersigned (the “Subscriber’’) hereby irrevocably subscribes for and agrees to purchase from Aptose Biosciences Inc. (the “Corporatio

APTO / Aptose Biosciences Inc. / Hanmi Pharmaceutical Co., Ltd. - AMENDMENT NO. 1 TO SCHEDULE 13D Activist Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 1) Aptose Biosciences Inc. (Name of Issuer) Common Shares, no par value (Title of Class of Securities) 03835T200 (CUSIP Number) Tony Koh Hanmi Pharmaceutical Co., Ltd. 14 Wiryeseong-Daero, Songpa-Gu Seoul, Republic of Korea, 05545 +82 (2) 410 0436 with a c

Aptose Announces Closing of $9.7 Million Public Offering and Concurrent $4 Million Private Placement with Hanmi Pharmaceutical, Including Full Exercise of Over-Allotment Option

EXHIBIT 99.1 Aptose Announces Closing of $9.7 Million Public Offering and Concurrent $4 Million Private Placement with Hanmi Pharmaceutical, Including Full Exercise of Over-Allotment Option SAN DIEGO and TORONTO, Jan. 31, 2024 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (Nasdaq: APTO, TSX: APS), a clinical-stage precision oncology company developing highly differentiated

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): January 31, 2024 Aptose Bioscienc

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): January 31, 2024 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission

Funding Satisfaction Agreement

Exhibit 10.3 January 25, 2024 Hanmi Pharmaceutical Co., Ltd. 14 Wiryeseong-daero, Songpa-gu, Seoul, 05545, Korea Re: Completion of Funding Obligation under Subscription Agreement dated September 6, 2023 (the “Subscription Agreement”) by and between Aptose Biosciences Inc. (the “Corporation”) and Hanmi Pharmaceutical Co., Ltd. (“Hanmi”). Gentlemen: This letter serves to confirm the agreement betwee

Form of Underwriter Warrant

Exhibit 4.4 UNDERWRITER WARRANT TO PURCHASE COMMON SHARES THE REGISTERED HOLDER OF THIS WARRANT TO PURCHASE COMMON SHARES BY ITS ACCEPTANCE HEREOF, AGREES THAT IT WILL NOT SELL, TRANSFER OR ASSIGN THIS WARRANT TO PURCHASE COMMON SHARES EXCEPT AS HEREIN PROVIDED AND THE REGISTERED HOLDER OF THIS WARRANT TO PURCHASE COMMON SHARES AGREES THAT IT WILL NOT SELL, TRANSFER, ASSIGN, PLEDGE OR HYPOTHECATE

Subscription Agreement

Exhibit 10.1 Certain portions of this Exhibit have been redacted pursuant to Item 601(b)(10) of Regulation S-K and, where applicable, have been marked with “[***]” to indicate where redactions have been made. The marked information has been redacted because it is both (i) not material and (ii) is the type of information the Corporation treats as private and confidential. APTOSE BIOSCIENCES INC. SU

Amended and Restated Investor’s Rights Agreement

Exhibit 10.2 Certain portions of this Exhibit have been redacted pursuant to Item 601(b)(10) of Regulation S-K and, where applicable, have been marked with “[***]” to indicate where redactions have been made. The marked information has been redacted because it is both (i) not material and (ii) is the type of information the Corporation treats as private and confidential. AMENDED AND RESTATED INVES

Form of Public Offering Warrant

Exhibit 4.3 APTOSE BIOSCIENCES INC. WARRANT TO PURCHASE COMMON SHARES Warrant No.:      Number of Common Shares:      Date of Issuance:     , 202  (“Issuance Date”) Aptose Biosciences Inc., a company organized under the Canada Business Corporations Act (the “Company”), hereby certifies that, for good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, [HOLDER]

Form of Hanmi Warrant

Exhibit 4.1 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

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): January 25, 2024 APTOSE BIOSCIENC

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): January 25, 2024 APTOSE BIOSCIENCES INC. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission

Form of Placement Agent Warrant

Exhibit 4.2 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

Underwriting Agreement

Exhibit 1.1 APTOSE BIOSCIENCES INC. 4,912,280 Common Shares 4,912,280 Warrants UNDERWRITING AGREEMENT January 25, 2024 Newbridge Securities Corporation as Representative of the several Underwriters named in Schedule I hereto 1200 North Federal Highway, Suite 400 Boca Raton, FL 33432 Ladies and Gentlemen: Aptose Biosciences Inc., a company incorporated under the Canada Business Corporations Act (th

4,912,280 Common Shares 4,912,280 Warrants to Purchase 4,912,280 Common Shares Up to 4,912,280 Common Shares Underlying Warrants Up to 343,860 Common Shares Underlying Underwriter’s Warrants

Table of Contents Filed Pursuant to 424(b)(4) Registration No. 333-275870 PROSPECTUS 4,912,280 Common Shares 4,912,280 Warrants to Purchase 4,912,280 Common Shares Up to 4,912,280 Common Shares Underlying Warrants Up to 343,860 Common Shares Underlying Underwriter’s Warrants We are offering 4,912,280 common shares, no par value (“Offered Shares”), together with Warrants to purchase Offered Shares

Aptose Announces Pricing of $8.4 Million Public Offering and a Concurrent $4 Million Private Placement with Hanmi Pharmaceutical

EXHIBIT 99.1 Aptose Announces Pricing of $8.4 Million Public Offering and a Concurrent $4 Million Private Placement with Hanmi Pharmaceutical SAN DIEGO and TORONTO, Jan. 26, 2024 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (Nasdaq: APTO, TSX: APS), a clinical-stage precision oncology company developing highly differentiated targeted agents to treat hematologic malignanci

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): January 26, 2024 Aptose Bioscienc

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): January 26, 2024 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission

As filed with the Securities and Exchange Commission on January 25, 2024

As filed with the Securities and Exchange Commission on January 25, 2024 Registration No.

Filing Fees

Exhibit 107 Calculation of Filing Fee Tables Form S-1 (Form Type) Aptose Biosciences Inc.

January 24, 2024

January 24, 2024 VIA EDGAR U.S. Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549 Re: Aptose Biosciences Inc. Registration Statement on Form S-1 File No. 333-275870 Request for Acceleration of Effective Date Ladies and Gentlemen: In accordance with Rule 461 under the Securities Act of 1933, as amended (the “Act”), we, as underwriter for th

Aptose Biosciences, Inc. 251 Consumers Road, Suite 1105 Toronto, Ontario, Canada M2J 4R3

Aptose Biosciences, Inc. 251 Consumers Road, Suite 1105 Toronto, Ontario, Canada M2J 4R3 January 24, 2024 VIA EDGAR United States Securities and Exchange Commission Division of Corporation Finance 100 F. Street, N.E. Washington, D.C. 20549 Attention: Jason Drory Re: Aptose Biosciences Inc. – Registration Statement on Form S-1 (File No. 333-275870) Ladies and Gentlemen: In accordance with Rule 461

As filed with the Securities and Exchange Commission on January 19, 2024

Table of Contents As filed with the Securities and Exchange Commission on January 19, 2024 Registration No.

Filing Fees

EX-FILING FEES Exhibit 107 Calculation of Filing Fee Tables Form S-1 (Form Type) Aptose Biosciences Inc.

Form of Underwriter’s Warrant

Exhibit 4.4 Underwriter’s Warrant Agreement THE REGISTERED HOLDER OF THIS PURCHASE WARRANT BY ITS ACCEPTANCE HEREOF, AGREES THAT IT WILL NOT SELL, TRANSFER OR ASSIGN THIS PURCHASE WARRANT EXCEPT AS HEREIN PROVIDED AND THE REGISTERED HOLDER OF THIS PURCHASE WARRANT AGREES THAT IT WILL NOT SELL, TRANSFER, ASSIGN, PLEDGE OR HYPOTHECATE THIS PURCHASE WARRANT FOR A PERIOD OF ONE HUNDRED EIGHTY DAYS FOL

As filed with the Securities and Exchange Commission on December 29, 2023

Table of Contents As filed with the Securities and Exchange Commission on December 29, 2023 Registration No.

Form of Underwriting Agreement

Exhibit 1.1 APTOSE BIOSCIENCES INC. [●] Common Shares [●] Pre-Funded Warrants [●] Warrants UNDERWRITING AGREEMENT [●], 2024 Newbridge Securities Corporation as Representative of the several Underwriters named in Schedule I hereto 1200 North Federal Highway, Suite 400 Boca Raton, FL 33432 Ladies and Gentlemen: Aptose Biosciences Inc., a company incorporated under the Canada Business Corporations Ac

Calculation of Filing Fee Tables Form S-1 (Form Type) Aptose Biosciences Inc. (Exact Name of Each Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation or Car

Exhibit 107 Calculation of Filing Fee Tables Form S-1 (Form Type) Aptose Biosciences Inc.

As filed with the Securities and Exchange Commission on December 11, 2023

S-1/A Table of Contents As filed with the Securities and Exchange Commission on December 11, 2023 Registration No.

Aptose Tuspetinib Clinical Data Featured in Oral Presentation at the 2023 ASH Annual Meeting

EXHIBIT 99.1 Aptose Tuspetinib Clinical Data Featured in Oral Presentation at the 2023 ASH Annual Meeting Reporting Complete Response Data from the Ongoing APTIVATE International Phase 1/2 Study of Tuspetinib (TUS) in Relapsed/Refractory AML Patients TUS Single Agent and TUS/VEN Combination Demonstrate Favorable Safety and Tolerability TUS/VEN Combination Active Across Broad Populations of AML and

Form of Pre-Funded Warrant Offered in this Offering

Exhibit 4.3 APTOSE BIOSCIENCES INC. PRE-FUNDED WARRANT TO PURCHASE COMMON SHARES Warrant No.: Number of Common Shares: Date of Issuance: , 202 (“Issuance Date”) Aptose Biosciences Inc., a company organized under the Canada Business Corporations Act (the “Company”), hereby certifies that, for good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, [HOLDER], th

Calculation of Filing Fee Tables Form S-1 (Form Type) Aptose Biosciences Inc. (Exact Name of Each Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation or Car

EX-FILING FEES Exhibit 107 Calculation of Filing Fee Tables Form S-1 (Form Type) Aptose Biosciences Inc.

Form of Underwriting Agreement

EX-1.1 Exhibit 1.1 APTOSE BIOSCIENCES INC. [●] Common Shares [●] Pre-Funded Warrants [●] Warrants UNDERWRITING AGREEMENT [●], 2023 Oppenheimer & Co. Inc. as Representative of the several Underwriters named in Schedule I hereto 85 Broad Street New York, New York 10004 Ladies and Gentlemen: Aptose Biosciences Inc., a company incorporated under the Canada Business Corporations Act (the “Company”), pr

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): December 9, 2023 Aptose Bioscienc

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): December 9, 2023 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission

Form of Warrant Offered in this Offering

EX-4.2 Exhibit 4.2 APTOSE BIOSCIENCES INC. WARRANT TO PURCHASE COMMON SHARES Warrant No.: Number of Common Shares: Date of Issuance: , 202 (“Issuance Date”) Aptose Biosciences Inc., a company organized under the Canada Business Corporations Act (the “Company”), hereby certifies that, for good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, [HOLDER], the re

As filed with the Securities and Exchange Commission on December 1, 2023

S-1 Table of Contents As filed with the Securities and Exchange Commission on December 1, 2023 Registration No.

Calculation of Filing Fee Tables Form S-1 (Form Type) Aptose Biosciences Inc. (Exact Name of Each Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation or Car

EX-FILING FEES Exhibit 107 Calculation of Filing Fee Tables Form S-1 (Form Type) Aptose Biosciences Inc.

Aptose Appoints Fletcher Payne Chief Business Officer, Expanding his Executive Role

EXHIBIT 99.1 Aptose Appoints Fletcher Payne Chief Business Officer, Expanding his Executive Role SAN DIEGO and TORONTO, Nov. 30, 2023 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (NASDAQ: APTO, TSX: APS), a clinical-stage precision oncology company developing highly differentiated oral targeted agents to treat hematologic malignancies, today announced the appointment of F

Regulation FD Disclosure, Financial Statements and Exhibits

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): November 30, 2023 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

on UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Quarterly Period Ended September 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Transition Period from to Commission File Number: 1-32001 APTOSE BIOSCIEN

Aptose Reports Results for the Third Quarter 2023

EXHIBIT 99.1 Aptose Reports Results for the Third Quarter 2023 Tuspetinib (TUS) Targets Venetoclax (VEN) Resistance Mechanisms TUS/VEN Combination Therapy Active in R/R VEN Failure AML Patients – Guides Toward Accelerated Approval Path, Including FLT3 Mutated and Wildtype TUS/VEN Overall Response Rate of 48% in Heavily Pre-Treated Relapsed/Refractory AML Patients Tuspetinib Favorable Safety Profil

Financial Statements and Exhibits, Results of Operations and Financial Condition

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): November 9, 2023 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission

Aptose Tuspetinib Clinical Data Selected for Oral Presentation at the 2023 ASH Annual Meeting Data from the Ongoing APTIVATE International Phase 1/2 Study in Relapsed/Refractory AML Patients

EXHIBIT 99.1 Aptose Tuspetinib Clinical Data Selected for Oral Presentation at the 2023 ASH Annual Meeting Data from the Ongoing APTIVATE International Phase 1/2 Study in Relapsed/Refractory AML Patients SAN DIEGO and TORONTO, Nov. 02, 2023 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (NASDAQ: APTO, TSX: APS), a clinical-stage precision oncology company developing highly

Regulation FD Disclosure, Financial Statements and Exhibits

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): November 2, 2023 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission

Regulation FD Disclosure, Financial Statements and Exhibits

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): October 30, 2023 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission

Aptose Presents Highlights from Clinical Update Webcast Featuring Latest Available Data on AML Drug Tuspetinib

EXHIBIT 99.1 Aptose Presents Highlights from Clinical Update Webcast Featuring Latest Available Data on AML Drug Tuspetinib Tuspetinib (TUS) Combination with Venetoclax (VEN) Clinical Findings Highlighted TUS Targets VEN Resistance Mechanisms to Re-sensitize VEN Failure Patients to VEN 44% ORR with TUS/VEN in Difficult-to-Treat VEN Failure R/R AML Patients 48% ORR with TUS/VEN in Heavily Pre-treat

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): October 26, 2023 Aptose Bioscienc

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): October 26, 2023 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission

Aptose to Report Third Quarter 2023 Financial Results and Hold Conference Call on Thursday, November 9, 2023

EXHIBIT 99.1 Aptose to Report Third Quarter 2023 Financial Results and Hold Conference Call on Thursday, November 9, 2023 SAN DIEGO and TORONTO, Oct. 26, 2023 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (Nasdaq: APTO; TSX: APS), a clinical-stage precision oncology company developing highly differentiated oral targeted agents to treat hematologic malignancies, will report financial results for the t

Regulation FD Disclosure, Financial Statements and Exhibits

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): October 23, 2023 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission

Aptose to Hold Clinical Update and KOL Data Review of AML Drug Tuspetinib on Monday, October 30th

EXHIBIT 99.1 Aptose to Hold Clinical Update and KOL Data Review of AML Drug Tuspetinib on Monday, October 30th SAN DIEGO and TORONTO, Oct. 23, 2023 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (NASDAQ: APTO, TSX: APS), a clinical-stage precision oncology company developing highly differentiated oral kinase inhibitors to treat hematologic malignancies, today announced that

Regulation FD Disclosure, Financial Statements and Exhibits

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): October 16, 2023 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission

Aptose Clinical and Preclinical Data to be Presented at European School of Haematology (ESH) 6th International Conference Company to Hold Clinical Update Webcast; Details Forthcoming

EXHIBIT 99.1 Aptose Clinical and Preclinical Data to be Presented at European School of Haematology (ESH) 6th International Conference Company to Hold Clinical Update Webcast; Details Forthcoming SAN DIEGO and TORONTO, Oct. 16, 2023 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (NASDAQ: APTO, TSX: APS), a clinical-stage precision oncology company developing highly differen

As filed with the Securities and Exchange Commission on September 21, 2023

As filed with the Securities and Exchange Commission on September 21, 2023 Registration No.

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Table Form S-8 (Form Type) Aptose Biosciences Inc.

Aptose Biosciences Inc. 2021 Stock Incentive Plan

Exhibit 4.1 APTOSE BIOSCIENCES INC. 2021 STOCK INCENTIVE PLAN, AS AMENDED Section 1. Purpose The purpose of the Plan is to promote the interests of the Company and its shareholders by aiding the Company in attracting and retaining employees, officers, consultants, advisors, independent contractors and non-employee Directors capable of assuring the future success of the Company, to offer such perso

Regulation FD Disclosure, Financial Statements and Exhibits

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): September 18, 2023 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commissio

Aptose to Present at the Cantor Global Healthcare Conference

EXHIBIT 99.1 Aptose to Present at the Cantor Global Healthcare Conference SAN DIEGO and TORONTO, Sept. 18, 2023 (GLOBE NEWSWIRE) - Aptose Biosciences Inc. (“Aptose” or the “Company”) (NASDAQ: APTO, TSX: APS), a clinical-stage precision oncology company developing highly differentiated oral kinase inhibitors to treat hematologic malignancies, today announced that the Aptose management team will par

Subscription Agreement, dated September 6, 2023, by and between the Company and Hanmi Pharmaceutical Co., Ltd. (incorporated herein by reference to Exhibit 10.1 to the Company’s Current Report on Form 8-K filed with the SEC on September 12, 2023)

Exhibit 10.1 Certain portions of this Exhibit have been redacted pursuant to Item 601(b)(10) of Regulation S-K and, where applicable, have been marked with “[***]” to indicate where redactions have been made. The marked information has been redacted because it is both (i) not material and (ii) is the type of information the Corporation treats as private and confidential. APTOSE BIOSCIENCES INC.  S

APTO / Aptose Biosciences Inc / Hanmi Pharmaceutical Co., Ltd. - SCHEDULE 13D Activist Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 Aptose Biosciences Inc. (Name of Issuer) Common Shares, no par value (Title of Class of Securities) 03835T200 (CUSIP Number) Tony Koh Hanmi Pharmaceutical Co., Ltd. 14 Wiryeseong-Daero, Songpa-Gu Seoul, Republic of Korea, 05545 +82 (2) 410 0436 with a copy to: Robert F. Gr

Investor Rights Agreement, dated September 6, 2023, by and between the Company and Hanmi Pharmaceutical Co., Ltd. (incorporated herein by reference to Exhibit 10.2 to the Company’s Current Report on Form 8-K filed with the SEC on September 12, 2023)

Exhibit 10.2 Certain portions of this Exhibit have been redacted pursuant to Item 601(b)(10) of Regulation S-K and, where applicable, have been marked with “[***]” to indicate where redactions have been made. The marked information has been redacted because it is both (i) not material and (ii) is the type of information the Corporation treats as private and confidential. INVESTOR’S RIGHTS AGREEMEN

Entry into a Material Definitive Agreement, Unregistered Sales of Equity Securities, Financial Statements and Exhibits

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): September 6, 2023 Aptose Biosciences Inc. (Exact name of registrant as specified in its charter) Canada 001-32001 98-1136802 (State or Other Jurisdiction of Incorporation) (Commission

Subscription Agreement, dated as of September 6, 2023, by and between the Reporting Person and the Issuer.

Exhibit 99.1 EXECUTION PAGE – SUBSCRIPTION FOR COMMON SHARES TO: Aptose Biosciences Inc. ( the “Corporation”) The undersigned (the “Subscriber”) hereby irrevocably subscribes for and agrees to purchase from Aptose Biosciences Inc. (the “Corporation”) that number of common shares of the Corporation (individually, a “Common Share” and collectively, the “Common Shares”) as will be equal to the Aggreg