Hanmi Pharmaceutical Co. Ltd. (“Hanmi”)

On November 4, 2021, Aptose entered into a licensing agreement (the "Tuspetinib Licensing Agreement") with the South Korean company Hanmi. Under the terms of the Tuspetinib Licensing Agreement, Hanmi granted Aptose exclusive worldwide rights to tuspetinib for all indications. Hanmi received an upfront payment of $12.5 million, including $5 million in cash and $7.5 million in Common Shares. Aptose issued Hanmi 7,190 Common Shares in this upfront licensing payment. Hanmi will also receive up to $407.5 million in future milestone payments contingent upon achieving certain clinical, regulatory and sales milestones across several potential indications, as well as tiered royalties on net sales. The term of the agreement will continue on a product-by-product and country-by-country basis until the expiration of the royalty period for such product in such country. The licenses to Aptose will survive and become non-exclusive, perpetual, irrevocable and fully paid-up on a product-by-product and country-by-country basis, upon their natural expiration under the terms of the agreement.

In 2022, the Company and Hanmi also entered into a separate supply agreement for additional production of new drug substance and drug product to support further tuspetinib clinical development (the “Supply Agreement”), for which the Company pays Hanmi per batch of production. For the years ended December 31, 2024 and 2023 expenses related to the Supply Agreement totaled nil and $3.6 million, respectively. Since inception to December 31, 2024, $7.1 million had been expended under the Supply Agreement.

Under the Supply Agreement, the Company paid to Hanmi $2.6 million and $4.5 million for the years ended December 31, 2024 and 2023, respectively. Upon paying Hanmi $2.6 million in 2024, the Company reduced its accounts payable to Hanmi to nil. At December 31, 2024 and 2023 accounts payable and accrued liabilities to Hanmi were nil and nil, and $2.6 million and nil, respectively.

On August 27, 2024, the Company and Hanmi entered into a loan agreement with Hanmi, pursuant to which Hanmi agreed to loan $10 million to Aptose. Under the terms of the Hanmi Loan Agreement, the loan proceeds are restricted to be used for Tuspetinib related business operation purposes, unless otherwise authorized by Hanmi. The use of the funds is also contingent upon the Company meeting specific manufacturing and clinical milestones as outlined in the agreement. The loan is repayable in full on January 31, 2027, with an initial interest period ended on September 30, 2024 and subsequent interest payments due at the end of each three-month period thereafter. Aptose may repay all or any portion of the outstanding principal at any time without penalty, provided that any accrued and unpaid interest on the principal amount being repaid is also settled. The accrued interest on the unpaid principal loan is payable at the periods specified on the Hanmi Loan Agreement at a rate of 6% per annum. During the year ended December 31, 2024, Aptose paid $189 thousand of interest pursuant to the Hanmi Loan Agreement. And as of December 31, 2024, interest expense, related party was $207 thousand and accrued interest was $18 thousand, which is added to the principal of $10 million in non-current liabilities on the statement of financial position.

On September 2, 2024, and in connection with the Hanmi Loan Agreement, Aptose and Hanmi executed a letter of understanding, which outlines the steps associated with the negotiation of a co-development collaboration agreement for the advancement of tuspetinib (the "Future Collaboration Agreement"). Under the terms of the Future Collaboration Agreement, upon execution, the loan principal and any accrued and unpaid interest under the Hanmi Loan Agreement will automatically convert to Hanmi's prepayment of future milestone obligations under the Future Collaboration Agreement. Upon conversion, the Hanmi Loan Agreement, consisting of the $10 million loan principal

with any accrued and unpaid interest, would be deemed fully paid and satisfied. Hanmi has a security interest over all inventory of drug substances and drug products related to the Tuspetinib License Agreement.

As of December 31, 2024 Hanmi held 99,647 Common Shares and 77,972 warrants to purchase Common Shares at an exchange price of $51.30 per Common Shares of Aptose. See also Note 12, Share capital.