Hanmi Pharmaceutical Co. Ltd.

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 215,703 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 ("API") and drug product to support further tuspetinib clinical development, for which the Company pays Hanmi per batch of production. Expenses related to this supply agreement have been recognized by the Company, amounting to $3.5 million and approximately $3.6 million, for the years ended December 31, 2023 and 2022, respectively. Since inception to December 31, 2023, $7.1 million has been recognized for the period under the supply agreement.

The Company paid supply costs to Hanmi of $4.5 million and nil in the years ended December 31, 2023 and 2022, respectively. Since inception to December 31, 2023, payments of $4.5 million have been made under the supply

agreement. At December 31, 2023, there was $2.6 million in accounts payable and nil in accrued liabilities to Hanmi related to the supply agreement. (At December 31, 2022, there was $3.0 million in accounts payable and $0.6 million in accrued liabilities). Transactions involving related parties cannot be presumed to be carried out on an arm's-length basis, as the requisite conditions of competitive, free-market dealings may not exist.

On August 10, 2023, the Company entered into a binding term sheet with Hanmi whereby Hanmi agreed at their sole discretion to invest, up to a maximum of $7 million in Aptose up to a total ownership of 19.99 percent of Aptose by Hanmi. On September 6, 2023, the Company entered into a subscription agreement with Hanmi, pursuant to which the Company sold 668,449 Common Shares to Hanmi for gross proceeds of $3 million. The issuance of shares, in exchange for gross proceeds of $3 million, is recorded in Common Shares on the balance sheet as of December 31, 2023. For information regarding Hanmi's investment subsequent to December 31, 2023, see Note 17, Subsequent events.

Hanmi held 884,152 Common Shares of Aptose as of December 31, 2023. As of the filing date, the total common share ownership by Hanmi was 2,989,414, representing ownership of 19.03% of the outstanding Common Shares of the Company. Hanmi also owns 2,339,181 warrants to purchase Common Shares at an exchange price of $1.71 per Warrant Share. See Note 17, Subsequent events for information about shares sold to Hanmi subsequent to December 31, 2023 and the Nasdaq Deficiency Letter.