X0609 4 2026-06-30 true 0000882361 Aptose Biosciences Inc. APTO 0001789042 Seizinger Bernd R. true C/O APTOSE BIOSCIENCES INC. 251 CONSUMERS ROAD, SUITE 1105 TORONTO A6 M5J 4R3 ONTARIO, CANADA false false false true FORMER DIRECTOR false Common Shares 2026-06-30 4 D false 17000 1.72 D 0 D Director Stock Option (Right to Buy) 2 2026-06-30 4 D false 3333 0 D 2034-02-05 Common Shares 3333 0 D Stock Option (right to buy) 0.66 2026-06-30 4 D false 100000 0 D 2033-01-19 Common Shares 100000 0 D Stock Option (right to buy) 0.74 2026-06-30 4 D false 50000 0 D 2032-09-14 Common Shares 50000 0 D Disposed of pursuant to a board, shareholder and court-approved business arrangement agreement between the Issuer and Hammi Pharmaceuticals Co. Ltd., a South Korean Corporation ("Hammi") whereby a subsidiary of Hammi acquired all outstanding shares of the Issuer at a price of C$2.41 per share. Converted from Canadian price of C$2.41 per share using an exchange rate of C$1.4 = US$1.00. Options vest 50% on first anniversary of grant date; remaining options vest 1/3 annually beginning on second anniversary of the grant date. TOTAL OPTIONS AND OPTION EXERCISE PRICE SUBJECT TO ADJUSTMENT AS A RESULT OF THE ISSUER'S 1:30 REVERSE STOCK SPLIT ON 2/26/2025 AND 1:15 REVERSE STOCK SPLIT ON 6/6/2023. /s/ Bernd R. Seizinger 2026-07-02