Former Director Warren Whitehead Disposes All Aptose Biosciences Holdings Following Acquisition

This Form 4 filing reports that former director Warren Whitehead disposed of all his holdings in Aptose Biosciences Inc. (APTO) on June 30, 2026, following the company's acquisition by Hammi Pharmaceuticals Co. Ltd. The transaction involved the disposition of 33 common shares at $1.72 per share (converted from C$2.41) and the cancellation of nine separate stock option grants totaling 549,833 options with various exercise prices ranging from $0.66 to $6.91. All transactions were conducted pursuant to a board, shareholder, and court-approved business arrangement agreement where Hammi acquired all outstanding shares of Aptose. The filing notes that option totals were adjusted due to reverse stock splits in 2023 and 2025. Following these transactions, Whitehead holds zero shares and zero options in the company.