Aptose shareholders approve 1-for-15 reverse stock split; board implements immediately

Proposal No. 4—Amendment to Articles The Corporation’s shareholders voted to approve a special resolution providing for an amendment to the Corporation’s Articles to effect a reverse stock split of the Corporation’s outstanding common shares at a ratio in the range of 1-for-10 to 1-for-20, such amendment to become effective at an exact ratio and a date to be determined by the board of directors of the Corporation if the board of directors considers it to be in the best interests of the Corporation to implement such reverse stock split. Votes For % Votes For Vote Against % Votes Against Abstain Broker Non- Votes 38,399,205 93.44 2,517,058 6.12 181,200 1

Proposal No. 2—Appointment of Independent Registered Public Accounting Firm The Corporation’s shareholders voted to approve the appointment of KPMG LLP as the independent registered public accounting firm of the Corporation for the fiscal year ended December 31, 2023. Votes For % Votes For Vote Against % Votes Against Abstain Broker Non- Votes 39,648,697 96.48 1,303,802 3.17 144,965 0

Proposal No. 5—Meeting Adjournments The Corporation’s shareholders voted to approve a resolution permitting one or more adjournments of the meeting, if necessary or appropriate, if a quorum is present, to permit further solicitation of proxies if there are not sufficient votes at the time of the meeting to approve Proposals No. 3 and 4. Votes For % Votes For Vote Against % Votes Against Abstain Broker Non- Votes 33,325,854 81.09 7,660,406 18.64 111,202 2

At the meeting, shareholders voted in favor of all items of business, as indicated below: Proposal No. 1—Election of Directors The Corporation’s shareholders voted to elect the following persons to the board of directors of the Corporation, each to serve until the 2024 Annual General Meeting: Nominee Votes For % Votes For Votes Against %Votes Against Broker Non-Votes Ms. Carol G. Ashe 20,399,773 90.69 2,093,509 9.31 18,604,182 Dr. Denis Burger 20,214,219 89.87 2,279,063 10.13 18,604,182 Dr. Erich Platzer 20,485,136 91.07 2,008,146 8.93 18,604,182 Dr. William G. Rice 14,862,859 66.08 7,630,423 33.92 18,604,182 Dr. Mark D. Vincent 20,417,576 90.77 2,075,706 9.23 18,604,182 Mr. Warren Whitehead 20,482,405 91.06 2,010,877 8.94 18,604,182 Dr. Bernd Seizinger 20,498,713 91.13 1,994,569 8.83 18,604,182

Proposal No. 3—Amendment to Stock Incentive Plan The Corporation’s shareholders voted to approve an amendment to the Corporation’s 2021 stock incentive plan to increase the number of common shares reserved for issuance thereunder by 1,027,758 common shares. Votes For % Votes For Vote Against % Votes Against Abstain Broker Non- Votes 13,780,728 61.26 8,645,485 38.44 67,068 18,604,183

Proposal No. 6—Compensation of Named Executive Officers The Corporation’s shareholders voted to approve a non-binding resolution to approve the compensation paid to the Corporation’s named executive officers. Votes For % Votes For Vote Against % Votes Against Abstain Broker Non- Votes 19,458,544 86.50 2,736,388 12.17 298,350 18,604,182