PMN ProMIS Neurosciences Inc

Your Vote Counts! *Please check the meeting materials for any special requirements for meeting attendance. Smartphone users Point your camera here and vote without entering a control number For complete information and to vote, visit www.ProxyVote.com Control # V56236-S95978 Vote Virtually at the Meeting* October 23, 2024 10:00 am, Eastern Time Virtually at: www.virtualshareholdermeeting.com/PMN2024SM PROMIS NEUROSCIENCES INC. 2024 Special Meeting Vote by October 21, 2024 11:59 PM ET You invested in PROMIS NEUROSCIENCES INC. and it’s time to vote! You have the right to vote on proposals being presented at the Special Meeting. This is an important notice regarding the availability of proxy materials for the shareholder meeting to be held on October 23, 2024. Get informed before you vote View the Notice and Proxy Statement online OR you can receive a free paper or email copy of the material(s) by requesting prior to October 9, 2024. If you would like to request a copy of the material(s) for this and/or future shareholder meetings, you may (1) visit www.ProxyVote.com, (2) call 1-800-579-1639 or (3) send an email to sendmaterial@proxyvote.com. If sending an email, please include your control number (indicated below) in the subject line. Unless requested, you will not otherwise receive a paper or email copy. PROMIS NEUROSCIENCES INC. ONE BROADWAY SUITE 1400 CAMBRIDGE, MA 02142 USA

THIS IS NOT A VOTABLE BALLOT This is an overview of the proposals being presented at the upcoming shareholder meeting. Please follow the instructions on the reverse side to vote these important matters. Vote at www.ProxyVote.com Prefer to receive an email instead? While voting on www.ProxyVote.com, be sure to click “Delivery Settings”. Voting Items Board Recommends V56237-S95978 1. Approval of Issuance Proposal: To approve, for purposes of complying with Nasdaq Listing Rule 5635(d), the potential issuance of our Common Shares underlying the (a) Tranche A Common Share purchase warrants and (b) Tranche B Common Share purchase warrants, each sold in our private placement offering, which closed on July 31, 2024; and For 2. Adjournment of Special Meeting: In the event there are not sufficient votes in favor of the foregoing proposal and such proposal is not approved by shareholders, to approve the adjournment of the Special Meeting by the Chairperson to a later date no later than November 22, 2024 at 10:00 a.m., Eastern time, in accordance with the Company’s Bylaws, to solicit additional proxies; provided, the Company shall provide updated instructions to attend such adjournment as necessary. For NOTE: Such other business as may properly come before the meeting or any adjournment thereof.