Milestone Pharmaceuticals Inc.

**2026 ANNUAL MEETING OF SHAREHOLDERS

TO BE HELD ON JUNE 10, 2026

This Management Proxy Circular and Proxy Statement (“Proxy Statement”) contains information about the 2026 Annual Meeting of Shareholders of Milestone Pharmaceuticals Inc., a corporation existing under the laws of the province of Québec (the “Company” or “Milestone”). The meeting will be held on Wednesday, June 10, 2026, at 11:00 a.m., Eastern Time, (such meeting, and any adjournments or postponements thereof the “Annual Meeting”), for the purposes set forth in this Proxy Statement and in the accompanying Notice of Annual Meeting of Shareholders. The Meeting will take place via a virtual meeting portal through which you can listen to the Annual Meeting, submit questions and vote online. The Annual Meeting can be accessed by visiting https://meetnow.global/MUAPKKN . You will not be able to attend the Annual Meeting in person.

In this document, the words “Milestone,” “we,” “our,” “ours” and “us” refer only to Milestone Pharmaceuticals Inc. and not to any other person or entity. References to “US$” or “$” are to United States dollars. Unless otherwise indicated, the statistical and financial data contained in this Proxy Statement are as of December 31, 2025.

We are providing you with this Proxy Statement and related materials in connection with the solicitation of proxies by our management. See “Proxy Solicitation” below for additional information.

We are providing access to our proxy materials, including our Annual Report on Form 10-K for the fiscal year ended December 31, 2025, in a fast and efficient manner via the Internet. On or around April 30, 2026, we will begin mailing a Notice Regarding Internet Availability of Proxy Materials (the “Notice”) to all shareholders of record as of the Record Date and post our proxy materials on the website referenced in the Notice (www.envisionreports.com/milestone2026). As more fully described in the Notice, all shareholders may choose to access our proxy materials on the website referred to in the Notice or may request to receive a printed set of our proxy materials. In addition, the Notice and website will provide information regarding how you may request to receive proxy materials in printed form by mail or electronically by email on an ongoing basis. For those shareholders who have previously provided instructions to receive paper copies of our proxy materials, a paper copy will be sent to you in addition to the Notice. All properly executed written proxies, and all properly completed proxies submitted by mail, facsimile or telephone or via the Internet, which are delivered pursuant to, and which appoint Joseph Oliveto and Amit Hasija as proxyholders in accordance with, this solicitation will be voted at the Annual Meeting in accordance with the directions given in the proxy, unless the proxy is revoked prior to completion of voting at the Annual Meeting.