Company: SION
Filing Date: 2025-04-29
Form Type: DEFA14A
Source: 0001193125-25-101834
Chunk: 1

Company: Sionna Therapeutics, Inc.
Filing Date: 2025-04-29
Form: DEFA14A
Chunk 1
---
) in the subject line. Unless requested, you will not otherwise receive a paper or email copy. For complete information and to vote, visit www.ProxyVote.com Control 

# Smartphone users Vote Virtually at the Meeting* Point your camera here and June 12, 2025 10:00 AM EDT vote without entering a control number Virtually at: www.virtualshareholdermeeting.com/SION2025 *Please check the meeting materials for any special requirements for meeting attendance.
Vote at www.ProxyVote.com THIS IS NOT A VOTABLE BALLOT This is an overview of the proposals being presented at the upcoming stockholder meeting. Please follow the instructions on the reverse side to vote on these important matters. Board Voting Items Recommends 1. To elect three class I directors to serve until our 2028 annual meeting of stockholders and until his or her successor has been duly elected and qualified, or until his or her earlier death, resignation or removal. Nominees: For 01) Joshua Resnick, M.D., M.B.A. 02) Bruce Booth, D.Phil. 03) Lucian Iancovici, M.D. 2. To ratify the appointment of Deloitte & Touche LLP as our independent registered public accounting firm for the For fiscal year ending December 31, 2025. NOTE: In their discretion, the proxies are authorized to vote upon such other business as may properly come before the meeting or any continuation, adjournment or postponement thereof. Prefer to receive an email instead? While voting on www.ProxyVote.com, be sure to click “Delivery Settings”. V72402-P31556