Company: SION
Filing Date: 2025-04-29
Form Type: DEF 14A
Source: 0001193125-25-101830
Chunk: 11

Company: Sionna Therapeutics, Inc.
Filing Date: 2025-04-29
Form: DEF 14A
Chunk 11
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 of our certificate of incorporation and bylaws, our board of directors is divided into three classes, class I, class II and class III, with members of each class serving staggered three-year terms. The members of the classes are divided as follows:

| • |     | the class I directors are Joshua Resnick, M.D., M.B.A., Bruce Booth, D.Phil., and Lucian Iancovici, M.D. and their terms will expire at the Annual Meeting; |

| • |     | the class II directors are H. Edward Fleming, Jr., M.D., Peter A. Thompson, M.D., Joanne Louise Viney, Ph.D., and Marcella Kuhlmann Ruddy, M.D. and their terms will expire at the annual meeting of stockholders to be held in 2026; and |

| • |     | the class III directors are Paul Clancy, M.B.A., Michael Cloonan, M.B.A., and Laurie Stelzer, M.B.A. and their terms will expire at the annual meeting of stockholders to be held in 2027. |

Upon the expiration of the term of a class of directors, directors in that class will be eligible to be elected for a new three-year term at the annual meeting of stockholders in the year in which their term expires. Our certificate of incorporation and bylaws provide that the authorized number of directors may be changed only by resolution of our board of directors. Our certificate of incorporation also provides that our directors may be removed only for cause by the affirmative vote of the holders of at least two-thirds(2/3) of the voting power of the outstanding shares then entitled to vote in an election of directors, and that any vacancy on our board of directors, including a vacancy resulting from an enlargement of our board of directors, may be filled only by the affirmative vote of a majority of our directors then in office, even if less than a quorum. This year, the term of our class I directors, Joshua Resnick, M.D., M.B.A., Bruce Booth, D.Phil., and Lucian Iancovici, M.D., is expiring. The nominees are presently directors, and have indicated a willingness to continue to serve as directors, if elected. In addition to the information presented below regarding each of the nominees and continuing directors’ specific experience, qualifications, attributes and skills that our board of directors and our nominating and corporate governance committee considered in determining that he or she should serve as a