Company: SION
Filing Date: 2025-04-29
Form Type: DEF 14A
Source: 0001193125-25-101830
Chunk: 24

Company: Sionna Therapeutics, Inc.
Filing Date: 2025-04-29
Form: DEF 14A
Chunk 24
---
 board of directors, except Michael Cloonan, are independent directors, including for purposes of the rules of Nasdaq and the SEC. In making such independence determination, our board of directors considered the relationships that each non-employee director has with us and all other facts and circumstances that our board of directors deemed relevant in determining their independence, including the beneficial ownership of our capital stock by each non-employee director. In considering the independence of the directors listed above, our board of directors considered the association of our directors with the holders of more than 5% of our common stock. There are no family relationships among any of our executive officers or directors. Michael Cloonan is not an independent director under these rules because he is our President and Chief Executive Officer.

Board Committees

Our board of directors has established an audit committee, a compensation committee and a nominating and corporate governance committee. Each of the audit committee, compensation committee and nominating and corporate governance committee operates under a charter that satisfies the applicable standards of the SEC and Nasdaq. Each such committee will review its respective charter at least annually. A current copy of the charter for each of the audit committee, compensation committee and nominating and corporate governance committee is posted on the corporate governance section of our website, located at https://investors.sionnatx.com/corporate-governance/documents-charters.**

<div align='center'>16</div>

Audit Committee Laurie Stelzer, M.B.A., Paul Clancy, M.B.A. and H. Edward Fleming, Jr., M.D. serve on the audit committee, which is chaired by Ms. Stelzer. Our board of directors has determined that each member of the audit committee is “independent” for audit committee purposes as that term is defined by the rules of the SEC and Nasdaq, and that each has sufficient knowledge in financial and auditing matters to serve on the audit committee. Our board of directors has determined that each of Ms. Stelzer and Mr. Clancy is an “audit committee financial expert,” as defined under the applicable rules of the SEC. The audit committee was established in June 2024. During the fiscal year ended December 31, 2024, the audit committee met twice. The audit committee’s responsibilities include:

| • |     | helping our board of directors oversee our corporate accounting and financial reporting processes; |

| • |     | managing the selection, engagement, qualifications, independence and performance of a qualified firm to serve as the independent registered public accounting firm to audit our consolidated