Company: SION
Filing Date: 2025-04-29
Form Type: DEF 14A
Source: 0001193125-25-101830
Chunk: 37

Company: Sionna Therapeutics, Inc.
Filing Date: 2025-04-29
Form: DEF 14A
Chunk 37
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 Viney each became a member of our board of directors on January 6, 2025 and each received an Initial Grant on February 6, 2025, with terms in accordance with the non-employeedirector compensation policy described above. Furthermore, on the date of each annual meeting of stockholders, each non-employeedirector who continues as a non-employeedirector following such meeting (other than a director receiving an Initial Grant on the date of such meeting) will be granted an annual stock option award to purchase 19,959 shares of our common stock (the “Annual Grant”). The Annual Grant will vest in full upon the earlier of (i) the first anniversary of the date of grant or (ii) the date of the next annual meeting of stockholders, subject to continued service through the applicable vesting date. If a non-employeedirector joins our board of directors on a date other than the date of the annual meeting of stockholders, then in lieu of a full Annual Grant, such non-employeedirector will be granted a pro-ratedportion of the Annual Grant based on the number of full months between the director’s initial election or appointment and such annual meeting of stockholders, which will vest in accordance with the same 25

terms as the Annual Grants. The Initial Grants and Annual Grants (including any pro rata portions thereof) will each expire ten years from the applicable date of grant and have an exercise price per share equal to the fair market value of our common stock on the date of grant.

The Initial Grants and the Annual Grants (including any pro rata portions thereof) are subject to full accelerated vesting upon a sale event (as defined in the 2025 Stock Option and Incentive Plan (the “2025 Plan”)).

The aggregate amount of compensation, including both equity compensation and cash compensation, paid to any non-employee director for service as a non-employee director in a calendar year period will not exceed $1,000,000 in the first calendar year such individual becomes a non-employee director and $750,000 in any other calendar year (or such other limits as may be set forth in the 2025 Plan or any successor plan).

We will reimburse all reasonable out-of-pocket expenses incurred by non-employee directors for their attendance at meetings of our board of directors or any committee thereof.

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EXECUTIVE COMPENSATION This section describes the material elements of compensation awarded to, earned by or paid to our