Company: SION
Filing Date: 2025-02-07
Form Type: 424B4
Source: 0001193125-25-022709
Chunk: 246

Company: Sionna Therapeutics, Inc.
Filing Date: 2025-02-07
Form: 424B4
Chunk 246
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 earned an annual bonus for fiscal year 2024 equal to $278,404, $197,976 and $197,976, respectively. Equity-Based Compensation Each of our NEOs holds outstanding equity awards under our 2020 Stock Option and Grant Plan (the “2020 Plan”). We believe that equity grants provide our executives with a strong link to our long- term performance, create an ownership culture, help to align the interests of our executives and our 181

stockholders, and enhance executive retention. The market for qualified and talented executives in the biopharmaceutical industry is highly competitive, and we compete for talent with many
companies that have greater financial resources than we do. Accordingly, we believe equity compensation is a crucial component of any competitive executive compensation package we offer. As such, our board of directors or our compensation committee
periodically reviews the equity incentive compensation of our executives and may grant equity incentive awards to them from time to time.

In March
2024, following the sale and issuance of our Series C Preferred Stock, pursuant to the Series C Preferred Stock Purchase Agreement, dated as of March 4, 2024, our board of directors granted Mr. Cloonan, Ms. Ridloff and Dr. McKee an
incentive stock option to purchase 656,984, 145,751 and 141,865 shares of our common stock, respectively. Such options vest in 48 equal monthly installments over a period of four years following March 4, 2024, subject to each applicable NEO’s
continued service with us through the applicable vesting dates; provided that the vesting of such shares will fully accelerate upon a “sale event” (as defined in the 2020 Plan and which does not include this offering) and as provided in
the Severance and CIC Agreements and/or the New Severance and CIC Plan (each as defined below). Each NEO’s outstanding awards as of December 31, 2024 are set forth in more detail in the “Outstanding Equity Awards at Fiscal 2024 Year-End” table below.

Perquisites or Personal Benefits

We did not provide perquisites or personal benefits to our NEOs during the fiscal year ended December 31, 2024.

401(k) Plan

We currently maintain a tax-qualified 401(k) retirement savings plan for our employees, including our NEOs, who satisfy certain eligibility requirements. Our NEOs are eligible to participate in the 401(k) plan on the same terms