Company: SION
Filing Date: 2025-02-07
Form Type: 424B4
Source: 0001193125-25-022709
Chunk: 308

Company: Sionna Therapeutics, Inc.
Filing Date: 2025-02-07
Form: 424B4
Chunk 308
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 restricted stock units) pursuant to employee equity-based compensation plans, incentive plans, stock plans, dividend reinvestment plans or other arrangements in
place as of the date of this prospectus and described in this prospectus, (iv) the filing of a registration statement on Form S-8 in connection with the registration of securities issuable under any
employee equity-based compensation plan, incentive plan, stock plan or dividend reinvestment plan adopted and approved by the company’s board of directors prior to the date of this prospectus and as described in this prospectus and (v) shares
of common stock or other securities issued in connection with any bona fide merger, joint venture, strategic alliance, commercial or other collaborative transaction, or the acquisition or license by the company of the business, property, technology
or other assets of another individual or entity that is an unaffiliated third party of the company, or the assumption of an employee benefit plan in connection with such a merger or acquisition. In the case of clause (v), the aggregate number of
shares of our common stock that we may sell or issue or agree to sell or issue may not exceed 5.0% of the total number of shares of our common stock issued and outstanding immediately following this offering, and each recipient of any such shares of
our common stock issued pursuant to clause (v) during such period must execute and deliver to the representatives an agreement having substantially the same terms as those agreements governing the Lock-Up Securities described above prior to, or
concurrently with, such issuance or sale.

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Prior to the offering, there has been no public market for the shares. The initial public offering
price has been negotiated among the company and the representatives. Among the factors to be considered in determining the initial public offering price of the shares, in addition to prevailing market conditions, will be the company’s
historical performance, estimates of the business potential and earnings prospects of the company, an assessment of the company’s management and the consideration of the above factors in relation to market valuation of companies in related
businesses.

We have been approved to list the common stock on The Nasdaq Global Market under the symbol “SION.”

In connection with the offering, the underwriters may purchase and sell shares of common stock in the open market. These transactions may include short
sales, stabilizing transactions and purchases to cover positions created by short sales. Short sales involve the sale by the underwriters of a greater number of shares than they are required to purchase in the offering, and a short position