Company: SION
Filing Date: 2025-02-03
Form Type: S-1/A
Source: 0001193125-25-018825
Chunk: 126

Company: Sionna Therapeutics, Inc.
Filing Date: 2025-02-03
Form: S-1/A
Chunk 126
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946,388 shares of our common stock, which will be granted to certain of our    
 executive officers, directors and employees at the time of effectiveness of the 2025 Plan with an exercise price equal to the initial public offering price per share, as well as any automatic increases in the number of shares of common stock 
 reserved for future issuance under the 2025 Plan and any shares underlying outstanding stock awards granted under the 2020 Plan that expire or are repurchased, forfeited, cancelled or withheld.                                                 |

90

DILUTION If you invest in our common stock in this offering, your ownership interest will be diluted to the extent of the difference between the initial public offering price per share of our common stock and the pro forma as adjusted net tangible book value per share of our common stock immediately after this offering. Our historical net tangible book deficit as of September 30, 2024 was $(150.5) million, or $(31.46) per share of our common stock. Our historical net tangible book deficit represents the amount of our total tangible assets less our total liabilities and preferred stock. Historical net tangible book deficit per share represents historical net tangible book deficit divided by the number of shares of our common stock outstanding as of September 30, 2024. Our pro forma net tangible book value as of September 30, 2024 was $179.9 million, or $5.63 per share. Pro forma net tangible book value per share represents the amount of our total tangible assets (net of deferred offering costs) less our total liabilities, divided by the number of shares of our common stock outstanding as of September 30, 2024, after giving effect to the automatic conversion of all outstanding shares of preferred stock into 27,149,206 shares of common stock immediately prior to the completion of this offering. After giving further effect to the sale of 8,823,529 shares of common stock that we are offering at the assumed initial public offering price of $17.00 per share, which is the midpoint of the estimated offering range set forth on the cover page of this prospectus, and after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us, our pro forma as adjusted net tangible book value as of September 30, 2024 would have been $317.1 million, or $7.78 per share. This amount represents an immediate increase in pro forma net tangible book value of $2.15 per share to our existing stockholders and an immediate dilution in