Company: SION
Filing Date: 2025-08-11
Form Type: 10-Q
Source: 0002036042-25-000047
Chunk: 339

Company: Sionna Therapeutics, Inc.
Filing Date: 2025-08-11
Form: 10-Q
Item: Part II, Item 8
Chunk 339
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 "2025 ESPP"), which became effective on February 5, 2025, the date immediately preceding the date that the registration statement on Form S-1 for the Company's IPO was declared effective by the SEC. The 2025 ESPP initially reserved 390,127 shares of common stock for future issuance and is subject to automatic increases in the number of shares of common stock reserved for future issuances in accordance with the evergreen provisions in the 2025 ESPP. As of June 30, 2025, no offering periods had commenced under the 2025 ESPP.Stock Option Activity The following table summarizes the Company’s common stock option activity for the six months ended June 30, 2025: Number ofCommonStockOptionsWeighted-AverageExercise PriceWeighted-AverageRemainingContractual TermAggregateIntrinsic Value(in years)(in thousands)Outstanding as of December 31, 20243,700,335$5.87 8.3$16,522 Granted2,305,76017.40 Exercised(7,944)0.76 Cancelled or forfeited(24,000)10.16 Outstanding as of June 30, 20255,974,151$10.31 8.5$43,341 Exercisable as of June 30, 20252,097,556$6.39 7.4$23,089 The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the stock options and the estimated fair value of the Company’s common stock for those stock options that had exercise prices lower than the fair value of the Company’s common stock. The weighted-average grant date fair value of options granted during the three and six months ended June 30, 2025, was $10.20 per share and $12.74 per share, respectively. The total intrinsic value of stock options exercised was $0.1 million for the three and six months ended June 30, 2025.

F-12

Stock-Based Compensation Expense During the three and six months ended June 30, 2025, and 2024, the Company recorded stock-based compensation in the accompanying condensed consolidated statements of operations and comprehensive loss as follows (in thousands): Three Months EndedJune 30,Six Months EndedJune 30,2025202420252024Research and development expense$1,084 $396 $1,888 $