Company: SION
Filing Date: 2025-02-07
Form Type: 424B4
Source: 0001193125-25-022709
Chunk: 98

Company: Sionna Therapeutics, Inc.
Filing Date: 2025-02-07
Form: 424B4
Chunk 98
---
 stockholders in the future; |

| • |     | disputes or other developments relating to proprietary rights, including patents, litigation matters and our ability to 
 obtain patent protection for our product candidates;                                                                    |

| • |     | significant lawsuits, including patent or stockholder litigation; |

| • |     | changes in the structure of healthcare payment systems; |

| • |     | changes in accounting standards, policies, guidelines, interpretations or principles; |

| • |     | regulatory or legal developments in the U.S. and foreign countries; |

| • |     | general political and economic conditions; and |

| • |     | other events or factors, many of which are beyond our control. |

The stock market in general, and the market for biotechnology companies in particular, have experienced extreme price and volume fluctuations that have often been unrelated or disproportionate to the operating performance of these companies. Broad market and industry factors may negatively affect the market price of our common stock, regardless of our actual operating performance. The realization of any of the risks described in this section, or any of a broad range of other risks, could have a material adverse impact on the market price of our common stock. In the past, stockholders have initiated class action lawsuits against pharmaceutical and biotechnology companies following periods of volatility in the market prices of these companies’ stock. Such litigation, if instituted, could result in substantial costs and divert management’s attention and resources. We may not be able to satisfy listing requirements of Nasdaq or obtain or maintain a listing of our common stock on Nasdaq. If our common stock is listed on Nasdaq, we must meet certain financial and liquidity criteria to maintain such listing. If we violate Nasdaq’s listing requirements, our common stock may be delisted. If we fail to meet any of Nasdaq’s listing standards, our common stock may be delisted. In addition, our board of directors may determine that the cost of maintaining our listing on a national securities exchange outweighs the benefits of such listing. A delisting of our common stock from Nasdaq may materially impair our stockholders’ ability to buy and sell our common stock and could have an adverse effect on the market price of, and the efficiency of the trading market for, our common stock. The delisting of our common stock could significantly impair our ability to raise capital and the value of your investment. 70

If you purchase shares of our common stock in this offering, you will suffer immediate and substantial dilution of your investment.

The initial public offering price of our