Company: SION
Filing Date: 2025-01-17
Form Type: S-1
Source: 0001193125-25-008474
Chunk: 22

Company: Sionna Therapeutics, Inc.
Filing Date: 2025-01-17
Form: S-1
Chunk 22
---
 inception. Identifying potential product candidates and conducting preclinical testing and clinical trials is a time-consuming, expensive and uncertain process that takes years to complete, and we may never generate the necessary data or results required to obtain regulatory approvals and achieve product sales. We expect to continue to 17

incur significant and increasing expenses and operating losses for the foreseeable future as we initiate and conduct clinical trials of our current and future product candidates, scale-upand manufacture our product candidates, advance our preclinical programs, seek marketing and regulatory approvals for any product candidates that successfully complete clinical trials and commercialize our products, if approved. Because the outcome of any clinical trial or preclinical study is highly uncertain, we cannot reliably estimate the actual amount of financing necessary to successfully complete the development and commercialization of any of our product candidates. We believe that the anticipated net proceeds from this offering, together with our existing cash, cash equivalents and investments in marketable securities, will be sufficient to fund our operating expenses and capital requirements into . This estimate is based on assumptions that may prove to be wrong, and we could use our available capital resources sooner than we expect. Changes may occur beyond our control that would cause us to consume our available capital before that time, including but not limited to changes in progress of our development activities, acquisitions of additional product candidates and changes in regulation. Our future capital requirements will depend on many factors, including:

| • |     | the scope, timing, progress, costs, complexity and results of discovery, preclinical development and clinical trials for                                                                                                  
 our current or future product candidates, including our planned clinical trials of our lead nucleotide-binding domain (“NBD1”) stabilizer product candidate in combination with Vertex Pharmaceuticals, Inc.’s (“Vertex”) 
 Trikafta, the current standard of care for the treatment of CF, and in combination with our lead complementary modulator product candidate;                                                                               |

| • |     | the number of clinical trials required for regulatory approvals of our current or future product candidates; |

| • |     | the extent to which we develop, in-license or acquire other product candidates in 
 our pipeline;                                                                     |

| • |     | the costs and timing of process development and manufacturing scale-up activities                                                                              
 associated with our product candidates and other programs as we advance them through preclinical and clinical development and, if approved, commercialization; |

| • |     | the number and development requirements of product candidates that we may pursue; |

| • |     | the timing and amount of the milestone, royalty or