Company: SION
Filing Date: 2025-01-17
Form Type: S-1
Source: 0001193125-25-008474
Chunk: 130

Company: Sionna Therapeutics, Inc.
Filing Date: 2025-01-17
Form: S-1
Chunk 130
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 on interim Phase 1 clinical data as of the cutoff date of January 14, 2025. In these
trials, at both single and multiple doses, SION-719 and SION-451 exposures were achieved that have the potential, based on our preclinical CFHBE model, to provide clinically meaningful benefit if SION-719 or SION-451 were administered as part of a
dual combination or as an add-on to the standard of care (“SOC”). We plan to continue enrolling healthy subjects in the trial.

We are
also developing a portfolio of complementary CFTR modulators designed to work synergistically with our NBD1 stabilizers to improve CFTR function, as seen in preclinical models. In July 2024, we in-licensed
three clinical-stage compounds from AbbVie to expand our portfolio of combination product opportunities, including galicaftor (SION-2222), which targets CFTR’s transmembrane domain 1 (“TMD1”), and has completed Phase 2 clinical
trials. In addition, we have recently completed a Phase 1 clinical trial evaluating SION-109, which targets CFTR’s intracellular loop 4 (“ICL4”) region.

We believe our robust pipeline of NBD1 stabilizers and complementary modulators provide multiple potential pathways to achieving our goal, either in
combination with each other to produce a proprietary combination CF therapy, or in combination with the current standard of care. We plan to evaluate multiple NBD1 stabilizer candidates and complementary modulator candidates and select the most
promising candidates to advance into later-stage development. Initially, we intend to evaluate the lead NBD1 stabilizer candidate in combination with the current standard of care in a
proof-of-concept

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trial. In parallel, we will determine the proprietary dual combination that we believe is optimal to advance into a Phase 2b dose-ranging trial in CF patients. We currently have exclusive rights to develop and commercialize our compounds. Since our inception in 2019, we have not generated any revenue. To date, we have funded our operations primarily with proceeds from the sale and issuance of our preferred stock. We have received aggregate net proceeds of $330.4 million from the sale and issuance of our preferred stock. Due to our significant research, development and manufacturing expenditures, we have accumulated substantial losses and negative cash flows since our inception, including net losses of $45.8 million and $35.4 million for the nine months ended September