Company: SION
Filing Date: 2025-02-03
Form Type: S-1/A
Source: 0001193125-25-018825
Chunk: 184

Company: Sionna Therapeutics, Inc.
Filing Date: 2025-02-03
Form: S-1/A
Chunk 184
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, ppFEV1 and CFQ-R at day 29                                                                                                                                                                                    
 were also assessed as secondary endpoints. The galicaftor 300 mg QD treatment group had a statistically significant LS means with CI difference compared to placebo of -11.7 (95% CI, -21.1; -2.2) mmol/L (p=0.0170). There were no statistically      
 significant changes in sweat chloride in the 150 mg and 300 mg treatment groups. Lung function and CFQ-R did not significantly improve in any group. All results are described for the modified intent to treat population, which excluded one subject 
 who received an incorrect trial kit.                                                                                                                                                                                                                   |

These Phase 2 results demonstrated that galicaftor as a single agent increased CFTR activity in patients with the F508del mutation. The activity of galicaftor in combination with navocaftor in Trial M19-530was similar to the activity of approved dual combination modulators, as seen via indirect, cross-trial comparisons and as predicted based on our CFHBE model (Figure 25). These data supported the selection of a 200 mg dose QD of galicaftor for subsequent trials in combination with navocaftor. Figure 25. Galicaftor + Navocaftor Combination Showed Similar Activity to Symdeko in Phase 2 Cross-Trial Comparison In addition to galicaftor, we licensed SION-2851 from AbbVie in July 2024. SION-2851 is a potent TMD1-directed corrector that has completed a Phase 1 SAD trial in 16 healthy volunteers. The trial was conducted by AbbVie and Galapagos in Belgium in 2018. The primary endpoint was safety and tolerability, assessed by the number of subjects with adverse events. Based on its mechanism of action and preclinical studies, we believe it may be potentially synergistic with NBD1 stabilizers. ICL4 Program—SION-109 We are also advancing SION-109,which targets the ICL4 interface, for development in combination with an NBD1 stabilizer. In December 2024, we completed our evaluation of SION-109in a randomized, double blind, placebo-controlled Phase 1 clinical trial in healthy subjects, following clearance of its Investigational New Drug application (“IND”) by the U.S. Food and Drug Administration (the “FDA”) in June 2023. The trial was conducted in the