Company: SION
Filing Date: 2025-01-17
Form Type: S-1
Source: 0001193125-25-008474
Chunk: 182

Company: Sionna Therapeutics, Inc.
Filing Date: 2025-01-17
Form: S-1
Chunk 182
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 group.                                                                                                                                                   |

| • |     | Trial GLPG-2222-CL-201 was a Phase 2 trial conducted by Galapagos in Europe and Australia that evaluated the safety and                                                                   
 tolerability and the effect on CFTR function (sweat chloride), lung function (ppFEV1) and CFQ-R of galicaftor in 37 CF patients that were heterozygous for F508del and a gating mutation, 
 receiving ivacaftor. The trial was completed in August 2017.                                                                                                                              |

| • |     | Two doses of galicaftor were tested in this trial (150 mg or 300 mg QD) over 29 days. |

| • |     | Galicaftor was well-tolerated in this trial. Most treatment-emergent AEs were mild in severity, and there were no SAEs. |

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| • |     | Changes from baseline in sweat chloride, 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-