Company: SION
Filing Date: 2025-01-17
Form Type: S-1
Source: 0001193125-25-008474
Chunk: 157

Company: Sionna Therapeutics, Inc.
Filing Date: 2025-01-17
Form: S-1
Chunk 157
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-451 with one of our complementary modulators or ETI showed                                                     
 increased chloride transport, which indicates improvement in in vitro CFTR activity. Given the clinically predictive nature of the CFHBE model, we believe these data indicate the potential for an NBD1-anchored dual combination to improve CFTR 
 activity, which we believe will deliver clinically meaningful benefit to CF patients. Following completion of our ongoing Phase 1 clinical trials of SION-719 and                                                                                  
 SION-451, expected in the first half of 2025, we plan to select a lead NBD1 stabilizer and conduct a drug-drug interaction trial before initiating a Phase 2a proof-of-concept trial in CF patients.                                               |

| • |     | Develop and advance our pipeline of complementary modulators for proprietary combination product development. We are                                                                                                                                     
 developing a proprietary pipeline of complementary CFTR modulators designed to work synergistically with our NBD1 stabilizers to improve CFTR function, as seen in our CFHBE model. We have several CFTR modulators in development, including galicaftor 
 (SION-2222), a TMD1-directed corrector, which has recently completed a Phase 1 clinical trial.                                                                                                                                                           |

| • |     | Build upon our NBD1-centric CF franchise through a data-driven dual combination path. Our strategy is to                                                                                                                                               
 advance multiple NBD1 stabilizers and complementary compounds through Phase 1 development, with the goal of selecting the combinations with the best potential, based on human data. Following the selection of our lead NBD1 stabilizer, we intend to 
 begin MAD trials in healthy volunteers evaluating galicaftor and/or SION-109 in combination with our lead NBD1 stabilizer to assess the safety, tolerability and PK of each combination, with the goal of                                              
 developing proprietary combination therapies that provide clinically meaningful benefit to CF patients. Based on the results of these trials, we plan to select the most promising lead proprietary dual combination to advance into Phase 2b          
 dose-ranging trials in patients with CF.                                                                                                                                                                                                               |

| • |     | Fortify our CF franchise through continued research efforts and utilization of the translational CFHBE model. Our                                                                                                                                         
 goal is to build a CF franchise anchored by our NBD1 stabilizers and remain focused on our mission to deliver clinically meaningful benefit to CF patients. The CFHBE model has been highly predictive of clinical outcomes for approved CFTR modulators, 
 and our application of the model provides