Company: SION
Filing Date: 2025-02-03
Form Type: S-1/A
Source: 0001193125-25-018825
Chunk: 159

Company: Sionna Therapeutics, Inc.
Filing Date: 2025-02-03
Form: S-1/A
Chunk 159
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 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 a key translational roadmap for us to prioritize compounds for further evaluation. We believe the model allows us to determine the target exposure needed to achieve a desired level of clinical activity, such 
 as the level of improvement in a patient’s forced expiratory volume in one second (“FEV1”), a measure of lung function, and sweat chloride level, the clinical biomarker of CFTR                                                                          
 function. We intend to invest in research activities and leverage insights from the model in our pursuit of delivering additional differentiated product candidates that meaningfully impact the lives of CF patients and facilitate our company’s        
 long-term growth. We also intend to opportunistically consider strategic in-licensing opportunities to maximize the value of our pipeline.                                                                                                                |

Our Company’s History and Our Team Sionna was founded in 2019 to continue to explore novel approaches to treating CF by targeting NBD1. Our co-founders,Greg Hurlbut, Ph.D., and Mark Munson, Ph.D., spent over a decade extensively researching the NBD1 target as research leaders at Sanofi SA (f/k/a Sanofi Genzyme) (“Sanofi”). Dr. Hurlbut served as Head of Protein Conformational Diseases and Rare Pulmonary 116

Diseases Research, where he led a novel strategy focused on discovering small molecules that correct the F508del CFTR mutation. Dr. Munson served as U.S. Head of Medicinal Chemistry and oversaw a diverse group of scientists that advanced multiple development candidates in oncology and rare