Company: SION
Filing Date: 2025-02-03
Form Type: S-1/A
Source: 0001193125-25-018825
Chunk: 11

Company: Sionna Therapeutics, Inc.
Filing Date: 2025-02-03
Form: S-1/A
Chunk 11
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 volunteers. Our Strategy Our mission is to revolutionize the current treatment paradigm for CF patients by developing novel medicines that normalize the function of the CFTR protein to deliver clinically meaningful benefit to CF patients. The key pillars of our strategy are:

| • |     | Advance our novel NBD1 stabilizers. |

| • |     | Develop and advance our pipeline of complementary modulators for proprietary combination product development. |

| • |     | Build upon our NBD1-centric CF franchise through a data-driven dual combination path. |

| • |     | Fortify our CF franchise through continued research efforts and utilization of the translational CFHBE model. |

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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”). We have assembled a leadership team with deep expertise in drug discovery and developing CF and other rare disease therapies, launching and commercializing therapeutics globally, and building successful public pharmaceutical companies.

| • |     | Mike Cloonan, our President and Chief Executive Officer, has more than 20 years of leadership experience at                                                             
 global organizations, most recently as Chief Operating Officer at Sage Therapeutics, Inc. and prior to that as Senior Vice President of U.S. Commercial at Biogen, Inc. |

| • |     | Charlotte McKee, M.D., our Chief Medical Officer, is a pulmonologist with more than 20 years of drug                                                                                                                                      
 development experience who, while serving as Vice President of CF and Alpha-1 Antitrypsin Deficiency Clinical Development at Vertex, was instrumental in the development and regulatory approvals of three of Vertex’s five approved CFTR 
 modulators, including Trikafta.                                                                                                                                                                                                           |

| • |     | Elena Ridloff, C.F.A., our Chief Financial Officer                                                                                                                                        
 and Head of Corporate Development, has more than 20 years of experience in finance in the life sciences industry, most recently as Chief Financial Officer at Acadia Pharmaceuticals Inc. |

Since our inception, we have raised approximately $330 million from investors including RA Capital, TPG’s the Rise Fund, Atlas Venture, OrbiMed and Enavate Sciences. We also received founding support from the CFF, which has been a