Company: SION
Filing Date: 2025-02-07
Form Type: 424B4
Source: 0001193125-25-022709
Chunk: 277

Company: Sionna Therapeutics, Inc.
Filing Date: 2025-02-07
Form: 424B4
Chunk 277
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| (2) | Consists of (i) 61,463 shares of Series C preferred stock held by Atlas Venture Fund XI, L.P. and (ii) 1,092,504 shares                                                                                                                            
 of Series C preferred stock held by Atlas Venture Opportunity Fund II, L.P. Entities affiliated with Atlas Ventures beneficially own more than 5% of our outstanding capital stock. Bruce Booth, D.Phil., a member of our board of directors, is a 
 general partner at Atlas Ventures.                                                                                                                                                                                                                 |

| (3) | OrbiMed beneficially owns more than 5% of our outstanding capital stock. Peter A. Thompson, M.D., a member of our board 
 of directors, is a member at OrbiMed.                                                                                   |

| (4) | Consists of (i) 4,364,874 shares of Series C preferred stock held by RA Capital Healthcare Fund, L.P. and (ii) 1,091,219                                                                                                                                 
 shares of Series C preferred stock held by RA Capital Nexus Fund, L.P. Entities affiliated with RA Capital beneficially own more than 5% of our outstanding capital stock. Joshua Resnick, M.D., M.B.A., a member of our board of directors, is a senior 
 managing director at RA Capital.                                                                                                                                                                                                                         |

| (5) | Sionna Aggregator, LP beneficially owns more than 5% of our outstanding capital stock. Sionna Aggregator, LP is an                                                        
 affiliate of Enavate Sciences. H. Edward Fleming, Jr., M.D., a member of our board of directors, is an executive vice president of commercialization at Enavate Sciences. |

| (6) | Consists of 1,765,541 shares of Series C preferred stock held by The Rise Fund Sling II, L.P. Entities affiliated with                                                        
 TPG Growth beneficially owns more than 5% of our outstanding capital stock. Lucian Iancovici, M.D., a member of our board of directors, is a managing director at TPG Growth. |

| (7) | Consists of (i) 1,715,837 shares of Series C preferred stock held by Viking Global Opportunities Illiquid Investments Sub-Master LP and (ii) 845,113 shares of Series C preferred stock held by Viking Global Opportunities Drawdown (Aggregator) LP. Entities affiliated with Viking Global Opportunities beneficially own more than 5% of 
 our outstanding