Company: SION
Filing Date: 2025-02-07
Form Type: 424B4
Source: 0001193125-25-022709
Chunk: 282

Company: Sionna Therapeutics, Inc.
Filing Date: 2025-02-07
Form: 424B4
Chunk 282
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. The address for each of these entities and individuals is 300 Technology Square, 8th Floor, Cambridge, MA 02139.                                                                                       |

| (2) | Consists of (i) 1,752,755 shares of common stock issuable upon the conversion of Series B preferred stock held by                                                                                                                                         
 OrbiMed Private Investments VIII, LP (“OPI VIII”) and (ii) 1,402,204 shares of common stock issuable upon the conversion of Series C preferred stock held by OPI VIII. OrbiMed Capital GP VIII LLC (“GP VIII”) is the general                             
 partner of OPI VIII. OrbiMed Advisors LLC (“OrbiMed Advisors”) is the managing member of GP VIII. By virtue of such relationships, GP VIII and OrbiMed Advisors may be deemed to have voting power and investment power over the securities               
 held by OPI VIII and as a result, may be deemed to have beneficial ownership over such securities. OrbiMed Advisors exercises voting and investment power through a management committee comprised of Carl L. Gordon, Sven H. Borho, and W. Carter Neild, 
 each of whom disclaims beneficial ownership of the shares held by OPI VIII. The address for each of these entities and individuals is 601 Lexington Avenue, 54th Floor, New York, NY 10022.                                                               |

204

| (3) | Consists of (i) 878,789 shares of common stock held by RA Capital Healthcare Fund, L.P. (“RACHF”), (ii)                                                                                                                                                  
 560,642 shares of common stock issuable upon the conversion of Series Seed preferred stock held by RACHF, (iii) 841,716 shares of common stock issuable upon the conversion of Series A preferred stock held by RACHF, (iv) 632,244 shares of            
 common stock issuable upon the conversion of Series B preferred stock held by RACHF, (v) 2,987,388 shares of common stock issuable upon the conversion of Series C preferred stock held by RACHF, (vi) 342,207 shares of common stock held by            
 RA Capital Nexus Fund, L.P. (“Nexus”), (vii) 218,375 shares of common stock issuable upon conversion of Series Seed preferred stock held by Nexus, (viii) 309,069 shares of common stock issuable upon the conversion of Series A                        
 preferred stock held by Nexus, (ix) 1,475