SION-719 - (PreciSION CF)

May 12, 2026: Sionna Therapeutics, Inc. (NASDAQ: SION) reported Q1 2026 results and provided cystic fibrosis (CF) pipeline updates centered on NBD1 stabilizers. In April 2026, the company completed enrollment in the PreciSION CF Phase 2a proof-of-concept trial (NCT07108153) of SION-719 as an add-on to standard of care in CF patients; the study is assessing safety/tolerability/PK and change in CFTR function via sweat chloride, with topline data expected in summer 2026. Sionna also said its ongoing Phase 1 trial (NCT07035990) in healthy volunteers evaluating SION-451 in proprietary dual combinations with SION-2222 (galicaftor; TMD1-directed corrector) and with SION-109 (ICL4-directed corrector) remains on track for topline data in summer 2026. The company plans to present “encore” Phase 1 safety/tolerability/PK data for SION-719 and SION-451 and additional NBD1 stabilizer-related data at the 49th European Cystic Fibrosis Conference (ECFS), June 3–6, 2026 (Lisbon), including presentations on June 5, 2026. Cash, cash equivalents and marketable securities were $289.9 million as of March 31, 2026, expected to fund operations into 2028.