SION · Sionna Therapeutics, Inc.

Sionna Therapeutics announced its first quarter 2026 financial results alongside significant clinical milestones in its cystic fibrosis pipeline. The company completed enrollment in the PreciSION CF Phase 2a proof-of-concept trial (NCT07108153) evaluating NBD1 stabilizer SION-719 as an add-on to standard of care in CF patients, assessing safety, tolerability, pharmacokinetics, and CFTR function via sweat chloride levels. Topline data are expected in summer 2026. Similarly, the ongoing Phase 1 trial (NCT07035990) of SION-451 in dual combinations with SION-2222 (TMD1-directed corrector) and SION-109 (ICL4-directed corrector) in healthy volunteers remains on track for topline results this summer. CEO Mike Cloonan highlighted strong execution, emphasizing these first-in-class NBD1 stabilizers' potential to expand CF therapeutic options. Financially, operating expenses rose to $29.6 million from $19.7 million year-over-year, driven by $19.0 million in R&D (up from $13.7 million) due to clinical pipeline advancement and personnel costs including stock-based compensation, and $10.6 million in G&A (up from $6.0 million) for similar growth-related expenses. This resulted in a net loss of $26.8 million, or $(0.60) per share, compared to $16.5 million, or $(0.62) per share, in Q1 2025, partially offset by $2.8 million in interest income. Balance sheet remains robust with $289.9 million in cash, cash equivalents, and marketable securities as of March 31, 2026, down from $310.3 million at year-end 2025, expected to fund operations into 2028. Upcoming encore data presentations at the 49th European Cystic Fibrosis Conference in June 2026 will feature Phase 1 results for SION-719 and SION-451, and preclinical data on F508del-CFTR protein half-life.