Sionna Therapeutics, a Phase 2 biotech developing novel therapies for cystic fibrosis, filed on Friday with the SEC to raise up to an estimated $100 million in an initial public offering.
Sionna is developing therapies that normalize the function of the cystic fibrosis transmembrane conductance regulator (CFTR) protein as a treatment for CF patients. The company aims to restore CFTR function to as close to normal as possible by directly stabilizing CFTR’s nucleotide-binding domain 1 (NBD1), a different approach than the currently-approved CFTR modulator therapies marketed by Vertex Pharmaceuticals (Nasdaq: VRTX). Vertex currently markets all five approved CFTR modulators, which generated about $10 billion in sales in 2023, and Sionna emphasizes that its Chief Medical Officer previously served as VP of Cystic Fibrosis at Vertex. Sionna is currently conducting Phase 1 trials for its two lead NBD1 stabilizer candidates, and expects to begin Phase 2a trials in the 2H25. It is also in Phase 1 and 2 trials for a portfolio of complementary CFTR modulators, several of which are in-licensed from AbbVie.
The Waltham, MA-based company was founded in 2019 and plans to list on the Nasdaq under the symbol SION. Sionna Therapeutics filed confidentially on September 12, 2024. Goldman Sachs, TD Cowen, Stifel, and Guggenheim Securities are the joint bookrunners on the deal. No pricing terms were disclosed.
