SION-XX

SION-XX is a preclinical-stage small molecule CFTR modulator being developed by Sionna Therapeutics for the treatment of cystic fibrosis. It is characterized by a dual mechanism of action that combines stabilization of the first nucleotide-binding domain (NBD1) with engagement of the first transmembrane domain (TMD1) of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein. This "complementary modulator" approach is designed to overcome the folding and stability defects caused by the ΔF508 mutation, the most prevalent genetic cause of cystic fibrosis. By targeting multiple domains of the CFTR protein, SION-XX aims to enhance the trafficking and functional expression of the chloride channel at the cell surface more effectively than single-domain modulators.