SPX-101

SPX-101 is a novel, investigational synthetic peptide (SPLUNC1 mimetic) developed for the treatment of cystic fibrosis. It acts by targeting and inhibiting the epithelial sodium channel (ENaC) in airway epithelial cells. By mimicking the S18 binding site of SPLUNC1, SPX-101 binds to ENaC and induces its internalization from the cell membrane, resulting in a durable reduction of active ENaC on the cell surface. This mechanism reduces sodium absorption in airway epithelia, restores airway surface hydration, and improves mucociliary clearance—key therapeutic goals in cystic fibrosis management. Unlike previous small molecule ENaC inhibitors such as amiloride, SPX-101’s peptide-based approach provides prolonged action without significant systemic side effects like hyperkalemia or volume depletion observed with other agents[2][3][4][6][8]. The drug was developed by Spyryx Biosciences and has completed Phase 2 clinical trials for cystic fibrosis[5][7].

Other names

SPLUNC1-derived peptideSPLUNC-1-derived peptideSPLUNC 1-derived peptideSPLUNC1 mimeticSPLUNC-1 mimeticSPLUNC 1 mimetic