VX-809

VX-809 is a novel CFTR corrector that modulates the folding and trafficking of CFTR protein. VX-809 stabilizes an N-terminal domain in CFTR that contains only MSD1 (membrane-spanning domain 1) and efficaciously restores function to CFTR forms that have missense mutations in MSD1. The action of VX-809 on MSD1 appears to suppress folding defects in F508del-CFTR by enhancing interactions among the NBD1, MSD1, and MSD2 domains.