Lumacaftor (VX-809)

VX 809 is used in the stabilization of the CFTR protein used in the treatment of cystic fibrosis.

ChEBI: An aromatic amide obtained by formal condensation of the carboxy group of 1-(2,2-difluoro-1,3-benzodioxol-5-yl)cyclopropane-1-carboxylic acid with the aromatic amino group of 3-(6-amino-3-methylpyridin-2-yl)benzoic acid. Used for the treatment of cystic fi rosis.

CF is a hereditary condition caused by mutations in the CFTR gene, which provides instructions for producing an ion channel protein called CF transmembrane conductance regulator (CFTR). These mutations cause defects in the CFTR protein, which disrupts the normal salt-water transport across the cell membrane and produces thick, sticky mucus that may accumulate in different organs, including the lungs. One of the common mutations in the CFTR gene is the so-called F508del mutation, which results in a defective misfolded CFTR protein. The misfolded protein is degraded by the cell before it can reach the cell membrane. Even if some of the defective proteins reach the cell membrane, they are unable to open correctly and allow the passage of chloride ions. Lumacaftor and ivacaftor work together to restore the function of the CFTR protein at the cell membrane. Lumacaftor increases the stability of defective CFTR proteins, helping them reach the cell membrane and stay there longer. But because it does not address the problem with the opening of the channel, lumacaftor is generally used in combination with ivacaftor, which acts on the defective proteins, helping them to open more often so that the salt-water balance across the cell surface is restored.