Researchers publish data on Kalydeco/lumacaftor interaction

Data from a pair of in vitro studies published in Science Translational Medicine on Wednesday show cystic fibrosis drug Kalydeco ivacaftor from Vertex Pharmaceuticals Inc. (NASDAQ:VRTX) reduced the correction efficacy of the company's lumacaftor ( VX-809) in human cells with two copies of the delta F508 mutation in the CF transmembrane conductance regulator ( CFTR) gene. In a statement, Vertex said while the "preclinical experiments represent interesting cell biology that can inform our research efforts, what doctors and patients care about -- and what we're focused on -- is the benefit the combination has on people with CF."

The published studies showed that in cells with two copies of the delta F508 CFTR mutation, Kalydeco impaired the biochemical stability of the mutant CFTR, leading to reduced expression of lumacaftor-corrected delta F508 CFTR protein on the plasma membrane. One study was conducted by researchers at McGill University and colleagues. The second was conducted by researchers at the University of North Carolina at Chapel Hill. Lumacaftor is a small molecule CFTR corrector that works by partially restoring the defects caused by the delta F508 CFTR mutation to increase functional expression of the protein. Kalydeco is a small molecule potentiator of CFTR that works by improving gating defects caused by CFTR mutations. ...