Vertex Pharmaceuticals, Inc. has announced interim results from an ongoing study of the experimental drug VX-809, used in conjunction with the existing drug KALYDECO™, that show improvement in lung function among adults with cystic fibrosis (CF) who have two copies of the most common gene mutation associated with CF. Of those who received VX-809 and KALYDECO, 46 percent experienced an improvement in lung function of 5 percentage points or more and 30 percent experienced a 10 percent improvement. "Lung function is the single most important marker of disease progression for people with cystic fibrosis, and improvement in lung function is the goal of every new CF therapy," said Michael P. Boyle, Director of the Johns Hopkins Adult Cystic Fibrosis Center and lead investigator for this study. "While we still eagerly await the results from the remainder of the trial, we are definitely encouraged that this interim analysis showed a significant improvement in lung function."