Vertex Pharmaceuticals Inc. announced the results of a two-part proof-of-concept study of ivacaftor in 24 people with cystic fibrosis (CF) who have a residual function mutation. The first part of the study evaluated ivacaftor, compared with placebo, in a two-week crossover design over two treatment cycles, and the second part of the study evaluated ivacaftor in an eight-week open-label design. In part one, a statistically significant improvement in mean absolute lung function (percent predicted forced expiratory volume in one second; PPFEV1) was observed after treatment with ivacaftor for two weeks compared with placebo. In part two of the study, improvements in lung function (PPFEV1) were observed after eight weeks of treatment. In the study, ivacaftor was generally well-tolerated, and the most common adverse events in the treatment group were cough and respiratory tract infection.
This proof-of-concept study was the first to evaluate the use of ivacaftor in multiple residual function mutations and is supported by in vitro observations that showed ivacaftor enhanced the function of the cystic fibrosis transmembrane conductance regulator (CFTR) protein in cells with residual function mutations. Based on these data, Vertex plans to initiate a larger Phase 3 study in people with residual function mutations that will evaluate longer-duration treatment with ivacaftor, pending discussions with regulatory authorities.
There are more than 3,000 people ages six and older in North America, Europe and Australia who have a non-R117H residual function mutation.
“This study showed potential for ivacaftor to provide clinical benefit for many of the people who have a residual function mutation and provides important support for the initiation of a Phase 3 study in people with these mutations,” said Jeffrey Chodakewitz, senior vice president and chief medical officer at Vertex. “While this was a small proof-of-concept study, these data are another step forward in our commitment to expand the number of people who can benefit from ivacaftor.”
Date: June 4, 2014
Source: Vertex Pharmaceuticals