Vertex Pharmaceuticals Inc. reported that ivacaftor was generally well tolerated, and that there were no new safety concerns in a Phase 3 clinical trial of children who have one of 10 mutations that cause cystic fibrosis.

Although safety was the primary focus of the 24-week study, it also found that the children's sweat chloride was significantly reduced to within the normal range during the trial. Additionally, the children in the study had substantial improvements in their levels of fecal elastase (a type of digestive enzyme). Fecal elastase levels are often used as a measurement of how well the pancreas is working. These data support that early treatment with ivacaftor may help preserve pancreatic function.

The results lay the groundwork for Vertex's application to the U.S. Food and Drug Administration (FDA) for the approval of ivacaftor for children ages 1 to 2 in the first quarter of 2018. Ivacaftor is currently approved for the treatment of children ages 2 and older who have one of 38 mutations.

The study of ivacaftor in infants ages 0 to 1 is ongoing.

The mutations included in the trial are as follows: G551D, G178R, S549N, S549R, G551S, G1244E, S1251N, S1255P, G1349D, or R117H.

Ivacaftor was developed by Vertex with significant clinical, scientific, and financial support from the Cystic Fibrosis Foundation.

For additional information about the study, please see the Vertex press release.