Conditions: Cystic Fibrosis
Keywords: Fibrosis Pancreatic Diseases Lung Diseases Respiratory Tract Diseases Genetic Diseases, Inborn Infant, Newborn, Diseases Pathologic Processes
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 167
Healthy volunteers: no

Brief summary:
The purpose of this study was to evaluate the efficacy and safety of ivacaftor in subjects with cystic fibrosis aged 12 years and older who have the G551D mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Ivacaftor is a potent and selective CFTR potentiator of wild-type, G551D, F508del, and R117H forms of human CFTR protein. Potentiators are pharmacological agents that increase the chloride ion transport properties of the channel in the presence of cyclic AMP-dependent protein kinase A (PKA) activation.

Detailed description:
This was a phase 3 study in subjects with cystic fibrosis (CF) age 12 years and older who have a G551D-CFTR mutation and percent predicted forced expiratory volumn in 1 second (FEV1) between 40% and 90%.

Based on in vitro studies and pharmacologic, pharmacokinetic (PK), and safety profiles, ivacaftor was selected for clinical development as a possible treatment for patients with CF. Patients with the G551D mutation were the targeted population for this study because ivacaftor is a potentiator of the gating function of the CFTR protein, and the most prevalent mutation with a gating defect in CF is the G551D mutation.

This study was designed to further evaluate the efficacy of ivacaftor in subjects with CF who have a G551D-CFTR gene mutation and to evaluate safety in this population over a longer period than previously studied.

Arms:
arm 1: Subjects who received placebo every 12 hours (q12h) for up to 48 weeks. arm 2: Subjects who received 150 mg of ivacaftor q12h for up to 48 weeks.

Interventions: intervention 1: Ivacaftor intervention 2: Placebo
Intervention descriptions: intervention 1: 150-mg tablets given orally q12h for up to 48 weeks intervention 2: Tablet given orally q12h for up to 48 weeks

Protocol document: