Pilot Study Testing the Effect of Ivacaftor on Lung Function in Subjects With Cystic Fibrosis and Residual CFTR Function

FEV1 is the volume of air that can forcibly be blown out in one second, after full inspiration. Hankinson and Wang standards were used to calculate percent predicted FEV1 (for age, gender, and height). The Hankinson standard was used for male participants 18 years and older and female participants 16 years and older. The Wang standard was used for male participants aged 12 to 17 years and for female participants aged 12 to 15 years. Data was to be reported for each cycle (Cycle 1 and Cycle 2) and as per drug treatment, for overall participants and as per genotype (residual function mutation and mRNA splice site mutation).

LCI is a measure of ventilation inhomogeneity that is derived from a multiple-breath washout test. The LCI was calculated as the number of lung volume turnovers (cumulative expired volume divided by the functional residual capacity [FRC]) required to reduce end-tidal concentration of an inert gas to 1/40th of the starting value. Data was to be reported for each cycle (Cycle 1 and Cycle 2) and as per drug treatment. Data was to be reported for each cycle (Cycle 1 and Cycle 2) and as per drug treatment, for overall participants and as per genotype (residual function mutation and mRNA splice site mutation).

FEV1 is the volume of air that can forcibly be blown out in one second, after full inspiration. Hankinson and Wang standards were used to calculate percent predicted FEV1 (for age, gender, and height). The Hankinson standard was used for male participants 18 years and older and female participants 16 years and older. The Wang standard was used for male participants aged 12 to 17 years and for female participants aged 12 to 15 years. Data was to be reported for overall participants and as per genotype (residual function mutation and mRNA splice site mutation).

LCI is a measure of ventilation inhomogeneity that is derived from a multiple-breath washout test. The LCI was calculated as the number of lung volume turnovers (cumulative expired volume divided by the functional residual capacity [FRC]) required to reduce end-tidal concentration of an inert gas to 1/40th of the starting value. Data was to be reported for overall participants and as per genotype (residual function mutation and mRNA splice site mutation).

Sweat samples were collected using an approved Macroduct (Wescor, Logan, Utah) collection device. A volume of greater than or equal to (>=) 15 microliter was required for determination of sweat chloride. Data was to be reported for overall participants and as per genotype (residual function mutation and mRNA splice site mutation).

Data was to be reported for overall participants and as per genotype (residual function mutation and mRNA splice site mutation).

Adverse events (AEs) that started (or increased in severity) from first dose of study drug through completion of Follow-up were considered TEAEs, with exception that if an AE started during a Washout Period and was beyond 14 days from last dose date of preceding cycle, AE was considered as a "Washout Period" AE, and hence not TEAE. A TEAE was attributed to treatment in which it started or to the treatment in second cycling period of previous Crossover Period if it started during a Washout Period. SAE: medical event or condition, which falls into any of following categories, regardless of its relationship to study drug: death, life threatening adverse experience, in-patient hospitalization/prolongation of hospitalization, persistent/significant disability or incapacity, congenital anomaly/birth defect, important medical event. Data was to be reported by drug treatment for double-blind crossover period (Cycle 1 up to Washout Period 2) and open-label period.