- Relative Change From Baseline in Percent Predicted FEV1 at Week 24 [ Time Frame: Baseline, Week 16 and 24 ]
Assessed as the average treatment effect at Week 16 and at Week 24. FEV1 and percent predicted FEV1 are defined in Outcome Measure (OM) 1.
- Absolute Change From Baseline in Body Mass Index (BMI) at Week 24 [ Time Frame: Baseline, Week 24 ]
BMI was defined as weight in kilogram (kg) divided by height*height in square meter (m^2).
- Absolute Change From Baseline in Cystic Fibrosis Questionnaire-Revised (CFQ-R) Respiratory Domain Score at Week 24 [ Time Frame: Baseline, Week 24 ]
The CFQ-R is a validated participant-reported outcome measuring health-related quality of life for participants with cystic fibrosis. Respiratory domain assessed respiratory symptoms (for example, coughing, congestion, wheezing), the scaled score range: 0-100; higher scores indicating fewer symptoms and better health-related quality of life.
- Percentage of Participants With Response Based on Percent Predicted FEV1 [ Time Frame: Week 16 and 24 ]
A participant was considered as a responder if the participant had >=5% increase from baseline in average percent predicted FEV1 at Week 16 and at Week 24 (relative change). FEV1 and percent predicted FEV1 are defined in OM 1. A participant with a missing average relative change from baseline in percent predicted FEV1 at Week 16 and at Week 24 was considered as a non-responder.
- Number of Pulmonary Exacerbation Events [ Time Frame: through Week 24 ]
The total number of days on study is equal to the Week 24 date or the last dose date (whichever occurred last) minus the first dose date plus 1. The total number of years (48 weeks) on study is equal to the number of days on study divided by 336. Pulmonary exacerbation events per year (48 weeks) are reported.
- Absolute Change From Baseline in Weight at Week 24 [ Time Frame: Baseline, Week 24 ]
- Absolute Change From Baseline in BMI-for-age Z-score at Week 24 [ Time Frame: Baseline, Week 24 ]
Z-Score is a statistical measure to evaluate how a single data point compares to a standard. It describes whether a mean was above or below the standard and how unusual the measurement is with range from -infinity to +infinity; 0: same mean, >0: a greater mean, and <0: a lesser mean than the standard. BMI-for-age z-score was calculated by using centers for disease control and prevention (CDC) growth charts for the pediatric population.
- Time-to-First Pulmonary Exacerbation [ Time Frame: through Week 24 ]
Time to first pulmonary exacerbation was assessed using Cox Regression method. For participants who completed 24 weeks of treatment, participants without a pulmonary exacerbation before treatment completion were considered censored at the time of treatment completion or at the Week 24 Visit (whichever occurred last). For participants who prematurely discontinued study treatment, participants without a pulmonary exacerbation through the Week 24 Visit were considered censored at the time of the Week 24 Visit.
- Percentage of Participants With At Least 1 Pulmonary Exacerbation Event [ Time Frame: through Week 24 ]
- Absolute Change From Baseline in Euro Quality of Life Scale (EuroQol) 5-Dimension-3 Level (EQ-5D-3L) Index Score at Week 24 [ Time Frame: Baseline, Week 24 ]
EQ-5D-3L: participant rated questionnaire to assess health-related quality of life. It consists of EQ-5D descriptive system and EQ-5D Visual Analog Scale (VAS). EQ-5D-3L descriptive system comprises the following 5 dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension has 3 levels: no problems (1), some problems (2), and extreme problems (3). The 5 dimensional 3-level systems are converted into a single index utility score. Values for theoretically possible health states are calculated using a regression model and weighted according to the social preferences of the Unites States (US) general population. For this population, the possible EQ-5D-3L index scores ranges from -0.11 (that is, 3 for all 5 dimensions) to 1.0 (that is, 1 for all 5 dimensions), where higher scores indicate a better health state.
- Absolute Change From Baseline in EQ-5D-3L VAS Score at Week 24 [ Time Frame: Baseline, Week 24 ]
The EQ-5D-3L VAS records the participant's self-rated health on a vertical, visual analogue scale where the best state a participant can imagine is marked 100 and the worst state a participant can imagine is marked 0, higher scores indicates a better health state.
- Absolute Change From Baseline in Treatment Satisfaction Questionnaire for Medication (TSQM) Domain Scores at Week 24 [ Time Frame: Baseline, Week 24 ]
The TSQM is a 14-item self-administered questionnaire which measures participants' experiences with their medication on four dimensions: effectiveness, side effects, convenience and global satisfaction. For each dimension, responses are added and transformed to a scale from 0 to 100, where higher scores indicate greater satisfaction.
- Number of Participants With Treatment-Emergent Adverse Events (AEs) and Treatment-Emergent Serious Adverse Events (SAEs) [ Time Frame: up to Week 28 ]
AE: any untoward medical occurrence in a participant during the study; the event does not necessarily have a causal relationship with the treatment. This includes any newly occurring event or previous condition that has increased in severity or frequency after the informed consent form is signed. AE includes serious as well as Non-serious AEs. SAE (subset of AE): medical event or condition, which falls into any of the following categories, regardless of its relationship to the 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. Any AE that increased in severity or that was newly developed at or after the initial dosing of study drug to 28 days after the last dose of study drug is considered treatment-emergent.
- Pre-dose Concentration (Ctrough), Average Pre-dose Concentration (Ctrough,Avg), 3 to 6 Hours Post-dose Concentration (C3-6h), and Average 3 to 6 Hours Post-dose Concentration (C3-6h,Avg) [ Time Frame: For C3-6h: 3 to 6 hours after morning dose on Day 1 and 15, Week 4 and 8; For C3-6h,avg 3 to 6 hours after morning dose on Day 15, Week 4 and 8; For Ctrough and Ctrough,avg: before morning dose on Week 4, 8, and 16 ]
Ctrough, Ctrough,avg, C3-6h, and C3-6h,avg for lumacaftor, M28 lumacaftor (lumacaftor metabolite), ivacaftor, M1 ivacaftor (ivacaftor metabolite), and M6 ivacaftor (ivacaftor metabolite) were calculated. C3-6h,avg is average of individual 3 to 6 hours post-dose observed concentrations across Day 15, and Weeks 4 and 8 and Ctrough,avg is average of individual pre-dose observed concentrations across Weeks 4, 8, and 16. This outcome was not planned to be assessed in Placebo arm.