Study of Lumacaftor in Combination With Ivacaftor in Subjects 6 Through 11 Years of Age With Cystic Fibrosis, Homozygous for the F508del-CFTR Mutation

Part A: Number of Participants With Treatment-Emergent Adverse Events (AEs) and Serious Adverse Events (SAEs)

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, inpatient hospitalization/prolongation of hospitalization, persistent/significant disability or incapacity, congenital anomaly/birth defect, important medical event. AEs with start date or increased severity on or after the first study drug dose through the end of Part A were considered treatment-emergent.

Time frame: Day 1 up to Day 28

Part B: Average Absolute Change From Baseline in Sweat Chloride at Day 15 and at Week 4

Sweat samples were collected using an approved collection device. Baseline was defined as the average of the measurements at screening and on Day 1 pre-dose. Average of Day 15 and Week 4 measurements was taken and change was calculated as: Average (Day 15 and Week 4 measurement) minus Baseline measurement.

Time frame: Baseline, Day 15 and Week 4

Part B: Absolute Change in Sweat Chloride From Week 24 at Week 26

Sweat samples were collected using an approved collection device. Change = Week 26 minus Week 24.

Time frame: Week 24, Week 26

Part B: Absolute Change From Baseline in Body Mass Index (BMI) at Week 24

BMI was defined as weight in kilogram (kg) divided by height\*height in square meter (m\^2).

Time frame: Baseline, Week 24

Part B: Absolute Change From Baseline in BMI-for-age Z-score at Week 24

BMI was defined as weight in kg divided by height\*height in m\^2. 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; where 0: same mean, \>0: a greater mean, and \<0: a lesser mean than the standard. BMI, adjusted for age and sex, was analyzed as BMI-for-age z-score (BMI z-score). The BMI-for-age z-scores were calculated using National Center for Health Statistics growth charts.

Time frame: Baseline, Week 24

Part B: Absolute Change From Baseline in Weight at Week 24

Time frame: Baseline, Week 24

Part B: Absolute Change From Baseline in Weight-for-age Z-score at 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; where 0: same mean, \>0: a greater mean, and \<0: a lesser mean than the standard. Weight, adjusted for age and sex, was analyzed as weight-for-age z-score (weight z-score). The weight-for-age z-scores were calculated using National Center for Health Statistics growth charts.

Time frame: Baseline, Week 24

Part B: Absolute Change From Baseline in Height at Week 24

Time frame: Baseline, Week 24

Part B: Absolute Change From Baseline in Height-for-age Z-score at 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; where 0: same mean, \>0: a greater mean, and \<0: a lesser mean than the standard. Height, adjusted for age and sex, was analyzed as height-for-age z-score (height z-score). The height-for-age z-scores were calculated using National Center for Health Statistics growth charts.

Time frame: Baseline, Week 24

Part B: Absolute Change From Baseline in Cystic Fibrosis Questionnaire-Revised (CFQ-R) Respiratory Domain Score at Week 24

The CFQ-R is a validated patient-reported outcome measuring health-related quality of life for participants with cystic fibrosis. Respiratory domain assessed respiratory symptoms (for example, coughing, congestion, wheezing), score range: 0-100; higher scores indicating fewer symptoms and better health-related quality of life.

Time frame: Baseline, Week 24

Part B: Absolute Change From Baseline in Treatment Satisfaction Questionnaire for Medication (TSQM) Domains at 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.

Time frame: Baseline, Week 24

Part B: Pre-dose Concentration (Ctrough) and 3 to 6 Hours Post-dose Concentration (C3-6hr) of Lumacaftor, Lumacaftor Metabolite (M28-LUM), Ivacaftor and Ivacaftor Metabolites (M1-IVA and M6-IVA)

Ctrough and C3-6hr for lumacaftor, M28 lumacaftor (lumacaftor metabolite), ivacaftor, M1 ivacaftor (ivacaftor metabolite), and M6 ivacaftor (ivacaftor metabolite) were calculated. Ctrough was observed pre-dose concentration. C3-6hr was observed concentration at 3 to 6 hours post- dose.

Time frame: For Ctrough: pre-morning dose on Week 4, Week 6 and Week 24; For C3-6hr: 3 to 6 hours post-morning dose on Day 1, 15 and Week 4