Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Phase 3, 2-Part, Open-Label Study to Evaluate the Safety, Pharmacokinetics and Pharmacodynamics of Ivacaftor in Subjects With Cystic Fibrosis Who Are 2 Through 5 Years of Age and Have a CFTR Gating Mutation
Brief Summary: The purpose of this study is to evaluate the safety, pharmacokinetics (PK), and pharmacodynamics (PD), of ivacaftor in children with cystic fibrosis (CF) who are 2 through 5 years of age and have a CF Transmembrane Conductance Regulator (CFTR) gating mutation in at least 1 allele.

Part A is designed to evaluate the safety and PK of multiple-dose administration of ivacaftor in participants 2 through 5 years of age and to confirm the doses for Part B. Part B is designed to evaluate the safety, PK, PD, and efficacy of ivacaftor in participants 2 through 5 years of age.


Options:
A: Inclusion Criteria:

* Weighing at least 40 kg
* Confirmed diagnosis of cystic fibrosis (CF) and G551D mutation in at least 1 allele
* Forced expiratory volume in 1 second (FEV1) of at least 40% of predicted normal for age, gender, and height
* Willing to remain on stable medication regimen for the duration of study participation
* No significant clinical laboratory abnormalities, not pregnant, and willing to use at least 2 highly effective birth control methods during Part 1 and 1 highly effective birth control method during Part 2 of the study
* No clinically significant abnormalities that would have interfered with the study assessments, as judged by the investigator

Exclusion Criteria:

* History of any illness or condition that might confound the results of the study or pose an additional risk in administering study drug to the subject
* Ongoing acute respiratory infection, pulmonary exacerbation, or changes in therapy for pulmonary disease within 14 days of Day 1 of the study
* History of alcohol, medication or illicit drug abuse within one year prior to Day 1
* Abnormal liver function ≥ 3x the upper limit of normal
* History of abnormal renal function (creatinine clearance \< 50 mL/min using Cockcroft-Gault equation)
* History of solid organ or hematological transplantation
* Pregnant or breast-feeding (for women)
* Ongoing participation in another therapeutic clinical trial, or prior participation in an investigational drug study without appropriate washout
* Concomitant use of any inhibitors or inducers of cytochrome P450 3A4 (CYP3A4)
B: Inclusion Criteria:

* All participants will have CF proven based on established criteria (sweat test, genotype and phenotype).
* All participants will have at least one copy of the G551D mutation.
* All will be able to perform an exercise study and complete study questionnaires and assessments.
* Age range will be between 16 and 75 years of age.
* Lung function inclusion will be above 25% predicted FEV1.

Exclusion Criteria:

* Participants will not be included if they are unable to complete study assessments or have had a known adverse reaction to Ivacaftor.
* Female participants will be excluded if found to return a positive pregnancy test at screening.
* Participants will be excluded if using St. John's Wort or rifampicin (strong CYP3A inducers).
* Participants with significant liver dysfunction will be excluded (ALT or ALT above 5 times upper limit of normal).
C: Inclusion Criteria:

* Confirmed diagnosis of CF by sweat chloride value or CF mutation criteria.
* Have 1 of the following 10 CFTR mutations on at least 1 allele: G551D, G178R, S549N, S549R, G551S, G1244E, S1251N, S1255P, G1349D or R117H (eligible in regions where ivacaftor is approved for use). Part A/B group may also have other ivacaftor-responsive mutations.
* Hematology, serum chemistry, and vital signs results at screening with no clinically significant abnormalities that would interfere with the study assessments, as judged by the investigator.

Exclusion Criteria:

* History of any illness or condition that, in the opinion of the investigator, might confound the results of the study or pose an additional risk in administering study drug to the participant
* Colonization with organisms associated with a more rapid decline in pulmonary status at screening (Only for Parts A and B)
* History of abnormal liver function or abnormal liver function at screening
* History of solid organ or hematological transplantation
* Use of any moderate or strong inducers or inhibitors of cytochrome P450 (CYP) 3A within 2 weeks before Day 1
* Participation in a clinical study involving administration of either an investigational or a marketed drug within 30 days or 5 terminal half-lives before screening
* Hemoglobin (Hgb) \<9.5 g/dL at screening
* Chronic kidney disease of Stage 3 or above
* Presence of a non-congenital or progressive lens opacity or cataract at Screening

Other protocol defined Inclusion/Exclusion Criteria may apply.
D: Inclusion Criteria:

* Male or female with confirmed diagnosis of CF
* Must have a CFTR gating mutation in at least 1 allele
* Aged 2 through 5 years at screening and Day 1
* Weight \>= 8 kg at screening and Day 1
* Hematology, serum chemistry, coagulation, and vital signs results at screening with no clinically significant abnormalities that would interfere with the study assessments, as judged by the investigator

Exclusion Criteria:

* History of any illness or condition that, in the opinion of the investigator, might confound the results of the study or pose an additional risk in administering study drug to the participant
* An acute upper or lower respiratory infection, or pulmonary exacerbation, or changes in therapy for pulmonary disease within 4 weeks before Day 1
* Abnormal liver function, at screening
* History of solid organ or hematological transplantation
* Use of any moderate or strong inducers or inhibitors of cytochrome P450 (CYP) 3A within 2 weeks before Day 1
* Participation in a clinical study involving administration of either an investigational or a marketed drug within 30 days or 5 terminal half-lives before screening

Answer: D