Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Phase 2, Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Study to Evaluate the Safety and Efficacy of VX-770 in Subjects Aged 12 Years and Older With Cystic Fibrosis Who Are Homozygous for the F508del-CFTR Mutation
Brief Summary: The purpose of this study was to evaluate the safety and efficacy of ivacaftor in participants with cystic fibrosis (CF) who were aged 12 years or older and were homozygous for the F508del-CF transmembrane conductance regulator (CFTR) mutation. 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 adenosine monophosphate (AMP)-dependent protein kinase A (PKA) activation.


Options:
A: Inclusion Criteria:

* Confirmed diagnosis of cystic fibrosis (CF) and homozygous for F508del-CFTR mutation
* Forced expiratory volume in 1 second (FEV1) of at least 40% of predicted normal for age, gender, and height
* Willing to use at least 2 highly effective birth control methods during the study
* No clinically significant abnormalities that would have interfered with the study assessments, as judged by the investigator
* Able to understand and comply with protocol requirements, restrictions, and instructions and likely to complete the study as planned, 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
* Acute respiratory infection, pulmonary exacerbation, or changes in therapy for pulmonary disease within 4 weeks of Day 1 of the study
* History of alcohol, medication or illicit drug abuse within one year prior to Day 1
* Abnormal liver function \>=3 x the upper limit of normal
* Abnormal renal function at Screening
* History of solid organ or hematological transplantation
* Pregnant or breast-feeding (for women)
* Ongoing participation in another therapeutic clinical study or prior participation in an investigational drug study within 30 days prior to screening
* Previous participation in a VX-809 study
* Used inhaled hypertonic saline treatment
* Concomitant use of any inhibitors or inducers of cytochrome P450 3A4 (CYP3A4)
B: Inclusion Criteria:

* Participants from Study 110 or Study 111 entering the ivacaftor arm must have completed the assigned study drug treatment duration in the previous study.
* Participants from Study 113 entering the ivacaftor arm must have completed all study related treatments through the Follow-up Visit and met the Study 113 responder criteria during the previous study.
* Participants entering the observational arm must have completed at least 4 weeks of study drug treatment in their previous study (Study 110 or Study 111), must have completed the previous study but do not wish to enroll in the ivacaftor arm, or must have completed the previous study but do not meet the inclusion criteria of the ivacaftor arm.
* Participants of childbearing potential entering the ivacaftor arm must not be pregnant.
* Participants entering the ivacaftor arm must be willing to comply with contraception requirements.

Exclusion Criteria (Ivacaftor Arm Only):

* History of any illness or condition that might confound the results of the study or pose an additional risk in administering ivacaftor to the Participant.
* Use of moderate or strong inhibitors or inducers of cytochrome P450 (CYP) 3A.
* Evidence of cataract or lens opacity at or before the Day 1 Visit.
C: Inclusion Criteria:

* Confirmed diagnosis of CF with ∆F508-CFTR mutation in both alleles
* Forced expiratory volume in 1 second (FEV1) greater than or equal to (\>=) 40 percent (%) of predicted normal for age, gender, and height
* Weight \>=40 kilograms (kg) and body mass index greater than or equal to 18.5 kilogram per square meter (kg/m\^2)
* Screening laboratory values, tests, and physical examination within acceptable ranges
* Negative pregnancy test (for women of child-bearing potential)
* Able and willing to follow contraceptive requirements
* Willing to remain on a stable medication regimen for the duration of study participation

Exclusion Criteria:

* History of any illness, or any ongoing acute illness, that could impact the safety of the study participant or may confound results of study
* Pulmonary exacerbation or changes in therapy for pulmonary disease within 14 days before receiving the first dose of study drug
* Impaired hepatic or renal function
* History of organ or hematological transplant
D: Inclusion Criteria:

* Two mutations known to cause cystic fibrosis and a sweat chloride concentration greater than or equal to 55 mmol
* Greater than or equal to 6 years of age

Exclusion Criteria:

* Homozygous F508del with a sweat chloride greater than 85 mmol
* Taking medication known to interact with ivacaftor and chooses not to discontinue that medication
* Is pregnant or planning to become pregnant during the study period
* Less than 6 years of age

Answer: A