Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Phase 3, Randomized, Double Blind, Placebo Controlled, Parallel Group Study to Evaluate the Efficacy and Safety of VX-661 in Combination With Ivacaftor in Subjects Aged 12 Years and Older With Cystic Fibrosis, Homozygous for the F508del CFTR Mutation
Brief Summary: This is a Phase 3, randomized, double blind, placebo controlled, parallel group, multicenter study in people with cystic fibrosis (CF) who are homozygous for the F508del CF transmembrane conductance regulator (CFTR) gene mutation.


Options:
A: Inclusion Criteria:

* Completed study drug treatment in a parent study i.e.VX17-445-102 (NCT03525444) and VX17-445-103 (NCT03525548); or had study drug interruption(s) in a parent study but completed study visits up to the last scheduled visit of the Treatment Period in the parent study.

Exclusion Criteria:

* History of drug intolerance in a parent study that would pose an additional risk to the subject in the opinion of the investigator.
* Current participation in an investigational drug trial (other than a parent study)

Other protocol defined Inclusion/Exclusion criteria may apply.
B: Inclusion Criteria:

* Male or female participants with confirmed diagnosis of CF
* Must have the F508del-CFTR mutation on at least 1 allele.
* FEV1 greater than equal (\>=) 40% of predicted normal for age, gender, and height (Knudson standards)(Cohort 1, 2, and 3); FEV1 40-90% of predicted normal for age, gender, and height (Hankinson standards (Cohort 4)
* Participant of child-bearing potential and who are sexually active must meet the contraception requirements

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 (e.g., cirrhosis with portal hypertension).
* An acute illness including acute upper or lower respiratory infection, pulmonary exacerbation or changes in therapy (including antibiotics) for pulmonary disease within 14 days (Cohort 1, 2, and 3) or 28 days (Cohort 4) before receiving the first dose of study drug.
* History of solid organ or hematological transplantation.
* History of alcohol abuse or drug addiction in the past year, including cannabis, cocaine, and opiates.
* Ongoing participation in another therapeutic clinical study, or prior participation in an investigational drug study without appropriate washout
* Pregnant or nursing females; females of childbearing potential who are unwilling or unable to use an acceptable method of non-hormonal contraception
* Participants enrolled in Cohort 1 or Cohort 2 will not be eligible for Cohort 3
* Ongoing or prior participation in an investigational drug study within 30 days of the Screening Visit
* Heterozygous participants who participated in Cohort 2 and meet the eligibility criteria for Cohort 4 may participate in Cohort 4
* Evidence of lens opacity or cataract as determined by the ophthalmologic examination (Cohort 4 only)
C: Inclusion Criteria:

* Evidence of signed and dated informed consent/assent document(s) indicating that the subject (and/or his parent/legal guardian) has been informed of all pertinent aspects of the trial
* Age \>=6 years.
* Body weight \>=16 kg.
* Sweat chloride \>60 milliequivalent per liter (mEq/L)
* Documentation of the presence of a nonsense mutation in at least 1 allele of the cystic fibrosis transmembrane conductance regulator (CFTR) gene, as determined by genotyping performed at a laboratory certified by the College of American Pathologists (CAP), or under the Clinical Laboratory Improvement Act/Amendment (CLIA), or by an equivalent organization
* Verification that a blood sample has been drawn for sequencing of the CFTR gene
* Ability to perform a valid, reproducible spirometry test using the study-specific spirometer with demonstration of an FEV1 \>=40% and \<=90% of predicted
* Demonstration at Visit 2 of a valid %-predicted FEV1 within 15% of the Screening % predicted FEV1 value
* Resting oxygen saturation (as measured by pulse oximetry) \>=92% on room air.
* Confirmed screening laboratory values within pre-specified ranges
* In subjects who are sexually active, willingness to abstain from sexual intercourse or employ a barrier or medical method of contraception during the study drug administration and 60-day follow-up period
* Willingness and ability to comply with all study procedures and assessments, including scheduled visits, drug administration plan, study procedures, laboratory tests, and study restrictions

Exclusion Criteria:

* Known hypersensitivity to any of the ingredients or excipients of the study drug
* Previous participation in the Phase 3 trial of ataluren (PTC124-GD-009-CF).
* Any change (initiation, change in type of drug, dose modification, schedule modification, interruption, discontinuation, or re-initiation) in a chronic treatment/prophylaxis regimen for Cystic Fibrosis (CF) or for CF-related conditions within 4 weeks prior to screening
* Chronic use of inhaled aminoglycosides (eg, tobramycin) or use of inhaled aminoglycosides within 4 weeks prior to screening.
* Exposure to another investigational drug within 4 weeks prior to screening
* Ongoing participation in any other therapeutic clinical trial
* Evidence of pulmonary exacerbation or acute upper or lower respiratory tract infection (including viral illnesses) within 3 weeks prior to screening
* Treatment with intravenous antibiotics within 3 weeks prior to screening
* Ongoing immunosuppressive therapy (other than corticosteroids)
* Ongoing warfarin, phenytoin, or tolbutamide therapy
* History of solid organ or hematological transplantation
* Major complications of lung disease (including massive hemoptysis, pneumothorax, or pleural effusion) within 8 weeks prior to screening
* Known portal hypertension
* Positive hepatitis B surface antigen, hepatitis C antibody test, or human immunodeficiency virus (HIV) test
* Pregnancy or breast-feeding
* Current smoker or a smoking history of \>=10 pack-years (number of cigarette packs/day x number of years smoked).
* Prior or ongoing medical condition (eg, concomitant illness, alcoholism, drug abuse, psychiatric condition), medical history, physical findings, electrocardiogram (ECG) findings, or laboratory abnormality that, in the investigator's opinion, could adversely affect the safety of the subject, makes it unlikely that the course of treatment or follow-up would be completed, or could impair the assessment of study results
D: Inclusion Criteria:

* Homozygous for the F508del CFTR mutation, genotype to be confirmed at the Screening Visit
* Confirmed diagnosis of CF defined as a sweat chloride value ≥60 mmol/L by quantitative pilocarpine iontophoresis
* Forced expiratory volume at one second (FEV1) ≥40% and ≤90% of predicted normal for age, sex, and height during screening
* Stable CF disease as judged by the investigator
* Willing to remain on a stable CF medication regimen through Week 24 or, if applicable, the Safety Follow up Visit

Exclusion Criteria:

* History of any comorbidity 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, pulmonary exacerbation, or changes in therapy (including antibiotics) for pulmonary disease within 28 days before Day 1 (first dose of study drug)
* Pregnant or nursing females (females of childbearing potential must have a negative pregnancy test at Screening and Day 1)
* Sexually active participants of reproductive potential who are not willing to follow the contraception requirements

Answer: D