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, Heterozygous for the F508del-CFTR Mutation and With a Second CFTR Mutation That Is Not Likely to Respond to VX-661 and/or Ivacaftor Therapy (F508del/NR)
Brief Summary: Study to evaluate the efficacy of VX-661 in combination with ivacaftor (IVA, VX-770) through Week 12 in participants with cystic fibrosis (CF) who are heterozygous for the F508del mutation on the CF transmembrane conductance regulator (CFTR) gene and with a second CFTR mutation that is not likely to respond to VX-661 and/or IVA therapy (F508del/not responsive \[NR\]).


Options:
A: Key Inclusion Criteria:

* Homozygous for the F508del mutation or heterozygous for F508del and a minimal function (MF) mutation (F/F or F/MF genotypes)

Key Exclusion Criteria:

* Clinically significant cirrhosis with or without portal hypertension
* Lung infection with organisms associated with a more rapid decline in pulmonary status
* Solid organ or hematological transplantation

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

* Confirmed diagnosis of CF defined as a sweat chloride value greater than or equal to (\>=)60 millimole per liter (mmol/L) by quantitative pilocarpine iontophoresis.
* Heterozygous for the F508del-CFTR mutation and with a second CFTR mutation that is not likely to respond to VX-661 and/or ivacaftor therapy, genotype to be confirmed via assessment at the Screening Visit.
* Forced Expiratory Volume in 1 Second (FEV1) \>=40 percent (%) and less than or equal to (\<=)90% of predicted normal for age, sex, and height at Screening 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).
* History of solid organ or hematological transplantation.
* Ongoing or prior participation in an investigational drug study or use of commercially available CFTR modulator within 30 days of screening.
* Pregnant or nursing females.
C: Inclusion Criteria:

1. Male or female subject ≥ 18 years of age, on the day of signing the Informed Consent Form (ICF).
2. A confirmed clinical diagnosis of CF.
3. One F508del mutation on one allele in the CFTR gene, a gating (class III) mutation (one of the following: G551D, G1244E, G1349D, G178R, G551S, S1251N, S1255P, S549N, or S549R) on the 2nd allele in the CFTR gene (documented in the subject's medical record or CF registry).
4. Weight ≥ 40 kg.
5. Stable concomitant treatment for at least 4 weeks (28 days) prior to baseline (including physician prescribed ivacaftor (Kalydeco®) 150 mg b.i.d.).
6. Forced expiratory volume in 1 second (FEV1) ≥ 40% of predicted normal for age, gender and height at screening (pre- or postbronchodilator).

Exclusion Criteria:

1. History of clinically meaningful unstable or uncontrolled chronic disease that makes the subject unsuitable for inclusion in the study in the opinion of the investigator.
2. Unstable pulmonary status or respiratory tract infection (including rhinosinusitis) requiring a change in therapy within 4 weeks of baseline.
3. Need for supplemental oxygen during the day, and \>2 liters per minute (LPM) while sleeping.
4. History of hepatic cirrhosis with portal hypertension (e.g., signs/symptoms of splenomegaly, esophageal varices, etc).
5. Abnormal liver function test at screening; defined as aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT) and/or alkaline phosphatase and/or total bilirubin (\>1.5 times ULN (CTCAE Grade 2) and/or gamma-glutamyl transferase (GGT) ≥ 3x the upper limit of normal (ULN), and/or total bilirubin (\>1.5 times ULN (CTCAE Grade 2).
6. Estimated creatinine clearance \< 60mL/min using the Cockroft-Gault formula at screening.
D: Key Inclusion Criteria:

* Heterozygous for the F508del mutation (F/MF)
* Forced expiratory volume in 1 second (FEV1) value ≥40% and ≤90% of predicted mean for age, sex, and height

Key Exclusion Criteria:

* Clinically significant cirrhosis with or without portal hypertension
* Lung infection with organisms associated with a more rapid decline in pulmonary status
* Solid organ or hematological transplantation

Other protocol defined Inclusion/Exclusion criteria may apply

Answer: B