Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Phase 3, Randomized, Double-Blind, Placebo-Controlled, Crossover Study to Evaluate the Efficacy and Safety of Ivacaftor and VX-661 in Combination With Ivacaftor in Subjects Aged 12 Years and Older With Cystic Fibrosis, Heterozygous for the F508del-CFTR Mutation, and a Second Allele With a CFTR Mutation Predicted to Have Residual Function
Brief Summary: The purpose of this study is to evaluate the efficacy and safety of VX-661 in combination with ivacaftor (IVA, VX-770) and IVA monotherapy in participants with Cystic Fibrosis (CF) who are heterozygous for F508del-CFTR allele and a second allele with a CFTR mutation predicted to have residual function.


Options:
A: 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
B: Inclusion Criteria:

* Subject voluntarily agrees to participate in this study and signs an Institutional Review Board (IRB)-approved informed consent prior to performing any of the screening procedures and in the opinion of the PI complies with all the requirements of the study.
* Subject is healthy, determined at the screening medical evaluation (including but not limited to medical history, physical examination and clinical laboratory evaluations).
* Subject is Caucasian.
* Female subject must be of non-childbearing potential (surgically sterile \[hysterectomy or bilateral tubal ligation\] or post-menopausal ≥ 1 year with follicle stimulating hormone \[FSH\] \> 40 U/L). Women receiving hormone replacement therapy (HRT) are eligible to enroll.
* Male subject must agree to use condoms and refrain from sperm donation from Day 1 until 30 days post last dose or have documentation of vasectomy.
* Subject has a body weight \> 50 kg and body mass index (BMI) between 19.5 and 32 kg/m2, inclusive, at screening.
* Subject has no clinically significant abnormal findings related to their systolic or diastolic blood pressure (BP), per the investigator's judgment, at screening or Day 1.
* Subject has no clinically significant abnormal findings in 12 lead ECG, per the investigator's judgment, at screening.

Exclusion Criteria:

* Subject has clinically significant history or evidence of cardiovascular, respiratory, hepatic, renal, gastrointestinal, endocrine, neurological, immunological, or psychiatric disorder(s) as determined by the investigator or designee.
* Subject has clinically significant abnormalities on a 12 lead ECG done at screening
* Subject has clinically significant abnormalities on a 48-hour ambulatory ECG done at screening
* Subject has any disorder that would interfere with the absorption, distribution, metabolism, or excretion of drugs.
* Subject has any concurrent disease or condition that, in the opinion of the investigator, would make the subject unsuitable for participation in the clinical study.
* Subject is unlikely to comply with the protocol requirements, instructions, and study related restrictions; e.g., uncooperative attitude, unavailable for follow-up call, and/or improbability of completing the clinical study.
C: Inclusion Criteria:

Healthy Volunteers: PARTS A, B, and C

* Males and Females of non-childbearing potential.
* Between the ages of 18 and 60 years inclusive
* Healthy, as defined per protocol.
* Body mass index (BMI) of 18.0 to 32.0 kg/m2 inclusive
* Body weight \>50 kg

CF Patients: PART D

* Body weight ≥35 kg.
* Males and Females of non-childbearing potential.
* Sweat chloride value ≥ 60 mmol/L at screening.
* Heterozygous for F508del and a minimal function CFTR mutation
* Forced expiratory volume in 1 second (FEV1) ≥40% and ≤90% of predicted at screening

Exclusion Criteria:

Healthy Volunteers: PARTS A, B, and C

* History of any illness or any clinical condition that in the opinion of the investigator might confound the results of the study or pose additional risk to the subject.
* Any condition possibly affecting drug absorption.
* History of febrile illness within 14 days before the first study drug dose.
* Glucose-6-phosphate dehydrogenase (G6PD) deficiency assessed at Screening.

CF Patients: PART D

* History of any comorbidity that, in the opinion of the investigator, might confound the results of the study or pose an additional risk to the subject.
* History of cirrhosis with portal hypertension.
* Risk factors for Torsade de Pointes.
* G6PD deficiency assessed at Screening.
* Abnormal Laboratory Values.
* Lung infection with organisms associated with a more rapid decline in pulmonary status
* History of solid organ or hematological transplantation.
D: Inclusion Criteria:

* Heterozygous for F508del-CFTR and a second allele with a CFTR mutation predicted to have residual function
* Forced Expiratory Volume in 1 Second (FEV1) greater than or equal to (≥) 40 percent (%) and less than or equal to (≤) 90% of predicted normal for age, sex, and height during screening
* Sweat chloride value ≥60 millimole per liter (mmol/L) during screening OR as documented in the participant's medical record
* Stable CF disease as judged by the investigator

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
* History of solid organ or hematological transplantation
* Ongoing or prior participation in an investigational drug study (including studies investigating VX-661, lumacaftor \[VX-809\], and/or ivacaftor) within 30 days of screening
* Pregnant and nursing females
* Sexually active participants of reproductive potential who are not willing to follow the contraception requirements

Answer: D