Please select the eligibility criteria that correspond to the clinical trial below.
Title: Single Center, Double-blind, Randomized, Placebo-controlled, Two-period/Two-treatment Crossover Study Investigating the Effect of Miglustat on the Nasal Potential Difference in Patients With Cystic Fibrosis Homozygous for the F508del Mutation
Brief Summary: Single Center, Double-Blind, Randomized, Placebo-Controlled, Two-Period/Two-Treatment Crossover Study Investigating the Effect of Miglustat on the Nasal Potential Difference in Patients With Cystic Fibrosis Homozygous for the F508del Mutation


Options:
A: 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.
B: Inclusion Criteria:

* Subjects who weigh ≥15 kg without shoes a the Screening Visit
* Subjects with confirmed diagnosis of CF at the Screening Visit.
* Subjects who are homozygous for the F508del CFTR mutation
* Subjects with ppFEV1 of ≥70 percentage points adjusted for age, sex, and height
* Subjects with a screening LCI2.5 result greater than or equal to 7.5

Exclusion Criteria:

* History of any comorbidity reviewed at the Screening Visit 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 subject.
* Any clinically significant laboratory abnormalities at the Screening Visit that would interfere with the study assessments or pose an undue risk for the subject
* Clinically significant abnormalities in hemoglobin, liver function, or renal function at the Screening Visit.
* An acute upper or lower respiratory infection, pulmonary exacerbation, or changes in therapy for pulmonary disease within 28 days before Day 1
* History of solid organ or hematological transplantation at the Screening Visit
C: Inclusion Criteria:

* Aged 12 years and older
* Male or female Non-pregnant women who are to remain non-pregnant for 3 months after the end of the study. Women of childbearing potential must use a reliable method of contraception. Reliable methods of contraception for female patients include the following:
* barrier type devices (e.g., female condom, diaphragm and contraceptive sponge) used ONLY in combination with a spermicide
* intrauterine devices
* oral contraceptive agent
* Depo-Provera™ (medroxyprogesterone acetate)
* levonorgestrel implants Abstention, the rhythm method or contraception by the partner alone are NOT reliable methods of contraception. A woman is considered to have child-bearing potential unless she meets at least one of the following criteria:
* 6 weeks post-surgical bilateral salpingo-oophorectomy or hysterectomy
* Premature ovarian failure confirmed by a specialist gynecologist
* Age \> 50 years and not treated with any kind of HRT for at least 2 years prior to screening, and with amenorrhea for at least 24 consecutive months prior to screening and a serum FSH level of \> 40 IU/L at screening.
* Age \> 55 years and treated with HRT prior to screening with an appropriate medical documentation of spontaneous amenorrhea for at least 24 months. For female patients in the pediatric age range, a reliable method of contraception must be considered, if appropriate.

  * Male patients accepting for the duration of the study and for 3 months thereafter to use a condom and not to procreate a child (not in case of azoospermia)
  * Cystic fibrosis patients homozygous for the F508del mutation as confirmed by genetic test
  * Signed informed consent prior to any study-mandated procedure

Exclusion Criteria:

* Any condition prohibiting the correct measurement of the NPD such as upper respiratory tract infection
* Acute upper respiratory tract or pulmonary exacerbation requiring antibiotic intervention within 2 weeks of screening
* Severe renal impairment (creatinine clearance \< 30 mL/min as per Cockroft and Gault)
* Female patients of childbearing potential who will not undergo a pregnancy test prior to enrollment into the study
* History of significant lactose intolerance
* History of neuropathy
* Presence of clinically significant diarrhea (\> 3 liquid stools per day for \> 7 days) without definable cause within 1 month prior to screening
* Any known factor or disease that might interfere with treatment compliance, study conduct or interpretation of the results such as drug or alcohol dependence or psychiatric disease
* FEV1 \< 25% of predicted normal
* Oxygen saturation at rest \< 88%
* Active or passive smoking as measured using the Smokelyzer®
* Hypersensitivity to miglustat or any excipients
* Planned treatment or treatment with another investigationaldrug or therapy (e.g., gene therapy) within 1 month prior to randomization
* Breast-feeding, pregnant women or women who plan to become pregnant during the course of the study.
D: Inclusion Criteria:

* Currently participating in study VX17-659-105 (NCT03447262)

Exclusion Criteria:

* History of drug intolerance in study VX17-659-105 that would pose an additional risk to the participant in the opinion of the investigator
* Current participation in an investigational drug trial (other than study VX17-659-105)

Other protocol defined Inclusion/Exclusion criteria may apply.

Answer: C