A Phase 2 Study to Evaluate Effects of VX-661/Ivacaftor on Lung and Extrapulmonary Systems in Subjects With Cystic Fibrosis, Homozygous for the F508del-CFTR Mutation

A Phase 2, Randomized, Double-Blind, Placebo Controlled, Parallel-Group, Exploratory Study to Evaluate Effects of VX-661 in Combination With Ivacaftor on Lung and Extrapulmonary Systems in Subjects Aged 18 Years and Older With Cystic Fibrosis, Homozygous for the F508del-CFTR Mutation

To evaluate the clinical mechanisms of action in lung and extrapulmonary systems of VX-661 (tezacaftor; TEZ) in combination with ivacaftor (IVA) (TEZ/IVA) in participants with cystic fibrosis (CF) who are homozygous for the F508del mutation on the CF transmembrane conductance regulator (CFTR) gene.

Inclusion Criteria:

• Male and female participants, homozygous for the F508del CFTR mutation
• Confirmed diagnosis of CF by sweat chloride testing
• Forced Expiratory Volume in 1 Second (FEV1) ≥40% and ≤90% of predicted normal for age, sex, and height at Screening Visit
• 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 subject.
• An acute upper or lower respiratory infection, pulmonary exacerbation, or changes in therapy for pulmonary disease within 28 days before Day 1
• History or evidence of clinically significant findings on ophthalmologic examination during the Screening Period.
• History of solid organ or hematological transplantation
• Pregnant or nursing females
• Participants who have had radiation exposure within 1 year before the first mucociliary clearance (MCC) procedure that would cause them to exceed federal regulations by participating in this study
• In the opinion of the investigator, unable to adequately perform inhalation maneuvers during the MCC procedures