A Study of Lumacaftor in Combination With Ivacaftor in Cystic Fibrosis Subjects Aged 12 Years and Older Who Are Homozygous for the F508del-CFTR Mutation

Inclusion Criteria:

   - Confirmed diagnosis of CF

   - Homozygous for the F508del CFTR mutation

   - 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

   - Willing to remain on a stable CF medication regimen through Week 24 or, if applicable,
   the Safety Follow up Visit

Exclusion Criteria:

   - An acute upper or lower respiratory infection, pulmonary exacerbation, or changes in
   therapy (including antibiotics) for pulmonary disease within 4 weeks before first dose
   of study drug

   - History of solid organ or hematological transplantation

   - History of alcohol or drug abuse in the past year

   - Ongoing or prior participation in an investigational drug study (including studies
   investigating lumacaftor and/or ivacaftor) within 30 days of screening

   - Use of strong inhibitors, moderate inducers or strong inducers of Cytochrome P450 3A
   (CYP3A) within 14 days before Day 1 of dosing