The purpose of this study is to confirm the long-term safety and effectiveness of Kalydeco® (ivacaftor) in US CF patients with the R117H-CFTR mutation <18 years of age and to describe the long-term safety and effectiveness of Kalydeco in CF patients with the R117H-CFTR mutation overall and in patients ≥18 years. The long-term safety and effectiveness of Kalydeco will be examined in totality through the evaluation of the primary outcome measures.

Patient follow-up (i.e., collection of outcomes data after treatment initiation) in the Non-Interventional Cohort will be at least 36 months. The study also includes retrieval of retrospective data entered into the registry for 36 months before the initiation of Kalydeco treatment, from patients matched for Non-Interventional Cohorts. This will permit a within-group comparison of outcomes before and after Kalydeco treatment for effectiveness and safety. The interventional cohort will not be utilized.

Inclusion Criteria:

Non Interventional Cohort

• Male or female with confirmed diagnosis of CF
• Must have at least 1 allele of the R117H-CFTR mutation
• Enrolled in the US CFF Patient Registry
• With a record of Kalydeco treatment initiation from 01 January 2015 through 31 December 2016

Historical Cohort

• Patients with CF in the CFF Patient Registry as of 01 January 2009
• Must have at least 1 allele of the R117H-CFTR mutation
• Patients with no evidence of any prior Kalydeco exposure

Non Interventional Cohort - Patients Enrolled in the US CFF Patient Registry Historical Cohort - Patients with CF in the CFF Patient Registry as of 01 January 2009