Ivacaftor Treatment in 4 Month to 2 Year Old CF Subjects

Ivacaftor is a novel FDA approved therapy for patients with CF and gating mutations who are 4 months and older. This investigator-Initiated study is designed to evaluate the nutritional, growth and GI impact of ivacaftor treatment for the youngest (4-24 months) patient cohort and for whom FDA approval has recently been granted. This proposal directly extends the previous highly informative nutrition and weight gain investigation of ivacaftor treatment in the older patient cohort (1). The primary aims of the study are to evaluate the impact of 12 weeks of ivacaftor treatment in 4-24 month old subjects with CF and gating mutations on sleeping energy expenditure, growth status and gut health and function in 18 children with protocol evaluations at baseline (pre-treatment) and 6 and 12 weeks after clinically prescribed ivacaftor treatment has begun. Other outcomes of significant clinical interest in young subjects with CF will be explored. All subjects will be evaluated at the Children's Hospital of Philadelphia (CHOP) and will be recruited both regionally and nationally to ensure timely enrollment.