Study design (if review, criteria of inclusion for studies)
Interventional - Allocation: Randomized|Intervention Model: Parallel Assignment|Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)|Primary Purpose: Treatment
Cystic Fibrosis - 18 Years and older (Adult, Older Adult)
Drug: Ravicti low dose|Drug: Ravicti high dose|Drug: Placebo
The primary biological endpoint will be the change in average measurement of nasal potential difference between day 7 and baseline.|Change in other NPD measures from baseline and Days 4, 7, and 14 to include baseline PD, change in amiloride, low chloride, and low chloride plus isoproterenol.|Change in average sweat chloride measurement between days 4, 7, 14 and baseline.|Safety and tolerability.|Efficacy of PERT on absorption of Ravicti®.