Effect of Miglustat on the Nasal Potential Difference in Patients With Cystic Fibrosis Homozygous for the F508del Mutation

For this 2 x 2 (2 periods /2 treatments) crossover design each patient will receive Miglustat during the first period (2 weeks), following by a wash out period(14 days (up to 4 weeks)), then Placebo during the second period (2 weeks). 30 days follow-up will be carried out after end-of-treatment of the second period.

For this 2 x 2 (2 periods /2 treatments) crossover design each patient will receive Placebo during the first period (2 weeks), following by wash out period (14 days (up to 4 weeks)), then Miglustat during the second period (2 weeks). 30 days follow-up will be carried out after end of treatment of the second period.