The objective of this study is to describe the renal impact of Elexacaftor-Teacaftor-Ivacaftor, a triple modulator therapy of CFTR channel, in patients with cystic fibrosis. This new treatment acts on the CFTR channel, which is expressed at the level of the nephrons. The objective is to study the changes in plasma and urinary parameters, including metabolic explorations of urolithiasis, change in volemic parameters, renal function, urinary sediment and nutritional and glycemic parameters, in newly treated patients, through the data collected at introduction of the treatment and during the follow-up.