Targeting Inflammation With Losartan to Improve Response to Modulator Therapy in Cystic Fibrosis.

The goal of this clinical trial is to test use of losartan in those with cystic fibrosis (CF) on modulator therapy. The main question it aims to answer is if treatment with losartan improves response of the CF transmembrane conductance regulator (CFTR) channel to modulator therapy. Participants will be asked take losartan or placebo for twelve weeks and will have changes in sweat chloride levels measured as a marker of CFTR function.