The SIMPLIFY study is being done to test whether or not it is safe to stop taking inhaled hypertonic saline or Pulmozyme® (dornase alfa) in those people that are also taking Trikafta™. The SIMPLIFY studyl consists of two similar studies conducted within the same protocol that are being done to answer the following questions:
• Study A: For people with CF taking Trikafta, does stopping treatment with hypertonic saline (at least 3%) have a similar effect on lung function as continuing treatment with hypertonic saline?
• Study B: For people with CF taking Trikafta, does stopping treatment with Pulmozyme have a similar effect on lung function as continuing treatment with Pulmozyme?
There are a total of 4 study visits (a screening visit and three additional visits during the active part of the study). There is a 2-week screening period and a 6-week active study period.About 920 people with CF who are 12 years of age or older will take part in this study at approximately 80 hospitals and clinics around the country. Of this total, approximately 520 people will participate in the hypertonic saline (Study A) portion and 400 people with participate in the Pulmozyme (Study B) portion of the study.

This is an observational study which will collect sweat chloride values from approximately 1000 cystic fibrosis subjects who are currently on cystic fibrosis transmembrane conductance regulator (CFTR) modulators. This study will require one visit to an MUSC clinic which will last approximately 2 hours. Compensation is provided.