NACFC 2025 | S19: Navigating the Relationship Between Sweat Chloride & Clinical Outcomes in CF

CFTR modulators are rapidly changing care for many people with CF. CFTR modulators reduce sweat chloride, but the relationship between sweat chloride and clinical outcomes is complex. In this session, we discuss the relationship between sweat chloride and CFTR activity, review the use of sweat chloride as a biomarker in clinical trials and its association with clinical outcomes across study populations, and discuss the utility of sweat chloride for clinical monitoring of an individual with CF. Finally, we discuss implications for future CFTR modulator development in the context of therapeutic goals directed towards further increasing CFTR activity. Originally recorded Oct. 24, 2025. Recording may have been edited for time and/or content.