for people ages 4 months and up (full criteria)
at La Jolla, California and other locations
study started
estimated completion



This is a multicenter, cross-sectional, cohort study which will collect contemporary sweat chloride (SC) values from approximately 5000 Cystic Fibrosis (CF) patients prescribed and currently receiving commercially approved Cystic Fibrosis transmembrane conductance regulator (CFTR) modulator therapies.

Official Title

The CHEC-SC Cohort Study: CHaractErizing CFTR Modulated Changes in Sweat Chloride and Their Association With Clinical Outcomes


Eligible subjects who have been prescribed and chronically taking a commercially approved CFTR modulator for at least 3 months will be enrolled for a single visit to collect sweat to be analyzed for SC at their local site laboratory. Limited clinical data obtained at this visit will be augmented by retrospective and prospective data obtained from the Cystic Fibrosis Foundation Patient Registry (CFFPR). Study subjects who have been prescribed and switch to an alternative commercially approved CFTR modulator will be approached to re-enroll in the study after being on the alternative modulator for at least 3 months so that a new SC value can be obtained.


Cystic Fibrosis CF Sweat Sweat chloride CFTR Modulator Fibrosis


You can join if…

Open to people ages 4 months and up

  • Written informed consent (and assent when applicable) obtained from subject or subject's legal representative
  • Enrolled in the Cystic Fibrosis Foundation Patient Registry (CFFPR)
  • Male or female ≥ 4 months of age on day of study visit
  • Documentation of a CF diagnosis as evidenced by one or more clinical features consistent with the CF phenotype and one or more of the following criteria:
  • Sweat chloride equal to or greater than 60 milliequivalent (mEq)/liter by quantitative pilocarpine iontophoresis test (QPIT)
  • Two well-characterized mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene
  • Current treatment with a prescribed commercially approved CFTR modulator for at least 3 months prior to enrollment
  • Able to perform the testing and procedures required for this study, as judged by the investigator

You CAN'T join if...

  • Presence of a condition or abnormality that, in the opinion of the Investigator, would compromise the safety of the patient or the quality of the data
  • Currently enrolled in an investigational trial (including open-label follow-on studies and Expedited Access Pathway (EAP)) of an agent expected to have an impact on sweat chloride (refer to current list provided on study website)


  • University of California San Diego accepting new patients
    La Jolla California 92093 United States
  • Childrens Hospital Los Angeles accepting new patients
    Los Angeles California 90027 United States


accepting new patients
Start Date
Completion Date
Nicole Hamblett
Study Type
Last Updated