Trial Search Results

(Study: Vertex IIS) Does Ivacaftor Alter Wild Type CFTR-Open Probability In The Sweat Gland Secretory Coil?

Clinical studies of lumacaftor + ivacaftor (combo therapy) produced better FEV1 (forced expiratory volume in 1 second) improvements than ivacaftor alone, without further improvement in sweat chloride results.

To help understand why sweat chloride was unresponsive, the investigators will use a newly developed sweat secretion test that provides accurate, in vivo readout of CFTR (cystic fibrosis transmembrane conductance regulator) function in the sweat gland secretory coil.

The investigators devised a protocol to determine if short courses of ivacaftor (3.5 days) will produce significant increases in WT (Wild-Type, i.e. normal) CFTR open probability by measuring CFTR-dependent sweating (C-sweat) in subjects with WT CFTR.

Stanford is currently not accepting patients for this trial.

Lead Sponsor:

Richard Barry Moss

Stanford Investigator(s):


  • Drug: Ivacaftor
  • Drug: β-Adrenergic cocktail
  • Drug: Pilocarpine Nitrate 5%
  • Device: Macroduct sweat stimulator




Inclusion Criteria:

   - Healthy adults without a Cystic Fibrosis (CF) mutation

   - Carriers with a known CF mutation

Exclusion Criteria:

   1. Documented liver disease

   2. Participants should not be taking:

      - medicines that are strong CYP3A (Cytochrome P450, family 3, subfamily A)
      inducers, such as:

         - the antibiotics rifampin and rifabutin;

         - seizure medications (phenobarbital, carbamazepine, or phenytoin); and

         - the herbal supplement St. John's Wort, substantially decreases exposure of
         ivacaftor and may diminish effectiveness.

Ages Eligible for Study

18 Years - N/A

Genders Eligible for Study


Not currently accepting new patients for this trial

Contact Information

Stanford University
School of Medicine
300 Pasteur Drive
Stanford, CA 94305
Colleen Dunn, RRT, CCRC
Not Recruiting