This trial is active, not recruiting.

Condition cystic fibrosis
Treatment ivacaftor
Phase phase 0
Sponsor Richard Barry Moss
Start date July 2015
End date December 2016
Trial size 6 participants
Trial identifier NCT02310789, 31238


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.

United States No locations recruiting
Other countries No locations recruiting

Study Design

Allocation non-randomized
Endpoint classification pharmacodynamics study
Intervention model single group assignment
Masking open label
Primary purpose diagnostic
Diagnostic testing to be performed on Ivacaftor
ivacaftor Kalydeco
150mg Q12 p.o. Protocol describes Ivacaftor treatment to be given in two-week intervals. The patient will serve as their own controls. Diagnostic procedures to be performed on and off Ivacaftor.
(No Intervention)
Patients will be off drug and the same diagnostic procedures will be done during both periods. Therefore, patients are acting as their own controls in this crossover study.

Primary Outcomes

CFTR-dependent sweat rate
time frame: 21-35 days per subject

Secondary Outcomes

Sweat chloride concentration
time frame: 21-35 days per subject

Eligibility Criteria

Male or female participants at least 18 years old.

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.

Additional Information

Official title (Study: Vertex IIS) A Study To Access the Effects of Ivacaftor on Wild Type CFTR-Open Probability (PO) In The Sweat Gland Secretory Coil
Principal investigator Jeffrey Wine, PhD
Description Cystic fibrosis (CF) is a genetic disease caused by malfunctioning of a protein called CFTR. CF affects various organs including the sweat glands and the lungs. An FDA approved drug called ivacaftor helps some people with CF, and laboratory tests show that it produces further improvement when combined with an investigational drug called lumacaftor. However, results from clinical tests of the two drugs used together gave mixed results: lung function improved but sweat gland function did not improve. This study will measure CFTR-dependent sweat rate to test the hypothesis that CFTR in the normal sweat glands might be functioning at peak efficiency, and so can't be improved further with ivacaftor, thus accounting for the apparent discrepancy between lung function and sweat gland results. CFTR-dependent sweat rate is important to understanding CF because it is a very accurate measure of CFTR function.
Trial information was received from ClinicalTrials.gov and was last updated in April 2016.
Information provided to ClinicalTrials.gov by Stanford University.