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Study Name: Safety Study of VX 809 in People with CF and Homozygous for Delta F508 Gene Mutation
Study Type: Interventional
Intervention Category: CFTR Modulation
Study Sponsor: Vertex
Study Phase: 2
Recruitment Status: Trial Completed
Study Drug(s): VX-809
Number of Participants Being Recruited: 90
Single / Multi-Center: Multi-Center
This was a Phase 2, randomized, double-blind, placebo-controlled, multiple dose study of orally administered VX-809 in subjects with CF who are homozygous for the specific CFTR mutation known as delta F508del. Enrollment was planned for approximately 90 subjects at approximately 22 clinical sites in the U.S., Canada, Belgium, Germany, and The Netherlands. Subjects were randomized in a 2:1 ratio to receive 1 of 4 doses of VX-809 or placebo once a day for 28 days in a parallel design. Subjects were outpatients during the study, except for overnight stays on Days 1 and 28.
Age: >= 18 Years
FEV1: >= 40 Percent Predicted
P. aeruginosa status: Not applicable
B. cepacia status: Not applicable
Other Primary Eligibility Requirements:

To be included in this study, patients must have a confirmed diagnosis of CF with Delta F508-CFTR mutation in both alleles
Note: Detailed eligibility criteria information may be available on If a specific trial listing for this trial is available, a link to the specific listing will be present in the "More Information" section below.
Sponsor Contact Information:
Trial Specific Link on
Clinical Research Terms Glossary: Click here
Primary Efficacy:

Not applicable

Secondary Efficacy:

A dose response for change in sweat chloride was observed across the four dose groups. Statistically significant decline in sweat chloride was observed at 100 mg and 200 mg doses when comparing each patient to baseline and to placebo.
There were no significant changes in CFTR-dependent NPD parameters or in lung function.


This Phase 2 trial randomized 89 adult subjects with CF, homozygous for the F508del CFTR mutation, to evaluate safety and tolerability of VX-809. Subjects received one dose daily for 28 days of 25, 50, 100, or 200 mg VX-809 or placebo.
VX-809 was well tolerated. Adverse events were similar in both the VX-809 and placebo groups. Respiratory-related adverse events were the most commonly reported adverse event.


Thorax 2012;67(1):12-18

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