Cystic Fibrosis Foundation - Click here for homepage
Stay Informed  |  Volunteer  |  Clinical Trials

In This Section

Quick Links

Find a Chapter


Study Name: Vertex-770 and the G551D mutation (STRIVE)
Study Type: Interventional
Intervention Category: CFTR Modulation
Study Sponsor: Vertex

Funding for this trial has been provided in full or in part by Cystic Fibrosis Foundation Therapeutics, Inc.
Study Phase: 2
Recruitment Status: Trial Completed
Study Drug(s): Kalydeco
Number of Participants Being Recruited: 80
Single / Multi-Center: Multi-Center
Cystic Fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The CFTR protein is located on the cell membrane of the airways and sweat ducts. It is a chloride ion channel responsible for aiding in the regulation of salt and water absorption and secretion in tissues. Potentiators are pharmacological agents that increase the chloride ion transport properties of the channel. The increase in CFTR chloride ion channel opening may prevent hyperabsorption of water in the airway tissues, allowing for more favorable maintenance of airway hydration in people with CF.

This study looked at the effectiveness of VX-770 in people with CF and the G551D mutation by evaluating an absolute change from baseline in % predicted FEV1 through week 24 and safety over a longer treatment period than previously studied.
Age: >= 12 Years
FEV1: 40 - 90 Percent Predicted
P. aeruginosa status: Not applicable
B. cepacia status: Not applicable
Other Primary Eligibility Requirements:

To be eligible, subjects must have the G551D-CFTR mutation in at least 1 allele (any known or unknown mutations allowed in second allele).
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: Medical Monitor, Vertex
(617) 444-6777
Trial Specific Link on
Clinical Research Terms Glossary: Click here
Primary Efficacy:

This Phase 3 study evaluated safety and efficacy of VX-770 in 161 CF subjects with at least one G551D-CFTR allele. Subjects received either 150 mg VX-770 or placebo twice daily for 48 weeks.
The study met the primary endpoint of mean absolute change from baseline compared to placebo in FEV1 percent predicted through week 24. A mean absolute improvement from baseline compared to placebo of 10.6 percent was achieved (p<0.0001) and sustained through 48 weeks (10.5%; p<0.0001).

Secondary Efficacy:

Significant improvement in all key secondary endpoints (fewer pulmonary exacerbations, weight gain, reduction in sweat chloride) were also observed through week 48 in subjects who received VX-770. Improvements in CFQ-R respiratory domain were also reported.


The incidence of adverse events through week 48 was similar in the two groups. Discontinuation of study drug through week 48 due to adverse events was less frequent in the VX-770 treatment group (1 percent compared to 5 percent in the placebo group).


N Eng J Med 2011;365(18):1663-1672

Back to top