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Study Name: VX-770 Phase 2 study in People with CF and Genotype 551D
Study Type: Interventional
Intervention Category: CFTR Modulation
Study Sponsor: Vertex
Study Phase: 2
Recruitment Status: Trial Completed
Study Drug(s): Kalydeco
Number of Participants Being Recruited: 36
Single / Multi-Center: Multi-Center
This study evaluated the safety and tolerability of a drug that modifies a protein associated with CF. The faulty gene that causes CF produces a defective protein, called CFTR. The protein leads to the creation of thick mucus in the lungs of people with CF, making breathing difficult. Thick mucus also causes bacteria to get stuck in the airways causing inflammation and infections leading to lung damage. The oral study drug, VX-770, seeks to improve the function of the defective CFTR protein. This Phase 2 clinical trial studied the safety and tolerability of VX-770 compared with placebo in people with CF. It also assessed how well the body absorbs the drug and whether there are changes to biomarkers to show CFTR activity.
Age: >= 18 Years
FEV1: >= 40 Percent Predicted
P. aeruginosa status: Not applicable
B. cepacia status: Not applicable
Other Primary Eligibility Requirements:

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:

Not applicable

Secondary Efficacy:

VX-770 was associated with within-subject improvements in CFTR and lung function.


This Phase 2 trial evaluated the safety and adverse-event profile of VX-770 in adult CF subjects with at least one G551D-CFTR allele. Thirty-nine subjects were assigned to receive either oral VX-770 at doses of 25, 75, or 150 mg or placebo every 12 hrs for 14 days (during 2 14-day periods separated by a washout) [Part 1] or VX-770 at doses of 150 or 250 mg or placebo every 12 hrs for 28 consecutive days [Part 2]. The frequency of adverse events was similar between the groups and between parts of the study. Six severe adverse events occurred in 2 subjects (one incidence of diffuse macular rash and 5 of elevated blood and urine glucose levels in one subject with diabetes) All severe or serious adverse events (macular rash and hospitalization for pulmonary exacerbation in the same subject) resolved without discontinuation of study drug.


N Eng J Med 2010;363(21):1991-2003

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