Study ID number: VX11-661-101 
Official Title: A Phase 2, Multicenter, Double-Blinded, Placebo Controlled Study to Evaluate Safety, Efficacy, Pharmacokinetics, and Pharmacodynamics of VX-661 Monotherapy and VX-661/Ivacaftor Cotherapy in Subjects With Cystic Fibrosis, Homozygous or Heterozygous for the F508del-CFTR Mutation
Therapeutic Category: CFTR Modulator

VX-661 (Tezacaftor) and VX-770 (Ivacaftor) are two different but complementary drugs that may help correct some of the irregularities or deformities that the gene mutation causes. VX-661 and VX-770 were being studied together to see if they can help decrease some of the effects caused by CF. They are designed to help the mutated chloride channel work more effectively which could alleviate the cycle of mucus plugging, infection, and inflammation in the lungs caused by CF.

This was the first time VX-661 and VX-770 were given together. This was also the first time that VX-661 was given to subjects with CF. The study was done to learn more about the safety and effects of VX-661 when given alone and in comibation with VX-770 to subjects with CF. This also looked at how VX-661 and VX-770 may affect your body and how your body breaks down and eliminates the drugs. 

The study was completed and proceeded to a Phase 3 trial. 

Source: ClinicalTrials. gov: