Plain-English translation of NCT05076149 on ClinicalTrials.gov ↗ · Source last updated · Translation generated · How we translate trials
Read our Cystic fibrosis research guide →Phase 3 — Testing in thousands of people, comparing the treatment against what doctors currently use. This is the last big step before approval.
This trial studied whether VX-121/tezacaftor/deutivacaftor—a new three-drug combination—could help people with cystic fibrosis breathe better than the current standard treatment. The trial included people who carried specific genetic changes related to their cystic fibrosis. Researchers compared this new medication combination to an existing treatment over one year to see which worked better and was safer.
Cystic fibrosis is caused by defects in a protein called CFTR, and different genetic mutations need different treatments. This trial was designed to see whether this new medication combination could help more people with CF—especially those who carry less common mutations or whose current treatment isn't working well enough.
Participants started with a 4-week run-in period taking the existing standard medication, then were randomly assigned to either continue that medication or switch to the new combination for 52 weeks. Throughout the year, they received doses by mouth once or twice daily and visited the clinic for checkups to measure how well their lungs were working and to monitor for any side effects.
AI-generated summary from trial data · Sep 24, 2026 · Not medical advice
United States