What the trial was testing
The trial enrolled 225 patients with cystic fibrosis. The study was sponsored by Vertex Pharmaceuticals and tracked outcomes across the full group of patients who matched the trial's eligibility profile.
It was an early-stage trial — researchers are still confirming safety and getting an early look at how well the treatment works. Trials at this stage are designed to produce evidence regulators and physicians can act on — not just observations to follow up later.
What the results showed
Lung function jumped 13.8 percentage points in people with one hard-to-treat mutation.
New England Journal of Medicine · 2018 · NCT03227471
These findings — that improvement in lung function (FEV1) for people with one Phe508del and a minimal-function mutation — were published in the New England Journal of Medicine and represent the headline result of the study.
Researchers tracked outcomes across 225 patients enrolled in the trial. The result was consistent enough across the group that the team felt confident reporting it.
What this means for patients
For patients with cystic fibrosis, this result changes the calculus on what to ask their care team about. Whether it changes day-to-day care depends on factors like disease subtype, prior treatments, and where the patient is in their care journey.
What you can do now
Elexacaftor-tezacaftor-ivacaftor (Trikafta) is FDA-approved and available now for people 2 and older with cystic fibrosis who carry at least one Phe508del mutation — about 90% of patients. Most U.S. CF centers prescribe it as standard care. Ask your CF team if your specific mutation qualifies.
Eligibility for the treatments mentioned above depends on specific test results and clinical history. Bring this summary, the trial name, and your most recent labs or pathology report to your next visit.
Open cystic fibrosis trials
Xenon-129 and Inert Fluorinated Gas Lung MRI: Study of Healthy Volunteers and Participants With Pulmonary Disease
Aim of this study is to evaluate image quality and reproducibility of Xenon-129 and Inert fluorinated (19F) gas Magnetic Resonance Imaging (MRI) and to evaluate changes in lung structure and function in participants with cystic fibrosis (CF) and asthma compared to healthy controls.
Restarting Triple Therapy With Robust Monitoring for Adverse Events (RETRIAL)
RETRIAL is a multi-site observational study of people with Cystic Fibrosis (PWCF) ages 6 and up starting the new triple-therapy modulator (vanzacaftor/tezacaftor/deutivacaftor (VTD)), after having experienced neuropsychiatric events and/or liver injury while taking elexacaftor/tezacaftor/ivacaftor (ETI) that resulted in a modification or discontinuation of standard ETI dosing.