What the trial was testing
The SKYLINE TRIALS enrolled 435 patients with cystic fibrosis. The study was sponsored by Vertex Pharmaceuticals Incorporated and tracked outcomes across the full group of patients who matched the trial's eligibility profile.
It was a large trial designed to confirm whether the treatment works well enough for wider use. 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
The new once-daily treatment maintained lung function just as well as the current twice-daily standard.
The Lancet. Respiratory medicine · 2025 · NCT05033080
These findings — that the new once-daily treatment matched the current standard treatment for maintaining lung function — were published in the The Lancet. Respiratory medicine and represent the headline result of the study.
Researchers tracked outcomes across 435 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
This treatment is not yet FDA-approved. The trials showed the new drug combination is as effective as the current standard (elexacaftor-tezacaftor-ivacaftor, sold as Trikafta) with the benefit of simpler once-daily dosing. If you have cystic fibrosis, talk to your doctor about whether this might become an option for you or if there are open trials you could join.
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
Breathing Training and Exercise Capacity in Non-CFB
The purpose of this research is to investigate whether a home-based and health coach supported specific breathing and respiratory muscle training program improves the ability to exercise, the function of the lungs and breathing muscles, and general clinical status in people with non-cystic fibrosis bronchiectasis (non-CFB).
Role of Genetic Factors in the Development of Lung Disease
This study is designed to evaluate the genetics involved in the development of lung disease by surveying genes involved in the process of breathing and examining the genes in lung cells of patients with lung disease. The study will focus on defining the distribution of abnormal genes responsible for processes directly involved in different diseases affecting the lungs of patients and healthy volunteers. Optional CT Sub-study The standard CT scan will be compared to the low dose radiation CT scan for the 150 subjects enrolled in the sub-study to assess the variation between the two techniques. Specifically, the quantitative computer aided detection of lung CT abnormalities from LAM can be compared to assess whether low radiation dose CT exams is an alternative to conventional CT to monitor disease status. This optional sub-study will be offered to up to 100 adult subjects with lung disease and up to 50 children age 9 and older with CF. Children will not be enrolled in the optional CT sub-study unless they have had a standard CT scan for medical purposes to use in comparison. One additional low dose radiation CT scan of the chest may be done as part of this sub-study when these subjects have their next annual CT scan.