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
Studying the Presence of CFRD Complications With Thoughtful Recruitment (SPeCTRuM)
This multicenter cross-sectional study will include a diverse population of adolescents and adults with CF. The overall Aim is to describe prevalence of diabetes microvascular complications and macrovascular surrogates in people with established CFRD.
A Phase II Study of Ensifentrine in Non-Cystic Fibrosis Bronchiectasis
This study is a randomized, double-blind, placebo-controlled study designed to assess the efficacy and safety of ensifentrine inhalation suspension (3 mg) delivered twice daily via standard jet nebulizer over at least 24 weeks, compared to placebo, in subjects with non-cystic fibrosis bronchiectasis (NCFBE).