What the trial was testing
The EXTEND enrolled 1,131 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 rate of lung function decline was 62% lower in treated patients versus untreated matched controls.
The Lancet. Respiratory medicine · 2021 · NCT02565914
These findings — that the drug combo slowed the loss of lung function by nearly two-thirds versus no treatment — were published in the The Lancet. Respiratory medicine and represent the headline result of the study.
Researchers tracked outcomes across 1,131 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 FDA-approved and available now for people 12 and older with certain cystic fibrosis gene mutations (F508del). It helps slow lung damage over time. Ask your doctor if this combination is right for your specific gene type and whether it's covered by insurance.
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
Study to Enable New Diagnostics for Pulmonary Microbes in People With CF
Sputum culture has been the best approach to detect harmful bacteria in the lungs of people with cystic fibrosis (CF). With the widespread use of new CF therapies (like Trikafta and Alyftrak), it is more difficult for people with CF to produce sputum even though they still have harmful bacteria in their lungs. The SEND-CF study is being done to see if there are other ways to detect harmful bacteria in the lungs.
Safety, Tolerability and Efficacy Study of ARCT-032 in People With Cystic Fibrosis
ARCT-032-02 is a Phase 2, open-label, multicenter, multiple-ascending dose study of ARCT-032 in adults with CF who are not eligible for CFTR modulator therapy or are not taking CFTR modulators due to drug intolerance, poor response, or lack of access to modulators.