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
Lung Disease and Its Affect on the Work of White Blood Cells in the Lungs
The purpose of this study is to look at how Alpha-1-antitrypsin (AAT) deficiency and Cystic Fibrosis (CF) affect white blood cells in the lungs, called macrophages, and their ability to work.
Dose Range Finding, Efficacy, and Safety Study of Nebulized CSL787 in Adults With Non-cystic Fibrosis Bronchiectasis (NCFB)
This study is a phase 2b, multicenter, randomized, double-blind, placebo-controlled, parallel-group, dose range finding study designed to explore the efficacy, safety, and tolerability of 2 active treatment regimens of CSL787 (immunoglobulin G \[IgG\] inhalation solution) compared with placebo over a period of 6 to 12 months independent of the occurrence of pulmonary exacerbations. The primary aim of the study is to characterize the overall effect of CSL787 as well as the dose response of 2 active treatment regimens of inhaled CSL787 administered to participants with NCFB toward prolonging the TTF exacerbation.