New Treatments31 August 2026

CFTR modulators and the push to treat cystic fibrosis earlier

Drugs that correct the underlying protein defect have changed cystic fibrosis. The next question is how early in life they should start.

By NextGenHealth Editorial Team2 min read

Assorted medication tablets and capsules — Photo: freestocks / Unsplash

In brief

How CFTR modulators such as elexacaftor/tezacaftor/ivacaftor changed cystic fibrosis, and the push to start treatment in children as young as two.

Cystic fibrosis (CF) is caused by mutations in the CFTR gene, which makes a channel that moves chloride across cell membranes. When it fails, mucus in the lungs and digestive system becomes thick and sticky, leading to infections, lung damage and poor nutrition from early childhood.

For decades, treatment managed the consequences. CFTR modulators target the cause.

From one mutation to most patients

The first modulator, ivacaftor, was approved by the FDA in 2012 for patients with a specific gating mutation. It helped only a small fraction of people with CF, because the most common mutation, F508del, causes a different problem: the protein misfolds and never reaches the cell surface.

Combinations followed. The breakthrough was the triple combination of elexacaftor, tezacaftor and ivacaftor, approved in the US in 2019 for patients aged 12 and over with at least one copy of F508del. That covered the large majority of people with CF. Results in lung function and symptoms were substantial enough to change expectations of the disease.

Moving down the age range

Since then, the story has been one of label expansion. The triple combination was extended to children aged six to eleven, and later to children as young as two, with new formulations such as granules that can be mixed with soft food. Ivacaftor alone has been extended to infants.

The rationale is the same as in other progressive genetic diseases: lung damage in CF starts early, and preserving lung function is easier than restoring it.

Open questions

Long-term data in children who start modulators very young are still accumulating. Clinicians are watching growth, liver function and neuropsychiatric effects. And a minority of people with CF have mutations that modulators cannot help, which keeps genetic therapies for CF in development.

Cystic fibrosis
CFTR modulators
Label expansion
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