The US Food and Drug Administration (FDA) has approved ivacaftor (Kalydeco®) for the treatment of cystic fibrosis (CF) in pediatric patients ages 1 month to less than 4 months old who have at least 1 mutation in the CFTR gene that is responsive to ivacaftor based on clinical and/or in vitro assay data.

“Treating the underlying cause of CF as early as possible is important, and this approval, the first for a CFTR modulator in this age group, means families will now have a medicine for eligible infants,” Carmen Bozic, MD, executive vice president, global medicines development and medical affairs, and chief medical officer at Vertex, said in a press release.

“As a physician caring for infants and children with CF, I see the importance of initiating therapies early in life that may slow disease progression,” said Margaret Rosenfeld, MD, MPH, Seattle Children’s Research Institute and department of pediatrics, University of Washington School of Medicine, and one of the principal investigators for the ivacaftor study in less than 24-month-olds. “Today’s approval provides many families and caregivers comfort in knowing that there is a highly effective modulator therapy available for their babies with CF.”

The FDA approval followed the dissemination of positive results from a phase 3, 24-week, open-label study evaluating the safety, pharmacokinetics, and pharmacodynamics of ivacaftor in pediatric patients with CF who are less than 24 months of age and have an ivacaftor-responsive CFTR mutation. The safety profile of ivacaftor in this cohort was similar to that observed in older children and adults.

Read more about CF therapies

Ivacaftor was initially approved in 2012 in the US to treat the underlying cause of CF in people with specific mutations in the CFTR gene. Currently, ivacaftor is available in more than 30 countries for the treatment of CF in eligible patients ages 4 months and older.

Ivacaftor is an oral medicine known as a CFTR potentiator that helps CFTR proteins transport salt and water across the cell membrane. This aids hydration of the airways, as well as clearing them of mucus. Ivacaftor was the first medicine that treated the underlying cause of CF in those who had certain mutations in the CFTR gene.


Vertex announces U.S. FDA approval for KALYDECO® (ivacaftor) to treat eligible infants with CF ages 1 month and older. News release. Vertex Pharmaceuticals; May 3, 2023.