How a cystic fibrosis medication works in children's bodies

This trial is studying how Elexacaftor-Tezacaftor-Ivacaftor (a triple-combination medication) works in children with cystic fibrosis. Researchers want to understand how the medication moves through children's bodies and how that relates to its effectiveness and any side effects. By collecting blood samples from children already taking this treatment, the study aims to help doctors personalize dosing and predict who might experience problems.

While this medication has dramatically improved cystic fibrosis outcomes, some children experience side effects—especially mood or thinking changes and liver problems. Doctors need a better understanding of how children's bodies process the medication differently so they can predict and prevent these side effects while keeping the treatment effective.