Population Pharmacokinetics of Elexacaftor, Tezacaftor and Ivacaftor in a Real-World Cohort of Adults with Cystic Fibrosis.

Background And Objectives: Elexacaftor-tezacaftor-ivacaftor (ETI), a combination of cystic fibrosis transmembrane conductance regulator (CFTR) modulators, has become the therapeutic standard of care for most people with cystic fibrosis (pwCF). People with cystic fibrosis exhibit differences in CFTR genotypes and have important differences in phenotypic characteristics including age, body weight, pancreatic status, disease severity, and comorbidities. While these differences predict large interindividual variability (IIV) in ETI exposure, there is a unique dose regimen recommended for adults.