CFTR and cystic fibrosis: This study aimed to develop a population pharmacokinetic model (popPK) of tobramycin in children with CF and determine (i) the effect of concomitant CFTR modulators on tobramycin PK; (ii) the attainment of an AUC24,ss of 80–110 mg/L⋅h with standard dosing; and (iii) the attainment of this therapeutic target using a fully individualised dosing strategy in children with CF.