Elexacaftor/tezacaftor/ivacaftor in children aged ≥6 years with cystic fibrosis heterozygous for

backgroundElexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) was efficacious and safe in children aged 6-11 years with cystic fibrosis (CF) heterozygous for

methodsIn this phase 3b extension study, dosing was based on weight and age, with children weighing <30 kg and aged <12 years receiving ELX 100 mg once daily, TEZ 50 mg once daily and IVA 75 mg every 12 h, and children ≥30 kg or ≥12 years receiving ELX 200 mg once daily, TEZ 100 mg once daily and IVA 150 mg every 12 h. The primary end-point was safety and tolerability. Secondary and other efficacy end-points included absolute changes from parent study baseline in sweat chloride concentration, lung clearance index (LCI

resultsA total of 120 children were enrolled and dosed. 118 children (98.3%) had adverse events (AEs), which for most were mild (43.3%) or moderate (48.3%) in severity. The most common AEs (≥20% of children) were COVID-19 (58.3%), cough (51.7%), nasopharyngitis (45.0%), pyrexia (40.0%), headache (37.5%), upper respiratory tract infection (30.8%), oropharyngeal pain (26.7%), rhinitis (24.2%), abdominal pain (22.5%) and vomiting (20.0%). Children who transitioned from the placebo and ELX/TEZ/IVA groups of the parent study had improvements from parent study baseline at Week 96 in mean sweat chloride concentration (-57.3 (95% CI -61.6- -52.9) and -57.5 (95% CI -62.0- -53.0) mmol·L

conclusionsELX/TEZ/IVA treatment was generally safe and well tolerated, with a safety profile consistent with the parent study and older age groups. After starting ELX/TEZ/IVA, children had robust improvements in sweat chloride concentration and lung function that were maintained through 96 weeks. These results demonstrate the safety and durable efficacy of ELX/TEZ/IVA in this paediatric population.