Vanzacaftor-tezacaftor-deutivacaftor for children aged 6-11 years with cystic fibrosis (RIDGELINE Trial VX21-121-105): an analysis from a single-arm, phase 3 trial.

backgroundIn phase 2 trials in people with cystic fibrosis aged 18 years and older, vanzacaftor-tezacaftor-deutivacaftor has been shown to be a safe and effective, once-daily cystic fibrosis transmembrane conductance regulator (CFTR) modulator. Restoring normal CFTR function early in life has the potential to prevent manifestations of cystic fibrosis. We aimed to evaluate the safety, tolerability, efficacy, and pharmacokinetics of vanzacaftor-tezacaftor-deutivacaftor in children with cystic fibrosis aged 6-11 years.

methodsIn this multicentre, single-arm, phase 3 trial (RIDGELINE Trial VX21-121-105), participants were enrolled across 33 clinical sites that care for children with cystic fibrosis in eight countries (Australia, France, Germany, Netherlands, Sweden, Switzerland, the UK, and the USA). Eligible participants were aged 6-11 years with at least one elexacaftor-tezacaftor-ivacaftor-responsive CFTR variant, FEV

findingsBetween Feb 6 and May 18, 2023, 83 children were screened, of whom five were not eligible, and 78 children aged 6-11 years received at least one dose of vanzacaftor-tezacaftor-deutivacaftor. Median age was 9·3 years (IQR 7·6-10·4), 34 (44%) of 78 participants were female, 44 (56%) were male, 71 (91%) were White, one (1%) was Black or African American, and one (1%) was of multiple races. The analysis for these data was completed on Dec 15, 2023. Median exposure of participants to vanzacaftor-tezacaftor-deutivacaftor was 168 days (IQR 166-170). 75 (96%) of 78 participants had adverse events, all of which were mild or moderate; the most common events were generally consistent with cystic fibrosis manifestations, including, cough (36 [46%]), pyrexia (16 [21%]), headache (14 [18%]), infective pulmonary exacerbation of cystic fibrosis (13 [17%]), and oropharyngeal pain (13 [17%]). Serious adverse events occurred in six (8%) participants (two had infective pulmonary exacerbation, one of whom also had failure to thrive; one participant each had adenovirus infection, constipation, pulmonary function test decreased, and cough), and one (1%) participant discontinued due to adverse events of cough and fatigue that were considered possibly related to study drug.

interpretationVanzacaftor-tezacaftor-deutivacaftor was safe and well tolerated and maintained FEV

fundingVertex Pharmaceuticals.