Since 2012, the cystic fibrosis drug ivacaftor has been approved in Europe for patients aged six years and over with certain mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, but its safety in younger patients is unknown.
In a study, reported in The
Lancet Respiratory Medicine
(online, 20 January 2016), 33 children aged 2–5 years received ivacaftor for six months at doses of 50mg or 75mg every 12 hours.
The researchers say the safety profile was similar to that observed in adults, with cough (56%) and vomiting (29%) reported as the most common adverse events. However, they note that five children (15%) experienced elevations in liver function tests, suggesting younger patients would require more frequent monitoring.
The cohort is now being followed up to assess the long-term efficacy and safety of ivacaftor in this age group.
 Davies JC, Cunningham S, Harris WT et al. Safety, pharmacokinetics, and pharmacodynamics of ivacaftor in patients aged 2–5 years with cystic fibrosis and a CFTR gating mutation (KIWI): an open-label, single-arm study. Lancet Respiratory Medicine 2016. doi: 10.1016/S2213-2600(15)00545-7