Improvements in Glucose Regulation in Children and Young People with Cystic Fibrosis-Related Diabetes following Initiation of Elexacaftor/Tezacaftor/Ivacaftor.

INTRODUCTION: Cystic fibrosis transmembrane conductance regulator (CFTR) modulators are increasingly used in children and young people with cystic fibrosis (CF). Data in adults show there may be an impact on glycaemic control in those with CF-related diabetes (CFRD). Paediatric data are rare. Case Series/Presentation: Children aged >12 years with CFRD, who were eligible for elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) were commenced on treatment. Glucose monitoring via the FreeStyle Libre system was commenced prior to, immediately after, and several months after commencing ELX/TEZ/IVA. Glycaemic control, shown by time in range (3-10 mmol/L), percentage of time spent hypoglycaemic (<3 mmol/L), and percentage of time spent hyperglycaemic (>10 mmol/L) on Insulin doses were recorded. Following ELX/TEZ/IVA, four of seven children stopped insulin, two required substantially reduced doses of insulin, one showed no response. Glycaemic control remained similar on lower doses or no insulin. Hypoglycaemia was detected in those not requiring insulin.

CONCLUSION: ELX/TEZ/IVA has a positive impact on glycaemic control and insulin requirements in children with CFRD. Close monitoring is required when commencing treatment. Children with CFRD need counselling regarding possible reductions in insulin requirement and re-education regarding symptoms, signs, and management of hypoglycaemia.