Liver function tests in F508del homozygous paediatric patients with cystic fibrosis taking lumacaftor/ivacaftor combination therapy

In clinical trials, elevated liver transaminase levels in patients taking lumacaftor/ivacaftor therapy were reported. Our aim was to assess in clinical practice, whether F508del homozygous paediatric CF patients had a derangement of liver functions tests (LFTs) while on lumacaftor/ivacaftor therapy. Methods A retrospective chart review audit in a single CF centre. Results Thirty-nine (43%) patients out of 91 CF clinic patients met criteria to start treatment. We observed a statistically significant decrease in ALT, ALP, GGT and total bilirubin levels, and no change in AST levels during first 3 months of treatment. In two patients (5%) AST levels rose to greater than three times the upper limit of normal (ULN) during treatment, however, these levels then decreased with continued use. A similar trend of improved LFTs was seen in a subgroup of patients with pre-existing liver disease (6/15.4% of patients). No patients died or experienced hepatic encephalopathy. Conclusion Our results were unexpected and encouraging. They suggest that, although the clinical trials report a risk of derangement of LFTs, the risk appears to be low.