The use of elexacaftor/tezacaftor/ivacaftor in patients with cystic fibrosis post-liver transplant: a case series

Introduction Cystic fibrosis (CF) related liver disease (CFLD) manifests as a wide spectrum of hepatobiliary disease and can progress to need liver transplantation. Elexacaftor/tezacaftor/ivacaftor (elx/tez/iva) is a cystic fibrosis transmembrane conductance regulator (CFTR) modulator which has superior efficacy compared to previously approved modulators. Use of elx/tez/iva, should be approached with caution in individuals with CFLD or following liver transplantation due to possible increases in LFTs and drug-drug interactions with several immunosuppressant medications. Objective The purpose of this case series was to explore if the use of elx/tez/iva is safe and tolerable in patients with CF post-liver transplantation. Methods A retrospective case series including patients prescribed elx/tez/iva following liver transplantation and an immunosuppressive regimen consisting of drug therapy metabolized by P-glycoprotein was completed. Results Ten patients at six CF centers with a median age of 22.1 years (range 14-43.4 years) and median time from transplant of 6.9 years (range 0.6-22 years) were included. Most patients (8, 80%) received a reduced or full dose of elx/tez/iva for a mean duration of 10.4 months (range 7-12 months). Fluctuations in LFTs occurred in all patients (10, 100%) and led to therapy discontinuation in two patients (20%). Elx/tez/iva initiation resulted in elevations in tacrolimus trough concentration in 7 patients (70%). Most patients who tolerated elx/tez/iva had symptomatic and quality of life improvement, increased body-mass-index, and maintained or improved lung function. Conclusion Initiation of elx/tez/iva in patients with CF who received a liver transplantation may be safe with clinical benefits.