Elexacaftor/Tezacaftor/Ivacaftor Prescription in Lung Transplant Recipients with Cystic Fibrosis in the US

Elexacaftor/tezacaftor/ivacaftor (ETI) has dramatically improved pulmonary and extrapulmonary manifestations of cystic fibrosis (CF). ETI clinical trials excluded lung transplant (LTx) recipients, and current post-transplant prescribing practices are not evidence-based. We sought to identify the prevalence of new ETI prescriptions among CF LTx recipients in the United States (U.S.) and factors associated with ETI prescription after LTx. We also sought to identify factors associated with ETI prescription after LTx based on CF center prescribing practice and create a predictive model of post-LTx ETI prescription. We performed a retrospective cross-sectional study of LTx recipients through December 2022 using the Cystic Fibrosis Foundation Patient Registry. Eligible recipients were alive as of October 2019, had an ETI-eligible genotype, and were not prescribed ETI before LTx. Logistic regression was used to assess factors associated with ETI prescription. CF Center prescribing patterns were categorized based on the proportion of LTx recipients who were prescribed ETI after LTx at each center. Overall, 488/1,666 (29.3%) of patients were prescribed ETI after LTx. The presence of paranasal sinus disease (OR 2.04, 95% CI 1.46-2.84) and BMI<18.5 kg/m2 (OR 1.44, 95% CI 1.08-1.91) were positively associated with ETI prescription after LTx. Zero F508del alleles (OR 0.23, 95% CI 0.09-0.59; 1 or 2 alleles: reference group) was negatively associated with ETI prescription after LTx. Using BIC selection, sinus disease was the only variable included in the predictive model. Using AIC selection, sinus disease, BMI, low FEV1, and F508del genotype were included in the predictive model. ETI prescribing patterns varied significantly between different CF centers.