ETI Use After CF Lung Transplant in the US: Causes & Trends
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New research highlights significant variations in how triple-modulator ETI is prescribed to cystic fibrosis (CF) patients post-lung transplantation, wiht patient factors like BMI and sinus disease playing a role, but their influence is heavily dependent on the prescribing center.
Understanding ETI Prescription Patterns Post-Lung Transplant
A recent retrospective study has shed light on the complex landscape of ETI (elexacaftor/tezacaftor/ivacaftor) prescription following lung transplantation in patients with CF in the United States. The findings indicate that while certain patient characteristics are associated with ETI initiation, the prescribing patterns themselves differ dramatically based on the type of transplant center.
Methodology: A Deep Dive into US Transplant Centers
The research team conducted a comprehensive retrospective analysis to investigate the prescription patterns and influencing factors for triple-modulator ETI in CF patients who underwent lung transplantation. Data was collected up to December 2022 from a registry encompassing 157 centers. The study focused on patients who had an ETI-eligible genotype and were not receiving ETI prior to their transplant. The cohort comprised 1666 lung transplant recipients, with an average age of 39 years and a gender distribution of 50% women.
To categorize prescribing behaviors, centers were classified based on the proportion of their lung transplant recipients with CF who initiated ETI post-transplant.These categories included:
Low-prescribing centers: 0-1 patient initiated ETI.
Middle-prescribing centers: More than 1 patient but less than 50% of eligible patients initiated ETI.
High-prescribing centers: 50% or more of eligible patients initiated ETI.
Additionally, centers with fewer than 10 transplant recipients were designated as “small centers.”
Key Takeaways: Factors Influencing ETI Prescription
The study revealed several critical insights into ETI prescription trends:
Overall ETI Initiation: Across the study population, 29.3% of lung transplant recipients received new ETI prescriptions after their transplant.
Patient-Specific Predictors: The presence of sinus disease (odds ratio [OR] 2.12; 95% confidence interval [CI], 1.51-2.99) and a body mass index (BMI) below 18.5 (OR, 1.52; 95% CI, 1.13-2.04) were found to be positively associated with receiving an ETI prescription after transplant.
Center Type as a Major Factor: A significant finding was the impact of the transplant center’s prescribing pattern.Patients receiving care at middle-prescribing (OR, 0.19; 95% CI, 0.14-0.26) or low-prescribing centers (OR, 0.02; 95% CI, 0.01-0.04) had a substantially reduced likelihood of ETI prescription compared to those at high-prescribing centers.
Stratified Analysis by Center: When the data was analyzed by center type, the influence of patient factors became more nuanced. Low BMI was a strong predictor of post-transplant ETI use primarily in small and low-prescribing centers. Conversely,sinus disease predicted ETI use only in middle- and high-prescribing centers.
in Practice: Why the Discrepancies?
The authors of the study offered a compelling hypothesis for the observed differences,particularly regarding low BMI in smaller or less-prescribing centers. They suggested,”We hypothesize low BMI was more critically important for low-prescribing and small centers as low BMI is probably the most concerning extrapulmonary manifestation of CF to providers and may tip the scale to prescribe if there is reluctance.” This implies that in centers with a more cautious approach or less experience with ETI, a clear indicator of disease severity like low BMI might be a stronger driver for initiating treatment.
source and Further Reading
This pivotal study was led by Nora C. Burdis from the Department of Medicine at the University of Washington, Seattle. The full findings were published online on July 1, 2025, in the Journal of Cystic Fibrosis*.
Limitations of the Study
While providing valuable insights, the study acknowledges certain limitations.Difficulty in tracking long-term medication adherence posed a challenge.Furthermore, variations in follow-up