Impact of Elexacaftor/Tezacaftor/Ivacaftor on Fat-Soluble Vitamin Status in 2 to 5 Year-Old Children Using a Cystic Fibrosis-Specific Multivitamin Formulation.

Background

Young children with Cystic Fibrosis (CwCF) are at risk of fat-soluble vitamin (FSV) deficiencies due to pancreatic insufficiency, despite pancreatic enzyme supplementation. CFTR modulator therapy such as elexacaftor/tezacaftor/ivacaftor (ETI) may improve pancreatic function, but its impact on FSV levels in this age group remains unclear. We evaluated changes in FSV serum levels in a cohort transitioning to ETI, taking a CF-specific, multivitamin formulation with beta-carotene as the primary source of vitamin A (DEKAs Plus Liquid, DPL).

Methods

Retrospective data with paired analysis from 23 CwCF (2-5 years old) were analyzed. Serum FSV levels (D, E, A) and fecal elastase-1 (FE-1) were measured at baseline and 12 months post-ETI initiation. Daily FSV doses and covariates (FE-1, naive of CFTR modulators and ETI dose) were documented. Statistical analyses included Wilcoxon signed-rank tests and general linear models.

Results

No significant changes were observed in serum FSV levels, while FSV dosing and formulation remained unchanged. Covariates did not influence serum level changes. Interestingly, ETI significantly improved FE-1 (p = 0.018), with 6/18 children achieving pancreatic sufficiency (FE-1 > 200 µg/g).

Conclusions

In young CwCF initiating ETI, FSV levels were unchanged while pancreatic function improved. The use of provitamin A (beta-carotene) as in DPL resulted in no change in vitamin A levels and aligns with consensus guidance to prioritize provitamin A in ETI-treated children. Further validation in larger cohorts is warranted.