CYP3A5 pharmacogenetic testing for tacrolimus in pediatric heart transplant patients: a budget impact analysis.

Background: Pharmacogenomic testing can optimize drug efficacy and minimize adverse effects. CYP3A5 polymorphisms affect the metabolism of tacrolimus. We sought to estimate the budget impact of preemptive pharmacogenomic testing for CYP3A5 in pediatric heart transplantation patients from an institutional perspective.

Methods: A decision tree was constructed to estimate the budget impact of pediatric heart transplant patients (age ≤18 years) initiated on tacrolimus with and without CYP3A5 pharmacogenomic testing. The budget impact of preemptive pharmacogenomic testing versus no pharmacogenomic testing was calculated. One-way sensitivity analysis and alternative analyses were conducted to assess the robustness of results to changes in model parameters.

Results: CYP3A5 genotype-guided dosing provided savings of up to $17 225 per patient compared to standard dosing. These savings decreased to $11 759 when using another institution's data for the standard-dosing group. The time to achieve therapeutic concentration in the poor metabolizer genotype-guided dosing group had the largest impact on cost savings while the cost of the pharmacogenetic test had the smallest impact on cost savings.

Conclusion: Implementing CYP3A5 testing could save $17 225 per pediatric heart transplant patient receiving tacrolimus. As pharmacogenomic testing becomes more widespread, institutions should track resource requirements and outcomes to determine the best implementation policies going forward.