Page 183 - Personalised medicine of fluoropyrimidines using DPYD pharmacogenetics Carin Lunenburg

Cost analysis on DPYD genotype-guided dosing
genotyping, fluoropyrimidine drug therapy including visits to the medical doctor and day care, costs for treatment of adverse events (e.g. extra medication, extra doctor visits, extra assessments), and costs for hospitalization due to adverse events. Costs for other anticancer drugs than the fluoropyrimidine drugs were not included in the model, as they were expected to be equal in both arms. Cost-saving was calculated as the difference between the net direct costs of the DPYD screening strategy versus the non-screening strategy.
To examine the effects on variations in parameter values, one-way and probabilistic sensitivity analyses were performed. In the one-way sensitivity analysis, each parameter
was varied individually at ±20% of the baseline value. In the probabilistic sensitivity analysis,
all parameters were varied simultaneously by running 1,000 simulations (Monte Carlo).
Since the parameter values of the wild-type patients for both the screening and the non- screening arm are identical, these parameters remained fixed in the probabilistic sensitivity analysis. 6
Figure 1. Decision tree for cost analysis
Results
Patient characteristics and toxicity incidence
The study was open for inclusion between April 30th, 2015 and December 21st, 2017. In this period, a total of 1,103 evaluable patients were enrolled in this study, of whom 85 heterozygous DPYD variant allele carriers (7.7%) and 1,018 wild-type patients (92.3%). The group of DPYD variant allele carriers included 51 c.1236G>A carriers, 17 c.2846A>T
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