Individualization of tacrolimus dosage based on CYP3A 5 * 3 gene polymorphism——A prospective, randomized controlled study and economics evaluation / 中华器官移植杂志

ABSTRACT

Objective To investigate the efficacy,safety,economy evaluation of CYP3A5 * 3 gene polymorphism in providing individualized administration for the use of tacrolimus (Tac) in renal transplantation recipients.Method Pyrophosphate sequencing method was used to determine the CYP3A5 * 3 genotype of renal transplant patients in the first day after surgery.Computer-generated random numbers were used to assign 60 patients into experiment group or control group.Both groups of patients were routinely given the initial dose of Tac (4.0 mg/day) in the first day after surgery.The patients in the experiment group were given different doses of Tac based on the different CYP3A5 * 3 genotypes at the third day after surgery [for AA,AG0.12 mg/(kg day),and for GG0.06 mg/(kg day)].The patients in the control group were given different dosages of Tac according to drug concentration.The patients were followed up for 12 months,and different parameters were compared between two groups.A decision tree model was populated with data from the study and used to economics evaluation.Result At day 5 after the transplantation,significantly more patients in the experiment group were within the Tac target C0 range [90％ (27/30)] as compared to the control group [46.67％ (14/30) (P＜0.05).At this time point,the median Tac C0was 5.08 [(2.5-8.7) μg/ L] in the experiment group vs.5.29 [(1.3-13.6) μg/L] in the control group (P＜0.05).When C0/ D was analyzed according to CYP3A5 * 3 genotype,we found the mean C0/D in the both groups with CY3A5 * 3/* 3 ＞CYP3A5 * 3/* 1 ＞ CYP3A5 * 1/* 1.It was noted that the time to achieve target Tas was (4.40 ± 0.97) in the experiment group,vs.(7.57 ± 3.42) in the control group.In total,the number of daily dose modifications was 11 in the experiment group and 49 in the control group in two weeks after transplantation (P＜0.05).Renal function at day 14 after transplantation and adverse events during 12 months of follow-up were similar in both groups.In total,10 adverse events were reported in the experiment group and 11 in the control group (P＞0.05).The results of costeffectiveness analysis showed that the cumulative costs and effects in the experiment group were ￥ 38 067 and 0.90 quality-adjusted life years gained,and those in the control group were ￥38 681 and 0.87 quality-adjusted life years gained,respectively.In the base case analyses,experiment group was more cost-effective.Conclusion Individualized adjustment of Tac doses for patients according to recipients different CYP3A5 * 3 genotypes is beneficial for reaching target concentration as soon as possible and more cost-effective.But the demonstration of the clinical relevance of this approach was not achieved.Higher methodological quality,and larger sample size study are still needed.