Initial Dosage Range of Tacrolimus by Genotyping in Chinese Renal Transplantation (PSIDRTG)
Acute rejection (AR) is the main complication after transplantation, which is a severe risk of chronic rejection and implant devitalization.
Tacrolimus (FK506) is an immunosuppressant used for the prevention of episodes of acute rejection. Tacrolimus is characterized by a narrow therapeutic index and important interindividual variations of its pharmacokinetic characteristics.
Tacrolimus is metabolized through the liver by the cytochrome P450 system, the cytochrome P450 3A5 (CYP 3A5) isoenzyme specifically. Polymorphisms in the CYP 3A5 gene have been associated with changes in metabolic function of the translated isoenzyme. These polymorphisms result in metabolism acceleration of tacrolimus as compared to subjects having the wild type gene, consequently leading to insufficiency of tacrolimus; it is theorized that this leads to higher risk of acute rejection. Several retrospective studies suggested an association between a genetic polymorphism of CYP3A5 and the interindividual variations of tacrolimus blood concentration. In particular, our initial study showed that adult renal transplant recipients with the CYP3A5*1/*3 and *1/*1 （expressors） genotype require higher, fixed, starting dose compared with CYP3A5*3/*3 （nonexpressor）to reach the predefined target exposure early after transplantation.
This prospective study is designed to evaluate whether genetic testing of CYP 3A5 can improve tacrolimus initiation better than usual care. This study is a prospective, multicentric, open, parallel , efficacy study. 300 receivers of a renal transplant in 8 centres will be included.
The genotyping of gene CYP3A5 will be carried out in the 4-7days before renal transplantation. After transplantation, the patients will be treated by MMF, corticosteroids and tacrolimus at a dosage adapted to their genotype(0.15mg/kg/d for CYP3A5*1/*1 type and CYP3A5*1/*3 type，0.08mg/kg/d for CYP3A5*3/*3 type).
The determination of tacrolimus blood concentration will be carried out on Day 3,5,7,14,18,21,28,35,49,63,77,90. The daily amounts of tacrolimus could be modified if necessary to reach the desired blood concentrations. The total duration of the study for a patient is 3 months after transplantation.
The objective of this study is to determine the initial dosage of tacrolimus in Chinese renal transplantation patients by genotyping of the cytochrome P450 3A5
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||Prospective Study:Clinical Trial on the Tacrolimus Dosage Range in Chinese Renal Transplant Recipients With Different Genetic Phenotypes of Drug Metabolizing Enzymes(CYP3A5)|
- The time to obtain first target concentration of FK506 (8-13ng/ml) [ Time Frame: 1w ] [ Designated as safety issue: No ]The interval time (median) after transplantation to achieve first target tacrolimus blood concentration range (7~13ng/ml) by genotype was 7 days (3 to 28) for CYP3A5*1/*3&*1/*1 patients (N=59) and 3 days (3 to 14) for CYP3A5 *3/*3 patients (N=86)
- The proportion of patients reaching therapeutic concentration on Day 3 and 7 without dosage schedule adjustments [ Time Frame: 1 w ] [ Designated as safety issue: No ]As compared with patients with cyp3A5*1/*3 (expression，n=59)，patients with the CYP3A5*3/*3 (nonexpression, n=86) had a decreased time to the first tacrolimus blood concentration within the therapeutic range，but had a increased proportion of patients reaching therapeutic range on Day 3-7 after tranplantration（91.8% vs. 64.4%，P = 0.021).
- The total number of determination of FK506 therapeutic concentration (for safety, efficiency or dose insufficiency reasons) [ Time Frame: 3 months ] [ Designated as safety issue: No ]Tacrolimus blood concentration were measured 1566 times
- After transplantation,the average daily tacrolimus dose, occurrence of acute rejection，delayed renal graft events [ Time Frame: 3months ] [ Designated as safety issue: No ]
There were one acute rejection and thirteen delayed renal allograft function events involving 14 patients, The acute rejection event occurred within the first 14 days after the initiation of tacrolimus treatment at a mean dose of 0.11 mg/kg per day and a median TBC of 4.5ng/ml (range, 3.2 to 6.2ng/ml),and this patient was heterozygous for CYP3A5*1/*3.
Thirteen delayed renal allograft function occurred within the first 3 months including in 5 patients with CYP3A5*1/*3 genotype and in 8 patients with CYP3A5*3/*3 genotype.
- Survival of the grafts at M3 [ Time Frame: 3months ] [ Designated as safety issue: No ]In three months, 145 cases, 144 patients survived
- Duration of the hospitalizations during the first 3 months [ Time Frame: 3 months ] [ Designated as safety issue: No ]The average length of hospitalization for CYP3A5 *3/*3 and CYP3A5 *1/*3& *1/*1 patients were 38 days and 35 days, respectively (P＞0.05) ,sod there was no statistically significant difference.
|Study Start Date:||July 2009|
|Study Completion Date:||June 2011|
|Primary Completion Date:||December 2010 (Final data collection date for primary outcome measure)|
The genotyping of gene CYP3A5 will be carried out in the 4-7days before renal transplantation.After transplantation, the patients will be treated by MMF, corticosteroids and tacrolimus at a dosage adapted to their genotype(CYP3A5*1/*3 and *1/*1 ,expressors; CYP3A5*3/*3 nonexpressor）.
The objective is to determine the initial dosage Range of tacrolimus in Chinese renal transplantation patients by genotyping of the cytochrome P450 3A5
The genotyping of gene CYP3A5 will be carried out in the 4-7days before renal transplantation. After transplantation, the patients will be treated by MMF, corticosteroids and tacrolimus at a dosage adapted to their genotype(CYP3A5*1/*1 type and CYP3A5*1/*3 type administer 0.15mg/kg/d，CYP3A5*3/*3 type administer 0.08mg/kg/d).
Other Name: Prograf® capsules (tacrolimus)
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|The Second Artillery Gernal Hospital|
|BeiJing, Beijing, China, 100088|
|Chaoyang Hospital, affiliated Hospital of Capital Medical University|
|BeiJing, Beijing, China, 100020|
|General Hospital of Air Force of Chinese PLA|
|Beijing, Beijing, China, 100036|
|The First Affiliated Hospital of Zhengzhou University|
|Zhengzhou, Henan, China, 450052|
|Changzheng Hospital, the Second Affiliated Hospital of the Second Military Medical University|
|Shanghai, Shanghai, China, 200003|
|Study Chair:||LIHong LIU, MD Ph.D||The Second Artillery Genaral Hospital|