Clopidogrel and Response Variability Investigation Study 2

Study Overview
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Brief Summary
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To evaluate the role of the genetic variant 2C19*2 on the pharmacodynamic response as assessed by optical aggregometry and on the pharmacokinetic response as assessed by measuring active metabolites following an oral administration of a loading dose of 300/900mg of clopidogrel in patients with established coronary artery disease.

Detailed Description
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Rationale : Clopidogrel is a specific and irreversible of the P2Y12 platelet receptor leading to an inhibition of platelet aggregation. Clopidogrel is a prodrug that must be converted into an active metabolite that selectively and irreversibly binds to the P2Y12 platelet membrane receptor. As a consequence, a loading dose of 300 mg is necessary in percutaneous coronary intervention and in acute coronary syndrome, situations which require a rapid inhibition of platelet aggregation due to the high thrombotic risk. High platelet reactivity on clopidogrel may be due to various reasons including polymorphism in the gene encoding the cytochrome P-450 2C19 enzyme (CYP2C19) which has been shown to contribute to the variability of platelet response to clopidogrel. CYP2C19 is a key enzyme in this activation process and our group was the first to describe an association between the presence of the loss of function CYP2C19 681G>A polymorphism (also called *2) with lower clopidogrel responsiveness in healthy subjects. Poor responsiveness to clopidogrel has become a major concern given acute recurrent events following stent placement. Objective : To evaluate the role of the genetic variant 2C19*2 on the pharmacodynamic response as assessed by optical aggregometry and on the pharmacokinetic response as assessed by measuring active metabolites following an oral administration of a loading dose of 300/900mg of clopidogrel in patients with established coronary artery disease. Target population :Patients of less than 45 years of age and who survived a MI and enrolled in the AFIJI multicenter registry (Appraisal of risk Factors in young Ischemic patients Justifying aggressive Intervention). Primary end-point :Comparison of inhibition of the intensity of residual platelet aggregation (IRPA) measured 6 minutes after induction by 20 μmol/L following 300mg or 900 mg of clopidogrel with respect to the presence of the genetic variant CYP2C19*2 Maximum platelet aggregation instead of IRPA RPA with 5µM and 50 µM of ADP Measure of clopidogrel and its active metabolites (carboxylated and thiol) at different time points following the loading dose (H0, H1, H2 et H6) with respect to the presence of the genetic variant CYP2C19*2 Relationship between active metabolites concentration and IRPA Relationship between active metabolites and dose of clopidogrel Comparison of 300mg vs 900mg on IRPA in the whole population irrespective of the genetic variant Statistical analysis :Comparison of IRPA with respect to the presence of the genetic variant 2C19*2 by anova Area under the curve of the production of active metabolites with respect to the presence of the genetic variant 2C19*2 Agenda :November 2008 (inclusion of first patient) to december 2009 (analysis of the data)

Official Title
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Effect of the Genetic Variant 2C19*2 on Clopidogrel Biological Response in Patients With Premature Coronary Artery Disease

Conditions
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Coronary Artery Disease

Intervention / Treatment
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* Drug: clopidogrel


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age > 18 Male gender Included in the AFIJI registry No high bleeding risk profile No recent history of acute coronary syndrome (< 3 months) Written informed consent obtained Genotype CYP2C19 : *1/*1, *1/*2 ou *2/*2 Genotype P2Y12 : H1/H1 ou H1/H2 Exclusion Criteria: Female gender Patient with a contraindication to clopidogrel Patient who has received a loading dose of clopidogrel in the past 7 days Patient treated with ticlopidine or GP2B/3A receptor antagonist prior to loading Non compliance Génotype P2Y12 : H2/H2. Patient treated with drugs interacting with platelet aggregation (NSAID, persantine, serotonin inhibitors ) Patient treated with drugs interacting 2C19 Not affiliated to the national health insurance Patient participating to another randomized study

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: 1<br>patients homozygous for the 2C19*1 genetic variant | Drug: clopidogrel<br>* comparison of two loading strategies of clopidogrel (300mg vs 900mg) in the two genetic profiles<br>|
| Experimental: 2<br>carriers of the 2C19*2 genetic variant (homozygous or heterozygous) | Drug: clopidogrel<br>* comparison of two loading strategies of clopidogrel (300mg vs 900mg) in the two genetic profiles<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Inhibition of residual platelet activity 6 hours after a loading dose of clopidogrel |  | 6 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Maximum platelet aggregation instead of IRPA |  | during the study | 
| RPA with 5µM and 50 µM of ADP |  | during the study | 
| 3. Measure of clopidogrel and its active metabolites (carboxylated and thiol) at different time points following the loading dose (H0, H1, H2 ,H6) with respect to the presence of the genetic variant CYP2C19*2 |  | H0, H1, H2, H6 | 
| Relationship between active metabolites concentration and IRPA |  | during the study | 
| Relationship between active metabolites and dose of clopidogrel |  | during the study | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Platelet aggregation, Platelet, Thrombosis, Clopidogrel