PRO-GR: A Prospective, PRO-GR: A Prospective, Randomized, Crossover Study Randomized, Crossover Study

of Maintenance High-Dose of Maintenance High-Dose Clopidogrel vs. Prasugrel in Clopidogrel vs. Prasugrel in

Clopidogrel Resistant Patients Clopidogrel Resistant Patients With and Without the With and Without the

CYP2C19*2 Loss-of-Function CYP2C19*2 Loss-of-Function AlleleAllele

Dimitrios Alexopoulos, MDDimitrios Alexopoulos, MD

Patras University Hospital , Patras, Patras University Hospital , Patras, GreeceGreece

Disclosure Statement of Financial InterestDisclosure Statement of Financial Interest

I, Dimitrios Alexopoulos DO NOT have a I, Dimitrios Alexopoulos DO NOT have a financial interest/arrangement or financial interest/arrangement or affiliation with one or more organizations affiliation with one or more organizations that could be perceived as a real or that could be perceived as a real or apparent conflict of interest in the apparent conflict of interest in the context of the subject of this context of the subject of this presentation.presentation.

I. Xanthopoulou, MDI. Xanthopoulou, MDG. Dimitropoulos, MDG. Dimitropoulos, MDG. Kasimis, MDG. Kasimis, MDA. Panagiotou, MDA. Panagiotou, MDG. Hahalis MDG. Hahalis MDP. Davlouros, MDP. Davlouros, MD

Cardiology Department, Patras University HospitalCardiology Department, Patras University Hospital

E. Stavrou, PhDE. Stavrou, PhDA. Athanassiadou, PhDA. Athanassiadou, PhD

Department of Biology, Faculty of Medicine, University of PatrasDepartment of Biology, Faculty of Medicine, University of Patras

Price MJ, et al. Eur Heart J 2008

High on treatment platelet reactivity (HTPR), (clopidogrel resistance) and adverse events post-PCI

Events and CYP2C19*2 loss of function allele carriage

Mega JL et al. N Engl J Med 2009

v.Beckerath N et al, EHJ 2008

Doubling the maintenance dose of clopidogrel

Wiviott SD et al,Wiviott SD et al, Circulation 2007 Circulation 2007

Prasugrel compared to standard or high dose of Clopidogrel

DESIGNProspective, randomized, crossover, single-center, investigator-initiated study.

OBJECTIVE1. To investigate the antiplatelet effects of prasugrel 10 mg/d versus clopidogrel 150 mg/d in patients with clopidogrel resistance post-PCI.2. To evaluate the impact of the loss-of-function CYP2C19*2 on platelet reactivity changes.

MethodsMethods

• At the time of PCI, clopidogrel naïve patients and At the time of PCI, clopidogrel naïve patients and those on clopidogrel 75 mg for < 7 days without those on clopidogrel 75 mg for < 7 days without initial loading received a 600 mg clopidogrel initial loading received a 600 mg clopidogrel loading dose. loading dose.

• Patients on clopidogrel < 7 days but with a 300 Patients on clopidogrel < 7 days but with a 300 mg initial loading or those on clopidogrel for >7 mg initial loading or those on clopidogrel for >7 days did not receive any additional loading. days did not receive any additional loading.

• Use of periprocedural glycoprotein IIb/IIIa Use of periprocedural glycoprotein IIb/IIIa inhibitors was allowed, at the operator’s inhibitors was allowed, at the operator’s discretion. discretion.

MethodsMethods

EXCLUSION CRITERIAEXCLUSION CRITERIA• a history of bleeding diathesis,a history of bleeding diathesis,• chronic oral anticoagulation treatment,chronic oral anticoagulation treatment,• known platelet function disorders,known platelet function disorders,• PCI or CABG < 3 months,PCI or CABG < 3 months,• planned staged PCIplanned staged PCI in the next 60 days, in the next 60 days,• hemodynamic instability,hemodynamic instability,• platelet count <100 000/platelet count <100 000/ μμL,L, • hematocrit <30%, hematocrit <30%, • creatinine clearance <25 ml/min, creatinine clearance <25 ml/min, • iinability to give informed consent,nability to give informed consent,

MethodsMethods EXCLUSION CRITERIAEXCLUSION CRITERIA

• History of stroke History of stroke

Patients < 60 kg, or > 75 years and HTPR Patients < 60 kg, or > 75 years and HTPR were not excludedwere not excluded as they were considered as they were considered to be at high risk for ischemic events. to be at high risk for ischemic events.

MethodsMethods

Platelet function determinationPlatelet function determination• Peripheral venous blood sampling 24 hours post PCI Peripheral venous blood sampling 24 hours post PCI

(48 hrs if IIb/IIIa had be given).(48 hrs if IIb/IIIa had be given).• VerifyNowTM (Accumetrics, Inc., San Diego, CA, USA) VerifyNowTM (Accumetrics, Inc., San Diego, CA, USA)

point-of-care assay. point-of-care assay. • Results are reported as PRU with a value ≥ 235 Results are reported as PRU with a value ≥ 235

considered as an indication of HTPR.considered as an indication of HTPR.

Genotyping Genotyping for CYP2C19*2 (681G>A carriage)for CYP2C19*2 (681G>A carriage)

• Real time PCR (Real time PCR (Borlak J, Borlak J, Clin ChemClin Chem 2002) 2002)

MethodsMethods

• Primary end pointPrimary end point: platelet reactivity: platelet reactivity at at the end of the two (precrossover and the end of the two (precrossover and postcrossover) study periods. postcrossover) study periods.

• Secondary end pointSecondary end point: HTPR rate.: HTPR rate.

MethodsMethodsStatistical analysisStatistical analysis

• Hierarchical ANCOVA (or mixed-effects) model, Hierarchical ANCOVA (or mixed-effects) model, with patient indicator as random effect, period and with patient indicator as random effect, period and treatment as fixed factors and platelet reactivity at treatment as fixed factors and platelet reactivity at baseline as a covariate.baseline as a covariate.

• Chi-square Prescott test.Chi-square Prescott test.

• The study was approved by the ethics committee of The study was approved by the ethics committee of the University Hospital of Patras, Greece.the University Hospital of Patras, Greece.

• All patients gave written informed consent. All patients gave written informed consent. • ClinicalTrials.gov Identifier NCT 01109784ClinicalTrials.gov Identifier NCT 01109784

Study flow chart Study flow chart Patients post PCI with Platelet Reactivity

Assessment N=210

PRU≥235 N=71 (33.8%)

Clopidogrel 150mg/d N=35Side effects N=2, low compliance N=1Complete Day 30 data N=32

Prasugrel 10mg/d N=32Side effects N=0, lost follow-up N=5Complete Day 60 data N=27

Prasugrel 10mg/d N=36Side effects N=0, low compliance N=4Complete Day 30 data N=32

Clopidogrel 150mg/d N=32Side effects N=1, lost follow-up N=5Complete Day 60 data N=26

Randomized N=71

ResultsResultsSafetySafety

Pre-crossover periodPre-crossover period• 1 TIMI major bleeding 1 TIMI major bleeding • 1 AMI with documented in-stent thrombosis, both allocated 1 AMI with documented in-stent thrombosis, both allocated

to clopidogrel and both excluded from analysis. to clopidogrel and both excluded from analysis. • 3 patients (allocated to prasugrel) experienced minor 3 patients (allocated to prasugrel) experienced minor

bleeding events.bleeding events.

Post-crossover periodPost-crossover period• 1 TIMI major bleeding 1 TIMI major bleeding • 1 minor bleeding event (both allocated to clopidogrel).1 minor bleeding event (both allocated to clopidogrel).

No deaths or strokes occurred in either treatment group.No deaths or strokes occurred in either treatment group.

ResultsResultsBaseline characteristics of patients with complete

Day 30 data

Clopidogrel Clopidogrel N=32 N=32

PrasugrelPrasugrelN=32N=32

P P ValueValue

AgeAge 67.9±10.567.9±10.5 62.2±10.862.2±10.8 0.030.03

Male genderMale gender 28(87.5%)28(87.5%) 29(90.6%)29(90.6%) 1.01.0

BMIBMI 27.9±4.327.9±4.3 30.1±3.930.1±3.9 0.030.03

HyperlipidaemiaHyperlipidaemia 22(68.8%)22(68.8%) 19(59.4%)19(59.4%) 0.60.6

HypertensionHypertension 22(68.8%)22(68.8%) 21(65.6%)21(65.6%) 1.01.0

Diabetes mellitusDiabetes mellitus 13(40.6%)13(40.6%) 10(31.2%)10(31.2%) 0.60.6

SmokingSmoking 14(43.8%)14(43.8%) 16(50.0%)16(50.0%) 0.80.8

ResultsResults

Clopidogrel Clopidogrel N=32 N=32

PrasugrelPrasugrelN=32N=32

PP

valuevalue

Proton pump Proton pump inhibitorsinhibitors 32(100%)32(100%) 30(93.8)30(93.8) 0.50.5

IIb/IIIa inhibitors IIb/IIIa inhibitors 6(18.8%)6(18.8%) 4(12.5)4(12.5) 0.70.7

Platelet Reactivity Platelet Reactivity Units Day 0Units Day 0 292.0±50.4292.0±50.4 289.9±42.9289.9±42.9 0.90.9

One CYP2C19*2 One CYP2C19*2 alleleallele

N=29N=299(31.0%)9(31.0%)

N=30N=30

12(40.0%)12(40.0%)0.60.6

Baseline characteristics of patients with complete Day 30 data

ResultsResults

Prasugrel Prasugrel LS estimates LS estimates

(95%CI)(95%CI)

Clopidogrel LS Clopidogrel LS estimates estimates (95%CI)(95%CI)

LS mean LS mean difference difference

(95%CI)(95%CI)PP

Day 30 (pre-Day 30 (pre-crossover)crossover)

N=32N=32

130.2 (103.7-130.2 (103.7-156.7)156.7)

N=32N=32

196.9 (170.5-196.9 (170.5-223.5)223.5)

-66.8 (-104.3 -66.8 (-104.3 to -29.3)to -29.3) 0.0010.001

Day 60 (post-Day 60 (post-crossover) crossover)

N=27N=27

128.4 (103.2-128.4 (103.2-153.5)153.5)

N=26N=26

206.4 (180.8-206.4 (180.8-232.2)232.2)

-78.1 (-113.9 -78.1 (-113.9 to -42.2)to -42.2) <0.001<0.001

Combined data Combined data (pre and post-(pre and post-crossover)crossover)

N=59N=59

129.4 (111.1-129.4 (111.1-147.7)147.7)

N=58N=58201.7 (183.2-201.7 (183.2-

220.2)220.2)

-72.3 (-98.3 -72.3 (-98.3 to -46.4) to -46.4) <0.001<0.001

Platelet reactivity analysis

ResultsResultsPlatelet reactivity by treatment sequence

ResultsResults

PrasugrelPrasugrel ClopidogrelClopidogrelPP

valuevalue

Day 30 (pre-Day 30 (pre-crossover)crossover)

N=32N=32

2(6.3%)2(6.3%)

N=32N=32

10(31.3%)10(31.3%)0.0220.022

Day 60 (post-Day 60 (post-crossover)crossover)

N=27N=27

2(7.4%)2(7.4%)

N=26N=26

11(42.3%)11(42.3%)0.0040.004

Combined data (pre Combined data (pre and post-crossover)and post-crossover)

N=53N=53

4(7.5%)4(7.5%)N=53N=53

19(35.8%)19(35.8%) <0.001<0.001

HTPR rates

PPatients individual PR values against the HTPR threshold.atients individual PR values against the HTPR threshold.

HTPR threshold

ResultsResults

Prasugrel Prasugrel LS estimates LS estimates

(95%CI)(95%CI)

Clopidogrel LS Clopidogrel LS estimates estimates (95%CI)(95%CI)

LS mean LS mean difference difference

(95%CI)(95%CI)PP

Combined data Combined data (pre and post-(pre and post-crossover) crossover) non-carriersnon-carriers

N=37N=37

139.3 (117.1-139.3 (117.1-161.6)161.6)

N=35N=35186.8 (163.8-186.8 (163.8-

209.8)209.8)

-47.5 (-79.5 -47.5 (-79.5 to -15.4)to -15.4) 0.0040.004

Combined data Combined data (pre and post-(pre and post-crossover) crossover) carrierscarriers

N=20N=20112.4 (81.5-112.4 (81.5-

143.2)143.2)

N=20N=20

235.3 (204.7-235.3 (204.7-265.9)265.9)

-122.9 (--122.9 (-166.7 to -166.7 to -

79.2)79.2)<0.001<0.001

Platelet reactivity in patients with and without the CYP2C19*2 allele

ResultsResultsPlatelet reactivity by treatment sequence in non

carriers of CYP2C19*2 allele

ResultsResults

Platelet reactivity by treatment sequence in carriers of CYP2C19*2 allele

ResultsResults

• Non-carriersNon-carriers 10/34 (29.4%)10/34 (29.4%) had HTPR on high clopidogrel. had HTPR on high clopidogrel. 3/34 (8.8%)3/34 (8.8%) had HTPR on prasugrel (p=0.005). had HTPR on prasugrel (p=0.005).

• CarriersCarriers 9/19 (47.4%)9/19 (47.4%) had HTPR on high clopidogrel had HTPR on high clopidogrel 1/19 (5.3%)1/19 (5.3%) had HTPR on prasugrel (p=.0.007). had HTPR on prasugrel (p=.0.007).

• No period or carry-over effect was found. No period or carry-over effect was found.

ConclusionsConclusions

1.1. IIn patients with HTPR post PCI, n patients with HTPR post PCI, prasugrel is more effective compared prasugrel is more effective compared to high clopidogrel in reducing to high clopidogrel in reducing platelet reactivity.platelet reactivity.

2.2. This effect is more prominent in This effect is more prominent in patients carrying at least one loss-of-patients carrying at least one loss-of-function function CYP2C19*2CYP2C19*2 allele allele. .

Dimitrios AlexopoulosPRO-GR: A Prospective, Randomized, Crossover PRO-GR: A Prospective, Randomized, Crossover Study of Maintenance High-Dose Clopidogrel vs. Study of Maintenance High-Dose Clopidogrel vs. Prasugrel in Clopidogrel Resistant Patients With Prasugrel in Clopidogrel Resistant Patients With and Without the CYP2C19*2 Loss-of-Function Alleleand Without the CYP2C19*2 Loss-of-Function Allele

ConclusionsConclusions

3.3. In high risk individuals like clopidogrel In high risk individuals like clopidogrel resistant patients post PCI genotyping resistant patients post PCI genotyping seems to be helpful for selection seems to be helpful for selection between increasing between increasing clopidogrel clopidogrel maintenance dose and prasugrel maintenance dose and prasugrel administration.administration.

Dimitrios AlexopoulosPRO-GR: A Prospective, Randomized, Crossover PRO-GR: A Prospective, Randomized, Crossover Study of Maintenance High-Dose Clopidogrel vs. Study of Maintenance High-Dose Clopidogrel vs. Prasugrel in Clopidogrel Resistant Patients With Prasugrel in Clopidogrel Resistant Patients With and Without the CYP2C19*2 Loss-of-Function Alleleand Without the CYP2C19*2 Loss-of-Function Allele

Back up slides

G A

GG AA

GA

Real time PCR result picture

Real time PCR result explanation (G to A mutation)

Sample 1 (purple): homozygous for the normal G allele –GG-

Sample 2 (yellow): homozygous for the mutant A allele –AA-

Sample 3 (green): heterozygous contains one normal G allele and one mutant A allele –GA-

ResultsResults

Prasugrel Prasugrel LS estimates LS estimates

(95%CI)(95%CI)

Clopidogrel LS Clopidogrel LS estimates estimates (95%CI)(95%CI)

LS mean LS mean difference difference

(95%CI)(95%CI)PP

*Combined data *Combined data (pre and post-(pre and post-crossover)crossover)

N=59N=59131.5 (113.2-131.5 (113.2-

149.7)149.7)

N=58N=58

203.7 (185.1-203.7 (185.1-222.3)222.3)

-72.2 (-97.9 -72.2 (-97.9 to -46.5)to -46.5) <0.001<0.001

Platelet reactivity analysis

Analysis with age and BMI as additional fixed factors