Pharmacogenetics and Thienopyridines - 1st Latin American

Pharmacogenetics and

Thienopyridines

Sandra Close Kirkwood, PhD

Eli Lilly and Company

May 14, 2010

Conflict of Interest

Sandra Close Kirkwood is employed by and

owns stock in Eli Lilly and Company. Eli Lilly

and Company developed and markets

prasugrel.

The views and opinions expressed in the

following PowerPoint slides are those of the

individual presenter.

Adapted from Cannon CP. J Thrombolysis 1995:2:205-218

UA/NSTEMI STEMIStable Angina

Acute Coronary Syndromes

JJ

UA=Unstable angina; NSTEMI=Non–ST-elevation myocardial infarction; STEMI=ST-elevation myocardial infarction

Continuum of Severity

* Heart Disease and Stroke Statistics – 2007 Update. Circulation 2007; 115:69–171

1.57 Million Hospital Admissions in the US*

Stent Thrombosis

Coronary Artery Stenting

http://www.lightlabimaging.com/gallery/images/cahc01.jpg

Antiplatelet Therapy in ACS

0

108

Placebo APTC CURE

Reduction in

Ischemic Events

Increase in

Major Bleeds

Single

Antiplatelet Rx

Dual

Antiplatelet Rx

ASA

- 22%

ASA + Clopidogrel

- 20%

+ 60% + 38%

Platelet Activation Mechanisms

Thrombin

Thromboxane

A2

5HT

P2Y12

ADP ADPADP

5HT

PLATELET

ACTIVATION

P2Y15HT2A

PAR1

PAR4

Dense

granule

Thrombin

generation

Shape

change

aIIbb3

aIIbb3

FibrinogenaIIbb3

Aggregation

AmplificationAlpha

granule

Coagulation factors

Inflammatory mediators

TPa

Coagulation

GPVI

Collagen

ATPATP

P2X1

ASPIRIN

x TICLOPIDINE

CLOPIDOGREL

PRASUGREL

ACTIVE

METABOLITE

x AZD6140

CANGRELOR

GP IIb/IIIa ANTAGONISTS

xx

Storey RF. Curr Pharm Des. 2006;12:1255-59.

Benefit

Harm

Adapted from presentation by Dr. Barbara Evans, ASCPT Annual Meeting (2010)

Frequency of various responses in the RCT treated population

Mixed Benefit and Harm

Small benefit

Neither harm or benefit --

Nonresponders(

Harm Without Benefit

Large Benefit with little harm

Ma

gnitude

Green = Benefit

Red = Harm

Yellow = Mixed Benefit and Risk

Silver = Neither Benefit or Risk

Distribution of Individual Response Rates To

Medicines

Variable Response to Clopidogrel

24 hrs after 300 mg Clopidogrel

Gurbel PA et al. Circulation 2003; 107: 2908-2913

10

20

≤ -30

(-30,-20)

(-20,-10)

(-10,0)

(0,10)

(10,20)

(20,30)

(30,40)

(40,50)

(50,60)

>60

Platelet aggregation before and after Clopidogrel (%)

Patients

(%

)

“Resistance” = 31% N = 96, Elective PCI

“Resistance” = ≤ 10% platelet aggregation

Persistent Variability in Platelet Inhibition

(MPA) With High Dose Clopidogrel

von Beckerath N, et al. Circulation 2005;112(19):2946-2950

AD

P (

20

µm

ol/L

)-In

duced

Ag

gre

ga

tio

n (

%)

12

0

10

0

8

0

6

0

4

0

2

00

300 mg 600 mg 900 mg

P=0.004 P=0.39

P=0.001

MPA 4 Hours after dosing

MPA=Maximum Platelet Aggregation

Clopidogrel Dose

150 mg/day 75 mg/day0

20

40

60

80

100

120P < 0.001

Pharmacodynamic Non-response to Clopidogrel is Associated With an Increase in Ischemic Events

MYONECROSIS/ELEVATED ENZYME

MYOCARDIAL INFARCTION

CARDIOVASCULAR DEATH

STENT THROMBOSIS

Hochholzer 2006COMPOSITE ISCHEMIC ENDPOINTS

◄

1 10 100

3.3802 0.5Buonamici 2007 10.5804 2.7Trenk 2008 6.0765 2.0Geisler 2006 22.7363 5.6Suh 2006 7.3348 1.9Cuisset JACC 2006 31.0292 3.0Patti 2008 30.0160 10.0Angiolillo 2008 37.8173 13.2Cuisset JTH 2006 39.0106 4.0Bliden 2007 72.0100 9.0Matetzky 2004 47.060 2.0

Trenk 2008 1.3765 4.6Gori 2008 2.6746 13.3Buonamici 2007 2.3804 8.6Wenewaser 2005 31.273 25.0Klamroth 2004 36.740 90.0

Buonamici 2007 1.4804 8.6Geisler 2006 2.9363 18.2

Geisler 2006 1.2363 4.5

Lev 2006 17.3150 32.4

N Responders Non-respondersEvent rate

Favors Non-responders Favors Responders

Odds Ratio (95% CI)

►

►

Criteria for Clinical Biomarkers

• Strategic

– Clear Objective/Deliverable

• Biologic understanding

• Technologic Capabilities

• Clinical Relevance

• Regulatory

• Implementation

??

Criteria Clinical Biomarkers: Clear Strategy

Prodrug Conversion

to active

metabolite

(PK)

Platelet

response

(PD)

Clinical

response

CYP

Genotypes

• Does CYP variation effect generation of AM? PD?

• If so, does this affect clinical outcome rates?

•Efficacy: increased cardiovascular event rate in those unable to

effectively generate active metabolite.

• Bleeding: decreased bleeding in those unable to generate AM.

Criteria for Clinical Biomarkers: Biology

Active Metabolite Formation

Farid NA et al. Drug Metab Dispos 2007;35(7):1096-1104Rehmel JL et al. Drug Metab Dispos 2006;34(4):600-607Williams ET et al. Drug Metab Dispos 2008;36(7):1227-1232

Plavix® package insert, 2008Kurihara A et al. Drug Metab Rev 2005;37(S2):99 Tang M et.al. J Pharmacol Exp Ther 2006;319(3):1467-1476

Prasugrel

S

N

F

O

OCH3

O

N

F

O

HS

HOOC

Gut CYPs

(3A, 2C9, 2C19)

Clopidogrel

S

N

Cl

OCH3O

Prodrug

Thiolactone

metaboliteCl

N

OCH3O

S

O

Liver CYPs

(2C19, 1A2, 2B6)

Active

metaboliteN

Cl

OCH3O

HS

HOOC

Liver CYPs

(3A, 2B6, 2C19, 2C9)

EsterasesOHO

N hCE1

(mainly liver)

S

N

F

O

O

Esterases hCE2 (mainly gut)

Liver CYPs

(3A, 2B6, 2C9, 2C19)

hCE1

Inactive

Acid

Metabolite

(85% of

parent)

Translation into Star Allele Nomenclature

eg. CYP2C19 *2

54 Different Allele Calls (“normal” by default)

48 DNA Variants

Daly TM et al. Clin Chem 2007;53(7):1222-1230

Criteria for Clinical Biomarkers:

Technological Capabilities6 Genes: CYP 3A4/5, 2B6, 2C19, 2C9, 1A2

Genetic Variation: SNPs, in/del, STR

Predicted Genetic Functional Group

Extensive

Metabolizers

(EM)

Reduced

Metabolizers

(RM)

For 3A5 EM = EM + IM and RM = PM

For 2C19 the *17 necessitated a UM group for *1/*17. EM = UM + EM

Intermedite

Metabolizers

(IM)

Poor

Metabolizers

(PM)

Extensive

Metabolizers

(EM)

Close SL et al. Eur Heart J 2008;29(S1):759

Comparison by

predicted

metabolic function

Investigation in Healthy Subjects

• Model-based mean estimates and 95% confidence intervals for genetic effects in carriers vs. non-carriers of reduced function alleles

on the PK and PD parameters of clopidogrel and prasugrel in 346 healthy subjects (includes LD and MD data)

P value

-32.4 0.00003

-6.8 0.30

-15.7 0.017

5.6 0.70

11.2 0.78

-6.1 0.031

-5.3 0.14

-0.4 0.45

-0.8 0.41

-3.5 0.23

CLOPIDOGREL

CYP Gene

2C19

2C9

2B6

3A5

1A2

PRASUGREL

CYP Gene

2C19

2C9

2B6

3A5

1A2

-15

Pharmacokinetics (PK) Pharmacodynamics (PD)

-10 -5 0 5 10 15-40 -20 200-50 -30 -10 3010

P value

-9.0 0.00027

-0.6 0.43

-5.7 0.006

7.5 0.99

0.5 0.55

-1.3 0.31

-1.7 0.21

-0.6 0.33

1.3 0.81

-1.6 0.18

% Difference

In AUC0-t

Absolute

difference

in ∆MPA

Relative Percent Difference in AUC0-t Absolute Difference in ∆MPA

Genetic Effects on Pharmacokinetic and

Pharmacodynamic Parameters

Does the effect look dominant? Additive?

Is the genetic effect observed for both

loading doses and maintenance doses?

.

CYP2C19 Effect on Exposure and Platelet Aggregation Following Clopidogrel LD and MD

Percent Reduction in AUC0-t

CYP2C19 LD 300mg LD 600mg MD 75mg

IM vs EM

PM vs EM

P Value

-26.1

-55.2

<0.001 (n= 89)

-29.9

NA

0.047 (n = 42)

-30.7

-45.6

0.0023 (n = 87)

Absolute Decrease in ΔMPA

CYP2C19 LD 300mg LD 600mg MD 75mg

IM vs EM

PM vs EM

P Value

-10.6

-19.3

0.011 (n = 180)

-6.3

NA

0.024 (n = 155)

-9.1

-28.7

<0.001 (n = 197)

EM=extensive metabolizer; IM=intermediate metabolizer; PM=poor metabolizer

Mega J et al. NEJM 2009;360(4):354-362

Investigations in Patients

Is the genetic effect consistently

observed?

In patients with coronary artery disease

In those receiving a 600 mg loading doses

-40 -20 0 20 40

Difference in VASP-PRI

(EM - RM)

Loading Dose

24 ± 4 hr

-40 -20 0 20 40


(EM - RM)

Maintenance Dose

Day 14 ± 3 day

-40 -20 0 20 40


(EM - RM)

Maintenance Dose

Day 29 ± 3 day

Ratio of AUC

(RM/EM)

0.4 0.8 1.2 1.6

Loading Dose

24 ± 4 hr

CYP2C19

CYP2B6

CYP2C9

CYP3A5

CYP2C19

CYP2B6

CYP2C9

CYP3A5

Prasugrel

Clopidogrel

AUC=area under the concentration-time curve

EM=extensive metabolizer; RM=reduced metabolizer

PRI=platelet reactivity index; VASP=vasodilator-stimulated phosphoprotein

Pharmacokinetic and Pharmacodynamic

Responses for Other Cytochrome P450 Genes

Varenhorst C et al. Eur Heart J 2009;30(14):1744-1752

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

0.5

EM EMRM RM

Prasugrel Clopidogrel

Lo

g A

UC

(0-∞

)(m

M●h

)

*

**

*p=0.6361 vs. prasugrel EM

**p=0.0015 vs. clopidogrel EM

AUC=area under the concentration-time curve;

EM=extensive metabolizer; LD=loading dose;

RM = reduced metabolizer

Box represents median, 25th, and 75th

percentiles

Whiskers represent the

most extreme values within

1.5 times inter-quartile range of the box

Clopidogrel - Significantly

lower exposure to active

metabolite in CYP2C19 RM

Prasugrel - No relationship

between exposure and

CYP2C19 metabolizer status

Exposure to prasugrel’s active

metabolite was higher when

compared to clopidogrel

Varenhorst C et al. Eur Heart J 2009;30(14):1744-1752

Active Metabolite Exposure to Prasugrel 60 mg and

Clopidogrel 600 mg LD by CYP2C19 Function

Is the genetic effect consistently

observed?

For clinical outcomes

• Efficacy

• Safety

No significant genetic effect observed for bleeding. The

genetic bleeding analysis was underpowered .

Major bleeds: less than 40% power to detect a HR of 2.0

Maj/Min: 60% to detect a HR of 2.0

N=1,455Reduced n=407 (28%) Extensive n=1,048 (72%)

Hazard Ratio 0.89

(95% CI 0.60 - 1.31)

P=0.27

9.8%

8.5%

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

0 30 90 180 270 360 450

Days After Randomization

CV

Dea

th, N

on

fata

l MI,

or

Non

fata

l S

troke

(%

)

Extensive

Reduced


1.0%

0.5%

0

1

2

3

4

0 30 90 180 270 360 450

Definite

or

Pro

ba

ble

Ste

nt T

hro

mb

osis

(%

)

Hazard Ratio 0.58

(95% CI 0.13 - 2.69)

P=0.48

Extensive

Reduced


No Increased Rate of Primary Endpoint or Stent Thrombosis

in ACS Patients With Reduced Metabolism Variant of

CYP2C19 Treated with Prasugrel – TRITON-TIMI 38

Mega et al. Circulation. 2009;119:2553-2560.

Mega JL, et al. New Engl J Med 2009;360(4):354-362



Higher Rate of Primary Endpoint and Stent Thrombosis

in ACS Patients with Reduced Metabolism Variant of

CYP2C19 Treated With Clopidogrel – TRITON-TIMI 38


0.8%

2.6%

0

1

2

3

4

0 30 90 180 270 360 450

Hazard Ratio 3.09

(95% CI 1.19 - 8.00)

P=0.02

Definite

or

Pro

ba

ble

Ste

nt T

hro

mb

osis

(%

)

Extensive

Reduced8.0%

12.1%


0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

0 30 90 180 270 360 450

Hazard Ratio 1.53

(95% CI 1.07 - 2.19)

P=0.01

Extensive

Reduced

CV

Dea

th, N

on

fata

l MI,

or

Non

fata

l S

troke

(%

)

26

Primary Clinical Outcome by CYP2C19 for

Clopidogrel: TRITON-TIMI 38

4266.01

EM = Extensive Metabolizer, IM = Intermediate Metabolizer, PM = Poor Metabolizer

30 90 180 270 360 450

Hazard Ratio: PM vs. EM, 1.35

(95% CI, 0.49-3.69)

Hazard Ratio: IM vs. EM, 1.55

(95% CI, 1.07-2.25)

P=0.017

P=0.029 P=0.038

Days from Randomization

0

2

4

6

8

10

12

14

0

CV

De

ath

, N

on

fata

l M

I,or

Nonfa

tal S

troke (

%) IM

EM

PM

Genetics and Cardiovascular Event Rates

0.1 1 10 20

Shuldiner et al, JAMA 2009

Mega et al, N Engl J Med 2009

Simon et al, N Engl J Med 2009 ^

Sibbing et al, Eur Heart J 2009

Anderson et al, J Am Coll Cardiol 2009

Mega et al, Circulation 2009 ^^

429

1477

2208

2485

1250

9684

2.42 (1.18-4.99)

1.53 (1.07-2.19)

1.98 (1.10-3.58)

1.15 (0.082-1.61)

1.50 (1.00-2.24)

1.61 (1.28-2.02)

Hazard Ratios

Collet et al, Lancet 2009

Giusti et al, Am J Cardiol 2009

Bhatt et al, TCT 2009 ^

259

772

4862

3.69 (1.69-8.05)

2.70 (1.00-8.42)

2.38 (1.14-5.00)

0.5 5

Study HRN

^ *2/*2 vs. wt/wt ^^ meta analysis

Stent Thrombosis

0.1 1 10 20

Study N

Mega et al, N Engl J Med 2009

Sibbing et al, Eur Heart J 2009

Collet et al, Lancet 2009

Giusti et al, Am J Cardiol 2009

Trenk et al, J Am Coll Cardiol 2008 *

Mega et al, J Am Coll Cardiol 2009 ^^

1477

2485

259

772

797

5772

3.09 (1.19-8.00)

3.81 (1.45-10.02)

6.20 (1.81-20.00)

3.43 (1.01-12.78)

3.70 (1.40-9.60)

2.76 (1.77-4.30)

Hazard Ratios

HR

^^ meta analysis


• Strategic


• Biologic understanding

• Technologic Capabilities


• Regulatory

• Implementation

??


Regulatory Decision Making

What constitutes substantive evidence? Obligations for labeling?

• Efficacy, lack of efficacy, safety

• Clinical Studies

Randomized stratified

Prospective

Retrospective

Observational/Community Based

• Biological Plausibility

• Modeling

Genetic labeling both in the European and US labels


Is this information clinically relevant?

• Factors influencing

Magnitude of Effect

Available treatment options

Clinical condition

Population subgroups

• Patient characteristics such as age, weight, gender

• Co-morbid conditions

• Ethnicity

• etc etc

• Environmental exposures

• Concomitant medications, smoking, etc etc

Will clinical guidelines and practice be influenced?

Applying Clinical Biomarkers• Strategic


• Technologic– Information overload

– Platform challenges

• Lack of biologic understanding


• Regulatory

• Implementation– Medical Infrastructure

– Clinician education, understanding, and acceptance

– Pharmacoeconomic case

??

Implementation: The Clinical Information Problem

Annals of Surgery • Volume 250, Number 4, October 2009

Hypothetical number of

facts potentially

relevant in making a

typical clinical decision.

Ever-increasing accumulation of knowledge promises to rapidly exceed

human cognitive limits in medical decision-making.

The magic number seven, plus or minus two:limits on our capacity for processing information

Miller GA. Psychological Review 1956;63(2):81-97

Information Overload

“I’m sorry. It appears Dr. Mitchell won’t beaccepting any more information today.”

Implementation: The Clinical Information Problem

“As this information overload increases, truly personalized medicine will

only succeed if a multitude of factors can be effectively distilled along

relevant dimensions of clinical decisions.”

Thank you!

The Meeting Organizers

The TIMI Group

DS Colleagues

Lilly

• Prasugrel Team

• PGx and Translational Medicine

• Drug Disposition

• Statistics

• IT

• Regulatory

• GSIC

William Macias

Lei Shen

Brian Moser

Richard Hockett

Michael Man

Kathy Ruiz

Elizabeth Bearby

John Brandt

Nancy Bauer

Hollins Showalter

Baoguang Huang

Lee O’Brien

Regulatory Labels

Prasugrel Summary of Product

Characteristics (FDA and Eur Med Agency)

5.2 Pharmacokinetic properties

Metabolism

In healthy subjects, patients with stable atherosclerosis,

and patients with ACS receiving Efient, there was no

relevant effect of genetic variation in CYP3A5, CYP2B6,

CYP2C9, or CYP2C19 on the pharmacokinetics of

prasugrel or its inhibition of platelet aggregation.

Prasugrel – Boxed Warning

Plavix Label – US Boxed Warning

WARNING: DIMINISHCED EFFECTIVENESS IN POOR METABOLIZERS

See full prescribing information for complete boxed warning

Effectiveness of Plavix depends on activation to active metabolite by the

cytochrome P450 (CYP) system, principally CYP2C19 (5.1)

Poor metabolizers treated with Plavix at recommended doses exhibit

higher cardiovascular event rates following acute coronary syndrome

(ACS) or percutaneous coronary intervention (PCI) than patients with

normal CYP2C19 function (12.5)

Tests are available to identify a patient’s CYP2C19 genotype and can be

used as an aid in determining therapeutic strategy (12.5)

Consider alternative treatment or treatment strategies in patients

identified as CYP2C19 poor metabolizers (2.3, 5.1)

US Plavix LabelDose UM EM IM PM

Cmax (ng/ML)n=10 n=10 n=10 n=10

24 hr 300 mg 24 (10) 32 (21) 23 (11) 11 (4)24 hr 600 mg 35 (13) 44 (27) 39 (23) 17 (6)Day 5 75 mg 12 (6) 13 (7) 12 (5) 4 (1)Day 5 150 mg 16 (9) 19 (5) 18 (7) 7 (2)

IPA (%) **


VASP PRI (%) **


* Cross over study of 40 healthy subjects

** 5mM ADP

Clopidogrel, EU update September 2009

PHARMACOLOGICAL PROPERTIES

Pharmacokinetic properties

Pharmacogenetics

• Added subsection describing involvement of CYP2C19 in metabolic

conversion to clopidogrel active metabolite and the presence of CYP2C19

allelic variation, with CYP2C19*2 and CYP2C19*3 alleles corresponding

to reduced metabolism

• Includes a table from Xie et al1 (not actually cited in the spc) describing

CYP2C19 genotype frequencies conferring extensive, intermediate and

poor metabolism across White, Black and Asian populations

• Describes the association between CYP2C19 genotype and clopidogrel

treatment outcome and cites 2 post-hoc clinical trial analyses and 5

cohort studies

• Adds statement that pharmacogenetic testing can identify genotypes

associated with variability in CYP2C19 activity and that there may be

genetic variants of other CYP450 enzymes with effects on the formation

of clopidogrel active metabolite

• Adds statement that prevalence of CYP2C19 alleles that result in

intermediate and poor CYP2C19 metabolism differs according to

race/ethnicity 1Xie, et al. Annu Rev Pharmacol Toxicol 2001; 41: 815-50

Clopidogrel, EU update September 2009

PHARMACOLOGICAL PROPERTIES

Pharmacodynamic properties

• Added statement “Because the active metabolite is formed by CYP450

enzymes, some of which are polymorphic or subject to inhibition by other

drugs, not all patients will have adequate platelet inhibition.”

CLINICAL PARTICULARS

Posology and method of administration

• Added PGx“CYP2C19 poor metaboliser status is associated with

diminished response to clopidogrel. The optimal dose regimen for poor

metabolisers has yet to be determined.”

Special warnings and precautions for use

• Added text regarding association between genetically reduced

CYP2C19 function and lower systemic exposure to clopidogrel active

metabolite, diminished antiplatelet response, and “generally” higher

cardiovascular event rates following myocardial infarction compared to

patients with normal CYP2C19 function

• Use of drugs that inhibit CYP2C19 is discouraged, stating that

“concomitant use of Proton Pump Inhibitors should be avoided unless

absolutely necessary”

Documents

Pharmacogenetics and Thienopyridines - 1st Latin American