NicotineNicotine Dependence p

Treatment: From M t M tMouse to Man to

Medicine

Caryn Lerman, Ph.D. yTransdisciplinary Tobacco Use Research Center UPENNUPENN

About this presentation

Dr Lerman presented this onDr. Lerman presented this on December 1, 2009, as the Distinguished Lecture of the Institute for HealthLecture of the Institute for Health Research and Policy and the Center for Clinical and Translational Research atClinical and Translational Research at the University of Illinois at Chicago. The UIC CCTS is supported by the NationalUIC CCTS is supported by the National Center for Research Resources, Award No UL1RR029879 For moreNo. UL1RR029879. For more information, see www.ihrp.uic.edu.

Our Challenge

• 1 in 5 Americans is tobacco dependent.p• Current FDA-approved medications are

successful for only 1 in 3 smokers.successful for only 1 in 3 smokers.

Tobacco Use Research Center P50 (1999- 2014)Scientific Mission

To translate discoveries inTo translate discoveries in neuroscience, pharmacology, genetics and behavioral sciencegenetics and behavioral science to improve treatment for nicotine dependencedependence

Treatment Development for Tobacco Dependence

Target Identification (Discovery)

Transcriptional Profiling

Human Genetics

Initial Target ValidationProof of

MechanismInitial Target Validation(Development)Imaging

Mechanism Testing in

Rodents and Humans

Early Human Screening Models

Behavioral Pharmacology

Cost-Effectiveness

AnalysisTargeted Therapy

PharmacogeneticsTargeted Therapy

Trials

Nicotine Addiction is a Chronic, Relapsing Brain Disease

Lerman et al. Nature Reviews Drug Discovery, 2007

Nicotine-related Brain Reward Pathway

COMT

COMT val158met Polymorphism Predicts Smoking Relapse in Independent StudiesSmoking Relapse in Independent Studies

Odds Ratio

Case-Control Study (n=785)

Prospective Clinical Trial (n=290)

3.2

3

3.5Ratio (n 785)

OR (relapse v. quit)

(n 290)

OR (current v. former smoker)

2.5

3P=0.03 P=0.03

1.45 1 4

1.82

1.01 1.01

1.45 1.4

1

1.5

met/met val/met val/val met/met val/met val/val

Colilla et al., Pharmacogenetics and Genomics, 2005

met/met val/met val/val met/met val/met val/val

COMT is a Potential Therapeutic Targetp g

• Methylation enzyme involved in the inactivation of dopamineof dopamine

• Common functional val158met variant (1 in 4 are val/val)are val/val)

• Val allele is associated with an increase in COMT activity and corresponding decrease in dopamine in frontal cortex

• Carriers of the val allele exhibit deficits in cognitive functioncognitive function

Hypothesis: Nicotine deprivation will produce cognitive deficits in smokers with val/val genotypes, an effect that may prompt

smoking relapse to reverse deficits.

Imaging-Based Target Validation

Prospective genotyping

met/met: n=11

val/met: n=12

val/val: n=10

Smokers scanned on two occasions (counterbalanced): (1)

ki l (2) >14 hsmoking as usual vs. (2) >14 hrs. abstinent (confirmed with CO)

Fractal N-back (Working Memory Task)

0 – back Press the button when you 1 – back Press the button when the pict re is the same as the one immediatel

Participant responds to stimuli based on 3 rules:

see the target picture picture is the same as the one immediately before

2 – back Press the button when the picture is the same as the one two before

3 – back Press the button when the picture is the same as the one three before

Brain Signature of Abstinence Effect on Cognitive Function in COMT val/val group

Dorsolateral prefrontal cortex

Genotype x abstinence effect (p=0.0005)

•Brain activation in smokers with val/val genotypes is reduced in abstinence during performance of difficult cognitive task•Reduced activation is liked with slower performance in val/val

Loughead et al, Molecular Psychiatry, 2009

Reduced activation is liked with slower performance in val/val group at higher task difficulty (p=0.03)

Tolcapone as a “Tool Compound” for Proof of Mechanism Studyfor Proof of Mechanism Study

• Inhibitor of COMT in central• Inhibitor of COMT in central nervous system

• FDA-approved for the treatment of Parkinson’streatment of Parkinson s Disease

• Cognitive enhancing effects

Phase I Safety Study of Tolcapone in Smokers

•Short-term (7-day) treatment with tolcaponeCorrect response time (ms) on treatment with tolcapone 200mg t.i.d. is safe and well tolerated by smokers

Correct response time (ms) on working memory task

1520

VALMET

•Tolcapone (v. placebo) decreased speed of 0

510

MET

pperformance in val/val group, but not the met/met group

-20-15-10-5

•Reversal of dopaminergic d fi it i l/ l

-25-20

n=8 n=8deficit in val/val group may reduce abstinence-induced cognitive deficits

Phase II Study of Tolcapone in Smokers

Reversal of abstinence-induced cognitive deficits by tolcapone will provide “proof of mechanism”

Day 14 – 27 WASH-OUT

PLACEBO/TOLCAPONE® TOLCAPONE®/PLACEBO

Medication run up Medication run up

Day 1 - 9 Day 28 - 37Day 10 - 13 Day 38 - 41

3.5 days mandatory 3.5 days mandatory abstinence

abstinence (CO confirmed)

abstinence

fMRI Scan fMRI Scan

Correct Reaction Time ± 1 SE Faster (lower) reaction700

800

Correct Reaction Time ± 1 SE Faster (lower) reaction time on the N-back

400

500

600 working memory task predicts 7-day quit

200

300

400

success (p=.01; r2=.15)

0

100

Relapsers Abstainers Relapsers Abstainers

Variable Beta T p Model R2

Sex -0.015 0.104 .92 .01Baseline cigs. per day 0.437 3.049 .005 .15Baseline 3-Back performance -0.030 -0.166 .87 .25Abstinent 3-Back performance -0.482 -2.651 .013 .40

Summary: COMTCOMT val allele is risk

factor for nicotine dependence

Cognitive deficits are a core symptom of dependence and

predict relapse

Smokers with val/val genotype have altered brain function and cognitive deficits inbrain function and cognitive deficits in

abstinenceProof of mechanism experiments (tolcapone)

val

C t b h i l ti d h l i idConvergent behavioral, genetic, and pharmacologic evidence would support COMT as a therapeutic target for tobacco

dependence

Treatment Development for Tobacco Dependence

Target Identification (Discovery)

Transcriptional Profiling

Human Genetics

Initial Target ValidationProof of

MechanismInitial Target Validation(Development)Imaging

Mechanism Testing in

Rodents and Humans

Early Human Screening Models

Behavioral Pharmacology

Cost-Effectiveness

AnalysisTargeted Therapy

PharmacogeneticsTargeted Therapy

Trials

Opioid Mechanisms in Nicotine Reward

Nestler

Mouse Model of Nicotine Reward

Preconditioning DayA B

Day 1

A B

C

S

A B

C

S Pairing Days 2-8

A BC

S

A BC

S ??Test Day

Work by Julie Blendy

Naloxone on Test Day Blocks Conditioned Rewarding Effects of Nicotine in 129/C57 B16 MiceEffects of Nicotine in 129/C57 B16 Mice

400.00500.00

Saline

Treatment on Test Day*

n

100 00200.00300.00 Naloxone

s tim

e on

-100.000.00

100.00

red

min

usnp

aire

d

400 00-300.00-200.00

me

on p

air un

-500.00-400.00

SalineNicotine

(1.0mg/kg)Tim

Nicotine (2.0mg/kg)

Nicotine on Pairing Days*p<.05

Walters et al, Neuron, 2005

Nicotine on Pairing Days

The Human OPRM1 GenePROMOTOR EXON 1 EXON 2 EXON 3 EXON 4 3’UTR

A118G

•The human OPRM1 gene includes a common Exon 1 Asn40Asp (A118G) mis-sense single nucleotide polymorphism (SNP).

•G allele associated with reduced mRNA expression and protein levels and is present in 25-30% of persons of European ancestry

Hypothesis: Smokers with G allele will have a lower liability to l i ki ti t t trelapse in smoking cessation treatment

Open Label Pharmacogenetic Trial of NRT (TTURC 1, n=600*)( , )

Pre-treatment Assessment & Genotyping

Nicotine nasal TransdermalNicotine nasal spray x 8 wks

Transdermal nicotine x 8 wks

95%

Follow-Up: EOT, 6-months, and 12-months

retention rate

p , ,

*European ancestry only (n=420)

OPRM1 Asn40Asp Variant is Associated with Response to Nicotine Replacement Therapy p p py

60Treatment Phase Follow-up Phase% quit

41.5

52.450

60AA n=238GA GG n=82

Normal

Reduced activity

30

2226.8

33.329.8 31

30

40activity

22

12.51516.215.5

10

20

0All Patch Spray All Patch Spray

OR= 1.9, p=.01 Lerman et al., Pharmacogenomics J, 2004

What is the Mechanism of Enhanced Therapeutic Response in Smokers with the OPRM1 Asp40 (G) allele?Response in Smokers with the OPRM1 Asp40 (G) allele?

1. Do carriers of the OPRM1 G allele (loss of function) exhibit reduced nicotine reinforcement?

2. Does naltrexone reduce nicotine reinforcement particularly in smokersreinforcement—particularly in smokers with OPRM1 G allele?

3. Are females more sensitive to opioid system effects on nicotine reward?

Study Population (n=60)Study Population (n 60)

OPRM1 AA n=30OPRM1 AA n 30OPRM1 AG/GG n=30All European ancestrysmoke >10 cpdsmoke >10 cpd

Within Subject Designj g

Day 1 Day 2 Day 4

Study Phase 1 Study Phase 2Day 3 Day 1 Day 2 Day 3 Day 4

*NTX or PLACEBO *NTX or PLACEBOy

12.5mg*

y25mg*

y50mg*

5-7 day Washout

y50mg*

y12.5mg*

y25mg*

y50mg*

y50mg*

Observation Observation

Test Day Test Day

Observation Period

Observation Period

• CO, medication compliance, side effects assessed in person

• CO, medication compliance, side effects assessed in personassessed in-person

daily.assessed in-person daily.

Nicotine choice paradigm Nicotine choice paradigmNicotine choice paradigm Nicotine choice paradigm

Human Model of Nicotine Reward

• 2 hour deprivation period (to standardize i h i d i iexposure without inducing serious

withdrawal symptoms)

• Initial (blinded) exposure to 4 puffs of Quest cigarettes: denic. (.05 mg) vs nic. (.6 mg)

• Assess subjective effects

• Self-administer 4 puffs from either cigarette at 30 minute intervals in 6 trials over a 3-hour period

• Outcome measure is number of nicotine puffs chosen out of 24 = relative reinforcing value of nicotine

Reduced Activity OPRM1 Allele is A i t d ith R d d Ni ti R dAssociated with Reduced Nicotine Reward

Subjective Ratings (nicotine minus denicotinized cigarette)

1 61.8

2 AA(n=30)G*

Normal activity

11.21.41.6 G*

(n=30)Reduced activity

0.40.60.8

1

00.2

Satisfaction Strengthgp=.05 p=.03

Ray et al. Psychopharmacology, 2006

OPRM1 Genotype Predicts Nicotine Reinforcement in Females but not in Males

number of nicotine puffs in 24 (across treatments)

20AA n=30

24

75% of Puffs from Nicotine75% of Puffs from Nicotine

19.65

18 1815

GA GG n=30

13.58

5

10

50%

0Males Females

P (genotype by gender interaction)=.036Ray et al. Psychopharmacology, 2006

Estrogen Modulation of MOR Binding

Zubieta et al., J Neuroscience, 2006

Naltrexone Does Not Reduce Nicotine Reward or Interact with OPRM1 Genotype

number of nicotine puffs in 24

20

AA24

18.23

18.83

116.38

15

AG/GG

15.5516.38

5

10

0Naltrexone Placebo

Ray et al. Psychopharmacology, 2006

Using Targeted Genetic Mutations in the Mouse to Understand Human OPRM1 SNP (Blendy)( y)

Exon1*

Molecular Cellular Imaging Behavioral

MOPR expression is decreased in A112G knock-in mice

Female G/G mice failed to show a conditioned place preference to morphine-

paired environments (10 mg/kg)

Mague, Isiegas, Huang, Liu-Chen, Lerman, Blendy 2009©2009 by National Academy of Sciences

MOR Binding as Mechanism for Observed OPRM1 Association with Nicotine Reward

2x2 Factorial Design: (1) iv nicotine vs. saline

Association with Nicotine Reward MOR Binding Potential (BP) in Nicotine vs. Placebo Session

BP(within subject); (2) OPRM1 genotype (stratified by sex)

4

5

planic

N=4 (2 sessions/subject)

BP

(stratified by sex)

2

3nic

0

1

0rVST lVST rNAC lNAC rTHAL lTHAL rACC lACC OCC

VST=ventral striatum; NAC-nucleus accumbens; THAL=thalamus; ACC=anterior cingulate cortex; OCC=occipital cortex (reference region)

P=.18 P=.03 P=.14 P=.10 P=.07

ACC=anterior cingulate cortex; OCC=occipital cortex (reference region)

Nicotine abstinence-induced rCBF changes by OPRM1 Genotype g y yp

Hot color means greater in delta rCBF the AA subgroup. The color bar indicates the range of t-values displayed. Spatial location of each slice is indicated by the number in the upper left corner of the slice image and also is labeled by the white lines (for axial slices) and the green lines (for the sagittal slices).

Wang, Ray, Faith, Wileyto, Detre, Lerman, Neuroscience Letters, 2008; J. Neuroscience, 2007

Summary of OPRM1 Work

MOR antagonist blocks nicotine CPP in mice

Preclinical: Blendy Lab Clinical: Lerman Lab

Human OPRM1 G allele associated with quit successnicotine CPP in mice associated with quit success

Nicotine reward reduced in f l G ll l i s

Female mice with equivalent of human OPRM1 G show

female G allele carriersreduced morphine CPP

Smokers with G allele show MOR expression reduced in mice with G allele

less CBF change in nicotine abstinence

P ll l M H t d Eff t Ni ti MOR Parallel Mouse-Human study: Effects on Nicotine on MOR Binding in Males and Females

Treatment Development for Tobacco Dependence

Target Identification (Discovery)

Transcriptional Profiling

Genome-wide Association

Initial Target Validation Proof of M h iInitial Target Validation

(Development)Imaging Mechanism Testing in

Rodents and Humans

Early Human Screening Models

Behavioral Pharmacology

Cost-Effectiveness

AnalysisTargeted TherapyPharmacogenetics and

Targeted Therapy

Targeted Therapy Trials

Can we predict who will benefit from different Can we predict who will benefit from different treatments for smoking cessation?treatments for smoking cessation?treatments for smoking cessation?treatments for smoking cessation?

Nicotine Dependent Smokers Nicotine Dependent Smokers Alter Alter SmokingSmoking to Maintain Nicotine Levels:to Maintain Nicotine Levels:Smoking Smoking to Maintain Nicotine Levels:to Maintain Nicotine Levels:

Nicotine removal (i.e. metabolism)

Nicotine intake (i.e. smoking)

NICOTINENICOTINE COTININECOTININE 3’Hydroxycotinine3’Hydroxycotinine

Active Inactive Inactive

NICOTINENICOTINE COTININE COTININE 3 Hydroxycotinine3 Hydroxycotinine

CYP2A6 CYP2A6CYP2A6 CYP2A6

CYP2A6 Gene Mutations Alter Dependence Phenotypesp yp

Genetically slow metabolizers smoke fewer cigs/day and are

less dependent

CYP2A6 genotype alters enzyme activity and

metabolite ratiop

Malaiyandi et al., Molecular Psychiatry, 2006

Nicotine Metabolic Profile Benowitz et al

NICOTINE-1’-N-OXIDE NORNICOTINENICOTINE

9.8% 0.4%

NICOTINE

4.4%9.8%

NICOTINEGLUCURONIDE

~ 80%4.2% CYP2A6

COTININETRANS-3’-

HYDROXYCOTININE

TRANS-3’-

HYDROXYCOTININECOTININE

13 0% 33 6%

COTININE

GLUCURONIDE COTININE N OXIDETRANS-3’

13.0% 33.6%

GLUCURONIDE COTININE-N-OXIDE NORCOTININE HYDROXYCOTININE

GLUCURONIDE12.6% 2.4% 2% 7.4%

Nicotine Metabolite Ratio is a Phenotypic Measure of CYP2A6 ActivityMeasure of CYP2A6 Activity

• The ratio of nicotine metabolites: i i /3’h d i icotinine/3’hydroxycotinine

• A stable measure of nicotine metabolism rate derived from smoking

• Independent of time since last cigarettep g• Can be measured in plasma, urine or saliva• Reflects both genetic and environmental• Reflects both genetic and environmental

influences on nicotine clearance

Easy to perform in clinical practice

Nicotine Metabolite Ratio Predicts Therapeutic Response to Nicotine Patch

End of Treatment 6-Month Follow-up% Quit

Clinical Pharmacology & Therapeutics, 2006

OR=.72 (.57-.91) p=006)

3-HC: Cotinine Ratio in QuartilesSlow Fast Slow Fast

Nicotine Metabolite Ratio Predicts Response to Nicotine Patch: Independent Validation (n=568)

% QUITPharmacology, Biochem and Behavior, 2009

OR=.54 [95% CI:.36-.82], p=.003

Nicotine Metabolite Ratio Predicts Therapeutic Response to Bupropion (n=414)

% Quit

p p p p ( )

40 Placebo •Decreased quitOR=4.59 (1.5-13.6), p=.006

25

3230 30

3432

30

35Bupropion

Decreased quit rates also observed with placebo

20

15

20

25•Increased liability to relapse in fast metabolizers is10

5

10metabolizers is reversed by bupropion

01st Qrtl 2nd Qrtl 3rd Qrtl 4th Qrtl

Slow Fast

•Fast metabolizers are candidates for b i

Patterson et al., Clinical Pharmacology & Therapeutics, 2008

Slow Fast bupropion

Algorithm for Use of Nicotine Metabolite Ratio to Personalize Smoking Cessation Treatmentto Personalize Smoking Cessation Treatment

Plasma saliva or urinePlasma, saliva or urine Nicotine metabolite ratio

Slo F tSlow Metabolizer

Fast Metabolizer

Nicotine Patch Bupropion or Varenicline

Low costLow toxicity

Higher costGreater toxicity

Summary: Nicotine Metabolism

CYP2A6 gene linked with dependence

phenotypes

Nicotine metabolite ratio is a stable measure of CYP2A6

activity

Genetically slow metabolizers respond well to transdermal nicotine; fast metabolizerstransdermal nicotine; fast metabolizers

respond well to bupropion

Targeted therapy based on nicotine metabolite ratio can be cost-effective

Evidence from prospective targeted therapy trial will support

t l ti t ti

Test kit in development through industry

ll b titranslation to practice collaboration

Summary and Implications y p•Genetics and neuroimaging provide powerful new tools forprovide powerful new tools for probing the biobehavioral basis of nicotine dependencep

•A better understanding of behavior-biology linkages will leadbehavior biology linkages will lead to better treatments and tests to personalize treatment to individual smokers

•Reductions in tobacco use will have a significant public health impact

AcknowledgementsAcknowledgementsCOMT and NeuroimagingCOMT and NeuroimagingR.C. Gur, Loughead, Wileyto, Detre, WangNi ti O i id I t tiNicotine Opioid InteractionsBlendy, Berrettini, Ray, Perkins, Strasser, Jepson

Nicotine MetabolismSchnoll Wileyto PattersonSchnoll, Wileyto, Patterson Rachel Tyndale (U Toronto) Neal Benowitz (UCSF)FundingFundingNCI, NIDA, Commonwealth of PA