PHARMACOGENOMICSPHARMACOGENOMICS
John N. van den Anker, MD, PhD, FCP, FAAP
Children’s National Medical Center, Washington, DC, USA &Intensive Care, Erasmus MC-Sophia Children’s Hospital,
Rotterdam, the Netherlands
John N. van den Anker, MD, PhD, FCP, FAAP
Children’s National Medical Center, Washington, DC, USA &Intensive Care, Erasmus MC-Sophia Children’s Hospital,
Rotterdam, the Netherlands
Disclosure presentation John N. van den Anker
Disclosure presentation John N. van den Anker
I do not have anything to disclose related to the content of my presentation
I do not have anything to disclose related to the content of my presentation
Individual variability in drug response can have serious consequencesIndividual variability in drug response can have serious consequences
Stevens-Johnson Syndrome (SJS) Adverse Drug Reaction
Effectively treats or prevents disease
Effectively treats or prevents disease
The Ideal MedicationThe Ideal Medication
Has no adverse effects
Paradox of Modern Drug Development Paradox of Modern Drug Development
1. Clinical trials provide evidence of efficacy and safety at usual doses in populations
2. Physicians treat individual patients who can vary widely in their response to drug therapy
+ =
+ =
Efficacious & Safe
Efficacious & Safe
No Response
Adverse Drug Reaction
• 4-6th leading cause of death in the USA1
• Health care costs: $137-177 billion annually (USA)2-3
• Cause 7% of all hospital admissions4
• Cause serious reactions in over 2,000,000 hospitalized patients (6.7%) each year in the USA1
• Cause fatal reactions in over 100,000 hospitalized patients each year in the USA1
• 50% of newly approved therapeutic health products have serious ADRs, discovered only after the product is on the market (Health Canada, 2007)
• 95% of all ADRs are unreported
• 4-6th leading cause of death in the USA1
• Health care costs: $137-177 billion annually (USA)2-3
• Cause 7% of all hospital admissions4
• Cause serious reactions in over 2,000,000 hospitalized patients (6.7%) each year in the USA1
• Cause fatal reactions in over 100,000 hospitalized patients each year in the USA1
• 50% of newly approved therapeutic health products have serious ADRs, discovered only after the product is on the market (Health Canada, 2007)
• 95% of all ADRs are unreported
Adverse Drug Reactions
4. Pirmohamed et al, BMJ, 2004 5. MjoÈrndal et al, EACPT3, 1999
6. Moore et al., 2007
1. Lazarou et al, JAMA, 19982. Johnson et al, Arch Intern Med 1995
3. Ernst et al, J. Am. Pharm. Assoc. 2001
Patient genotype is currently an unknown Patient genotype is currently an unknown factor in the prescribing of medicinesfactor in the prescribing of medicines
Genetic FactorsGenetic Factors
20-95%20-95%
AgeAge
EthnicityEthnicityWeightWeightGenderGender
Concomitant DiseaseConcomitant Disease
Concomitant DrugsConcomitant Drugs
ComplianceComplianceDietDiet
Factors Contributing to Factors Contributing to Variability in Drug ResponseVariability in Drug Response
Growth and Development Growth and Development
Determinants of Drug Response in InfantsDeterminants of Drug Response in Infants
Drug Exposure
Response
AbsorptionDistribution
Receptor InteractionBiotransformation
Excretion
AbsorptionDistribution
Receptor InteractionBiotransformation
Excretion
Environment Genetics
DiseaseDisease
The Challenge of Optimizing the Use of Medicines in Paediatric Patients: Determining the Source(s) of Variability…...
The Challenge of Optimizing the Use of Medicines in Paediatric Patients: Determining the Source(s) of Variability…...
OntogenyOntogenyOntogenyOntogeny PharmacogeneticsPharmacogeneticsPharmacogeneticsPharmacogenetics
From DNA to mRNA to protein From DNA to mRNA to protein
ATG ATC CCC TTT
Met Ile Pro Phe
3 billion correct basepairs ….and 1 mutation3 billion correct basepairs ….and 1 mutation
• atgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcactacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgaattcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttca
• atgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgacttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttca
• atgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcactacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgaattcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttca
• atgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgacttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttcagtacgtacatgtccaggtgcaggacgagttca
gacgaattcagtacgtacatggacgacttcagtacgtacatg
CYP2D6slow
intermediaterapid
ultrarapid
CYP2C19
Poor metabolizer normal
anti-convulsants, proton pump inhibitors, benzodiazepines, anti-malarials
anti-depressants, anti-psychotics, anti-arrhythmics, beta-blockers, pain medications, anti-emetics, anti-cancer drugs
CYP2D6 PharmacogeneticsCYP2D6 Pharmacogenetics
DrugStable metabolites,
Excretion
Drug Stable metabolites,Excretion
EMEM
PMPM
“Functional” overdose“Functional” overdose
CYP2D6 PharmacogeneticsCYP2D6 Pharmacogenetics
CYP2D6 activity displays bimodal distribution in Caucasian subjects
5-10% of Caucasian population deficient in CYP2D6 activity
“Poor metabolizers” or “PMs” have two “inactive” forms (alleles) of the CYP2D6 gene
PMs at increased risk for concentration-dependent side effects with “normal” drug doses
Some drugs may not work (codeine; tramadol)
CYP2D6 activity displays bimodal distribution in Caucasian subjects
5-10% of Caucasian population deficient in CYP2D6 activity
“Poor metabolizers” or “PMs” have two “inactive” forms (alleles) of the CYP2D6 gene
PMs at increased risk for concentration-dependent side effects with “normal” drug doses
Some drugs may not work (codeine; tramadol)
CYP2D6 Pharmacogenetics:
CaucasiansBertilsson et al. Clin. Pharmacol. Ther. 51:288-97, 1992
CYP2D6 Pharmacogenetics:
CaucasiansBertilsson et al. Clin. Pharmacol. Ther. 51:288-97, 1992
120120
8080
4040
00
0.010.01 0.10.1 11 1010 100100
CYP2D6 ActivityCYP2D6 Activity
Num
ber
of I
ndiv
idua
lsN
umbe
r of
Ind
ivid
uals N = 1,011N = 1,011
12.612.6
SlowerFaster
CYP2D6 Activity: ChineseBertilsson et al. Clin. Pharmacol. Ther. 51:288-97, 1992
CYP2D6 Activity: ChineseBertilsson et al. Clin. Pharmacol. Ther. 51:288-97, 1992
120120
8080
4040
00
0.010.01 0.10.1 11 1010 100100
Num
ber
of I
ndiv
idua
lsN
umbe
r of
Ind
ivid
uals
N = 1,011N = 1,011
N = 695N = 695
12.612.6
CYP2D6 ActivityCYP2D6 Activity SlowerFaster
Indi
vidu
als
10
20
40
30
PMPoor Metabolizer~ 5-10 % Caucasians
EMExtensive
Metabolizer
IMIntermediateMetabolizer~ 10-15 %
UMultrarapidmetabolizer~ 10-15 %
0.1 100101 MRS
Unravelling CYP2D6 Pharmacogenetics
Griese et al. Pharmacogenetics 1998, Raimundo et al. CPT 2004, Toscano et al.Pharmacogenetics 2006
Griese et al. Pharmacogenetics 1998, Raimundo et al. CPT 2004, Toscano et al.Pharmacogenetics 2006
full-term healthy male infant day 7 pp: intermittent periods of difficulty in breastfeeding day 11: the baby had regained his birthweight day 12: grey skin, milk intake had fallen day 13: the baby was found dead
autopsy: no abnormality blood concentration of morphine (metabolite of codeine):
70 ng/mL versus 0-2.2 ng/mL (typical)
Pharmacogenetics of Codeinesite of actioncodeine
morphine
Cytochrome P4502D6
Blood brain barrier
Eckhardt et al., Pain 1998
0 5 10 15 20 250
10
20
30
40
50
60
mor
phin
e [p
mol
/ml]
Extensive Metabolizer
Poor Metabolizer
time [h]
plasma morphine levels
after 170 mg codeine p.o.
Explanation: medication mother due to episiotomy pain:
codeine 60 mg plus paracetamol 1000 mg every 12 hrs
for 2 weeks
Morphine concentration in stored milk: 87 ng/mL
mother: CYP2D6 genotype: CYP2D6*2x2 gene duplication
= Ultra rapid metabolizer phenotype
The American Academy of Pediatrics and “Drugs in Pregnancy in Lactation”, the major reference guide to fetal and neonatal risk, list
codeine as compatible with breastfeeding
– Briggs et al., 2005; Pediatrics, 2001
Prior to this publication!
FDA drug label change and FDA drug label change and public health advisories public health advisories
Health Canada Health Canada Public AdvisoryPublic Advisory
Aug. 21, 2008Aug. 21, 2008
Estimated 1846 newborn infants are at risk for Estimated 1846 newborn infants are at risk for this codeine ADR annually in Canadathis codeine ADR annually in Canada
(340,000 births, 73% breastfed, 52% mothers receive codeine post-childbirth,1.4% risk genotype)(340,000 births, 73% breastfed, 52% mothers receive codeine post-childbirth,1.4% risk genotype)
May 10, 2006May 10, 2006
Aug 17, 2007
2 year old boy
Received tonsillectomy for sleep apnea
Received standard codeine dose
Died of respiratory depression
High levels of morphine in blood
Boy carried CYP2D6 gene duplication
Kelly, Rieder, van den Anker et al. More codeine fatalities after
tonsillectomy in North American children. Pediatrics 2012;129(5):1343-7
August 20, 2009
BloodGI Lumen Cell
Transporters Receptors
Protein kinases
Phosphatases
2nd messengers Targets
Opioids and pharmacogenomicsOpioids and pharmacogenomics
Why personalizing opioid therapy?•Wide unpredictable interpatient variability•Narrow therapeutic indices Inadequate pain relief and side effects ~ 50%•Genetic factors: up to 60% (Angst 2012)
Why personalizing opioid therapy?•Wide unpredictable interpatient variability•Narrow therapeutic indices Inadequate pain relief and side effects ~ 50%•Genetic factors: up to 60% (Angst 2012)
Sadhasivam et al. (2012)
Candidate genesCandidate genes
1. 410 pain genes
2. <10% translated to human pain
3. Opioid + genetic ≈ 2000 hits
Division of genesDivision of genes
• Pharmacokinetic: affect the availability at the site of action
Phase I and II enzymes, transporters etc.
• Pharmacodynamic: target and downstream signaling cascade
Mu-opioid receptor, inwardly rectifying potassium channel etc
• Pain sensitivity: susceptibility to pain
Sodium channel, interleukines etc.
• Pharmacokinetic: affect the availability at the site of action
Phase I and II enzymes, transporters etc.
• Pharmacodynamic: target and downstream signaling cascade
Mu-opioid receptor, inwardly rectifying potassium channel etc
• Pain sensitivity: susceptibility to pain
Sodium channel, interleukines etc.
PK RELATED GENESPK RELATED GENES
Metabolism fentanylMetabolism fentanyl
CYP3A4 GeneCYP3A4 Gene
• Important drug metabolizing enzyme
Highly expressed in liver and intestine
broad substrate specificity (app. 50%)
• Identified SNPs
22 alleles identified (CYPallele homepage)
Rare or lack phenotypic effect
• Caucasian
*1G and *22 allele
• Important drug metabolizing enzyme
Highly expressed in liver and intestine
broad substrate specificity (app. 50%)
• Identified SNPs
22 alleles identified (CYPallele homepage)
Rare or lack phenotypic effect
• Caucasian
*1G and *22 allele
CYP3A4 SNPsCYP3A4 SNPsCYP3A4*1G reduced activity higher plasma levelsLess fentanyl requiredMore side effects
Studies
Dong (2012),Yuan (2011) and Zhang (2010): Lower fentanyl requirement postoperative
Yuan (2011) correlation between plasma levels and requirement (r=-0.552, p<0.001)
However, not associated with AEs and Pain score
CYP3A4*1G reduced activity higher plasma levelsLess fentanyl requiredMore side effects
Studies
Dong (2012),Yuan (2011) and Zhang (2010): Lower fentanyl requirement postoperative
Yuan (2011) correlation between plasma levels and requirement (r=-0.552, p<0.001)
However, not associated with AEs and Pain score
CYP3A4*22
PD RELATED GENESPD RELATED GENES
OPRM1 and FentanylOPRM1 and Fentanyl118A>G•Higher fentanyl requirement (Zhang 2011)•Higher VAS pain score (Wu 2009)
118A>G relevant?
Liao 2013: N=97, post-operative pain, fentanyl requirement+AEs
CYP3A4*18 >> A118G
304A>G
Lower fentanyl requirement (Landau 2009)
Association with morphine requirement not found
(Wong 2010)
118A>G•Higher fentanyl requirement (Zhang 2011)•Higher VAS pain score (Wu 2009)
118A>G relevant?
Liao 2013: N=97, post-operative pain, fentanyl requirement+AEs
CYP3A4*18 >> A118G
304A>G
Lower fentanyl requirement (Landau 2009)
Association with morphine requirement not found
(Wong 2010)
OPRM1 related genesOPRM1 related genes
Stat6Stat6
PAIN SENSITIVITY GENESPAIN SENSITIVITY GENES
Pain sensitivity genesPain sensitivity genes
Action potential•SCN9A
Α-subunit Nav1.7 channel, nociceptive neurons
R1150W increased sensitivity to pain (Reimann 2010)•KCNS1
Voltage gated K channel (Kv 9.1), sensory neurons
1465A>G increased sensitivity to pain (Costigan 2010)
Action potential•SCN9A
Α-subunit Nav1.7 channel, nociceptive neurons
R1150W increased sensitivity to pain (Reimann 2010)•KCNS1
Voltage gated K channel (Kv 9.1), sensory neurons
1465A>G increased sensitivity to pain (Costigan 2010)
NICU study NICU study
• n=132• Mechanical ventilation (PNA<3 days)• 2 level III NICUs
• Continous morphine vs placebo during max. 7 days• Loading dose 100 µg/kg 10 µg/kg/hr • Additional morphine (50 µg/kg 5-10 µg/kg/hr)
Objective
Determine if polymorphisms in PD related genes (OPRM1 118A>G, COMT Val158Met, ARRB2 8622C>T) are associated with additional morphine requirement (AMR) in newborns.
• n=132• Mechanical ventilation (PNA<3 days)• 2 level III NICUs
• Continous morphine vs placebo during max. 7 days• Loading dose 100 µg/kg 10 µg/kg/hr • Additional morphine (50 µg/kg 5-10 µg/kg/hr)
Objective
Determine if polymorphisms in PD related genes (OPRM1 118A>G, COMT Val158Met, ARRB2 8622C>T) are associated with additional morphine requirement (AMR) in newborns.
Results NICUResults NICU
OPRM1 % AMR OR* [95%CI]
118AA 31.0 4.93 [1.22-20]
118AG/118GG 34.3
COMT % AMR OR*[95%CI]
158Val/Val 57.1 0.161 [0.04-0.650]
158Val/Met or 158Met/Met 26.9
ARRB2 % AMR OR* [95%CI]
8622CC 11.1 5.52 [0.371-82.2]
8622CT/8622TT 34.3
*corrected OR and 95%CI for postconceptional age, sex, allocation group, location centre .
OPRM1 and COMT significant after Bonferroni correction
Pharmacogenomics Pharmacogenomics
Avoid adverse drug reactions
Maximize drug efficacy for individual patients
All Patients with Same
Diagnosis
treat with alternative drug or dose
Moderate risk of ADR (12.5%):
Low risk of ADR (0%):10% risk of
adverse reaction
Pharmacogenetic Profile:
HighHigh risk of ADR (50%):risk of ADR (50%):
treat with conventional dose
treat with alternative drug or dose
All children are at risk for ADRs, but not all children are at equal risk.
Find the kids at highest risk for serious ADRs due to genetic factors
What do we need to do!What do we need to do!
• Identify children with ADRs
• Identify ‘matched’ children on same medications, without ADRs
• Whenever possible, DNA samples are collected from biological parents of ADR patients
• Look for genetic variation in key drug ADME enzymes
• Develop new dosing guidelines
• Bedside-benchtop-bedside science
• Identify children with ADRs
• Identify ‘matched’ children on same medications, without ADRs
• Whenever possible, DNA samples are collected from biological parents of ADR patients
• Look for genetic variation in key drug ADME enzymes
• Develop new dosing guidelines
• Bedside-benchtop-bedside science
WE CAN’T TREAT CHILDREN LIKE ADULTS
Increased Risk of Severe ADRs in Children
>75% of approved drugs used in children are untested in
pediatric populations
Young children cannot evaluate or express their own
response to medications
Pediatric dosage forms not available
Children metabolize and transport drugs differently
than adults