11

Tolerability and safety: Tolerability and safety: Predictability of QT Predictability of QT

prolongation in healthy prolongation in healthy subjects from preclinical subjects from preclinical

experimentsexperiments

Henri CaplainHenri Caplain22ndnd Joint Annual Meeting Joint Annual Meeting

20072007Bad Homburg v.d.H., Bad Homburg v.d.H.,

GermanyGermany

22

Sanofi-Aventis (SA) Sanofi-Aventis (SA) Evaluation of Cardiac Evaluation of Cardiac

Repolarization Data for 15 Repolarization Data for 15 DrugsDrugs

33

SCOPE OF EVALUATIONSCOPE OF EVALUATION• 16 completed TES:16 completed TES:

– 2003-2007;2003-2007;– 15 compounds15 compounds..

• Degree of concurrence between Degree of concurrence between preclinical and clinical data:preclinical and clinical data:– Comparable methodologyComparable methodology for for

preclinical and clinical assessments.preclinical and clinical assessments.

44

Regulatory EnvironmentRegulatory Environment

• Guidance ICH S7BGuidance ICH S7B: Nonclinical Evaluation : Nonclinical Evaluation of the Potential for Delayed Ventricular of the Potential for Delayed Ventricular Repolarization (QT Interval Prolongation) Repolarization (QT Interval Prolongation) by Human Pharmaceuticals;by Human Pharmaceuticals;

• Guidance ICH E14Guidance ICH E14: Clinical Evaluation of : Clinical Evaluation of QT/QTc Interval Prolongation and QT/QTc Interval Prolongation and Proarrhythmic Potential for Non-Proarrhythmic Potential for Non-Antiarrhythmic Drugs.Antiarrhythmic Drugs.

55

ICH S7BICH S7B• One preclinical assay not sufficient;One preclinical assay not sufficient;

• In vitro In vitro and and in vivo in vivo complementary;complementary;

• Potential to delay ventricular repolarizationPotential to delay ventricular repolarization, , related to the extent to concentration (parent + related to the extent to concentration (parent + metabolites);metabolites);

• Estimate human riskEstimate human risk;;

• Integrated risk assessmentIntegrated risk assessment..

66

Ion channel assay

In vivo QT assay

In vitro IKr

assayIn vivo QT

assay

Chemical/Pharmacological

Class

-up studies if necessary

Follow-upStudies

*

Signal of riskNone Weak Strong

Evidence of RiskNone Weak Strong

Integrated risk assessmentIntegrated Risk Assessment

Relevant Non-clinical and Clinical

Information

ICHS7B: NonClinical Testing Strategy

Quantitative SCORING? Impact on Clinical Investigations

77

ICH E14: ScopeICH E14: Scope• Recommendations for clinical studies to Recommendations for clinical studies to

assess the potential of a drug to delay assess the potential of a drug to delay cardiac repolarization;cardiac repolarization;

• Determine whether a drug has a Determine whether a drug has a threshold threshold pharmacological effect on pharmacological effect on cardiac repolarizationcardiac repolarization, as detected by , as detected by QT/QTc prolongation;QT/QTc prolongation;

88

ICH E14: Positive StudyICH E14: Positive Study• Prolongation QT/QTc:Prolongation QT/QTc:

– Central tendency analysis:Central tendency analysis:•5 msec5 msec maximal mean maximal mean ↑↑ QTc (no TdP to QTc (no TdP to

date);date);•Difference of 10 msec on UB 95% Difference of 10 msec on UB 95%

confidence intervalconfidence interval around the mean around the mean effect on QTc.effect on QTc.

– Categorial analysis:Categorial analysis:•Absolute QTc prolongation: Absolute QTc prolongation: > 500 msec> 500 msec;;•Change from baseline in QTc: Change from baseline in QTc: > 60 msec> 60 msec. .

• Documented arrhythmias;Documented arrhythmias;

99

ICH E14: Potential ImpactICH E14: Potential Impact

• Determine whether or not the effect of a Determine whether or not the effect of a drug on the QT/QTc in target patient drug on the QT/QTc in target patient populations populations should be studied intensivelyshould be studied intensively during later stages of development;during later stages of development;

• Basis for Basis for nonapproval of a drug or nonapproval of a drug or discontinuationdiscontinuation of its clinical of its clinical development.development.

1010

SA Preclinical Experiments SA Preclinical Experiments for these 15 Compoundsfor these 15 Compounds

1111

SA Core Battery StudiesSA Core Battery Studies• In vitro In vitro hERG/IhERG/Ikrkr assay assay::

– Human ether-a-go-go-related gene Human ether-a-go-go-related gene (hERG) channel in CHO cells;(hERG) channel in CHO cells;

– APD: Papillary muscle (discovery) APD: Papillary muscle (discovery) /Rabbit Purkinje Fiber (development)./Rabbit Purkinje Fiber (development).

• In vivoIn vivo QT assay QT assay::– Conscious telemetered Dog;Conscious telemetered Dog;– Toxicology Study Non-Rodent (at Toxicology Study Non-Rodent (at

least 4 weeks).least 4 weeks).

1212

Criteria of evaluationCriteria of evaluation• hERG: hERG: IC50 µMIC50 µM (concentration ng/mL); (concentration ng/mL);• Effect on APD:Effect on APD:

– Global (concentration ng/mL);Global (concentration ng/mL);– Increase of APDIncrease of APD: concentration ng/mL.: concentration ng/mL.

• Telemetered dog: Telemetered dog: ↑↑QTc (concentration QTc (concentration ng/mL);ng/mL);

• Toxicology Non-Rodent: Toxicology Non-Rodent: ↑↑QTcQTc (concentration ng/mL).(concentration ng/mL).

Parent Compound + Relevant Metabolites

1313

SA Thorough ECG StudiesSA Thorough ECG Studies(TES)(TES)

1414

TES: DesignTES: Design• Population:Population:

– Healthy subjectsHealthy subjects (18/65 years): 16/16 (18/65 years): 16/16 [=Pharmacological model];[=Pharmacological model];

– Males Males ANDAND Females Females: 16/16 (50/50) : 16/16 (50/50) [Gender effect = +4 msec];[Gender effect = +4 msec];

– Mostly Caucasian.Mostly Caucasian.

• Repeated administrationRepeated administration: 15/16 (SS : 15/16 (SS of unchanged compound + of unchanged compound + metabolites). metabolites).

1515

TES: Study Drug DosesTES: Study Drug Doses2 doses: 16/16 (1 with 3)2 doses: 16/16 (1 with 3)

• Expected maximal therapeutic Expected maximal therapeutic dosedose;;

• + One supratherapeutic dose+ One supratherapeutic dose: DDI : DDI + concentration/effect: + concentration/effect:

•2 to 8x the expected 2 to 8x the expected maximalmaximal therapeutic therapeutic dose;dose;

•2 to 12x the expected maximal 2 to 12x the expected maximal concentration at the maximal therapeutic concentration at the maximal therapeutic dose.dose.

1616

TES: DesignTES: Design• Cross-over/Parallel:Cross-over/Parallel:

– Cross-over: 6/16 – 1 to 7 days;Cross-over: 6/16 – 1 to 7 days;– Parallel: 10/16 studies – 3 to 28 days.Parallel: 10/16 studies – 3 to 28 days.

• Sample size:Sample size:– Cross-over: 16 to 45;Cross-over: 16 to 45;– Parallel: 64 to 114.Parallel: 64 to 114.

• Randomized, Double BlindRandomized, Double Blind: 16/16;: 16/16;

• Placebo controlledPlacebo controlled: 16/16.: 16/16.

1717

TES: DesignTES: Design• Positive controlPositive control (establish assay (establish assay

sensitivity): Moxifloxacin 16/16;sensitivity): Moxifloxacin 16/16;• Active control (same chemical Active control (same chemical

/pharmacological class): 2/16;/pharmacological class): 2/16;• ECG:ECG:

– Manual ECG reading Manual ECG reading + + central labcentral lab: : 16/16;16/16;

– Tangent methodTangent method: 16/16;: 16/16;– Multiple ECGsMultiple ECGs at baseline + during at baseline + during

study: intrinsic variability;study: intrinsic variability;

1818

TES DesignTES Design– 0-12 h + window around the potential 0-12 h + window around the potential

Cmax;Cmax;– Timepoints in analysis window: 5 to 8.Timepoints in analysis window: 5 to 8.

• Central tendency analysis:Central tendency analysis:– Primary endpoint: average effect Primary endpoint: average effect

around the median Cmax;around the median Cmax;– Cross-over: raw QTcF;Cross-over: raw QTcF;– Parallel: QTcF change from baseline, Parallel: QTcF change from baseline,

with baseline as covariate.with baseline as covariate.

1919

Drug 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15hERGPFIn-vitroIn-vivoPC Signal

hERG: G = > 10 µM; Y = 1 to 10 µM ; O < 1 µMPF: G = 0; Y = ↑APD; O = ↑APD+EAD+triangulationIn vivo: G = 0; Y = ↑QTc (trend); O = ↑QTc (DP)

2020

QTcF/QTcN: G < 5 msec MMI; O > 5 msec MMIQTcN = Study specific correctionTD = Expected Max Ther Dose; STD = Supra Ther DoseDose = STD/TD; Conc = STDconc/TDconcHR effect: - = No effect; + = Significant effect (TD/STD)

Drug 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15QTcF/ TDQTcF/ STDDose/ Conc 4/4 4/12 2.5/2.5 5/7 8/8 3/3 2/2 4/4 2/2 2/2 6/5 4/3 4/3 3/2 2.5/2.5HR effect -/+ -/- -/- -/- -/- -/- -/+ -/- -/- +/+ -/- -/- -/- +/+ -/-

QTcNC Signal

2121

TN = true negative – 7/15FP = False positive – 2/15FN = False negative – 4/15TP = True positive – 2/15

Drug 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15PC Signal v h h/v h h h vC SignalSUMMARY TN FN TN FP TN TN TN TP TN TN FN TP FN FP FN

2222

Case Study #1: False Positive Case Study #1: False Positive (Drug 4)(Drug 4)

• hERG: IC50 = hERG: IC50 = 0.45 0.45 nMnM

• ↑ ↑ APD: 10 µM (DP)APD: 10 µM (DP)• In-vivo concious In-vivo concious

non-rodent: non-rodent: ↑ ↑ QTc QTc

• QTcF TD = 0.04 QTcF TD = 0.04 msecmsec

• QTcF STD = 2.18 QTcF STD = 2.18 msecmsec

• Dose STD/TD = 5Dose STD/TD = 5• Conc STD/TD = 7 Conc STD/TD = 7

((8.32 ng/mL8.32 ng/mL))• No HR effectNo HR effectPOSITIVE

SIGNALNEGATIVE

TES

FALSE POSITIVE

2323

Case Study #2: True Positive Case Study #2: True Positive (Drug 12)(Drug 12)

• hERG: IC50 = hERG: IC50 = 0.22 µM0.22 µM

• ↑ ↑ APD + EADAPD + EAD• In-vivo concious In-vivo concious

non-rodent: non-rodent: ↑ ↑ QTcQTc (trend) (trend)

• QTcF TD = 0.7 msecQTcF TD = 0.7 msec• QTcF STD = QTcF STD = 6.98** 6.98**

msecmsec• Dose STD/TD = 4Dose STD/TD = 4• Conc STD/TD = 3 Conc STD/TD = 3

(35.6 ng/mL)(35.6 ng/mL)• No HR effectNo HR effect

POSITIVESIGNAL

POSITIVETES

TRUE POSITIVE

2424

Case Study #3: True Negative Case Study #3: True Negative (Drug 5) (Drug 5)

• hERG: IC50 = 5.15 hERG: IC50 = 5.15 µM/M = 25.7 µMµM/M = 25.7 µM

• ↑ ↑ APD: NoAPD: No• In-vivo concious In-vivo concious

non-rodent: Nonon-rodent: No

• QTcF TD = -1.42 QTcF TD = -1.42 msecmsec

• QTcF STD = -2.95 QTcF STD = -2.95 msecmsec

• Dose STD/TD = 5Dose STD/TD = 5• Conc STD/TD = 8 Conc STD/TD = 8

((2250 ng/mL2250 ng/mL))• No HR effectNo HR effectNEGATIVE

SIGNALNEGATIVE

TES

TRUE NEGATIVE

2525

Case Study #4: False Negative (Drug Case Study #4: False Negative (Drug 11)11)

• hERG: IC50 > 11.1 hERG: IC50 > 11.1 µM (6133 ng/mL/M µM (6133 ng/mL/M = 2.8 µM= 2.8 µM

• ↑ ↑ APD: NoAPD: No• In-vivo concious In-vivo concious

non-rodent: No non-rodent: No ↑ ↑ QTcQTc

• QTcF TD = 0.0 msecQTcF TD = 0.0 msec• QTcF STD = 10.0*** QTcF STD = 10.0***

msecmsec• Dose STD/TD = 6Dose STD/TD = 6• Conc STD/TD = 5 (Conc STD/TD = 5 (881 881

ng/mL/M = 115 ng/mLng/mL/M = 115 ng/mL))• No HR effectNo HR effect

NEGATIVESIGNAL

POSITIVETES

FALSE NEGATIVE

2626

Summary of Evaluation of SA Summary of Evaluation of SA Cardiac Repolarization Data Cardiac Repolarization Data

for 15 Drugsfor 15 Drugs

2727

CONCLUSIONS ON PREDICTIVITY CONCLUSIONS ON PREDICTIVITY OF PRECLINICAL MODELSOF PRECLINICAL MODELS• ConsistentConsistent with previous data: with previous data:

– ILSI/HESI program;ILSI/HESI program;– ABPI retrospective analysis;ABPI retrospective analysis;– FDA experience on 19 drugs (2005).FDA experience on 19 drugs (2005).

• No universal predictivityNo universal predictivity::– False positive and false negative for every False positive and false negative for every

test;test;– Only one result should not to be Only one result should not to be

considered.considered.

2828

CONCLUSIONS ON PREDICTIVITY OF CONCLUSIONS ON PREDICTIVITY OF PRECLINICAL MODELSPRECLINICAL MODELS• Careful search for confounding factors (PK, Careful search for confounding factors (PK,

metab).metab).

• Knowledge in that field is rapidly evolving (CPMP, Knowledge in that field is rapidly evolving (CPMP, Points to consider in 12/1997 recommended PF Points to consider in 12/1997 recommended PF test; ICH S7B consider this test as only an test; ICH S7B consider this test as only an additional test and ask for hERG. In the (near?) additional test and ask for hERG. In the (near?) future, recommendations will evolve…future, recommendations will evolve…– Need to find a more accurate scoring for preclinical Need to find a more accurate scoring for preclinical

assessment;assessment;– Need of innovative methods of preclinical investigation.Need of innovative methods of preclinical investigation.

2929

Preclinical data captured the majority Preclinical data captured the majority but not all the drugs that prolong QT but not all the drugs that prolong QT

(2/15), even with a conscientious (2/15), even with a conscientious methodology consistent with ICH S7B methodology consistent with ICH S7B

and E14and E14

3030

Strong signal, shallow water…don’t go there! Same strong signal, but deep water…safe!

Regulatory guidance must not expect no signal…..very safe but potentially no drugs!

Never ?

Preclinical Evaluation

3131

SUMMARY ON PREDICTIVITY OF SUMMARY ON PREDICTIVITY OF CLINICAL THOROUGH ECG STUDYCLINICAL THOROUGH ECG STUDY

NEXT STEP ….. BE PATIENTNEXT STEP ….. BE PATIENT

AND ENJOY THIS NICE AND ENJOY THIS NICE MEETING!MEETING!

3232

Back-upBack-up

3333

The First The First in vitroin vitro Model: hERG Channel Model: hERG Channel

Used ProtocolUsed Protocol

Whole cell Patch clamp method: hERGhERG channel stably expressed in Chinese Hamster Ovarian cell (IIKrKr)

Recording

Ikr Inhibition / Cumulative Concentrations

3434

hERG Channel: Sources of VariabilityhERG Channel: Sources of Variability

Main hERGpatch -clamp

issues

Main hERGpatch -clamp

issues

Main hERGpatch -clamp

issues

Main hERGpatch -clamp

issues

Expression systemExpression system

[K+] in superfusion medium

[K+] in superfusion medium

Superfusion temperatureSuperfusion temperature

Stimulation protocol

Stimulation protocol

Rundown quantificationRundown quantification

Number of cells/ concentration

Number of cells/ concentration

Incubation timeIncubation time

Validation with a reference

Validation with a reference

Nature of blockade

ReversibillityReversibillity

Number of conc to built a conc - response curve

conc to built a conc - response curve

Analysis of conc -response curve

Analysis of conc -response curve

StatisticsStatistics

Current reading protocols

Current reading protocols

Experimental designExperimental design

Criteria of acceptation

Limitations of in vitro models

3535

The Second The Second in vitroin vitro Model Model

PAPILLARY MUSCLE: GUNEA-PIG (Discovery)PAPILLARY MUSCLE: GUNEA-PIG (Discovery)PURKINJE FIBER: RABBIT (Development)PURKINJE FIBER: RABBIT (Development)

•Measure the action potential of a conductive tissue (or cell);

•Action potential = result of the activity of the various channelsvarious channels involved in the depolarization and in the repolarization phases;

3636

The Second The Second in vitroin vitro Model Model

PAPILLARY MUSCLE: GUNEA-PIG (Discovery)PAPILLARY MUSCLE: GUNEA-PIG (Discovery)PURKINJE FIBER: RABBIT (Development)PURKINJE FIBER: RABBIT (Development)

•MicroelectrodeMicroelectrode technique;

•Tissue pacedpaced at fixed frequency; bradycardia can be simulated by pacing at low rate.

3737

The Second The Second in vitroin vitro Model: Model: Purkinje/PapillaryPurkinje/Papillary

1 Hz

EXAMPLE: EXAMPLE:

3838

Action Potential: Source of VariabilityAction Potential: Source of Variability

a: nœud sinusalb: tissu atrial (humain)c: fibre de Purkinje (chien)d: tissu épicardique (chien)e: tissu endocardique (chien)f: tissu myocardique (rat)

3939

Control Control

IIKrKr

Control

IIKsKs

But also: ICa INa-Ca

IKto1 IKto2 IK1

Action Potential: Effect of Various ChannelsAction Potential: Effect of Various Channels

INa

4040

ACTION POTENTIAL EXPERIMENTSACTION POTENTIAL EXPERIMENTS

•Not be used as a stand-alone experiment to appreciate the risk of TdP linked to hERG inhibition;

•Global view on the AP, taking into account all effects on the various channels;

•Considered as follow-up studies follow-up studies (in addition to hERG and in vivo tests) and can be used to perform the Integrated Integrated Risk AssessmentRisk Assessment before First-entry-Into-Man and then at every time new information is coming either from clinical trials or fromlong-term toxicological studies.

4141

Maximum Mean QTc

Mean QTc at Cmax

ANALYSIS

Method 1 =

Method 2 =

Q

Tc

Time of Cmax

Time

Q

Tc

Central Tendency:

4242

Placebo

Time

QTc

Drug

Time

QTc

Baseline

Baseline

Time

Q

Tc

CALCULATING MAX MEAN CHANGE

Time

QTc

BaselineSubtracted:

QTc =Responseadjusted () forbaseline effect

PlaceboSubtracted:

QTc =Responseadjusted ()for baseline &placebo effect

Mean QTc

MaximumMean QTc

4343

CALCULATING MEAN CHANGE AT CMAX

Placebo

Time

QTc

Drug

Time

QTc

Baseline

Baseline

Time

Q

Tc

Time

QTc

BaselineSubtracted:

QTc =Responseadjusted () forbaseline effect

PlaceboSubtracted:

QTc =Responseadjusted ()for baseline &placebo effect

Time of Cmax

Mean QTcat Cmax

Mean QTc