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<strong>Communicat<strong>in</strong>g</strong> <strong>the</strong> <strong>Value</strong> <strong>of</strong> <strong>Pharmacodynamic</strong> <strong>Modell<strong>in</strong>g</strong> <strong>in</strong><br />

<strong>Drug</strong> Development<br />

Helen Kastrissios, Ph.D.<br />

Senior Scientist, Pharsight Corp.<br />

ARCS Annual Congress<br />

30 May, 2008<br />

© Pharsight Corporation All Rights Reserved<br />

30 May 2008, ARCS


Traditionally, drug development is a lengthy and<br />

costly process.<br />

Significant <strong>in</strong>crease <strong>in</strong><br />

<strong>in</strong>vestment and productivity<br />

Productivity is decl<strong>in</strong><strong>in</strong>g<br />

A key problem is separat<strong>in</strong>g <strong>the</strong> w<strong>in</strong>ners from <strong>the</strong> losers early.<br />

slide 2<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


FDA Perspective<br />

There is a clear emerg<strong>in</strong>g message from <strong>the</strong> FDA regard<strong>in</strong>g <strong>the</strong>ir view <strong>of</strong> <strong>the</strong><br />

importance <strong>of</strong> <strong>Modell<strong>in</strong>g</strong> and Simulation (M&S) to reduce <strong>the</strong> cost, time, and<br />

uncerta<strong>in</strong>ty <strong>in</strong> gett<strong>in</strong>g new medical products to patients.<br />

Critical Path White Paper (March, 2004) and Report (March, 2006)*<br />

● Proposes utilization <strong>of</strong> model-based approaches to improve knowledge<br />

management and decision-mak<strong>in</strong>g<br />

Guidances<br />

● In 1999, FDA issued “Guidance for Industry | Population Pharmacok<strong>in</strong>etics”<br />

● In 2003, FDA issued “Guidance for Industry | Exposure-response<br />

relationships: Study Design, Data Analysis, and Regulatory Applications”<br />

New focus on End-<strong>of</strong>-Phase IIa meet<strong>in</strong>gs<br />

*http://www.fda.gov/oc/<strong>in</strong>itiatives/criticalpath/<br />

● Goal: Reduce unnecessary late stage (IIb, III) failures by<br />

• Review <strong>of</strong> dose vs. response models , exposure vs. response<br />

models, drug – disease models, simulations <strong>of</strong> phase IIb and<br />

preparation for phase III trial design<br />

• Review dose adjustment strategies for special populations<br />

• Review cl<strong>in</strong> pharm and biopharmaceutical issues, as well as<br />

newer areas <strong>of</strong> uncerta<strong>in</strong>ty: QT trial design, pharmacogenomic<br />

and paediatric considerations<br />

slide 3<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


Reasons for <strong>in</strong>efficiencies <strong>in</strong> cl<strong>in</strong>ical<br />

development …<br />

Inefficient decision mak<strong>in</strong>g processes (poor knowledge<br />

management)<br />

● lack <strong>of</strong> necessary <strong>in</strong>formation to make <strong>in</strong>formed decisions<br />

● decisions not based on quantitative <strong>in</strong>puts<br />

● focus on <strong>the</strong> wrong areas (e.g., speed to market as opposed to<br />

understand<strong>in</strong>g <strong>the</strong> dose response)<br />

● loss <strong>of</strong> knowledge due to changes <strong>in</strong> staff and assignments<br />

● <strong>in</strong>ability to capture <strong>in</strong>formation (such as how and why decisions<br />

were made, <strong>in</strong>tellectual property, etc.)<br />

Lack <strong>of</strong> (efficient) utilization <strong>of</strong> technology<br />

slide 4<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


…. And What Can Be Done About It?<br />

Model-Based <strong>Drug</strong> Development (MBDD)<br />

● Ra<strong>the</strong>r than fill<strong>in</strong>g <strong>in</strong> gaps <strong>in</strong> knowledge, M&S is now<br />

be<strong>in</strong>g used to better design future studies and drug<br />

development programs:<br />

• Optimize cl<strong>in</strong>ical drug development focus on<br />

establish<strong>in</strong>g exposure-response relationships to allow<br />

correct choice <strong>of</strong> dose(s)<br />

• Establish <strong>the</strong> use <strong>of</strong> drug-disease models and<br />

advanced pharmacometric concepts <strong>in</strong> early drug<br />

development<br />

• Promote <strong>the</strong> use <strong>of</strong> <strong>in</strong>novative cl<strong>in</strong>ical designs early <strong>in</strong><br />

cl<strong>in</strong>ical development to establish pro<strong>of</strong> <strong>of</strong> concept<br />

and exposure-response relationships<br />

slide 5<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


Model-Based <strong>Drug</strong> Development<br />

Key Considerations<br />

Goal<br />

● Tools for computer assisted trial simulation<br />

● Data repositories<br />

● Standardization <strong>of</strong> tools, databases and practices<br />

● <strong>Communicat<strong>in</strong>g</strong> outcomes to decision-makers<br />

● SMALLER NUMBER OF FAILED TRIALS<br />

• Reduced cost associated with trials<br />

• Increased certa<strong>in</strong>ty <strong>in</strong> trial designs<br />

• Lower rate <strong>of</strong> late-stage attrition<br />

• Studies <strong>in</strong> appropriate populations<br />

slide 6<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


Examples <strong>of</strong> Applications <strong>of</strong> MBDD<br />

Historically, typical PK/PD applications <strong>in</strong>clude:<br />

● What are <strong>the</strong> important determ<strong>in</strong>ants <strong>of</strong> drug exposure – age,<br />

weight, gender, ethnicity, renal function? Which is <strong>the</strong> most<br />

important?<br />

● What is <strong>the</strong> relationship between exposure and <strong>the</strong> <strong>in</strong>cidence<br />

<strong>of</strong> adverse events – eg nausea, fatigue, diarrhoea, major<br />

bleeds?<br />

● What is <strong>the</strong> relationship between exposure and cl<strong>in</strong>ical<br />

outcome – eg change <strong>in</strong> fast<strong>in</strong>g plasma glucose, LDL<br />

reduction, reduction <strong>in</strong> tumour size?<br />

slide 7<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


Newer focus <strong>of</strong> MBDD<br />

PK/PD applications <strong>in</strong> MBDD <strong>in</strong>clude:<br />

● Pre-cl<strong>in</strong>ical (In-vitro → <strong>in</strong>-vivo)<br />

• What is <strong>the</strong> effect <strong>of</strong> disease progression on<br />

PK/PD?<br />

• Selection <strong>of</strong> dose ranges for first <strong>in</strong> man (FIM)<br />

studies<br />

● Early Development<br />

• Identify doses and dose escalation steps →<br />

evaluate different study designs<br />

• Identify useful metrics <strong>of</strong> exposure and identify<br />

relationships with safety and efficacy<br />

slide 8<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


PK/PD applications <strong>in</strong> MBDD<br />

● Mid-late phase Development<br />

• What is <strong>the</strong> optimal number and tim<strong>in</strong>g <strong>of</strong> plasma<br />

samples to be drawn <strong>in</strong> a Phase 2a study to determ<strong>in</strong>e<br />

exposure-response?<br />

• Competitive position<strong>in</strong>g – what is <strong>the</strong> predicted fraction<br />

<strong>of</strong> patients and <strong>the</strong>ir characteristics who might achieve<br />

a response or develop adverse effects; who does it<br />

compare with competitors.<br />

• What dos<strong>in</strong>g regimens should be taken <strong>in</strong>to Phase 3?<br />

• What is <strong>the</strong> expected difference <strong>in</strong> response between<br />

naïve patients and patients non-naïve to ma<strong>in</strong>tenance<br />

treatment?<br />

• Evaluation <strong>of</strong> compet<strong>in</strong>g study designs – eg what is <strong>the</strong><br />

effect <strong>of</strong> a run-<strong>in</strong> period <strong>of</strong> vary<strong>in</strong>g lengths (0, 2 or 4<br />

weeks)?<br />

slide 9<br />

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… and from a cl<strong>in</strong>ical perspective:<br />

What is <strong>the</strong> expected cl<strong>in</strong>ical response for a treatment <strong>in</strong> a<br />

particular patient population?<br />

What is <strong>the</strong> level <strong>of</strong> certa<strong>in</strong>ty surround<strong>in</strong>g predicted response?<br />

How do different treatment strategies and target patient subpopulations<br />

impact response?<br />

What is <strong>the</strong> probability that response is less or greater than a<br />

specific target?<br />

What dose is required to achieve a target response?<br />

What is <strong>the</strong> probability <strong>of</strong> achiev<strong>in</strong>g a specific efficacy target while<br />

keep<strong>in</strong>g probability for adverse events below a certa<strong>in</strong> level?<br />

How do <strong>the</strong> attributes for <strong>the</strong> compound compare to competitors?<br />

What is optimal position<strong>in</strong>g strategy versus competitors to balance<br />

safety and efficacy?<br />

slide 10<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


To simulate drug development scenarios <strong>of</strong> <strong>in</strong>terest, a<br />

number <strong>of</strong> sub-models are developed and <strong>in</strong>tegrated<br />

Pharmaco<strong>the</strong>rapeutics<br />

<strong>Pharmacodynamic</strong>s<br />

Pharmacok<strong>in</strong>etics<br />

Dos<strong>in</strong>g<br />

Regimes<br />

Exposures<br />

Efficacy &<br />

tolerability<br />

endpo<strong>in</strong>ts<br />

Cl<strong>in</strong>ical<br />

Pr<strong>of</strong>ile<br />

Cl<strong>in</strong>ical<br />

Events<br />

1 or more drugs<br />

Information<br />

Sources<br />

• Precl<strong>in</strong>ical data<br />

• Early-phase trial results<br />

• Late phase results<br />

• In-house experts<br />

• Public <strong>in</strong>formation<br />

F<strong>in</strong>ancial<br />

<strong>Value</strong><br />

Market<br />

economics<br />

slide 11<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


Public-Source Data<br />

Provides rich <strong>in</strong>formation to better understand product pr<strong>of</strong>iles,<br />

competitive position<strong>in</strong>g, variability and uncerta<strong>in</strong>ty <strong>in</strong> drug<br />

development.<br />

Public data sources <strong>in</strong>clude<br />

•journal articles<br />

• regulatory documents (e.g., FDA Summary Basis for<br />

Approval)<br />

• package <strong>in</strong>serts<br />

• published abstracts or poster presentations<br />

• meet<strong>in</strong>g proceed<strong>in</strong>gs<br />

• onl<strong>in</strong>e resources (e.g., press releases about new<br />

cl<strong>in</strong>ical trial results, onl<strong>in</strong>e cl<strong>in</strong>ical trial registries)<br />

slide 12<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


Public-Source Data<br />

● Public-source data helps <strong>in</strong>form:<br />

• efficacy/safety pr<strong>of</strong>ile <strong>of</strong> established standards <strong>of</strong> care<br />

• <strong>the</strong> likely cl<strong>in</strong>ical pr<strong>of</strong>ile <strong>of</strong> an entity <strong>in</strong> <strong>the</strong> early stages <strong>of</strong><br />

cl<strong>in</strong>ical development<br />

• <strong>the</strong> natural progression <strong>of</strong> disease (model structures, parameter<br />

values, boundary conditions, placebo response)<br />

• effects <strong>of</strong> different treatment regimens, and potential<br />

covariates<br />

• comparative drug attributes (e.g.,relative potencies)<br />

• trends, relationships between endpo<strong>in</strong>ts, treatments<br />

• provides <strong>in</strong>itial estimates <strong>of</strong> variability and uncerta<strong>in</strong>ty<br />

• prediction <strong>of</strong> unobserved cl<strong>in</strong>ical outcomes: “borrow<strong>in</strong>g”<br />

<strong>in</strong>formation, such as response at time po<strong>in</strong>ts beyond those<br />

currently studied<br />

slide 13<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


An example <strong>of</strong> an approach used to predict doseresponse<br />

for a new drug us<strong>in</strong>g public-source data<br />

= competitor and analogues<br />

= NCE<br />

Commercial<br />

Efficacy/<br />

Safety<br />

Cl<strong>in</strong>ical<br />

Utility<br />

Phase 2/3 public trials<br />

Biomarkers<br />

Efficacy/<br />

Safety<br />

Dose<br />

PK Biomarkers Efficacy/<br />

Safety<br />

Cl<strong>in</strong>ical<br />

Utility<br />

Phase I PKPD data<br />

slide 14<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


Case Studies<br />

Example 1. How can precl<strong>in</strong>ical data be used to support<br />

dose selection for a FIM study?<br />

Example 2: How can M&S be used to support labell<strong>in</strong>g?<br />

Example 3: What is <strong>the</strong> product pr<strong>of</strong>ile <strong>of</strong> an NCE versus<br />

compet<strong>in</strong>g <strong>the</strong>rapies ?<br />

slide 15<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


Example 1. How can precl<strong>in</strong>ical data be used to<br />

support dose selection for a FIM study?<br />

Allometric scal<strong>in</strong>g was used to predict human<br />

pharmacok<strong>in</strong>etics.<br />

Precl<strong>in</strong>ical PK/PD data from cynomolgous monkey, relative<br />

potency <strong>in</strong>formation and literature data was used for<br />

simulation.<br />

A range <strong>of</strong> doses (30-fold), regimens (QD and BID) and<br />

bioavailability fractions (5 to 50%) were used to project<br />

human PK vs. response pr<strong>of</strong>iles The comb<strong>in</strong>ation <strong>of</strong> dose and<br />

bioavailability ranges was chosen to compensate for any<br />

misspecification due to projection method or underly<strong>in</strong>g<br />

assumptions.<br />

Target <strong>the</strong>rapeutic range was determ<strong>in</strong>ed us<strong>in</strong>g publicly<br />

available literature for three comparators.<br />

slide 16<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


Comparisons across regimens and drugs<br />

showed a favourable predicted response<br />

0 100 200 300<br />

%Time <strong>in</strong> Th. W<strong>in</strong>dow<br />

80<br />

60<br />

40<br />

20<br />

0<br />

Multiple BID<br />

Multiple QD<br />

0 100 200 300<br />

Dose (mg/day)<br />

slide 17<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


The response was comparable to competitors<br />

Advserse Event Probability (%)<br />

100<br />

80<br />

60<br />

40<br />

20<br />

0<br />

QD regimen<br />

BID regimen<br />

<strong>Drug</strong> C<br />

Human projections for<br />

<strong>the</strong> NCE <strong>of</strong> <strong>in</strong>terest<br />

identified a dose<br />

which provided a<br />

similar safety pr<strong>of</strong>ile<br />

to that <strong>of</strong><br />

comparators.<br />

A1 A2 A3 A4 A5 A6 0 B1 B2 B3 N1 N2 N3<br />

<strong>Drug</strong> A Dose <strong>Drug</strong> B Dose NCE Dose<br />

(mg/day) (mg/day) (mg/day)<br />

slide 18<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


Example 2: How can M&S be used to support<br />

labell<strong>in</strong>g?<br />

slide 19<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


Docetaxel exposure-response model<strong>in</strong>g was<br />

performed <strong>in</strong> 640 patients<br />

Patients with solid tumor <strong>in</strong>clud<strong>in</strong>g metastatic breast and<br />

non-small cell lung cancer<br />

Docetaxel clearance and AUCs were estimated us<strong>in</strong>g<br />

population PK<br />

Likelihood <strong>of</strong> tumor response (CR and PR), time to<br />

progression, survival and toxicity (grade 4 neutropenia,<br />

febrile neutropenia…) were analyzed<br />

Source: R. Bruno et al. J. Cl<strong>in</strong>. Oncology 16, 187-196, 1998<br />

slide 20<br />

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Docetaxel model<br />

Side effects<br />

Dose Exposure<br />

Biomarkers<br />

Tumor size<br />

dynamics<br />

Response<br />

rate Survival<br />

Progression<br />

Resistance<br />

slide 21<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


Adverse events were related to docetaxel<br />

exposure<br />

Docetaxel AUC at first cycle was a significant<br />

<strong>in</strong>dependent predictor <strong>of</strong>:<br />

● grade 4 neutropenia (n = 582)<br />

● febrile neutropenia (n = 582)<br />

● fluid retention (n = 631)<br />

Source: R. Bruno et al. J. Cl<strong>in</strong>. Oncology 16, 187-196, 1998<br />

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There was a cl<strong>in</strong>ically mean<strong>in</strong>gful <strong>in</strong>crease <strong>in</strong> <strong>the</strong> odds <strong>of</strong><br />

febrile neutropenia <strong>in</strong> patients with high exposure<br />

0.15<br />

Predicted Probability<br />

0.10<br />

0.05<br />

median AUC<br />

Generated <strong>the</strong> hypo<strong>the</strong>sis that<br />

patients with elevated LFTs<br />

might be at risk <strong>of</strong> <strong>in</strong>creased<br />

toxicity<br />

0.00<br />

2 4 6 8 10<br />

AUC (µg*h/mL)<br />

slide 23<br />

30 May 2008, ARCS<br />

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These results justified a safety analysis by liver enzymes<br />

that confirmed <strong>the</strong> risk <strong>in</strong> patient with elevated LFTs<br />

MBC patients treated at 100 mg/m 2 (Taxotere Package Insert)<br />

Side effects<br />

Febrile neutropenia<br />

Infection (grade 3-4)<br />

Stomatitis (grade 3-4)<br />

Toxic death<br />

Normal (n=730)<br />

2.4 %<br />

7.1 %<br />

7.8 %<br />

2.6 %<br />

Elevated (n=18)<br />

8.6 %<br />

33 %<br />

39 %<br />

17 %<br />

ODAC recommended approval <strong>in</strong> patients with normal LFTs without<br />

wait<strong>in</strong>g for Phase III results.<br />

Patients with elevated LFTs were excluded from Phase III studies.<br />

MBC = metastatic breast cancer; ODAC = Oncology <strong>Drug</strong>s Advisory Committee to US FDA<br />

slide 24<br />

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Contribution <strong>of</strong> this approach to first approval <strong>in</strong><br />

metastatic breast cancer<br />

“Taxotere: … <strong>the</strong> value <strong>of</strong> nonl<strong>in</strong>ear mixed effects model<strong>in</strong>g <strong>of</strong><br />

dose–PK–PD relationships… was demonstrated… PK/PD analysis<br />

identified patients at risk for neutropenia, and justified <strong>the</strong><br />

subsequent safety re-analysis <strong>of</strong> <strong>the</strong> cl<strong>in</strong>ical database to address<br />

questions posed by… regulatory authorities, that allowed <strong>the</strong><br />

sponsor to confirm <strong>the</strong> pr<strong>of</strong>ile <strong>of</strong> <strong>the</strong> drug without wait<strong>in</strong>g for<br />

Phase 3 data… population PK/PD studies provided many<br />

advantages <strong>in</strong>clud<strong>in</strong>g:<br />

● A scientific and cl<strong>in</strong>ical basis by which safety concerns were<br />

alleviated…<br />

● Accelerated approval <strong>of</strong> <strong>the</strong> drug for market access.<br />

● Provision <strong>of</strong> key <strong>in</strong>formation <strong>in</strong> <strong>the</strong> package <strong>in</strong>sert.”<br />

Source: Lesko et al. Eur. J. Pharm. Sci. 10, iv-xiv, 2000<br />

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Example 3: What is <strong>the</strong> product pr<strong>of</strong>ile <strong>of</strong> an NCE<br />

versus compet<strong>in</strong>g <strong>the</strong>rapies ?<br />

Gemcabene (CI-1027) is a non-stat<strong>in</strong> compound developed<br />

as a low-density lipoprote<strong>in</strong> cholesterol (LDL-C) lower<strong>in</strong>g<br />

compound.<br />

Based on a beneficial effect <strong>of</strong> <strong>the</strong> drug on LDL-C <strong>in</strong> several<br />

phase I and IIa trials. it was decided to <strong>in</strong>itiate a study <strong>in</strong><br />

hypercholesterolemia.<br />

Key question: “Given <strong>the</strong> LDL-C lower<strong>in</strong>g effect <strong>of</strong><br />

gemcabene <strong>in</strong> comb<strong>in</strong>ation with a stat<strong>in</strong> compared with<br />

compet<strong>in</strong>g <strong>the</strong>rapies, should cl<strong>in</strong>ical development<br />

cont<strong>in</strong>ue?”<br />

A second objective was to effectively communicate <strong>the</strong><br />

critical drug attributes to <strong>the</strong> cl<strong>in</strong>ical team to facilitate<br />

decision-mak<strong>in</strong>g<br />

Source: Hermann D, Wang W, Falcoz C, Hartman D, Mandema J. Strategies to Improve Model-Based<br />

Decision-Mak<strong>in</strong>g Dur<strong>in</strong>g Cl<strong>in</strong>ical Development. [poster]. Presented at: Annual Meet<strong>in</strong>g <strong>of</strong> <strong>the</strong> Population<br />

Approach Group <strong>in</strong> Europe (PAGE); June 2005; Pamplona, Spa<strong>in</strong>. Repr<strong>in</strong>ted courtesy <strong>of</strong> PAGE.<br />

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Strategy: Efficient Model-Based Development<br />

A Phase IIA trial was planned to assess gemcabene LDL-C<br />

lower<strong>in</strong>g ability, alone and <strong>in</strong> comb<strong>in</strong>ation with<br />

atorvastat<strong>in</strong><br />

To aid decision-mak<strong>in</strong>g, <strong>the</strong> team agreed to undertake a<br />

dose-response analysis <strong>of</strong> gemcabene trials as well as<br />

stat<strong>in</strong>s and ezetimibe (competitor) us<strong>in</strong>g literature data<br />

● 21 trials were <strong>in</strong>cluded (~10000 patients)<br />

● Stat<strong>in</strong>s (atorvastat<strong>in</strong>, rosuvastat<strong>in</strong>, simvastat<strong>in</strong>, pravastat<strong>in</strong>,<br />

lovastat<strong>in</strong>)<br />

● Nonstat<strong>in</strong>s (gemcabene historical data, ezetimibe, mono- and<br />

comb<strong>in</strong>ation <strong>the</strong>rapy)<br />

● Models were built for 7 efficacy and safety endpo<strong>in</strong>ts that drive<br />

decision-mak<strong>in</strong>g, and were updated with <strong>the</strong> Phase IIA trial<br />

results<br />

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Methods: Meta-Dose-Response Analysis<br />

Mono-<strong>the</strong>rapy LDL-C % change dose-response:<br />

Stat<strong>in</strong>s and Non-stat<strong>in</strong>s: gemcabene, ezetimibe<br />

E<br />

drug<br />

=<br />

Dose<br />

Dose<br />

n<br />

n<br />

+<br />

⋅<br />

E<br />

ED<br />

max<br />

50<br />

n<br />

Interaction term added to describe comb<strong>in</strong>ations<br />

LDL % change = E0<br />

+ E<br />

stat<strong>in</strong><br />

+ E<br />

non −stat<strong>in</strong><br />

+ γ ⋅ E<br />

stat<strong>in</strong><br />

⋅ E<br />

non −<br />

stat<strong>in</strong><br />

+ η + ε<br />

Weighted (by variance) non-l<strong>in</strong>ear mixed effects (study level random<br />

effect) regression to estimate model parameters.<br />

slide 28<br />

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© Pharsight Corporation All Rights Reserved


Results: The Model Described Mono- and Comb<strong>in</strong>ation<br />

Dose-Response Well for Ezetimibe …<br />

slide 29<br />

30 May 2008, ARCS<br />

E 0 = stat<strong>in</strong> alone<br />

© Pharsight Corporation All Rights Reserved<br />

E 10 = stat<strong>in</strong> + ezetimibe 10 mg


…And Gemcabene<br />

A 0 = gemcabene alone<br />

A 10 = gemcabene + atorvastat<strong>in</strong> 10 mg etc.<br />

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Summary <strong>of</strong> process so far ….<br />

Pre-Cl<strong>in</strong>ical<br />

Data<br />

Safety Trials<br />

Phase II Trials<br />

Competitor<br />

Label<br />

Information<br />

Response<br />

Scientific<br />

Literature<br />

Dose<br />

Population<br />

Model<strong>in</strong>g<br />

Techniques,<br />

Model<br />

qualification<br />

The model summarizes and<br />

quantifies what is known.<br />

The model assumptions detail<br />

what is not known.<br />

PK-PD Models<br />

C(t) = D / V<br />

(Ae -αt + Be -βt )<br />

E(t) = E 0<br />

+ (E max<br />

-E 0<br />

) • C(t)<br />

C(t) + EC 50<br />

+<br />

Model<br />

Assumptions<br />

1.<br />

2.<br />

3.<br />

Simulations<br />

Dimensions <strong>of</strong> Decision Space<br />

• X Endpo<strong>in</strong>ts<br />

• Y <strong>Drug</strong>s/Doses<br />

• Z Covariates<br />

X*Y*Z dimensions<br />

e.g.,1000 simulations/dimension<br />

= [X*Y*Z]* 10 3 data po<strong>in</strong>ts<br />

slide 31<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


Models provide answers to important cl<strong>in</strong>ical<br />

questions.<br />

What is <strong>the</strong> expected cl<strong>in</strong>ical response for a treatment <strong>in</strong> a particular<br />

patient population?<br />

What is <strong>the</strong> level <strong>of</strong> certa<strong>in</strong>ty surround<strong>in</strong>g predicted response?<br />

How do different treatment strategies and target patient sub-populations<br />

impact response?<br />

What is <strong>the</strong> probability that response is less or greater than a specific<br />

target?<br />

What dose is required to achieve a target response?<br />

What is <strong>the</strong> probability <strong>of</strong> achiev<strong>in</strong>g a specific efficacy target while keep<strong>in</strong>g<br />

probability for adverse events below a certa<strong>in</strong> level?<br />

How do <strong>the</strong> attributes for <strong>the</strong> compound compare to competitors?<br />

What is optimal position<strong>in</strong>g strategy versus competitors to balance safety<br />

and efficacy?<br />

slide 32<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


Models provide answers to important cl<strong>in</strong>ical<br />

questions.<br />

What is <strong>the</strong> expected cl<strong>in</strong>ical response for a treatment <strong>in</strong> a particular<br />

patient population?<br />

What is <strong>the</strong> level <strong>of</strong> certa<strong>in</strong>ty surround<strong>in</strong>g predicted response?<br />

How do different treatment strategies and target patient sub-populations<br />

impact response?<br />

But <strong>of</strong>ten <strong>the</strong> challenge is <strong>in</strong> communicat<strong>in</strong>g this<br />

<strong>in</strong>formation to nonmodellers<br />

What is <strong>the</strong> probability that response is less or greater than a specific<br />

target?<br />

who lack familiarity with <strong>the</strong> models,<br />

What dose is required to achieve a target response?<br />

but who need to be <strong>in</strong>formed <strong>of</strong> <strong>the</strong> drugs key<br />

attributes <strong>in</strong> order to make cl<strong>in</strong>ical development<br />

decisions.<br />

What is <strong>the</strong> probability <strong>of</strong> achiev<strong>in</strong>g a specific efficacy target while keep<strong>in</strong>g<br />

probability for adverse events below a certa<strong>in</strong> level?<br />

How do <strong>the</strong> attributes for <strong>the</strong> compound compare to competitors?<br />

What is optimal position<strong>in</strong>g strategy versus competitors to balance safety<br />

and efficacy?<br />

slide 33<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


Gemcabene: The next step: Effectively Communicate<br />

Key <strong>Drug</strong> Attributes to Decision- Makers<br />

Estimate predictive distribution by re-sampl<strong>in</strong>g from model<br />

parameter covariance matrix (simulate large multidimensional data<br />

set)<br />

Perform simulations and display <strong>in</strong> <strong>Drug</strong> Model Explorer® (DMX®)<br />

● A visualization and communication tool to explore M&S results and<br />

facilitate quantitative decision-mak<strong>in</strong>g<br />

● Allows exploration <strong>of</strong> key drug attributes and <strong>the</strong>ir respective uncerta<strong>in</strong>ties<br />

by <strong>the</strong> team<br />

<strong>Drug</strong><br />

Model<strong>in</strong>g-<br />

Build<strong>in</strong>g<br />

<strong>Drug</strong><br />

Attribute<br />

Expectations<br />

Non-Technical<br />

User<br />

Interface<br />

Attribute<br />

Simulations<br />

DMX Users<br />

slide 34<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


Our purpose is to view and query model-based attributes based on<br />

simulation <strong>of</strong> mean responses.<br />

We can achieve detailed exploration <strong>of</strong> <strong>the</strong> dose-response curve for many<br />

comb<strong>in</strong>ations <strong>of</strong> endpo<strong>in</strong>ts, treatments, covariates, and compet<strong>in</strong>g products<br />

%Change from Basel<strong>in</strong>e <strong>of</strong> <strong>Drug</strong> B<br />

Response Selection<br />

Covariates, Assumptions<br />

Plots Display Trends<br />

Shaded area shows prediction<br />

<strong>in</strong>terval for expected doseresponse<br />

or response as a<br />

function <strong>of</strong> o<strong>the</strong>r explanatory<br />

variables (e.g., dose, time)<br />

Controllable Inputs<br />

(Treatments, Compet<strong>in</strong>g<br />

Therapies & Doses)<br />

Tables Display Details<br />

Dotted horizontal l<strong>in</strong>e(s) show<br />

def<strong>in</strong>ed success ranges, or “cut<br />

po<strong>in</strong>ts” based on product<br />

pr<strong>of</strong>iles<br />

Vertical l<strong>in</strong>es show explanatory<br />

variables <strong>of</strong> <strong>in</strong>terest (e.g., dose,<br />

time)<br />

Output Controls<br />

Tables display quantitative<br />

estimates <strong>of</strong> prediction <strong>in</strong>tervals<br />

or o<strong>the</strong>r <strong>in</strong>formation<br />

slide 35<br />

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Q1: What is <strong>the</strong> probability that gemcabene mono<strong>the</strong>rapy<br />

is cl<strong>in</strong>ically superior to ezetimibe 10 mg?<br />

Difference <strong>in</strong> LDL % change frm basel<strong>in</strong>e vs CI1027<br />

Inferior<br />

Equal<br />

Atorvastat<strong>in</strong>: 0<br />

Ref: Atorvastat<strong>in</strong>: 0 + Ezetimibe: 10<br />

Superior<br />

Difference <strong>in</strong><br />

LDL % change frm basel<strong>in</strong>e<br />

20<br />

10<br />

0<br />

-10<br />

Gemcabene Inferior Equal Superior<br />

(mg)<br />

300 10.0% 89.9% 0.1%<br />

450 0.0% 53.5% 46.5%<br />

600 0.0% 7.2% 92.8%<br />

900 0.0% 2.8% 97.3%<br />

Range ± 5%<br />

slide 36<br />

30 May 2008, ARCS<br />

-20<br />

0 200 400 600 800 1000<br />

CI1027<br />

© Pharsight Corporation All Rights Reserved


Q1: What is <strong>the</strong> probability that gemcabene mono<strong>the</strong>rapy<br />

is cl<strong>in</strong>ically superior to ezetimibe 10 mg?<br />

Difference <strong>in</strong> LDL % change frm basel<strong>in</strong>e vs CI1027<br />

Inferior<br />

Equal<br />

Atorvastat<strong>in</strong>: 0<br />

Ref: Atorvastat<strong>in</strong>: 0 + Ezetimibe: 10<br />

Superior<br />

Difference <strong>in</strong><br />

LDL % change frm basel<strong>in</strong>e<br />

20<br />

Gemcabene 10 at a dose <strong>of</strong> 600 mg or more is<br />

0<br />

-10<br />

Gemcabene Inferior Equal Superior<br />

(mg)<br />

300 10.0% 89.9% 0.1%<br />

450 0.0% 53.5% 46.5%<br />

600 0.0% 7.2% 92.8%<br />

900 0.0% 2.8% 97.3%<br />

superior to ezetimibe<br />

Range ± 5%<br />

slide 37<br />

30 May 2008, ARCS<br />

-20<br />

0 200 400 600 800 1000<br />

CI1027<br />

© Pharsight Corporation All Rights Reserved


Q2: What is <strong>the</strong> probability that, <strong>in</strong> comb<strong>in</strong>ation with a<br />

stat<strong>in</strong>, gemcabene is cl<strong>in</strong>ically superior to ezetimibe?<br />

LDL % Change<br />

from Basel<strong>in</strong>e<br />

1 Plot<br />

Treatments<br />

LDL % change frm basel<strong>in</strong>e vs Atorvastat<strong>in</strong><br />

1 Plot<br />

Treatments<br />

LDL % change frm basel<strong>in</strong>e vs Atorvastat<strong>in</strong><br />

20<br />

20<br />

.<br />

.<br />

CI1027 0<br />

CI1027 900<br />

LDL % change frm basel<strong>in</strong>e<br />

.<br />

0<br />

-20<br />

-40<br />

-60<br />

Atorvastat<strong>in</strong><br />

alone<br />

Ezetimibe 0<br />

Ezetimibe 10<br />

LDL % change frm basel<strong>in</strong>e<br />

.<br />

0<br />

-20<br />

-40<br />

-60<br />

Atorvastat<strong>in</strong><br />

alone<br />

.<br />

-80<br />

.<br />

-80<br />

0 20 40 60 80<br />

0 20 40 60 80<br />

Atorvastat<strong>in</strong><br />

+ Gemcabene 900 mg + Ezetimibe 10 mg<br />

Atorvastat<strong>in</strong><br />

Atorvastat<strong>in</strong><br />

dose (mg)<br />

slide 38<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


Q2: What is <strong>the</strong> probability that, <strong>in</strong> comb<strong>in</strong>ation with a<br />

stat<strong>in</strong>, gemcabene is cl<strong>in</strong>ically superior to ezetimibe?<br />

LDL % Change<br />

from Basel<strong>in</strong>e<br />

1 Plot<br />

Treatments<br />

LDL % change frm basel<strong>in</strong>e vs Atorvastat<strong>in</strong><br />

1 Plot<br />

Treatments<br />

LDL % change frm basel<strong>in</strong>e vs Atorvastat<strong>in</strong><br />

.<br />

20<br />

.<br />

20<br />

CI1027 0<br />

CI1027 900<br />

LDL % change frm basel<strong>in</strong>e<br />

.<br />

0<br />

0<br />

-20 Gemcabene Atorvastat<strong>in</strong> comb<strong>in</strong>ation will -20 not provide<br />

alone<br />

alone<br />

Ezetimibe 0<br />

-40superior LDL-C lower<strong>in</strong>g relative . -40<br />

to ezetimibe<br />

Ezetimibe 10<br />

-60<br />

LDL % change frm basel<strong>in</strong>e<br />

-60<br />

Atorvastat<strong>in</strong><br />

.<br />

-80<br />

0 20 40 60 80<br />

Atorvastat<strong>in</strong><br />

.<br />

-80<br />

0 20 40 60 80<br />

+ Gemcabene 900 mg + Ezetimibe 10 mg<br />

Atorvastat<strong>in</strong><br />

Atorvastat<strong>in</strong><br />

dose (mg)<br />

slide 39<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


Q3: Given <strong>the</strong> magnitude <strong>of</strong> LDL-C lower<strong>in</strong>g across <strong>the</strong><br />

gemcabene + stat<strong>in</strong> dose range should cl<strong>in</strong>ical<br />

development cont<strong>in</strong>ue?<br />

Data<br />

Analysis<br />

Method<br />

ANCOVA<br />

Meta-Dose-<br />

Response<br />

Meta-Dose-<br />

Response<br />

Data Base<br />

Phase IIA trial<br />

only (n=255)<br />

Phase IIA trial<br />

pooled with<br />

relevant<br />

historic data<br />

Phase IIA trial<br />

pooled with<br />

relevant<br />

historic data<br />

Assumpt<br />

ions<br />

Mean (95% CI)<br />

Gemcabene<br />

Combo - mono<br />

Few -4.8<br />

(-12.3 to 2.7)<br />

Many<br />

-2.5<br />

(-5.8 to 1.2)<br />

Many<br />

Ezetimibe<br />

Combo - mono<br />

-8.6<br />

(-9.1 to -8.3)<br />

Comments<br />

Traditional analysis<br />

Width <strong>of</strong> CI decreased ½<br />

compared to traditional<br />

analysis<br />

Gemcabene comb<strong>in</strong>ation<br />

has very low probability<br />

<strong>of</strong> reach<strong>in</strong>g target<br />

competitor level <strong>of</strong> LDL-<br />

C lower<strong>in</strong>g<br />

slide 40<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


Q3: Given <strong>the</strong> magnitude <strong>of</strong> LDL-C lower<strong>in</strong>g across <strong>the</strong><br />

gemcabene + stat<strong>in</strong> dose range should cl<strong>in</strong>ical<br />

development cont<strong>in</strong>ue?<br />

Data<br />

Analysis<br />

Method<br />

Data Base<br />

Assumpt<br />

ions<br />

Mean (95% CI)<br />

Comments<br />

Gemcabene<br />

Combo - mono<br />

ANCOVA Phase IIA trial Few -4.8<br />

Traditional analysis<br />

only (n=255)<br />

(-12.3 to 2.7)<br />

Meta-Dose- Phase IIA trial Many<br />

Width <strong>of</strong> CI decreased ½<br />

Response The gemcabene pooled with CI from <strong>the</strong> -2.5 meta-analysis compared to does traditional<br />

relevant<br />

(-5.8 to 1.2)<br />

analysis<br />

not overlap historic ezetimibe data CI, clearly suggest<strong>in</strong>g that<br />

gemcabene is unlikely to<br />

Ezetimibe<br />

lower LDL-C to <strong>the</strong><br />

Combo - mono<br />

Meta-Dose- extent Phase necessary IIA trial Many to compete with Gemcabene ezetimibe. comb<strong>in</strong>ation<br />

Response pooled with<br />

relevant<br />

historic data<br />

-8.6<br />

(-9.1 to -8.3)<br />

has very low probability<br />

<strong>of</strong> reach<strong>in</strong>g target<br />

competitor level <strong>of</strong> LDL-<br />

C lower<strong>in</strong>g<br />

slide 41<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


Q3: Given <strong>the</strong> magnitude <strong>of</strong> LDL-C lower<strong>in</strong>g across <strong>the</strong><br />

gemcabene + stat<strong>in</strong> dose range should cl<strong>in</strong>ical<br />

development cont<strong>in</strong>ue?<br />

Data<br />

Analysis<br />

Method<br />

Data Base<br />

Assumpt<br />

ions<br />

Mean (95% CI)<br />

Comments<br />

Gemcabene<br />

Combo - mono<br />

ANCOVA Phase IIA trial Few -4.8<br />

Traditional analysis<br />

only (n=255)<br />

(-12.3 to 2.7)<br />

Meta-Dose- Phase IIA trial Many<br />

Width <strong>of</strong> CI decreased ½<br />

Response The gemcabene pooled with CI from <strong>the</strong> -2.5 meta-analysis compared to does traditional<br />

Development relevant <strong>of</strong> gemcabene (-5.8 to was 1.2) discont<strong>in</strong>ued.<br />

analysis<br />

not overlap historic ezetimibe data CI, clearly suggest<strong>in</strong>g that<br />

gemcabene is unlikely to<br />

Ezetimibe<br />

lower LDL-C to <strong>the</strong><br />

Combo - mono<br />

Meta-Dose- extent Phase necessary IIA trial Many to compete with Gemcabene ezetimibe. comb<strong>in</strong>ation<br />

Response pooled with<br />

relevant<br />

historic data<br />

-8.6<br />

(-9.1 to -8.3)<br />

has very low probability<br />

<strong>of</strong> reach<strong>in</strong>g target<br />

competitor level <strong>of</strong> LDL-<br />

C lower<strong>in</strong>g<br />

slide 42<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


<strong>Value</strong> <strong>of</strong> MBDD approach for gemcabene<br />

Application <strong>of</strong> exposure-response based model allowed <strong>the</strong><br />

team to extract knowledge from all relevant gemcabene and<br />

competitor data, m<strong>in</strong>imiz<strong>in</strong>g uncerta<strong>in</strong>ty<br />

The availability <strong>of</strong> <strong>in</strong>tegrated dose-response models for<br />

gemcabene and competitors guided <strong>in</strong>formed decision-mak<strong>in</strong>g<br />

dur<strong>in</strong>g early development.<br />

● 7 key efficacy and safety endpo<strong>in</strong>ts could be <strong>in</strong>tegrated to make<br />

trade-<strong>of</strong>fs<br />

Based, <strong>in</strong> part, on <strong>the</strong> quantitative knowledge obta<strong>in</strong>ed<br />

through M&S <strong>the</strong> development <strong>of</strong> gemcabene was<br />

discont<strong>in</strong>ued after one Phase IIA trial <strong>in</strong> <strong>the</strong> target population<br />

This approach resulted <strong>in</strong> a more confident decision without<br />

fur<strong>the</strong>r <strong>in</strong>vestment <strong>of</strong> time and money.<br />

slide 43<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved


Conclud<strong>in</strong>g Remarks<br />

Model<strong>in</strong>g provides <strong>the</strong> means for <strong>in</strong>tegrat<strong>in</strong>g knowledge and us<strong>in</strong>g it for<br />

quantitative decision-mak<strong>in</strong>g.<br />

Exposure – response models are key to allow extrapolation to o<strong>the</strong>r<br />

populations and to design<strong>in</strong>g fur<strong>the</strong>r studies.<br />

Cl<strong>in</strong>ical <strong>in</strong>formation about previously developed drugs may be exploited to<br />

develop models for predict<strong>in</strong>g cl<strong>in</strong>ical outcomes.<br />

Such prior knowledge (prior <strong>in</strong>formation + models) can be exploited to<br />

accelerate cl<strong>in</strong>ical development.<br />

M&S can be exploited to answer important cl<strong>in</strong>ical questions; appropriate<br />

display <strong>of</strong> <strong>the</strong> results is critical to <strong>in</strong>formation transfer and decisionmak<strong>in</strong>g<br />

with<strong>in</strong> cl<strong>in</strong>ical teams.<br />

slide 44<br />

30 May 2008, ARCS<br />

© Pharsight Corporation All Rights Reserved

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