The NCI Approach To Drug Development

The NCI Approach To Drug Development

Edward A. Sausville, M.D., Ph.D.

Developmental Therapeutics Program

National Cancer Institute

Goals Of Preclinical Drug StudiesGoals Of Preclinical Drug Studies

• Discovery of “lead structures”

• “Refinement”: chemistry, pharmacology, efficacy =“Early” development

• Late development: formulation, dose form, toxicology

Scientific framework

Goals Of Preclinical Drug StudiesGoals Of Preclinical Drug Studies

• IND = “Investigational New Drug” application= approval by FDA to conduct human studies; main criterion : SAFETY AND LIKELY REVERSIBLE TOXICITY = allows start of Phase I trials

• NDA = “New Drug Application”= basis for sale to public;main criteria: SAFETY AND SOME MEASURE OF EFFICACY = result of Phase II/III trials

Regulatory framework

Cancer Drugs:How Do We Know We Have A Winner?Cancer Drugs:How Do We Know We Have A Winner?

- PHASE III CLINICAL TRIAL= WINNER

- PHASE II= POTENTIAL WINNER

Rx

; Time?

Treatment B or no Rx

Time

%Alive

Treatment A

- PRECLINICAL MODEL(e.g., mouse or rat)

Cytotoxic

TumorSize

Time

Untreated

Cytostatic

Rx

Cancer Drugs: How To Pick A Winner?Cancer Drugs: How To Pick A Winner?

“VALIDATED” CANCER TARGETS DNA

Alkylators Antimetabolites Topo I / II

Tubulin

Receptors Nuclear Cell Surface (Immune?)

Oncogene Proteins (2001: AT LAST!)

“Empirical” Drug Discovery“Empirical” Drug Discovery

SCREEN

+ ANTI-TUMORACTIVITY!!

(in vitro/in vivo)

PHARMACOLOGY

CHEMISTRY

OPTIMIZED SCHEDULE (in vivo)

IND-DIRECTED TOX/FORMULATION

PHASE I: DOSE/SCHEDULE HUMAN PHARM/TOX

PHASE II: ACTIVITY = SHRINKAGE

PHASE III: COMPARE WITH STANDARD

Problems With Empirical ModelsProblems With Empirical Models

• Lack of predictive power in vivo

• Poor correlation of non-human with human pharmacology

• Divorced from biology

• Inefficient: many compounds screened;developed, but have “late” = clinical trials outcomeat Phase III to define “validation” of compound action

N

N

N

NH

O

OHHO

NHHOOH

Me( CH2)8CH=CHCH=CHC(O)NHCH2C(O)NH

KRN5500

N

N

N

NH

O

OHHO

NHHOOH

Me( CH2)8CH=CHCH=CHC(O)NHCH2C(O)NH

N

N

N

NH

O

OHHO

NHHOOH

H2NCH2C(O)NHH3C(CH2)8CH=CHCH=CHCO2H

Deacylation SAN-Gly

Protein Synthesis

Effect Of KRN5500 On Colo-205 Athymic Mouse XenograftsEffect Of KRN5500 On Colo-205 Athymic Mouse Xenografts

Me

dia

n T

um

or W

eig

ht (

mg)

Day Posttumor Implantation

5000

4500

4000

3500

3000

2500

2000

1500

1000

500

08 12 15 18 22 26 29 33 36 41

vehicle13.5 qdx533.5 q4dx322.4 q4dx320 qdx550 q4dx330 qdx5

+

X

0.1

1

10

0 1 2 3 4 5

KRN5500 Plasma Concentrations On Effective Schedule(20 mg/kg/d) In MiceKRN5500 Plasma Concentrations On Effective Schedule(20 mg/kg/d) In Mice

Pla

sma

Con

cent

ratio

n (

M)

Time (days)

Summary Of KRN5500 Phase ISummary Of KRN5500 Phase I

• 26 patients as IV once per day over 5 days

• Dose limiting toxicity = interstitial pneumonitis

• MTD = 2.9 mg/M2/d x 5

• Achieve only 0.75 - 1 M at 3.7 mg/M2/d x 5

• 4/6 patients with >25% incr Cmax havegrade 4 toxicity

Data of J. P. Eder, DFCI

In Vivo i.e., Intact Animal Tumor ModelsIn Vivo i.e., Intact Animal Tumor Models

• The information received depends on the question asked:not all models are appropriate for all questions

• Drugs need different types of models at different timesin their “discovery / development” life cycle

• “Pharmacology” models to qualify compound• “Efficacy” models to define potential for biologic effect

Target driven Target unselected

• “Biology” models to confirm ONLY the targetor molecular events related to target are affected

In Vivo Activity vs Clinical Activity (39 Agents) In Vivo Activity vs Clinical Activity (39 Agents)

0

5

10

15

20

25

<33% >=33% <33% >=33%

Percentage of Xenograft Models That Were Active (T/C<=40%)

Nu

mb

er o

f A

gen

ts

Clinically Active Clinically Inactive

a. 20% or greater responsein any phase II trial

b. 20% or greater responsein >1 disease

p=0.14 p=0.04

“Rational” Drug Discovery“Rational” Drug Discovery

TARGET-DEPENDENT IN VIVO MODEL

IND DIRECTED TOX/FORM

PHASE I: DOSE/SCHEDULE: HUMAN PHARM/TOX;? AFFECT TARGET

PHASE II: ACTIVITY = ? AFFECT TARGET

PHASE III: SURVIVAL/TIME TO PROGRESSION

PHARMACOLOGY(to affect target)

CHEMISTRY

MOLECULAR TARGET SCREENBiochemicalEngineered cellAnimal (yeast/worm/fish)

• “Misfiring” or Abnormality of Cell Cycle

• Imbalance of Genes Regulating Cell Death

• Immortality / Telomerase• Angiogenesis / Invasion Phenotype

How To “Build” A Cancer CellHow To “Build” A Cancer Cell

Cancer cells possess defined “families” of lesionswith common outcomes

G1

S

G2

M

G0

- “Oncogenes” turned on- “Suppressor genes” turned off- Mimic Growth Regulatory

“Signal Transduction”

Tumor SizeCell DeathCell Proliferation

(After Varmus, Bishop, Weinberg, Croce, Folkman, Hanahan … etc.)

* Cytogenetics Breakpoints Molecules (bcr-abl)* “Positive” selection from tumor DNA Active oncogenes (signal transduction)* Tumor gene expression profiling (CGAP)

* Binding partners (geldanamycin, rapamycin, fumagillin)* Computational algorithm (molecule target)

* Cell metabolism / Cell cycle effects* Suggest single targets Inefficient

* Libraries of molecules and precisely defined organisms

Molecular Target Definition - How To?Molecular Target Definition - How To?

• BIOLOGY:

• “ RETROFIT” ACTIVE MOLECULES:

• “CLASSICAL:”

• CHEMICAL GENETICS:

- COMPARE- Cluster analysis

bcr-abl As Target: Rationalebcr-abl As Target: Rationale

• Apparently pathogenetic in t9:Q22 (Ph+) CML/ALL

• Absence in normal tissues

• Modulate signal transduction events downstreamMaintenance of chronic phaseAdjunct to bone marrow transplantation

bcr-abl Fusion Proteinbcr-abl Fusion Protein

bcr SH2 SH2 V SH2/SH3 kinase NT DNA Actin

bcr

autophosphorylation

Phosphorylation ofother substances

McWhirter JR, EMBO 12:1533, 1993

Example Of “Rational” Approach:bcr-abl directed agentsExample Of “Rational” Approach:bcr-abl directed agents

OH

OH

NHCHOOH

OH

N

HO

OH

CO2H

HO

HO

OH

OH

OH

OH

NH

CO2Me

HN CN

NHN

CN

NH2

N

N

N

NH NH

O

N

NMe

Me

erbstatin lavendustin piceatannol

AG957 AG1112

CGP 57148B = STI571

Naturalproductempiric lead

1st generationsynthetic

2nd generationsynthetic;in clinic

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

0 5 10 15 20

Tu

mo

r W

eig

ht

(g)

control mice 3x160 mg/kg oral

STI571:An Oral In Vivo Bcr-abl Kinase InhibitorSTI571:An Oral In Vivo Bcr-abl Kinase Inhibitor

N

N

N

NH NH O

Me

N

N

Me

Tyr phosphorylation in vivo

le Coutre et al, JNCI 91:163, 1999

Antitumor activity in vivo

0

20

40

60

80

100

120

0 1 2 3 4 5 6 7 8 9

% P

ho

sph

ory

lati

on

Intraperitoneal Oral

0

10

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50 60

% T

um

or

Fre

e S

urv

ival

KU812 control mice

U937 control mice

KU812 3x50 mg/kg i.p.

U937 3x50 mg/kg i.p.

KU812 3x160 mg/kg oral

U937 3x160 mg/kg oral

(hrs) (days)

(days)

NEJM 344: 1031, 2001

Efficacy And Safety Of A Specific Inhibitor Of The Bcr-abl Tyrosine Kinase In Chronic Myeloid Leukemia

BRIAN J.DRUKER,M.D.,MOSHE TALPAZ,M.D.,DEBRA J.RESTA,R.N.,BIN PENG,PH.D.,ELISABETH BUCHDUNGER,PH.D.,JOHN M.FORD,M.D.,NICHOLAS B.LYDON,PH.D.,HAGOP KANTARJIAN,M.D.,

RENAUD CAPDEVILLE,M.D.,SAYURI OHNO-JONES,B.S.,AND CHARLES L.SAWYERS,M.D.

% in

Met

ap

hase

0 100 200 300 400

100

80

60

40

20

0

Ph Chromosome + CellsWhite Cell Count

(cel

ls x

10-

3 /

mm

3)

0 30 60 90 120 150

100

10

1

Duration of Treatment with STI571 (Days)

NCI Drug DiscoveryNCI Drug Discovery

• Aids to find targets / link targets with drugs-Cancer Genome Anatomy Project (CGAP) -Developmental Therapeutics Program In Vitro Drug Screen

• Where the target is known: build its assessment into the selection and development of a compound: e.g., 17-allylamino 17-demethoxy geldanamycin (17-AAG)

• Where the target is unknown, define it or a proximal indicator of effect in parallel with conventional development path: e.g., UCN-01 protein kinase inhibitor

A Marriage Of Empirical And Rational Opportunities

Cancer Genome Anatomy Project: PROCESSCancer Genome Anatomy Project: PROCESS

• Tumor material (archival)

• “Laser capture microdissection” of tumor cells

• Creation of tumor-derived cDNA libraries

• Sequence to establish uniqueness

• Deposit in public domain

from defined sections

Establishing for a cell the repertoire of genes expressed, togetherwith the amount of gene products produced for each, yields apowerful "fingerprint". Comparing the fingerprints of a normal versusa cancer cell will highlight genes that by their suspicious absence orpresence (such as Gene H ) deserve further scientific scrutiny todetermine whether such suspects play a role in cancer, or can beexploited in a test for early detection.

Normal CellCancer Cell

Gene Expression: The Cell’s Fingerprint

http://cgap.nci.nih.gov

NCI In Vitro Drug ScreenNCI In Vitro Drug Screen

1985 Hypothesis:

Emerging Realities:

• Cell type specific agents• Activity in solid tumors

• Unique patterns of activity, cut across cell types

• Correlations of compound activity

ANDCell type selective patterns found

- relate to molecular “target” expression- generate hypothesis re: molecular target

All Cell Lines

Log10 of Sample Concentration (Molar)

Pe

rce

nta

ge

Gro

wth

100

50

0

-50

-100-9 -8 -7 -6 -5 -4

National Cancer Institute Developmental Therapeutics ProgramDose Response Curves

NSC: 643248-Q/2 (a rapamycin) Exp. ID: 9503SC35-46

Pattern Recognition Algorithm:COMPAREPattern Recognition Algorithm:COMPARE

• Goal: COMPARE degree of similarity of a newcompound to standard agents

• Calculate mean GI50, TGI or LC50

• Display behavior of particular cell line as deflectionfrom mean

• Calculate Pearson correlation coefficient:1 = identity ; 0 = no correlation

resistant mean sensitive

Taxol Halichondrin B Daunorubicin

Topoisomerase II

Leukemia

NSCLC

Small Cell Lung

Colon

CNS

Melanoma

Ovarian

Renal

Agents With Similar Mechanisms HaveSimilar Mean GraphsAgents With Similar Mechanisms HaveSimilar Mean Graphs

Tubulin

Drug Target ClusteringsReveal Clues To MechanismDrug Target ClusteringsReveal Clues To Mechanism

Nature Genetics 24: 236, 2000; http://dtp.nci.nih.gov

5FU/DPYD L-Asparaginase/ASNS

Geldanamycin

17-AAG

122750

330507

OMe

NHCH2CH=CH2

RNSC

Geldanamycin StructureGeldanamycin Structure

O

O

R

NH

O

OCONH2

OH

O

MeO

Me

carbamateansa ring

benzoquinone

Benzoquinoid AnsamycinsInitial Cell Pharmacology Benzoquinoid AnsamycinsInitial Cell Pharmacology

Reduce levels or inhibit transformation by a large number of PTKs: src, yes, fps, erbB1, lck

e.g., 17AAG decrease erbB2 under conditions where overall transcription/translation little affected

(Miller et al, Cancer Res 54: 2724, 1994)

Effect of 6 hr, 0.35 Mherbimycin A on SKBr3 cells

p185 proteinp185 Y-PerbB2 RNAProt synRNA synATPATP/ADP

355

130849099

108

Parameter % of control

0 2 4 6 8

150

100

50

0

MDA MB 453

% C

on

tro

l p185 Proteinp185 PY

Hours

DTP, NCI In Vivo EvaluationOf Geldanamycin In PC3 Prostate CADTP, NCI In Vivo EvaluationOf Geldanamycin In PC3 Prostate CA

#

20

6

6

6

Dose(mg/kg)

0

3.4

2.3

1.5

Route of administration – i.p.

Schedule

qd x 5 (9)

qd x 5 (9)

qd x 5 (9)

qd x 5 (9)

DrugDeaths

0

3

1

0

% OptT/C (D)

---

Toxic

33(22)

90(15)

GrowthDelay

---

---

50

3

Conclude: Narrow therapeutic index on this scheduleSolubility of agent major problem for other schedules

Early Stage, Athymic Mouse Xenograft

18 Atom Spacer

Bead

O

O

R4

NH

O

Me

Me

R2

OMeMeMe

H2NC(O)O

R1MeO

Geldanamycin Bead

Geldanamycin BeadsIdentify Hsp90 As Binding PartnerGeldanamycin BeadsIdentify Hsp90 As Binding Partner

Neckers et al, PNAS 91:8324, 1994

1 2 3 4

p90

R. Lysate

1) Bead-Geld

2) Bead-Geld + Geld

3) Bead-Geld + Geldampicin

4) Bead

C.

ERPRetc

Cyclin D

Hsp 90pAKT EIF2kinase

raf

erbB2EGFR

lck, met,etc

G0

telomerase

B.

nucleus

*

hsp90

*hsp90

*hsp90

A.X

degradation

nucleus

Xhsp90

ImmatureX

MatureX

ERfolding

X-mRNA

X

Hsp 90

Three Dimensional View Of Geldanamycin Binding Pocket In Amino Terminus Of Hsp90

Three Dimensional View Of Geldanamycin Binding Pocket In Amino Terminus Of Hsp90

Stebbins et al, Cell 89:239, 1997

17-AAG Binds To Hsp90 & Shares Important Biologic Activities With Geldanamycin17-AAG Binds To Hsp90 & Shares Important Biologic Activities With Geldanamycin

dose (nM)

erb

B2

(%

of b

ase

lin

e)

Ra

f-1

(% o

f ba

se li

ne

)

Schulte & Neckers, Cancer Chemother Pharmacol 42: 273, 1998

120

100

80

60

40

20

00 1 10 100 1000 10000

17-AAGGA

120

100

80

60

40

20

00 1 10 100 1000 10000

17-AAGGA

dose (nM)

p185erbB2

17-AAG GA (M)

0.03

0.1

0.3

0.5

2 0.03

0.1

0.3

0.5

2

cont

rol

Raf-1

17-AAG GA (M)

0.03

0.1

0.3

0.5

2 0.03

0.1

0.3

0.5

2

cont

rol

UCN-01UCN-01

N N

NHO OH

OMe

OMe

NHMePotent antiproliferative agent

Cell cycle arrest

DNA-damage G2 checkpoint abrogation

37nM

300-600 nM

~50nM

IC50

(DTP screen)

A DNA Damage G2 Checkpoint Is Mediated By CDKs: UCN-01 ActionA DNA Damage G2 Checkpoint Is Mediated By CDKs: UCN-01 Action

spRad3(hATM/hATR)

Chk1-PChk114-3-3

Cdc25-P(Ser216) Cdc25-P(Ser216)-14-3-3

Cdc2

Active Active?

Active

Inactive

Inactive

G2 arrest Enter mitosis

Cdc25

Cdc2-P(Tyr15)

Adapted from Weinert,Science 277:1450, 1997

UCN-01

Chk 1 mediatesthe G2 checkpoint

UCN-01 Infusional Phase I TrialG2 Checkpoint AbrogationUCN-01 Infusional Phase I TrialG2 Checkpoint Abrogation

% G

2 ch

eckp

oint

abr

ogat

ion

% G

2 ch

eckp

oint

abr

ogat

ion70

60

50

40

30

20

10

00 10 1000 100000

nM UCN-01

70

60

50

40

30

20

10

0

30 40 50 60

UCN-01 (mg/m2/day)

UCN-01 w/o plasmaUCN-01 in plasma

Challenges In Pursuing TheMolecular Therapeutics Of CancerChallenges In Pursuing TheMolecular Therapeutics Of Cancer

• Must change thinking from histologic to moleculardiagnoses (CGAP, array technology)

• Develop new means (imaging, probes) to assessmolecular pharmacodynamics

• Must move away from cytotoxicity as sole primaryendpoint: assess and evaluate cytostatic effect

• Promote patient participation in clinical trials

• Develop speed and efficiency in answering critical clinical questions

Goals For Cancer Drug ScreeningIn The New MillenniumGoals For Cancer Drug ScreeningIn The New Millennium

• Associate novel chemotypes with defined targets• may utilize purified targets at the “front end”• may define targets in pathway/organisms• may “retrofit” molecules to targets or pathways

by statistical approaches

• Allows facile tools for chemical/pharmacologicaloptimization

• Define targets of relevance to and translatable inearly clinical trials

Summary:Developmental Therapeutics Program, NCISummary:Developmental Therapeutics Program, NCI

• Novel agents directed at molecular targetsimportant to cancer pathogenesisand progression

• Interdisciplinary collaborators: academia,industry, intramural NCI

• Contribute agents and regimens for use byintra / extramural investigators

AcknowledgementsAcknowledgements

NCIV. Narayanan, R. SchultzJ. Johnson, S. O’BarrM. Hollingshead, S. StinsonL. RubinsteinA.Monks, N. ScudieroK. Paull, D. Zaharevitz, S. BatesS. Holbeck, J. WeinsteinA. SenderowiczA. Murgo, S. ArbuckG. Kaur, P. Worland, Q. WangP. O’ConnorL. Neckers, L. WhitesellD. Newman

H. Piwnica-Worms Wash UV. Pollack PfizerM. Roberge U. Brit. Columbia

Our next speaker is:

Ms. Shannon DeckerOffice of the Associate DirectorDevelopmental Therapeutics Program