1

Prostate Cancer and 2Prostate Cancer and 2°°ChemopreventionChemoprevention

Ralph W. de Vere White, MDRalph W. de Vere White, MDDirector, UC Davis Cancer CenterDirector, UC Davis Cancer Center

Associate Dean for Cancer Programs Associate Dean for Cancer Programs Professor, Department of UrologyProfessor, Department of Urology

Definition of 2Definition of 2 ChemopreventionChemoprevention

Diagnose the disease Diagnose the disease

Then use non toxic intervention to:Then use non toxic intervention to:

–– Slow disease progressionSlow disease progression

–– Stop disease progressionStop disease progression

–– Eliminate diseaseEliminate disease

All without increasing the chance of dying All without increasing the chance of dying from the diseasefrom the disease

2

While Waiting to Cure Prostate While Waiting to Cure Prostate Cancer Cancer

Maximize ScreeningMaximize Screening

Increase PreventionIncrease Prevention

Prostate Cancer Ideal Target for Prostate Cancer Ideal Target for ChemopreventionChemoprevention

Long natural history Long natural history

One doubling = 7 yearsOne doubling = 7 years

High prevalenceHigh prevalence

200,000 men diagnosed200,000 men diagnosed

30,000 men die (2005)30,000 men die (2005)

3

Problems with Primary PreventionProblems with Primary Prevention

Required time of exposureRequired time of exposure

Personal choices Personal choices –– (smoking, diet)(smoking, diet)

Expense diet/pillsExpense diet/pills

One plan will not fit allOne plan will not fit all

Worry about side effectsWorry about side effects

How to prove it worksHow to prove it works

PCPTPCPT

Need to treat 71 healthy men for 7 Need to treat 71 healthy men for 7 years to prevent one case of CaP. Of years to prevent one case of CaP. Of these cases, 50% will be low risk.these cases, 50% will be low risk.

4

How to Solve a ProblemHow to Solve a Problem

Start with 2Start with 2 chemopreventionchemoprevention

–– More likely to be acceptedMore likely to be accepted

–– Quicker to prove it worksQuicker to prove it works

–– Considerably less expensiveConsiderably less expensive

CardiopreventionCardioprevention

StatinsStatins

AntihypertensivesAntihypertensives

AsprinAsprin

5

Has PSA Saved Lives?Has PSA Saved Lives?

YES!!YES!!

Prostate Cancer Death RateProstate Cancer Death Rate

Population growth 11%Population growth 11%

24% Drop in per capita death rate24% Drop in per capita death rate

Fortune 11/21/04

Death Death Year Year

34,90034,900 19931993

29,00029,000 20042004

27,56027,560 20062006

6

PSA: Stage MigrationPSA: Stage Migration

Pre PSAPre PSA Post PSAPost PSA

D2 at RXD2 at RX 30%30% 3%3%

Node Positive 22%Node Positive 22% 2%2%

Margin Positive 30%Margin Positive 30% 15%15%

T1CT1C 10%10% 84%84%

PSA Screening:PSA Screening:Opportunity for 2Opportunity for 2oo ChemopreventionChemoprevention

Predictions of National Incidence and MortalityProstate Cancer

1984 1986 1988 1990 1992 1994 1996 1998 2000 2002

Year

0

100

200

300

400

500

600

700

800

900

Age-a

dju

ste

d in

cid

ence p

er 100,0

00 m

en o

ver 50

0

40

80

120

160

200

240

280

Age-a

dju

ste

d m

ortality p

er 100,0

00 m

en o

ver 50

Incidence: Observed Mortality: Observed Mortality: UCD Model prediction Mortality: UCD Model prediction w/o PSA

Tsodikov

T1C 10% 84%

7

At the Time of Diagnosis in the At the Time of Diagnosis in the U.S. and in EuropeU.S. and in Europe

50% of Prostate Cancers are no 50% of Prostate Cancers are no immediate threat to the patient immediate threat to the patient

“Insignificant CaP”

Opportunity for 2Opportunity for 2˚ Chemoprevention˚ Chemoprevention

Maximize benefits from screeningMaximize benefits from screening–– Lives savedLives saved

Minimize risks from screening Minimize risks from screening –– Over treatmentOver treatment

Make surveillance active therapy Make surveillance active therapy

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Rational for Active SurveillanceRational for Active Surveillance

Over Treatment of Prostate CancerOver Treatment of Prostate Cancer

Incidence of CaP Incidence of CaP 170/100,000170/100,000

Die from CaP Die from CaP 32/100,00032/100,000

Die of something elseDie of something else 138/100,000138/100,000

Active SurveillanceActive Surveillance

## Median FUMedian FU WithdrawWithdraw

*206*206 29 Months29 Months 33%33%

**81**81 23 Months23 Months 31%31%

*Choo, R J Urol 2002, (167)1664-1669

**Carter HD, J Urol 2002, (107) 1231-1234

8% of Men suitable for Active Surveillance go on it (Capsure)

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#1 Pre Study #2 Pre Study Baseline 6 Mo

PSA

PSAPSA PSA

PSA Tests

AHCC Study

PSA

4 Mo

AHCCAHCC

AHCCAHCC

Final Patient StatusFinal Patient StatusCRCR 0/610/61

PRPR 0/610/61

StableStable 4/61 (7%)4/61 (7%)

ProgressedProgressed 23/6123/61

PUBLICATIONSEffects of a Mushroom Mycelium Extract on the Treatment of Prostate Cancer. Urology 60 (4), 2002.

10

GCP a GenisteinGCP a GenisteinGCP a GenisteinGCP a Genistein----Rich Compound Rich Compound Rich Compound Rich Compound The Road from Bench to BedsideThe Road from Bench to BedsideThe Road from Bench to BedsideThe Road from Bench to Bedside

Ralph W. deVere White, M.D.Ralph W. deVere White, M.D.Ralph W. deVere White, M.D.Ralph W. deVere White, M.D.Assistant Dean of Cancer Programs Director, UC Davis Cancer Center Professor, Department of Urology University of California, Davis Medical Center

GCP (Genistein Combined Polysaccharide)

“GCP is a natural anti-tumor substance containinglegumenous isoflavones and basidiomycetes polysaccharide.”

“GCP is produced by a special soybean fermentation technique involving isoflavone extracts and medicinalmushrooms.”

“Isoflavone glycosides are transformed into aglycones usingb-glucosidase producing basidomycetes using an innovativeJapanese technology.”

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Genistein Content in Soyfoods Genistein Content in Soyfoods and GCPand GCP

0.55 0.05 0.16

92.8

0

50

100

Concentration

mg/g

Soybeans

Soymilk

Tofu

GCP

Zyo-Kyo 90:592-6, 1995New Food Industry 40:59-64, 1998

Serum Serum DaidzeinDaidzein ConcentrationConcentrationin Men with Prostate Cancerin Men with Prostate Cancer

0

4000

8000

Conc

ng/ml

Jpn J ClinOncol 2002

UC DavisStudy

35.735.735.735.7

6,347

178x178x178x178x

12

Genistein Combined Polysaccharide (GCP)Effects in Prostate Cancer

Led to ongoing double-blind randomized trial in patients on active surveillance with prostate cancer (2o chemoprevention)

PC3 Xenografts Human Study

P=0.002

0

20

40

60

80

100

120

140

160

180

0 5 8 12 15 19 22 26 29 31 33 36 40 43 47 50

Days after inoculation

Control

GCP

Days after inoculation

Tu

mo

r S

ize (

mm

3)

Percent change in 6 month PSA over baseline PSA by treatment

Active Surveillance

Increased p21, p27Decreased VEGFTUNEL +

G C P vs . P laceb o in A c tive S u rve illan c e

R eg istra tio n

R a n d om iz a tio n (D ou b le -B lin d )

G C P x 6 M o n ths P lac eb o x 6 M o n th s

Init

ial

Ph

ase

(0-6

mo)

Cro

sso

ver/C

on

tin

uati

on

(6-1

2 m

o)

Lo

ng

-term

(>1

2 m

o)

P S A P S A P S AP S A

A ll p a t ien ts u nb lind ed a t 6 m on th s

O F F ST U D Y (N o F ree G C P )

P S A In c re ase

P S A D ecrease

P S A Stab le

O F F ST U D Y (Fre e G C P )P S A M an d a tory ev ery 6 m o b y P C P u n ti l PS A

F r ee G C P x 6-1 2 M o nth s(J o in t D o c to r /P a tie nt D ec is ion )

P S A M and ato ry a t 9 and 1 2 m o

P S A P S A

Completed GCP Clinical Trial

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53 Participants Completed Baseline and 6 Month PSA Assessment

# of Pts# of Pts GroupGroup Mean AgeMean Age RangeRange Gleason Gleason ScoreScore

22--4 54 5--7 87 8--1010

2525 PlaceboPlacebo 68.668.6 52.852.8--80.680.6 3 22 03 22 0

2828 GCPGCP 70.570.5 51.051.0--86.286.2 0 27 10 27 1

13 Participants OFF-STUDY Prior to 6 Month PSA Assessment

# of Pts# of Pts Adverse EventAdverse Event

77 DiarrheaDiarrhea

11 Skin RashSkin Rash

22 Other TherapyOther Therapy

22 Unrelated Medical IssueUnrelated Medical Issue

11 Too Many CapsulesToo Many Capsules

1313 TOTALTOTAL

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Absorption of GCP

19 / 20 Caucasians

0 / 3 African-Americans

1. 0 0

10 . 0 0

10 0 . 0 0

10 0 0 . 0 0

10 0 0 0 . 0 0

10 0 0 0 0 . 0 0

10 0 0 0 0 0 . 0 0

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 2 0 2 1 2 2 2 3

Pat ient s

GCP Patients % GENISTEIN CHANGE (Base to 6 Mo)

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PSA RESPONSE at 6 MONTHSPSA RESPONSE at 6 MONTHS

STABLE / STABLE / REDUCTIONREDUCTION

INCREASEDINCREASED

TotalTotal >20% >20%

decrease*decrease*TotalTotal >20% >20%

increase*increase*

## %% ## %% ## %% ## %%

GCPGCP 14/2814/28 5050 3/283/28 1111 14/2814/28 5050 6/286/28 2121

PlaceboPlacebo 8/258/25 3232 1/251/25 44 17/2517/25 6868 7/257/25 2828

4 Participants Biopsied Post GCP

3 of 4 pT0

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Question that study raises:

Is 6 Month GCP Long Enough?

YES* Katz: 6 wks GCP, 1.5 gm Daily, PSA 19.7 ng/mL to 4.2

ng/mL at Radical Prostatectomy (p0)

*,**

** Schröder: 49 pts 10 wks of nutrients PSADT 445 to 1150 Days

Is PSA / PSADT Valid Surrogate?

• Worked For Others

• Standard for Active Surveillance Studies

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Role of Prostate Biopsies

3 of 4 of our cases were pT0

• Due to affect of GCP?

• Missed by biopsy?

HOWEVER If no evidence of progression on biopsy, should GCP be stopped?

Can CGP be Made More Effective?Can CGP be Made More Effective?

Does Basic Science Data Support Does Basic Science Data Support Continued Use of GCP?Continued Use of GCP?

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PROSTATE CANCER CELLSPROSTATE CANCER CELLSAFTER ANDROGEN WITHDRAWALAFTER ANDROGEN WITHDRAWALINITIATE MOLECULAR SURVIVAL INITIATE MOLECULAR SURVIVAL

PROGRAMPROGRAM

KEYKEY

Blocking Initial Survival Blocking Initial Survival Increasing ApoptosisIncreasing Apoptosis

LNCaP, Fetal Bovine Serum

Counted Day Three

0

20

40

60

80

100

120

0 50 100 150 200 250

ug/ml GCP

% C

ha

ng

e i

n C

ell

N

um

be

r

100

LNCaP, Fetal Bovine Serum Counted Day Three

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Increasing Apoptosis after Increasing Apoptosis after Androgen WithdrawalAndrogen Withdrawal

LNCaP grown in androgenLNCaP grown in androgen--deprived deprived media: media: 55--15%15% apoptosisapoptosis

Addition of phosphoAddition of phospho--AKT inhibitor AKT inhibitor (wortmannin) increases apoptosis to (wortmannin) increases apoptosis to ~75% (~75% (WM: 100nM; LY: 1uM)WM: 100nM; LY: 1uM)

Goal is to achieve the maximum Goal is to achieve the maximum degree of apoptosis with an degree of apoptosis with an acceptable sideacceptable side--effect profileeffect profile

LNCaP cells

subG1: 17.93%

GCP

subG1: 5.42%

Vehicle

LNCaP-R273H

Vehicle

subG1: 3.23%

GCP

subG1: 11.24%

LY294002

subG1: 14.12%

LY + GCP

subG1: 48.97%

LNCaP

GCP Induces Apoptosis

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Can we in Patients Safely Block Can we in Patients Safely Block P. AKTP. AKT

Yes Yes

PerifosinePerifosine

0

25

50

75

100

125

0 20 40 60 80 100 120

Perifosine (uM)

% G

row

th

LNCaP-R273H, CSS

LNCaP-R273H

0

25

50

75

100

125

0 20 40 60 80 100 120

Perifosine (uM)

% G

row

th

C42, CSSC4-2

0

25

50

75

100

125

0 20 40 60 80 100 120

Perifosine (uM)

% G

row

th

LNCaP, FBSLNCaP

0

25

50

75

100

125

0 20 40 60 80 100 120

Perifosine (uM)

% G

row

th

PC3, CSSPC-3

0

25

50

75

100

125

0 20 40 60 80 100 120

Perifosine (uM)

% g

row

th

LNCaP, myrAkt

Perifosine ICPerifosine IC5050

LNCaP, FBS, 72hLNCaP, FBS, 72h ~8uM~8uM

LNCaP, FBS, 72hLNCaP, FBS, 72h ~22uM~22uM

C42, CSS, 72hC42, CSS, 72h ~64uM~64uM

PC3, CSS, 24hPC3, CSS, 24h ~1uM~1uM

Perifosine IC50 Values; Myristoylated Akt can prevent perifosine-induced growth inhibition in LNCaP.

A B

C D

E F

21

0

20

40

60

80

100

120

vehicle

GCP

perif

osine

G+P

vehicle

GCP

perif

osine

G+P

vehicle

GCP

perif

osine

G+P

vehicle

GCP

perif

osine

G+P

vehicle

GCP

perif

osine

G+P

% C

olo

ny F

orm

ati

on

LNCaP R273H C42 cds1 PC3

Clonogenic Assay; as single agents GCP and perifosine can inhibit Growth. In combination growth is further inhibited.

PARP

B-actin

Veh GCP peri G+P veh GCP peri G+P

FBS CSS

LNCaP

Cleaved PARP

PARP Cleavage; Confirmation that treatment with a combination

of GCP and Perifosine increases levels of apoptosis.

22

MECHANISM OF ACTION

MECHANISM OF ACTIONMECHANISM OF ACTION

P-Akt

B-actin

Total Akt

Veh GCP peri G+P

Phospho p70S6K

B-actin

veh GCP peri G+P

Total p70S6K

1. Increased inhibition

of Akt activity.

2. Increased inhibition of

mTOR activity.

23

GCP Antagonizes Androgen Receptor Signaling

GCP diminishes AR-dependent gene expression

GCP treatment markedly down-regulates AR levels

PSA RT-PCRVeh GCP -ve

AR

PSA

B-actinveh GCP veh GCP

FBS CDT-FBS

AR

B-actin

0

100

200

300

400

500

600

700

800

vehicle GCP perifosine G+P

ng

/ml

PS

A

control siRNA

AR siRNA

MECHANISM OF ACTION

0%10%20%30%40%50%60%70%80%90%

100%

ve

hic

le

GC

P

pe

rifo

sin

e

G+

P

ve

hic

le

GC

P

pe

rifo

sin

e

G+

P

control si AR si

Ce

ll C

yc

le

G1

S

G2

subG1*** ***

******

3. Simultaneous inhibitionof Akt activity AND ARPathway.

24

Is Effect of GCP Seen Only Is Effect of GCP Seen Only With Androgen Withdrawal?With Androgen Withdrawal?

Figure 1 Day 2A

B

0

100000

200000

300000

0.0

0.1

0.2

0.3

0.4

0.5

*

*

*Apoptosisnormalized to cellnumber

MTT

OD

Day 2

RF

U/O

D

Active Caspases 3 and 7 measured using a flourescent plate reader. Normalized to cell numbers

25

1 U

ntr

eate

d2 G

CP

3 D

oceta

xel

4 B

icalu

tam

ide

5 pp2

6 G

CP

+

Doceta

xel

7 G

CP

+

Bic

alu

tam

ide

8 G

CP

+ p

p2

LNCaP lysates

PARP

β-actin

Cells Harvested at 24 hours post treatment

PARP

1 U

nt

2 G

CP

24

3 G

CP

48

4 D

oceta

xel 24

5 D

oceta

xel 48

6 D

oceta

xel to

GC

P

7 G

CP

to D

oceta

xel

8 G

CP

+ D

oceta

xel

pAKT

AKT

p21

β-actin

LNCaP harvested day 3.

InPress BJU, Burich, RW de Vere White, Mack, P.

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Dutesteride Vs. Dutesteride + GCP + Perifosine in Patients on Active Surveillance for Prostate Cancer.

Randomization

ARM 1 ARM 2

Dutesteride X 9 Months Dutesteride + GCP +

Perifosine X 9 Months

OFF TREATMENT at 9 Months

Prostate Biopsy at 12 Months (All Patients)

PSA at 18 + 24 Months

OFF STUDY Endpoints: PSA, PSA Velocity, Biopsy Path,

Subsequent Therapy

deVere White

Lab