C. Erlichman M.D. OUTLINE Preclinical Development

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DEVELOPMENT OF NEW TREATMENTS IN CANCER

• C. Erlichman M.D.

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OUTLINE

• Preclinical Development
• Trials Phase 1 Phase 2 Phase 3
• Biomarkers in Cancer Treatment Trials
• Informed Consent and Regulations

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PRECLINICAL STUDIES
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LET ME SEE, WHICH DRUG SHOULD I TEST?
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NCI Drug Development Stages
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NCI Drug Development Stages
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SCREENING FOR NEW DRUGS

• Testing in tissue culture (in vitro)
• 60 human cancer cell lines
• patterns identified that suggest a new way of
  killing cancer cells
• interesting agents tested in animal models

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Advantages and Disadvantages of Cancer Cell Line
Drug Screens

• Advantages
• Tumor cell lines have identified active agents in
  clinical use
• Identifies agents with antitumor activity in a
  cell type
• May provide useful clue for clinical testing
• Disadvantages
• Mechanism of action not elucidated
• Does not distinguish between nonspecific cell
  toxins and potentially useful agents

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Preclinical Pharmacology

• Development of Drug Plasma Method
• Determine the extent of protein binding
• Plasma elimination kinetics of i.v.
  administration
• Other routes of administration such as oral, may
  be evaluated as well
• The in vitro and in vivo metabolism is
  characterized using liver extracts

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Preclinical Pharmacology

• Preliminary (Range-Finding) Toxicity
• For each drug, it is necessary to establish a
  maximum tolerated dose (MTD) and dose limiting
  toxicities (DLT) in both rodent and non-rodent
  species.
• Testing in human tumor models growing in mice to
  determine whether the drug has activity
• For each drug, the effect of treating animals
  with different tumors is evaluated looking at
  stopping tumors from growing and prolonging of
  the animals life
• tumor types tested depends in part of the
  mechanism of action and where there is activity
  in tissue culture

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IND Toxicology

• Single or multiple daily dose schedules such as
  Dx1, q3hr x 3, q8hr x 15, q4D x 3, etc.
• Up to twenty-eight days or more of repeated
  administration of drug to rodents and
  non-rodents.

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IND Toxicology

• Multiple cycle studies may be required if delayed
  or cumulative toxicity is anticipated.
• Special studies such as cardiotoxicity,
  neurotoxicity evaluations, and immunotoxicity
  studies may be required as part of an existing
  study or in a separate study.

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CANCER CLINICAL TRIALS
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ELIGIBILITY CRITERIA

• Primarily to ensure safety
• To ensure some level of uniformity of the study
  population
• To select a population of interest

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COMMON ELIGIBILITY CRITERIA

• Evidence of cancer
• Age
• Performance status
• Adequate blood counts
• Adequate liver function blood tests
• Adequate kidney function
• Reasonable life expectancy ? 3 months
• Capable of giving informed consent

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COMMON INELIGIBILITY CRITERIA

• Has had therapy (XRT, Chemo) within 4 weeks
• Pregnancy
• Breast feeding
• Prior treatments that may be similar
• Recovery from surgery
• Infections
• Brain metastases
• Cannot take oral medications

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Phase I Trial Goals

• 1. To determine MTD and phase II recommended dose
• 2. To describe all toxicities
• 3. To determine the clinical pharmacokinetics
  (PK)
• 4. To report any responses
• 5. To relate PK to toxicities and/or biologic
  effect
• 6. To evaluate potential markers of biologic
  endpoints (pharmacodynamics)
• 7. To relate PK to genetic polymorphisms

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Pharmacokinetics Pharmacodynamics Pharmacogenetics

• Pharmacokinetics
• What the body does to the drug
• AUC, clearance, t1/2, volume of distribution,
  Cmax, CSS, Tmax, renal clearance

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Pharmacokinetics Pharmacodynamics Pharmacogenetics

• Pharmacodynamics
• What the drug does to the body
• Toxicity Grade
• Effect on ANC, platelets
• Tumor response
• Normal Tissue Surrogates
• Effect on Imaging characteristics

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Pharmacokinetics Pharmacodynamics Pharmacogenetics

• Pharmacogenetics
• Genetic variation in enzymes that metabolize
  drugs
• Single nucleotide polymorphisms (SNPs)
• Functional SNPs
• Differences between ethnic groups
• Frequency could be common or relatively rare
• Not analyzed for cancer risk, screening, or
  prevention

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Phase I Trial Design Considerations

• Starting dose
• 1/10 LD10 in mice provided the dose lt TLD (toxic
  low dose) in dog
• If toxic in dog, then start with1/3 TLD in dog

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Phase I Trial Design Considerations

• Standard cohort-escalation design
• 3 patients per dose level
• If 2 or 3 DLTs stop escalation
• If 1 DLT add 3 patients and if no further DLT
  continue dose escalation, i.e. 1/6 DLT
• MTD is 1 dose level lower

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ASSESSMENT OF DRUG TOXICITY (SIDE EFFECTS)
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TOXICITY GRADING ATTRIBUTION

• NCI common toxicity criteria (CTC v3.0)
• Not related
• Possible related
• Probably related
• Definitely related

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Example of CTC Toxicity Tables
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PHASE 2 AND 3 STUDY GOALS

• Response Rate What percent of patients have
  significant tumor shrinkage
• Time to Progression The time it takes for the
  tumor to grow by a certain amount after starting
  the study
• Disease Free Survival The time it takes for the
  tumor to come back after starting the study
• Overall Survival The time patients live after
  starting the study

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PHASE 2 CLINICAL TRIALS

• Initiated when a safe dose and schedule define in
  phase I
• Performed in specific tumor types
• Tumor types selected for testing depending on a
  variety of criteria
• Overall purpose is to determine whether there is
  any clinically meaningful activity

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PHASE 2 CLINICAL TRIALS

• Criteria for tumor types to study
• hint of effect in phase I
• specific target is present in that cancer
• a clinical need is identified
• competitors in the market place
• potential market size

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PHASE 2 CLINICAL TRIALS GOALS

• To determine the response rate, time to
  progression and survival
• To determine the frequency and spectrum of all
  toxicities
• To relate potential markers of biologic endpoints
  to clinical effect
• To relate pharmacogenetics to toxicity and
  efficacy

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Phase I vs PHASE 2 CLINICAL TRIALS

• Phase I trials include 20-25 patients with many
  tumor types and patients are treated at different
  doses
• Phase 2 trials can include from 14 to 100
  patients with one tumor type treated with one dose

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PHASE 2 CLINICAL TRIALS

• If a phase 2 trial meets its objective then phase
  3 trials are needed
• However, phase 2 trial results can be used for
  accelerated approval by FDA
• This needs to be established in consultation with
  FDA before the plan for the trial is finalized
  and will still require a phase III trial

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PHASE 3 CLINICAL TRIALS

• Definitive comparative trials
• Requires a randomization
• Rarely blinded in Cancer trials
• Primary endpoints can include response rate, time
  to progression, overall survival and disease-free
  survival

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PHASE 3 CLINICAL TRIALS

• As follow-up on patients may be long results can
  take 5 and 10 years to be realized
• Size of the study can vary from a few hundred
  patients to thousands

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Molecularly Targeted Therapies

• A new paradigm for cancer treatment
• Cancer as a chronic disease like diabetes,
  hypertension
• Although cure is still the ultimate goal,
  control can achieve valuable benefit for the
  patient
• Treatment are less toxic and chronic

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Natural History of Cancer
Cellular Dedifferentiation
Growth Dysregulation
Loss of Apoptosis
Invasion and Metastasis
Unlimited Cell Division
Angiogenesis
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Molecular Events in Cancer
Dysregulation of Growth Factors or Receptors
Aberrant Signal Transduction
Secretion of Autocrine Growth Factors
Secretion of Angiogenic Growth Factors
Secretion of Matrix Metalloproteinases
Expression of Oncogenes Loss of Tumor Suppressor
Genes
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Receptor Tyrosine Kinases Overexpressed in Breast
Cancer
Extracellular
region
Flt-1
Flk-1
a
ß
a
a
N-Flg
ß
ß
TRK-B
(TK-)
TRK family
FGF receptor
Tie
Insulin
Ltk
EPH/ECK
Ret
Ros/Sev
Met/Sea
Axl/Ark
family
PDGF receptor
receptor
Family
Trk
EGF
family
Family
family
family
family
Trk-B
receptor
Flg
Trk-C
family
c-Ros
Met (HGFR)
Eph
Axl
a
N-Flg
PDGFR-
INS.R
Sevenless
c-Sea?
Eck
Ark
Bek
IGF1R
PDGFR-ß
EGFR
Elk
FGFR-3
c-Fms(CSF1-R)
Neu
Eek
FGFR-4
IgG-like domain
c-Kit(SGFR)
ErbB3
Hek
Cysteine-rich box
Flt-1
EGF-like repeats
Flk-1
Fn type III repeats
Flk-2 (Flt-3)
Transmembrane helix
Intracellular
Flt-4
Plasma membrane
region
Catalytic domain
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Molecularly Targeted Therapies

• Drugs that target receptor tyrosine kinases
  Gleevec, Tarceva
• Antibodies that target receptors Herceptin,
  Erbitux
• Antibodies that target receptor ligands - Avastin

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Anti-EGF Agents (Antibodies)

• MoAb
• Erbitux
• ICR62
• mAb425
• Ior egf/r3
• Pantuzamab
• h-R3
• EMD72000

• Bispecific Antibodies
• MDX-447
• Toxin-Linked Conjugates
• ScFV (14E1)-ETA
• ScFV (225)-ETA
• MRI (Fv)-PE38
• TP40
• DAB389-EGF

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Anti-EGF Agents (Drugs)

• AG1478
• CGP59326
• CI1033
• EKB569

• IRESSA
• TARVECA
• LAPATINIB
• PKI-166
• PD158780

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Tumor AngiogenesisAngiogenic Balance or Switch
VEGF, bFGF, TGF-?, integrins, MMP, IL8, hypoxia,
NO (etc)
Angiostatin, endostatin, interferons, TIMP (etc)
Growing capillaries
Metastasis
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VEGF Ligands and Receptors
VEGFR-2 (Flk-1/KDR)
VEGFR-3 (Flt-4)
VEGFR-1 (Flt-1)
Angiogenesis
Angiogenesis
Lymphangiogenesis
Lymphangiogenesis
PlGF Placental growth factor
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Anti-Angiogenesis Agents

• Tyrosine Kinase Inhibitors
• Sorefinib
• Sunitinib
• CHIR-258
• AEE788
• BIBF1120
• AZD 2171

• Biologic Agents
• Bevacizumab
• VEGFR-TRAP

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Biomarkers in Cancer Clinical Trials

• Should we treat only those patients that express
  the target?
• Do we need to treat at doses that cause some side
  effects like with chemotherapy?
• Should we measure the benefit in the same way
  e.g. response rate?

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Biomarkers in Cancer Clinical Trials

• Should the agent be highly specific or affect
  several target?
• If the latter then how many?
• Should these agents be used in combination with
  chemotherapy?
• Should these agents be combined with each other?

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By Liz Szabo, USA TODAY
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Can we improve the effectiveness and/or decrease
the risk associated with cancer treatment while
keeping costs under control?
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Biomarkers for Target Effect

• Presence of the target eg ER, PR, HER2
• Effect of treatment on plasma tumor marker eg
  CA125, PSA, aFP.
• Effect of treatment on a downstream molecule eg
  phospho-p70S6K with CCI-779 or RAD001
• Depletion of circulating tumor cells after
  treatment
• Decrease in metabolic imaging after treatment

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Types of Biomarkers

• Biologic Fluids plasma, serum, urine, CSF,
  effusions
• Tissue Normal or tumor
• Proteomic, Genomic, DNA
• Imaging
• PET scanning 18FDG, 18FLT, H2O15
• MRI
• CT perfusion

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IRESSA
Albanell. J Clin Oncol 20(1)7110-124, 2001.
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IRESSA
Albanell. J Clin Oncol 20(1)7110-124, 2001.
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IRESSA
Albanell. J Clin Oncol 20(1)7110-124, 2001.
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Therapy of Patients with Metastatic Colon Cancer

• How do we know if the treatment is working?
• Wait 2 months and expose the patient to the side
  effects
• Does a test that predicts the effectiveness
• Blood test
• Imaging

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GIST PET Shows a complete response before and
after 5 days of Gleevec
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FDG-PET predicts response to chemotherapy in
NSCLC. Median PFS and OS are significantly longer
for responders than nonresponders (163 versus 54
days and 252 versus 151 days, respectively).
Kelloff, G. J. et al. Clin Cancer Res
2005112785-2808
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Circulating tumor cells

• Peripheral blood epithelial cells shed from tumor
  surface of cancer patients
• Defined by phenotypic characteristics
• Expression of cytokeratin or mucin markers such
  as CK18, CK19, and MUC-1
• Phenotypically similar to primary and/or
  metastatic tumor cells

Fehm T, et al. Clin Cancer Res. 200282073-2084.
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Detection Methods

• Direct methods (enrichment/detection)
• Immunomagnetic
• Immunohistochemistry (IHC)
• PCR analysis
• Automated fluorescent methods

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Prognostic and Predictive Value of CTCs in MBC

• Hypothesis
• Measurement of CTCs in metastatic breast cancer
  may
• Identify aggressive disease (prognostic value)
• Provide early determination of treatment
  efficacy/benefit (predictive value)

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Prognostic Value of Baseline CTC Counts
Overall Survival
100
90
80
70
60
Log rank P lt .0001
Probability of Progression-Free Survival
21.9 months
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10.9months
40
30
20
n 87 (49)
10
0
0
2
4
6
8
10
12
14
16
18
22
24
26
28
30
20
Time From Baseline (Months)

Cristofanilli M, et al. N Engl J Med.
2004351781-791.
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Change in CTC Count During Therapy Predicts
Overall Survival
1
lt5 CTCs at all time points
83 (47)
2
gt 5 at baseline and lt 5 CTC at last draw
38 (21)
3 lt 5 at Early Draw and gt 5 CTC at last
draw 17 (10)
100
4
gt 5 CTCs at all time points
39 (22)
90
1
vs
2
P .3188
80
1
vs
3
P .0014
70
1
vs
4
P lt .0001
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Probability of Survival
2
50
1
40
2
vs
3
P .0397
30
20
2
vs
4
P lt .0001
10
3
vs
4
P .0051
4
3
0
0
2
6
8
10
12
14
16
18
22
24
26
28
20
4
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Time From Baseline (Months)

Cristofanilli M, et al. ASCO
2005. Abstract 524.
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Tamoxifen metabolic pathway
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Tamoxifen Pharmacogenetics(Goetz, Ingle,
Weishilboum, Flockhart)

• Does CYP2D6 genetic variation affect the clinical
  outcomes of women receiving tamoxifen?
• Do women who are co-prescribed medications which
  inhibit CYP2D6 have a higher risk of breast
  cancer relapse?

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CYP2D6 Gene

• Encompasses nine exons with an open reading frame
  of 1383 bp coding for 461 amino acids. Highly
  polymorphic
• At least 46 major polymorphic alleles with 4
  well-defined phenotypes
• Poor metabolizers (PM)
• Intermediate metabolizers (IM)
• Extensive metabolizers (EM)
• Ultra-rapid metabolizers (UM)

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CYP2D6 Gene

• CYP2D6 PM 7-10 of Caucasians lack functional
  CYP2D6
• CYP2D6 4 Most common variant leading to null
  CYP2D6 enzyme in Caucasians (accounts for 75 of
  the Caucasian PM)

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NCCTG 89-30-52
RANDOMIZATION
Postmenopausal women Early ER breast cancer
5 years of Tamoxifen
5 yrs of Tamoxifen 1 yr of Fluoxymesterone
(10 mg po bid)
541 women accrued
5 years total therapy
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NCCTG 89-30-52

• Median follow-up of 12 years
• Accrual completed in April 1995
• No difference between the arms in terms of
  primary endpoint (breast cancer relapse)
• Ingle J, Suman V, Mailliard J, et al Breast
  Cancer Res Treat (In Press)

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Tamoxifen only arm

• 230/257 eligible patients--Formalin fixed
  paraffin-embedded tumor blocks
• Three 10 micron sections
• DNA extracted
• Genotyping
• CYP2D6 (4) (n190)
• CYP3A5 (3)
• SULT1A1 (2)

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Relapse-free Time
CYP2D6 Wt/Wt
CYP2D6 4/Wt
CYP2D6 4/4

P0.030
Years after randomization
CP1193836-1
Goetz et al J Clin Oncol. 200523(36)9312-8.
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Relapse-free Survival
CYP2D6 WT/WT
CYP2D6 4/WT

CYP2D6 4/4
P0.020
Years after randomization
Goetz et al J Clin Oncol. 200523(36)9312-8.
CP1193836-2
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Informed Consent and Regulations
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Ethics of Phase I Trials

• No known benefit
• Risk of toxicity is unknown
• Patients expectations are high
• Patients discount risk of toxicity

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Ethics of Phase I Trials

• Patient assessment of benefit
• Phase I 59.8
• Standard 36.8
• Patient assessment of toxicity
• Phase I 29.8
• Standard 45.6
• Based on analyses of multiple phase I trials
• Benefit (Response) 5
• Toxicity (Death) 0.5

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INFORMED CONSENT
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Consent Form Excerpts

• Why is this study being done?
• This study is being done to
• Learn the highest safe dose of the
  investigational drug 17-AAG when it is given over
  1 hour once each week for 3 out of every 4 weeks
  to patients with advanced cancer.
• Learn the side effects of 17-AAG and how the body
  responds to and removes 17-AAG.

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Consent Form Excerpts
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Consent Form Excerpts
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Consent Form Excerpts

• Are there benefits to taking part in this study?
• No help can be promised by taking part in this
  study, and the chance of help from this study
  cannot be accurately predicted.

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Consent Form Excerpts
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Consent Form Excerpts

• During the first month of this study, the
  following additional tests and procedures will be
  done to test the amount of 17-AAG in your body
  and to learn what effect it has on your body.
  These will be done at no additional cost to you
  and/or your health plan and include
• Nineteen (19) blood samples (totaling about 1¼
  cup) will be collected.
• Before and at one day after your first and third
  weekly 17-AAG treatments, samples of tissue will
  be taken by gently scraping the inside of your
  cheeks or mouth with a tongue depressor.
• You will need to save your urine for 24 hours
  before and after your first 17-AAG treatment.
• If you have a tumor that can be safely and easily
  biopsied, you may be asked to have two additional
  biopsies. One before you start and the other one
  day after the start of your treatment.

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Consent Form Excerpts (HIPAA)

• Authorization To Use And Disclose Protected
  Health Information
• By signing this form, you authorize Mayo Clinic
  Rochester and the investigators to use and
  disclose any information created or collected in
  the course of your participation in this research
  protocol.
• This information may include information relating
  to sexually transmitted disease, acquired
  immunodeficiency syndrome (AIDS), or human
  immunodeficiency virus (HIV). It may also include
  information relating to behavioral or mental
  health services or treatment and treatment for
  substance abuse.

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Consent Forms in Phase I Oncology Trials

• S. Horng et al NEJM 2002 347(26)2134-2140
• never promise benefit
• rarely mention cure
• communicate risk and its unpredictability
• do not contribute to patients expectation of
  benefit

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ADHERENCE TO STUDY PROTOCOL IS CRITICAL
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COMPLIANCE WITH REGULATIONS

• NCI regulations
• Cancer Center
• Cooperative groups
• FDA regulation
• OHRP regulations as interpreted by IRB

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INVESTIGATOR OBLIGATIONS

• Ensure informed consent is obtained
• Report serious adverse events
• Report adverse events
• Data monitoring safety plan
• Data safety monitoring committee
• Protocol compliance
• Regular auditing of cases on study

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QUESTIONS ARE WELCOME