# Presentation: 875954

## Non-Clinical Drug Development

**Chris H. Takimoto, MD, PhD**
**Institute for Drug Development**
**San Antonio Cancer Institute**
**University of Texas Health Science Center**
**San Antonio, TX**

## Drug Development

**Drug discovery & screening**
**Non-clinical development**
**Animal scale up**
**Phase I studies**
**Phase II studies**
**Phase III studies**

*Specific examples from anticancer drug development*

## Overview of Anticancer Drug Development

**IND**

**NDA**

**Chemical Synthesis and Formulation Development**

**Animal Models for Efficacy**

**Assay Development**

**Animal PK and PD**

**Dose Escalation and Initial PK **

**Proof of Concept and Dose Finding**

**Large Efficacy Trials **
**with PK Screen**

**PHASE I**

**PHASE II**

**PHASE III**

**Pre-Clinical Development**

**Clinical Development**

**PK/PD Studies in Special Populations**

## Goals of Non-Clinical Testing of Small Molecule Drugs and Biologicals

**To characterize potential adverse drug effects**
**Define end organ toxicities**
**Define reversibility of toxicity**
**To characterize pharmacokinetic profile**
**To characterize beneficial pharmacodynamic effects**
**Proof of principle**
**To guide safe use in human clinical studies**
**To determine a safe & reasonable starting dose**
**Provide monitoring guidelines for the clinical study**
**Provide sufficient data to conclude that patients are not exposed to unreasonable risks**
**Potential for benefit must also exist**

## Oncology drug development is changing in the new era of targeted cancer therapies

## Conventional Wisdom in the New Age of Modern Drug Development

**Targeted therapies are unique and distinct from classic cytotoxic chemotherapies**
**Classical chemotherapy = poisons**
**All new agents entering the clinical have well defined molecular targets**
**Conventional clinical study designs are outdated, outmoded, and poorly-suited to develop targeted therapies**
**Biomarkers rule!**

## What are Targeted Therapies?The NCI’s Definition

**From the NCI’s internet fact sheet **
***Targeted cancer therapies use drugs that block the growth and spread of cancer. ***
***They interfere with specific molecules involved in carcinogenesis ... and tumor growth. ***
***Because scientists call these molecules “molecular targets,” these therapies are sometimes called “molecularly-targeted therapies.”***
***By focusing on molecular and cellular changes that are specific to cancer, targeted cancer therapies may be more effective than current treatments and less harmful to normal cells.***

- (http://www.cancer.gov/cancertopics/factsheet/Therapy/targeted)

## Poster Child for Targeted Therapies

**Prototypical targeted agent is imatinib**
**A selective inhibitor of BCR-Abl tyrosine kinase in CML or c-Kit in GIST**

- Imatinib (GleevecTM)

## Chronic Myelogenous Leukemia and the Ph Chromosome

**Abnormal Philadelphia (Ph) chromosome identified in most patients with chronic myelogenous leukemia (CML)**
**Identified in over 90% of CML, 20% of adult ALL and 5% of pediatric ALL patients**
**Piece of chromosome 9 is abnormally linked to chromosome 22**
**9:22 translocation**
**c-Abl, the cellular homologue of the transforming retrovirus oncogene (*****v-Abl*****), is located on chromosome 9**
**Activation of c-Abl signals the cell to proliferate and grow**

## Slide 10

## Targeted Therapy with Imatinib 

**Imatinib is a potent inhibitor of the BCR-Abl and the c-Kit tyrosine kinases**
**Generates marked growth inhibition of CML cells and Gastrointestinal Stromal Cell Tumors (GIST)**
**Early Phase I data in CML**
**Hematological response in 98% and cytogenetic remissions in 13% of patients treated in Phase I**
**Substantial single agent activity in GIST tumors**

## Targeted Therapies & Preclinical Development(adapted from Paoletti 2005)

| Characteristic | Cytotoxic Agents | Targeted Agents |
| --- | --- | --- |
| Discovery | Cell based, empirical | Receptor based screen, rationale |
| Mechanism | Often unknown | Basis for screening |
| Pharmacological Effect | Cytotoxic | Cytostatic |
| Specificity | Non-selective | Selective |
| Dose and schedule | Pulsed, cyclical at MTD | Continuous, at tolerable dose |

## Targeted Therapies & Phase I Trials(adapted from Paoletti 2005)

| Characteristic | Cytotoxic Agents | Targeted Agents |
| --- | --- | --- |
| Objectives | PK, MTD | Optimal biological dose (OBD), PK, PK-PD |
| Disease | All types | All types or target bearing |
| Dose | Toxicity-guided escalation | Biomarker-guided escalation |
| Endpoints | Toxicity, MTD, PK  | Target inhibition, OBD, PK |
| Design | Dose escalation in small cohorts | Dose escalation to target inhibition |

## Components of Non-Clinical Drug Development

**In vitro studies: Cell lines, cell-free systems (drug screening)**
**Drug formulation **
**Chemistry, Manufacturing, and Controls: Drug supply & quality**
**In vivo efficacy studies: Animal models and proof of principle**
**5.****	****Non-clinical safety studies**

## In Vitro Study Goals: Define the Drug’s Pharmacology

**Molecular mechanism of action and specific drug targets**
**Molecular pharmacology**
**Determinants of response **
**Intracellular pharmacodynamics**
**Mechanisms of drug resistance**

## In Vitro Study Systems

**Cell-free assay for specific molecular effects**
**Enzyme inhibition, receptor blockade, etc.**
**Yeast-based screening in genetically defined target**
**Mammalian cell lines: (murine, human, etc.)**

## Preclinical PharmacologyIn Vitro Studies of Cancer Agents (1)

**Define anticancer effects**
**Growth inhibition, differentiation, apoptosis, etc**
**Impact on defined biochemical and molecular pathways**
**RNA, DNA and protein biosynthesis, signaling kinases, etc**
**Spectrum of antitumor activity**
**Human tumor cell lines**

## Preclinical PharmacologyIn Vitro Studies of Cancer Agents (2)

**Cellular uptake and membrane transport**
**MDR, MRP, etc**
**Mechanisms of resistance**
**In vitro drug metabolism**
**P450 isoenzymes**
**Effects on hERG channels (prolonged QT interval risk)**
**Preliminary protein binding studies**

## Components of Non-Clinical Drug Development

**In vitro studies: Cell lines, cell-free systems (drug screening)**
**Drug formulation **
**Chemistry, Manufacturing, and Controls: Drug supply & quality**
**In vivo efficacy studies: Animal models and proof of principle**
**5.****	****Non-clinical safety studies**

## Drug Supply and Formulation

**Drug supply: bulk chemical synthesis, natural product isolation, etc.**
**Good Manufacturing Practice (GMP) guidelines for pharmaceutical product manufacturing**
**Formulation for clinical delivery of drug: vehicles for intravenous or other routes of administration**

## Drug Supply Issues

**Paclitaxel source from the bark and wood of the Pacific Yew tree**
**Early drug supply limited the amount available for initial clinical trials **
**Newer semisynthetic production from the needles of the Yew tree (renewable)**

## Drug Formulation Issues

**Poor water solubility of natural products**
**Paclitaxel formulation in Cremophore EL****TM**** (increased toxicity?)**
**Camptothecin derivatives formulated in a dimethylacetamide, polyethylene glycol and phosphoric acid vehicle**
**Later formulated as a lipid colloidal dispersion**

## Components of Non-Clinical Drug Development

**In vitro studies: Cell lines, cell-free systems (drug screening)**
**Drug formulation **
**Chemistry, Manufacturing, and Controls: Drug supply & quality**
**In vivo efficacy studies: Animal models and proof of principle**
**5.****	****Non-clinical safety studies**

## In Vivo Study Goals:Animal Models

**Efficacy: Proof of therapeutic principle**
**Toxicology: Toxicity profile**
**Practical Issues:**
**Animal pharmacokinetics and pharmacodynamics**
**Starting dose and schedule for clinical trials**

## Animal ModelsProof of Principle

**Animal screening is too expensive for routine use**
**Efficacy in animal models of specific disease states occurs after in vitro studies**
**Evaluation of therapeutic index**
**Toxicity versus efficacy**

## Ideal Animal Model

- Validity
- Selectivity
- Predictability
- Reproducibility

- “There is no perfect tumor model”

## Endostatin: An Endogenous Inhibitor of Angiogenesis and Tumor GrowthO'Reilly et al, Cell 88:277-285 (1997) 

## Animal Models in Cancer

**Spontaneous tumors**
**Idiopathic**
**Carcinogen-induced**
**Transgenic/gene knockout animals: p53, RB, etc**
**Transplanted tumors**
**Animal tumors: Lewis lung, S180 sarcoma, etc**
**Human tumor xenografts: human tumor lines implanted in immunodeficient mice (current NCI standard in vivo efficacy testing system)**
**Human tumors growing in vivo in implantable hollow fibers**

## Human Tumor Xenografts

**Athymic “nude”mice developed in 1960’s**
**Mutation in nu gene on chromosome 11**
**Phenotype: retarded growth, low fertility, no fur, immunocompromised**
**Lack thymus gland, T-cell immunity**
**First human tumor xenograft of colon adenocarcinoma by Rygaard & Poulson, 1969**

## Athymic Nude Mice

## Murine Xenograft Sites

**Subcutaneous tumor (NCI method of choice) with IP drug administration**
**Intraperitoneal**
**Intracranial**
**Intrasplenic**
**Renal subcapsule**
**Site-specific (orthotopic) organ inoculation**

## Xenograft Study Endpoints

**Toxicity Endpoints:**
**Drug related death**
**Net animal weight loss**
**Efficacy Endpoints**
**Clonogenic assay****	**
**Tumor growth assay (corrected for tumor doubling time)**
**Treated/control survival ratio**
**Tumor weight change**

## Xenograft Tumor Weight Change

**Tumor weight change ratio (used by the NCI in xenograft evaluation)**
**Defined as: treated/control x 100%**
**Tumor weight in mg = (a x b****2****)/2**
**a = tumor length**
**b = tumor width**
**T/C < 40-50% is considered significant**

## Xenograft Advantages

**Many different human tumor cell lines transplantable**
**Wide representation of most human solid tumors**
**Allows for evaluation of therapeutic index**
**Good correlation with drug regimens active in human lung, colon, breast, and melanoma cancers**

## Xenograft Disadvantages

**Brain tumors difficult to model**
**Different biological behavior, metastases rare**
**Survival not an ideal endpoint: death from bulk of tumor, not invasion**
**Shorter doubling times than original growth in human**
**Less necrosis, better blood supply**
**Difficult to maintain animals due to infection risks**
**Host directed therapies (angiogenesis, immune modulation) may not be applicable**
**Human vs. murine effects**

## Other Animal Models

**Orthotopic animal models: Tumor cell implantation in target organ**
**Metastatic disease models**
**Transgenic Animal Models**
**P53 or other tumor suppressor gene knockout animals**
**Endogenous tumor cell development**
**May be of high value for mAb therapies**

## Non-Clinical Efficacy TestingThe FDA Perspective(J. Leighton, FDA ODAC Meeting, March 13, 2006)

**Pharmacological activity assessed by models of disease are generally of low relevance to safety (IND) and efficacy (NDA) decisions**
**Efficacy in vivo and in vitro from non-clinical studies may not dependably predict clinical efficacy**
**Heterogeneity of disease**
**Interspecies differences in ADME**
**Role of immune system**
**Pharmacology studies are useful for:**
**Assessing an appropriate schedule (daily, weekly, q3wks)**
**Justification for a drug combination**
**Understanding effect at a molecular target**
**Examine receptor specificity**
**Identifying and evaluating biomarkers**

## Components of Non-Clinical Drug Development

**In vitro studies: Cell lines, cell-free systems (drug screening)**
**Drug formulation **
**Chemistry, Manufacturing, and Controls: Drug supply & quality**
**In vivo efficacy studies: Animal models and proof of principle**
**5.****	****Non-clinical safety studies**

## Non-Clinical Safety Studies

**Safety pharmacology**
**Toxicokinetics & pharmacokinetic studies**
**Single dose toxicity studies**
**Repeated dose toxicity studies**

## Safety Pharmacology

**Assessment of drug on vital functions**
**Examples:**
**Cardiovascular: heart rate, BP, ECG, QT interval**
**Central nervous system: locomotor activity, coordination, proconvulsive effects, analgesic effects**
**Respiratory system: respiratory rate, tidal and minute volumes**
**Should complete prior to FIH studies**
**May be separate or a component of toxicity studies**

## Pharmacokinetic & Toxicokinetic Studies

**Analytic assay development and testing**
**Preclinical PK/PD efficacy and toxicity relationships**
**Initial drug formulation testing**
**Testing of different schedules and routes of administration**
**Animal ADME**

## Non-Clinical Toxicology Studies

**GLP Toxicology is expected**
**Use the clinical schedule, route, and formulation**
**Single dose acute toxicity studies required in 2 mammalian species prior to FIH studies**
**Classically rat and dog for small molecules**
**Non-human primates for biologicals**
**Repeat dose toxicology required for anticipated duration of clinical use for most non-oncology agents**
**3 mo. toxicology for ≤ 3 mo. clinical study**
**Recommendations for agents used in the treatment of advanced cancer differs**

## Expected Toxicology Testing for Phase I Oncology Drug Studies(J. Leighton, FDA ODAC Meeting, March 13, 2006)

| Clinical Schedule | Preclinical study schedule * |
| --- | --- |
| Every 21 d | Single dose study |
| Every 14 d | 2 doses, 14 d apart |
| Weekly x 3, week off | Weekly x 3 |
| Daily x 5, break | Daily x 5 |
| Continuous daily | Daily for 28 days |

- * Study schedule does not include a a recovery period
- -- 28 day toxicology is generally sufficient for DRUG trials
- 	extending beyond 28 days

## Non-Clinical Toxicology Studies For Oncology Drug Combinations

**May not be necessary for testing in advanced cancer patients**
**May exclude if:**
**No PK, PD, or metabolic interactions anticipated**
**Drugs are not packaged as a combination**
**All components well studied individually**

## Single Dose Toxicity Studies

**Dose escalation study may be an alternative to a single dose design**
**Dose range should include maximally tolerated dose (MTD) and no adverse effect level (NOAEL)**
**Standard design**
**Early sacrifice at 24 to 48 hr and after 14 days**

## Repeated Dose Toxicity Studies

**Duration of repeated dose studies related to duration of anticipated clinical use**
**Use same schedule and duration**
**Typically 14-28 days**
**Should include recovery group**
**Use can support repeat dose clinical studies**

## Non-Clinical Toxicology Ongoing Endpoints

**Ongoing**
**Clinical signs, behavior**
**Body weights and food consumption**
**Clinical pathology (in larger species)**
**Hematology**
**Chemistry panels**
**Toxicokinetics**
**End of Study**
**Macroscopic changes at necropsy**
**Organ weights**
**Histopathology of all organs**

## Other Toxicology Studies

**Local tolerance studies**
**If warranted by route of administration**
**Genotoxicity studies**
**Reproductive Toxicity studies**
**Carcinogenicity studies**

## Genotoxicity studies

**General**
**Normally done prior to FIH studies, but not required prior to phase I studies in oncology patients**
**Standard battery of genotoxicity tests required prior to initiation of phase II**
**Specific genotoxicity studies**
**In vitro bacterial reverse mutation assays: Ames test, point mutation test**
**In vitro chromosome damage tests in mammalian cells: metaphase cell analysis, murine lymphoma gene mutation assays**
**In vivo chromosomal damage assays: rodent micronucleus tests**

## Reproductive Toxicity Studies

**Men**
**May include in Phase I/II after relevant repeated dose toxicity studies**
**Male fertility study should be completed prior to initiation of Phase III**
**Women not of childbearing potential**
**May include in clinical trials after relevant repeated dose toxicity studies**
**Women of childbearing potential**
**May include in carefully monitored early studies with precautions**
**Fertility and embryo-fetal toxicity studies should be completed prior to entry of women into phase III trials**
**Pregnant women**
**All reproductive toxicity and genotoxicity studies must be completed prior to entry of these women in trials**

## Carcinogenicity studies

**Usually not needed prior to clinical trial initiation**
**Not needed in advanced cancer indications**

## Preclinical ToxicologyGoals

**Estimate a “safe” starting dose for phase I studies**
**Determine the toxicity profile for acute and chronic administration**
**NCI guidelines recommend single dose and multidose toxicity in two species (one non-rodent)**
**Historical guidelines are 1/10 the LD****10 ****in mice **
**Death, as an endpoint no longer required**

## Current FDA Approach to Starting Doses

**Starting dose of 1/10 the dose causing severe toxicity (or death) in 10% of rodents (STD****10****) on mg/m****2**** basis**
**Provided the same dose causes no severe irreversible toxicity in a non-rodent species (usually dogs)**
**If irreversible toxicities are seen, then 1/6 of the highest dose tested in non-rodents that does not cause severe, irreversible toxicity**
**Occasionally, species specific difference may mandate the use of alternative species for selection of starting dose**

## NO

**10% of rodents (STD****10****)**

**Convert from mg/kg to mg/m****2**
**Mouse x 3; Rat x 6; Guinea-pig x 7.7**
**Hamster x 4.1**

**Determine non-rodent Highest**
**Non-Severely Toxic Dose**
**(HNSTD)**

**Is rodent an**
**inappropriate species?**
**(biochem, ADME, target, etc)**

**Is 1/10**
**rodent STD10 (mg/m****2****)**
**severely toxic to**
**non-rodents?**

**Is non-rodent inappropriate?**

**Convert from mg/kg to mg/m****2**
**Dog x 20; Monkey x 10**
**Rabbit x 11.6**

**Start Dose =1/6**
**Non-Rodent HNSTD**

**NO**

**YES**

**YES**

**YES**

**NO**

**Start Dose =1/10**
**Rodent STD****10**

**NO**

## Non-Clinical Drug Safety Testingfor Summary of the FDA Perspective(J. Leighton, FDA ODAC Meeting, March 13, 2006)

**Conduct 2 pivotal toxicology studies using the same schedule, formulation, and route as the proposed clinical trial**
**Conduct a rodent study that identifies life-threatening doses**
**Conduct a non-rodent study that confirms non-life threatening doses have been identified**
**Studies of 28 days should be provided for continuous administration**
**Studies for one or several administrations, depending on the schedule for intermittent schedules**
**Provide full histopathology in one of these studies**
**Conduct other studies as needed**

## Non-Clinical Drug Safety TestingSummary of the FDA Perspective(J. Leighton, FDA ODAC Meeting, March 13, 2006)

**Multiple cycles/continuous treatment generally acceptable, assuming acceptable safety profile in the non-clinical setting**
**Pre-IND meeting with sponsors are encouraged to discuss problem areas and provide alternative pathways to initiation of the phase I trial**
**Most potential clinical holds resolved through discussion with sponsor**
**Guidelines for biologicals (monoclonal antibodies, etc) are in preparation but may differ from small molecule recommendations**

## An Excellent Resource for Anticancer Drugs(DeGeorge et al Cancer Chemother Pharmacol 1998;41:173)

- Plus numerous FDA guidances at http://www.fda.gov/cder/Guidance

## Monoclonal Antibody (mAb) Therapeutics

**Targeted mAb are distinct from small molecule therapeutics**
**Explosion in popularity**
**Higher approval rates in oncology (~21% vs. <5%)**
**High specificity, less off target risk**
**Long t1/2 (10-21 days)**
**Novel targets that are difficult or impossible to modulate by small molecules**
**Flexible bioengineered design**
**Modulation of functional domains**

## Non-Clinical Toxicology for mAb Therapies

**mAb present major safety challenges**
**Safety toxicology studies in primates**
**Old world primates most common**
**May exceed primate toxicology resources**
**Chimpanzees in rare specialized cases**
**Primate toxicology may still not predict human effects**
**TGN1412 anti CD28 super agonist causes non-specific broad T-cell activation in humans with catastrophic consequences****	**
**Transgenic rodents engineered to express human target may be selectively employed (knock out/knock in animals)**
**Surrogate mAb (mouse equivalent) toxicity and efficacy studies to support clinical studies**

## Starting Doses for Biological Therapies

**Historically, some fraction of the no adverse event level (NOAEL)**
**If species specific differences preclude precise dose calculations, then...**
**Consider estimations of receptor occupancy, cellular dose response studies from best available models to estimate a Minimum Anticipated Biological Effect Level (MABEL)**
**Recommendations for biological therapies are in evolution **

## An Example of a Phase I study of a Targeted Therapy that Incorporates Biomarkers Developed in Preclinical Development

## AEE788, A Dual EGFR & VEGFR Targeting Agent

- Oral receptor tyrosine kinase inhibitor
- A “dirty” kinase inhibitor
- 7H-pyrrolo[2,3-d] pyrimidine derivative
- Inhibits EGFR and ErbB-2 receptor tyrosine kinases with IC50’s of 2-6 nM
- Also inhibits multiple other kinases

## In Vitro AEE788 Pharmacology

- _Kinase__	__IC_50_ (uM)_
- EGFR	0.002
- ErbB2	0.006
- KDR		0.077
- HER4	0.059
- C-Abl		0.052
- C-Src		0.061
- RET		0.74

- _Kinase__	__ IC_50_ (uM)_
- C-Kit		0.790
- C-Met	2.90
- Flk, Tek	>2
- IGF-1R	>2
- PKC-a	>10
- CDK1/2	>10

## AEE788 Study Design

- Three center N. American/European study
- C.H. Takimoto, IDD/CTRC, San Antonio
- J. Baselga, Vall d’Hebron, Barcelona, Spain
- A.T. van Oosterom, Catholic University Leuven, Belgium
- Dose escalation design of AEE788 orally on a daily dose schedule in advanced cancer patients
- Standard adult phase I patient population
- 3-6 patients per dose level allowed
- Endpoints:
- Determine the MTD and DLT of AEE orally on a daily dose schedule
- Characterize drug pharmacokinetics
- Extensive pharmacodynamic assessments

## Dose Levels and DLTs During Cycle 1(Baselga ASCO 2005)

| Dose Level, mg | Enrolled | Pts with DLT, n | DLT (n) |
| --- | --- | --- | --- |
| 25 | 5 | 0 | -- |
| 50 | 6 | 0 | -- |
| 100 | 5 | 0 | -- |
| 150 | 5 | 0 | -- |
| 225 | 7 | 0 | -- |
| 300 | 7 | 0 | -- |
| 400 | 7 | 0 | -- |
| 450 | 7 | 0 | -- |
| 500 | 6 | 2 | Gr 3 diarrhea (2) |
| 550 | 9 | 2 | Gr 3 diarrhea (2) |
| Total | 64 | 4 |  |

## AEE788 Skin Rash

**AEE788 Skin Rash**

- Skin rash
- Any grade = 42.7%
- Gr 3 or 4 = 0%
- Dry skin, fine rash seen at lower dose levels
- Pustular macular papular skin rash seen at higher dose levels (>225 mg/d)

## AEE788 Other Toxicities

- Grade 3 diarrhea (10 pts)
- Grade 3 fatigue (5 pts)
- Grade 3 anorexia (4 pts)
- Grade 3 hyperbilirubinemia (3 pts)
- No evidence of cardiac toxicity or QTc changes in 2811 EKGs in 96 pts

## Delayed Onset Reversible Hepatic Transaminase Elevation

- Reversible grade 3 / 4 elevations of AST/ALT at doses ≥300 mg seen in 12 pts
- Median onset of 99 days (after 4 cycles)
- Observed in presence and absence of liver metastases
- Total bilirubin generally unaffected
- Dose and duration of treatment dependent
- Dosing at ≥300 mg/d for 4+ cycles is problematic

## AEE788 Efficacy Data

- 83 Patients treated with doses up to 550 mg
- One PR in angiosarcoma at 400 mg now completed 5 cycles
- 36 of 83 pts (43%) with stable disease beyond 2 cycles
- Median number of cycles that patients remained on study is 2 (range 0.5-14)

## Planned PD Assessments

- Skin biopsies in 53 pts
- Vascular IHC analyses in 32 pts
- Tumor biopsy IHC data from 15 pts

## Biopsy samples were evaluated by immunohistochemistry (IHC) and scored by Hscore.  Hscore = (% faint stained cells) + (% moderate stained cells)*2 + (% strong stained cells)*3.  Ki67 was scored by % positive cells

- --Baselga et al, ASCO 2005

## Results: Skin (basal epidermis) p-EGFR

- --Baselga et al, ASCO 2005

## Pharmacodynamic Modeling

- --Baselga et al, ASCO 2005

## Tumor Biopsy IHC Results (n=15)

_**25 mg**_
- Pre-Rx
- During Rx

_**550 mg**_
- Pre-Rx
- During Rx

- --Baselga et al, ASCO 2005

## PD Tumor Marker Changes

- --Baselga et al, ASCO 2005

## Pharmacodynamic Findings

- Inhibition of molecular targets was dose and serum concentration dependent with significant variablity
- Active concentration = AEE788 (parent) + AQM674 (active metabolite)
- Tumor pEGFR inhibition (IC50 18 nM) agrees with A431 cell line data (IC50 = 11 nM)
- Skin PD Potency
_**Test**_**	****	****	**_**ID80**_
- pEGFR/pMAPK		225-250 mg
- Ki67			50-100 mg
- Tumor PD Potency (greater than skin)
_**Test**_			_**ID80**_
- pEGFR			150 mg
- pAkt			100-150 mg
- Optimal biological dose may be ~250 mg(?)

## AEE788 Phase I Study Conclusions

- Cycle 1 DLT was grade 3 diarrhea despite supportive care at 500-550 mg/d
- Other toxicities: fatigue, nausea, rash, anorexia, vomiting, stomatitis
- Chronic dosing revealed grade 3/4 hepatic transaminitis at doses >300 mg after 4 cycles
- PK/PD analysis suggests dose ≥250 mg may optimally modulate biological target(s)
- Further exploration of daily 250 mg dosing and alternative schedules is ongoing
- PK/PD biomarker data highly useful in clinical decision making process

## The Clinical Trial Challenge

**We stand at the dawn of the post genomic era when new targets for novel treatments for human cancer are just being discovered and defined**
**Basic research is the engine that drives this process**
**Clinical researchers have to take these promising agents and test them in the best and most efficient ways possible **
**Traditional clinical endpoints, and...**
**Molecular target endpoints in clinical studies**

## The Challenge!

**Preclinical**
**Pharmacology**

**Traditional animal        ****	****studies**
**PK/PD**
**Toxicology**
**Molecular targets**

**Clinical**
**Pharmacologist**

**Early Phase I**
**Pharmacokinetic**
**Clinical Trials**

**Traditional dose and**
**   ****toxicity endpoints**
**Traditional PK/PD**
**Molecular and**
**biochemical**
**endpoints**

## New Paradigms for Drug Development in the Post Genomic Era

**Expanding role for translational studies in Phase I clinical trials **
**Bridge the gap between preclinical pharmacologic studies and early clinical trials**
**New molecular and biochemical endpoints are essential for cancer prevention and antimetastatic agents**
**This is an exciting time to be developing new anticancer drugs!**

## New Phase I Paradigms: Evolution not Revolution!