Drug Discovery and Preclinical Development Neal G . Simon , Ph . D. Professor Department of Biological Sciences Disclaimer “Those wh o h ave k nowl ed ge, d on’t predi ct . Those who predict, don’t have knowledge.” Lao Tzu, 6th Century BC Chinese Poet Discovery and Preclinical Development I. Background II. The R&D Landscape III. ItidTftiInnovation and Transformation IV. The Preclinical Development Process V. Case Study: Stress-related Affective Disorders Serendipity or Good Science: Building Opportunity Hoffman Osterhof I. Background Drug Development Process Biopharmaceutical Drug Development: Attrition Drug FDA Large Scale Discovery Pre-Clinical Clinical Trials Review Manufacturing / Phase IV Phase I Phase III 20-100 1000-5000 Volunteers Volunteers 10,000 bmitted 1 FDA Com- bmitted 250 Compounds 5 Compounds uu pound uu AdApproved s Drug NDA S NDA IND S Phase II 100-500 Volunteers 5 years 1.5 years 6 years 2 years 2 years Quelle: Burrell Report Biotechnology Industry 2006 Capitalized Cost Estimates per New Molecule *All R&D costs (basic research and preclinical development) prior to initiation of clinical testing ** Based on a 5-year shift and prior growth rates for the preclinical and clinical periods. DiMasi and Grabowski (2007) II. The Research & Developppment Landscape R&D Expenditures and Return on Investment: A Declining Function Phrma (2005); Tufts CSDD (2005) R&D Expenditures 1992-2004 and FDA Approvals Hu et al (2007) NIH Budget by Area Pharmaceutical Industry: Diminishing Returns “That is why the business model is under threat: the ability to devise new molecules through R&D and bring them to market is not keeping up with what ’s being lost to generic manufacturers on the other end. This situation requires new thinking, new urgency, new capabilities.” FdHFred Hassan, CEOShiCEO Schering-Plough , 2005 Saltzmann (2006) III. Innovation and Transformation Innovation Models and Transformation Hu et al (2007) Innovation Models: In-licensing and Acquisitions Saltzmann (2006) Me Too Drugs: Antidepressants 1986 Fluvoxamine (Luvox; Solvay) SSRI 1987 Fluoxetine (Prozac; Lilly) SSRI 1992 Sertraline* (Zoloft; Pfizer) SSRI/NRI 1993 Venlafaxine (Effexor; Wyeth) SSRI/NRI 1996 Buproprion (Wellbutrin; Wyeth) SNRI/DRI 2002 Escitalopram (Lexapro; Forrest) SSRI 2004 Duloxetine (Cymbalta; Lilly) SSRI/NRI Personalized Medicine (sort of) Discovery & Preclinical Development IV. Discovery and Preclinical Development Discovery and Preclinical Development Lead Selection and Drug Candidate Preclinical Drug Optimization (iterative) Confirmation Characterization Regul a Efficacy Assessment: Does it work? tory Sub ADME Profiling: How can it be delivered and what does the body do? m ission t Toxicology/Safety Pharmacology Assessment: Is it safe? o FDA Pharmaceutics: Is the manufacture viable and controllable? Adapted from TetraQ Stage 1: Lead Selection and Optimization Essential Pharmaceutics • Structural Characterization • Impurity Identification • Solubility assessment • Prototype formulation • Stability testing Screening Efficacy Early Toxicology Early ADME • In silico profiling • Off targe t screen • In vitro models • Develop simple • In vitro cytotoxicity • In vivo models analytical method • Preliminary AMES • Other • Measure membrane • hERG binding permeability • Plasma Stability Adapted from TetraQ Stage 2: Drug Candidate Confirmation Data from Lead Optimization Stage Preliminary CMC “Benchmark” in Preliminary (Chemistry, ADME Profiling Manufacture and vivo Models Toxicology Control) • Optimized • Formulation for analytical • Maximum GLP Toxicology method tolerated dose • Sta bility t esti ng • IiIn vivo modldels development (MTD) of active • Validated • Basic pharma- • Repeat Dose ingredient models cokinetics (PK) (non-GLP) • Detailed • Models in other &Oral& Oral • Preliminary phihysicoch emi ilcal disease areas Bioavailability Cardiovascular characterization • Determine Safety • Impurity metabolism of Pharmacology analysis drug Adapted from TetraQ Stage 3: Preclinical Drug Characteristics Data from Prior Stages Detailed Preclinical Comprehensive GLP Toxicology CMC ADME Package • analytical method • acute study • ICH Stability development • subchronic repeat Testing • Comprehensive dose study • ICH impur ity Pharmacokinetics • Genotoxicity analysis • GLP TK Battery •Develop prototype • Comprehensive • Safety clinical formulation identification of Pharmacology metabolites Regulatory Submission or Presentation to Pharma Adapted from TetraQ V. Case Study: Stress-related Affective Disorders Overview GPCR‐targeted oral small molllecule drugs for stress, mood, and behavior disorders First compounds: vasopressin receptor antagonists Somewhere between skunk works, serendippyity, and good planning AVP: Biological Diversity Invertebrate & Vertebrate Vertebrate Behavior Physiology fluid regulation communication carbhdbohydrat e met tbliabolism sexualbl beh avi or thermoregulation pair bonding reproductive function paternal/maternal care social memory stress-related disorders imppyulsivity/violence Hypothalamic-Pituitary Adrenal Axis Compound #1 Profile: • Novel oral vasopressin AVP receptor antagonist • Initial clinical development for stress‐related affective illness • Serenic activity established in rodent models Market: • $20+ billion World Wide Market • 35 million people affected by anxiety and depression in US alone Status: • Phase I completed • Phase II in planning Compound #1: Preclinical Development I. in vitro Biology and PK II. IND-directed Toxicology and Pharmacolo gy III. Behavior and Neuroimaging * NIMH (MH063663), NIH Roadmap Initiative, NCI Binding and Function at Human AVP Receptor A competitive binding assay was conducted in CHO cells transfected with human AVP receptor (left panel). Compound #1 inhibited AVP - mediated phosphatidyl inositol turnover with a Ki value at 0.16 nM (right panel). In hibition of H uman AVP Bi ndi ng b y Inhibition of AVP Induced IP3 Production 1000 3500 VP AA 800 3000 EC50 = 0 .87 nM 3 H- 3 Ki = 0.16 nM 2500 600 H-IP IC50 = 0.49 nM 3 2000 Ki = 0.30 nM 400 M of 1500 of Bound PP C 1000 200 CPM 500 0 0 -13 -12 -11 -10 -9 -8 -7 -6 -5 -13 -12 -11 -10 -9 -8 -7 -6 -5 Concentration: Log M Concentration: Log M Compound #1: Selectivity Tested at vs 64 receptors including 35 GPCRs Receptor Class #1 (% inhibition) Vasopressin 1 80.40% NtNeurotransm ittltditter related -20% to +20% Steroids -20% to +20% Ion channels -20% to +20% Second messengers -20% to +20% Prostaglandins -20% to +20% Gthft/hGrowth factors/hormones -20% to +20% Brain/gut peptides -20% to +20% (not including Vasopressin 1) Enzymes -20% to +20% *-20% to +20% is considered “baseline,” which is defined as “inactive” Compound #1: IND-Directed Studies Genetic Safety Mammalian Toxicology Pharmacology Toxicology AMES hERG 7-day Repeat Oral (gavage) in Rats Chromosomal Rat Irwin Aberration 28-day Repeat Oral Cardiovascular & (gavage) dose in Rats Pulmonary Safety in Dogs 7-day DRF in Dogs 28-day Repeat Oral (capsule) dose in Dogs (just completed) Compound #1: hERG Test for QT Prolongation Values shown are Inhibition of Current (%) + SEM Test Compound % Inhibition SEM Compound 1 32.9 1.5 Positive Control 76.7 2.8 (tfterfena dine 60 nM) Conducted by ChanTest, Inc; Covance GLP study 7252-117 Results: IC50 = 1.9 μM indicating low risk of cardiac arrhythmias based on anticipated clinical dosing Compound #1 Blocks Vasopressin-induced Increases in Blood Pressure Blood Pressure 25 Blood Pressure 20 Hg) Hg) mmmm 15 ** sure (msure (m 10ssss 5 ** lood prelood pre 0BB AVPvehicle Only 0.16 0.4 1 2.5 Dose (mg/kg) ** p<0.05 vs vehicle Vasopressin is Linked to Stress-related Disorders R. Landgraf (2006). Involvement of the vasopressin system in stress-related disorders. CNS & Neurological Disorders – Drug Targets 5, 167-179 Increased synthesis, content, and release of AVP in PVN in HAB and LAB rats under basal conditions Elevated Vasopressin is Linked to Stress-related Disorders: Rodent Model AVP in the paraventricular nucleus (PVN) flanking the 3rd ventricle (3V) in HAB (high anxiety) and LAB (low anxiety) mice. Elevated Plus Maze Forced Swim Test Bunck et al. (2009) AVP mRNA in Supraoptic and Paraventricular Nuclei from Depressed and Control Individuals AVP mRNA in PVN and SON in depressed (n=9) and Signal on film in SON and PVN control patients (n=8) Meynen et al (2006) fMRI: Imaging Stress/Arousal in Awake Animals Piloerection is an index of autonomic activation Compound #1 Blocks Stress & Arousal: Composite View Mate/Intruder + Compound #1 Imaging on awake rats Treatment Mate & Intruder Major Brain Stress/Arousal in #1: Blockadeof Compound Amygdala Cortex Hippocampus Thalamus Regions Activation of Olfactory and Reward Pathways in the Presence of Compound #1 but not Fluoxetine Serendipity or Good Science: Building Opportunity Hoffman Osterhof Thanks for Your Time and Attention.