Optimizing the "Drug-Like" Properties of Leads in Drug Discovery (Biotechnology: Pharmaceutical Aspects Book 4)

Drug discovery and development is a very complex, costly, and ti- consuming process. Because of the uncertainties associated with predicting the pharmacological effects and the toxicity characteristics of new chemical entities in man, their clinical development is quite prone to failure. In recent years, phar- ceutical companies have come under increasing pressure to introduce new blockbuster drugs into the marketplace more rapidly. Companies have responded to these pressures by introducing new technologies and new strategies to expedite drug discovery and development. Drug discovery and development have traditionally been divided into three separate processes (i. e. , discovery research, preclinical development, and clinical development) that ideally should be integrated both organizationally and functionally. Instead, separate and distinct discovery research, preclinical development, and clinical development divisions were created within many companies during the 1980s and 1990s, Because of their isolation, scientists in the discovery research divisions often were advancing drug candidates into preclinical development that had marginal drug-like properties. For the purpose of this presentation, “drug-like” properties refer to the molecule’s physicochemical, absorption-distribution-metabolism-excretion (ADME), and toxicological properties. Lacking optimal drug-like properties often caused these drug candidates to fail in preclinical or clinical development.

Traditionally, incorporating optimal drug-like properties into a structural lead was not considered by medicinal chemists to be their responsibility. Instead, medicinal chemists felt that the undesirable drug-like properties in their drug candidates would be fixed by preclinical development scientists. However, that view has changed in the past 5-10 years, resulting in another significant paradigm shift in drug discovery. The most significant aspect of this latest paradigm shift is the recognition by medicinal chemists that the drug-like properties of structural hits, structural leads, and drug candidates are intrinsic properties of the molecules and that it is the responsibility of the medicinal chemist to optimize not only the pharmacological properties but also the drug-like properties of these molecules. Therefore, assessment of these drug-like properties is now done early in the drug discovery process on structural hits and structural leads as well as the design of screening libraries. Optimization of these drug-like properties is done through an iterative process in close collaboration with preclinical development scientists. This process is analogous to the process used by the medicinal chemist to characterize and optimize the pharmacological activity of their structural hits, leads and drug candidates.

Recognizing these changes in the paradigm by which drugs are discovered, the American Association of Pharmaceutical Scientists (AAPS) has recently organized and sponsored two focused workshops in the area of profiling drug-like properties during drug discovery.

The first workshop, entitled "Pharmaceutical Profiling in Drug Discovery for Lead Selection", took place in Whippany, NJ on May 19-21, 2003. This workshop, which was co-sponsored by the American Chemical Society-Medicinal Chemistry Division and the Society for Biomolecular Screening, was focused on prediction, measurement, and utilization of drug-like properties during lead selection. From this workshop arose the book entitled Pharmaceutical Profiling in Drug discovery for Lead Selection, which was edited by Ronald T. Borchardt, Edward H. Kerns, Christopher A. Lipinski, Dhiren R. Thakker and Binghe Wang and published by AAPS Press (Arlington, VA) in 2004.

The second workshop entitled "Optimizing the Drug-Like Properties of Leads in Drug Discovery" took place in Parsippany, NJ on September 19-22, 2004. This workshop, which was co-sponsored by the American Chemical Society-Medicinal Chemistry Division, American Chemical Society-North Jersey Section, American Society for Clinical Pharmacology and Therapeutics, European Federation for Pharmaceutical Sciences, International Society for the study of Xenobiotics, and the Society of Toxicology, was focused on the optimization of the drug-like properties of leads in drug discovery. If the strategies and the methodologies presented at this workshop were to be adopted by pharmaceutical and biotechnology companies, it is the belief of the workshop’s organizers that more higher quality drug candidates would be advancing into preclinical and clinical development resulting in more efficacious and safer drugs.

Traditionally, incorporating optimal drug-like properties into a structural lead was not considered by medicinal chemists to be their responsibility. Instead, medicinal chemists felt that the undesirable drug-like properties in their drug candidates would be fixed by preclinical development scientists. However, that view has changed in the past 5-10 years, resulting in another significant paradigm shift in drug discovery. The most significant aspect of this latest paradigm shift is the recognition by medicinal chemists that the drug-like properties of structural hits, structural leads, and drug candidates are intrinsic properties of the molecules and that it is the responsibility of the medicinal chemist to optimize not only the pharmacological properties but also the drug-like properties of these molecules. Therefore, assessment of these drug-like properties is now done early in the drug discovery process on structural hits and structural leads as well as the design of screening libraries. Optimization of these drug-like properties is done through an iterative process in close collaboration with preclinical development scientists. This process is analogous to the process used by the medicinal chemist to characterize and optimize the pharmacological activity of their structural hits, leads and drug candidates. Recognizing these changes in the paradigm by which drugs are discovered, the American Association of Pharmaceutical Scientists (AAPS) has recently organized and sponsored two focused workshops in the area of profiling drug-like properties during drug discovery. The first workshop, entitled Pharmaceutical Profiling in Drug Discovery for Lead Selection, took place in Whippany, NJ on May 19-21, 2003. This workshop, which was co-sponsored by the American Chemical Society-Medicinal Chemistry Division and the Society for Biomolecular Screening, was focused on prediction, measurement, and utilization of drug-like properties during lead selection. From this worksho Front Matter....Pages i-x Strategic Use of Preclinical Pharmacokinetic Studies and In Vitro Models in Optimizing ADME Properties of Lead Compounds....Pages 1-23 Role of Mechanistic Transport Studies in Lead Optimization....Pages 25-47 Metabolic Activation-Role in Toxicity and Idiosyncratic Reactions....Pages 49-80 Case History — Use of ADME Studies for Optimization of Drug Candidates....Pages 81-97 Solubility, Solubilization and Dissolution in Drug Delivery During Lead Optimization....Pages 99-130 Lipid-based Systems, Drug Exposure and Lead Optimization....Pages 131-150 Biopharmaceutics Modeling and the Role of Dose and Formulation on Oral Exposure....Pages 151-166 Application of Physicochemical Data to Support Lead Optimization by Discovery Teams....Pages 167-193 Computational Models Supporting Lead Optimization in Drug Discovery....Pages 195-219 Prodrug Strategies for Improving Drug-Like Properties....Pages 221-242 The Application of Multivariate Data Analysis to Compound Property Optimization....Pages 243-254 Case History: Toxicology Biomarker Development Using Toxicogenomics....Pages 255-270 Predicting Idiosyncratic Drug Reactions....Pages 271-299 Elementary Predictive Toxicology for Advanced Applications....Pages 301-322 The Application of PK/PD Modeling and Simulations During Lead Optimization....Pages 323-353 Early Preclinical Evaluation of Brain Exposure in Support of Hit Identification and Lead Optimization....Pages 355-410 Optimizing Biomarker Development for Clinical Studies at the Lead Optimization Stage of Drug Development....Pages 411-421 The Relevance of Transporters in Determining Drug Disposition....Pages 423-459 Back Matter....Pages 461-511 From this workshop arose the book entitled Pharmaceutical Profiling in Drug discovery for Lead Selection, which was edited by Ronald T. Borchardt, Edward H. Kerns, Christopher A. Lipinski, Dhiren R. Thakker and Binghe Wang and published by AAPS Press (Arlington, VA) in 2004. The second workshop entitled "Optimizing the Drug-Like Properties of Leads in Drug Discovery" took place in Parsippany, NJ on September 19-22, 2004. This workshop, which was co-sponsored by the American Chemical Society-Medicinal Chemistry Division, American Chemical Society-North Jersey Section, American Society for Clinical Pharmacology and Therapeutics, European Federation for Pharmaceutical Sciences, International Society for the study of Xenobiotics, and the Society of Toxicology, was focused on the optimization of the drug-like properties of leads in drug discovery. If the strategies and the methodologies presented at this workshop were to be adopted by pharmaceutical and biotechnology companies, it is the belief of the workshop's organizers that more higher quality drug candidates would be advancing into preclinical and clinical development resulting in more efficacious and safer drugs."--Publisher's description This book arises from a workshop organized by the American Association of Pharmaceutical Scientists entitled "Optimizing the Drug-Like Properties of Leads in Drug Discovery," which took place in Parsippany, NJ in September 2004. The workshop focused on the optimization of the drug-like properties of leads in drug discovery. The volume outlines strategies and methodologies designed to guide pharmaceutical and biotechnology companies through the drug discovery and development process. Based on the workshop, entitled "Pharmaceutical Profiling in Drug Discovery for Lead Selection", which took place in Whippany, on May 19-21, 2003. The workshop was focused on prediction, measurement, and utilization of drug-like properties during lead selection