Dedication

*Dedicated to my Parents & Family who believed in academics as the way forward for an intelligent mind and to the Teachers who introduced me the the subject and nurtured my interest in it.*

Preface

This book provides a comprehensive overview of drug repurposing as well as its role in developing drugs for infectious diseases. These drugs include antivirals and antibacterial and anticancer drugs, and several immunotherapeutics. It highlights recent advancements as well as future directions for effective utilization of drug repurposing. Due to the high costs and time associated with the new drug discovery process, the inclination towards drug repurposing is increasing for common as well as rare diseases. The book covers various aspects and features of drug repurposing, which is crucial for promptly identifying drugs of choice for communicable and

Drug repurposing (also known as drug repositioning, reprofiling, or re-tasking) is a drug discovery strategy for identifying new uses for already approved or investigational drugs that are not envisaged by the original medical indication. The drug repurposing approach has numerous advantages over new drug discovery. The most important is the reduction of risk of failure due to the available safety data of the repurposed drugs. Another important aspect of drug repurposing is that the time frame required for the development of drugs can be reduced due to available preclinical safety assessments. Moreover, the investment is less in the case of repurposed drugs. However, the regulatory and phase 3 trial costs may be similar to those of new drugs. Importantly, the cost for repurposed drugs to come to the market is estimated to be US\$300 million in comparison with the estimated cost

This book discusses research methodologies, resources, and technologies for identifying molecular aspects and therapeutic applications of drug repurposing for various communicable and non-communicable diseases. Within the frame of drug discovery, the book includes seven chapters, each of which focuses on a specific aspect of drug repurposing. This book is a self-contained collection of scholarly contributions targeting an audience of practicing researchers, academics,

I am overwhelmed in all humbleness and gratefulness to acknowledge all the contributors who trusted me and supported me in this work. I am especially thankful to Dr. Raymond Chang (Institute of East-West Medicine, New York, USA) and Dr. Angus Dalgleish (St. Georges, University of London, London, UK) for providing excellent assistance in editing Chapters 9–11 on drug repurposing for anticancer drug discovery. My research fellows and students are central to all my research and academic work. They are the motivating force behind anything constructive I do. They are truly brilliant and have a bright future. I would like to express our special thanks to our mentors, teachers, and students who gave me the strength to see this project to fruition. Also, I would like to thank the

non-communicable diseases.

of US\$2-3 billion for new drug discovery.

Ph.D. students, and other scientists.
