Drug Repurposing in COVID-19 and Cancer: How Far Have We Come?

ABSTRACT

Drug repurposing is a strategy for ascertaining new implications for already approved drugs. Historically, this field started with the serendipitous and inadvertent findings of a drug that was found to have an effect other than its original indication that was previously unrecognized and that had potential application in an entirely different disease. The fact that the rate of failure associated with the development of new drugs is high and the funds needed are enormous, it has compelled the scientific fraternity to look for alternatives and thus the drug repurposing approach has gained traction in the scientific community. The havoc that COVID-19 wreaked is unprecedented and till date it has led to the death of around 5.7 million people worldwide. The scientific fraternity, the world over, has embarked on the journey of getting a sure shot treatment for this deadly disease and till date many studies have been published discussing the role of various repurposed drug candidates in COVID-19 treatment. A majority of these studies have been carried out using structural bioinformatics and have not been validated by in vitro experiments. There is a pressing need for the treatment of COVID-19 disease using repurposed drugs by experimental validation and clinical testing, and augmented by the modern Machine Learning (ML)-and Artificial Intelligence (AI)-based approaches. A number of drug candidates have been investigated for their potential applications in cancer therapy, however the conundrum about the utility of either repurposed drug candidates or only active anti-cancer drugs for cancer therapy is to be pursued thoroughly so that mankind gets the most out of whatever potential the drug candidates, whether old or new, have in store for us. This chapter discusses the utility of drug repurposing approach as an alternative strategy for drug discovery that is intended to find treatment for new and emerging infectious diseases, viz. COVID-19 and cancer. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023.