From Lab to Clinic: Success Stories of Repurposed Drugs in Treating Major Diseases

Drug repurposing, the process of identifying new therapeutic uses for existing drugs, has emerged as a cost-effective and time-saving alternative to traditional drug development. This strategy leverages the known pharmacological and safety profiles of approved or investigational drugs to accelerate their clinical application for other diseases. In recent years, repurposed drugs have played a crucial role in addressing treatment gaps in complex and multifactorial diseases such as cancer, neurodegenerative disorders and infectious diseases. This review highlights prominent examples where repurposed drugs have successfully transitioned from laboratory findings to clinical application. We discuss key molecular mechanisms, including polypharmacology and target pathway modulation that enable repositioning. Emphasis is also placed on advances in computational approaches, network pharmacology and data-driven tools that enhance repurposing efforts. Additionally, we outline the challenges related to regulatory hurdles, intellectual property and clinical validation. By analysing these success stories, we aim to provide a strategic framework to guide future drug repurposing initiatives.