Drug repurposing, or identifying new therapeutic uses for existing drugs, is gaining significant momentum as a promising approach to accelerate drug development and reduce costs. This book chapter provides a comprehensive overview of the principles, strategies, and real-world examples of successful drug repurposing efforts.
The chapter highlights several compelling advantages of drug repurposing over traditional drug discovery from scratch. These include substantial cost and time savings by leveraging existing safety data, reduced risk by starting with known compounds, and the potential to address rare and neglected diseases.
Key principles discussed include utilizing knowledge from approved drugs, identifying new therapeutic targets through approaches like genomics and systems biology, and gaining mechanistic insights into off-target effects that could reveal repurposing opportunities.
Strategies covered range from computational methods like virtual screening and machine learning, to experimental techniques such as high-throughput screening and structure-activity relationship analysis. The chapter examines notable success stories like repurposing aspirin for cardiovascular disease prevention, thalidomide for leprosy and cancer treatment, and dexamethasone for severe COVID-19 cases.
While promising, drug repurposing faces hurdles such as limited funding incentives, regulatory complexities around new indications, and challenges in identifying suitable repurposing candidates. However, the authors argue the opportunities, including accelerated timelines, cost-efficiency and expanding treatment options, make this a valuable area deserving further research and investment.
Looking ahead, the future of drug repurposing is expected to involve increasing precision through advanced technologies, exploring drug combinations through network pharmacology, and greater use of AI and cross-sector collaboration to propel new therapeutic discoveries.
