Drug Repurposing Advances in Oncology

**121**

**Chapter 7**

**Abstract**

metformin

**1. Introduction**

**1.1 What are the problems?**

Drug Repurposing in

Repurposing or repositioning means validating and application of previously approved drugs in the treatment of another disease that might be relevant or irrelevant to existing use in disease based on the principle of polypharmacology. Repurposed drugs are already well documented for pharmacokinetic, pharmacodynamic, drug interaction, and toxicity parameters. In 1962, thalidomide treatment in pregnant women led to phocomelia in their newborn but while repurposed based on anti-angiogenesis property, it showed efficacy in hematologic malignancies like multiple myeloma. The repurposing is becoming an essential tool in the anti-cancer drug development due to existing drugs are not effective, high cost of treatment, therapy may degrade the quality of life, improvement of survival after treatment is not guaranteed, relapse may occur, and drug resistance may develop due to tumor heterogeneity. Repurposing can be addressed well with the help of literature-based discovery, high throughput technology, bioinformatics multi-omics approaches, side effects, and phenotypes. Many regulatory bodies like EML, NIH, and FDA promote repurposing programs that support the identification of alternative uses of existing medicines. Cancer becomes the major health issue, and the need to discover promising anti-cancer drugs through repurposing remains very high due to decline in FDA approval since 1990, huge expenses incurred in

the drug development and prediction of dangerous future burden.

**Keywords:** repurposing, cancer, bioinformatics, multi-omics, thalidomide tragedy,

Cancer is the second deadliest disease after cardiovascular diseases, causing loss of billions of lives across the world. Although human kind has developed so many anti-cancer medicines, none of them are able to cure the disease. After spending of around \$650 million for the development in research and development of New Chemical Entity (NCE) during time periods of 12–17 years, successful outcome compared to standard drugs is less [1]. The success ratio for this NCE in clinical trial is less than 10%. Many times, the effects on outcomes like disease free survival, quality of life treatment related side effects and complications are discouraging. According to ESMO 2019 press release, there was no link between drug cost and clinical benefit measured by ESMO-MCBS and the American Society of Clinical Oncology Value Framework (ASCO-VF) for various drugs approved for adult solid tumor in four European countries and the USA from 2009 to 2017. So, it would

Oncotherapeutics

*Alkeshkumar Patel*
