Drug repositioning is a "universal strategy" for neglected diseases due to 1) reduced number of required clinical trial steps could reduce the time and costs for the medicine to reach market, 2) existing pharmaceutical supply chains could facilitate "formulation and distribution" of the drug, 3) known possibility of combining with other drugs could allow more effective treatment, 4) the repositioning could facilitate the discovery of "new mechanisms of action for old drugs and new classes of medicines", 5) the removal of “activation barriers” of early research stages can enable the project to advance rapidly into disease-oriented research.
Often considered as a serendipitous approach, where repurposable drugs are discovered by chance, drug repurposing has heavily benefited from advances in human genomics, network biology, and chemoproteomics. It is now possible to identify serious repurposing candidates by finding genes involved in a specific disease and checking if they interact, in the cell, with other genes which are targets of known drugs. It was shown that drugs against targets supported by human genetics are twice as likely to succeed than overall drugs in the pharmaceutical pipeline. Drug repurposing can be a time and cost effective strategy for treating dreadful diseases such as cancer and is applied as a means of solution-finding to combat the COVID-19 pandemic.
Computational drug repurposing is the in silico screening of approved drugs for use against new indications. It can use molecular, clinical or biophysical data. Electronic health records and real-world evidence gained popularity in drug repurposing, for instance for COVID 19. Computational drug repurposing is expected to reduce drug development costs and time.