Researchers have designed a web-based tool that can quickly identify new uses of existing drugs. The tool called 'New use of Old Drugs’ (NOD), will reduce the overall time and cost in discovering novel therapeutic agents, they say.

The tool can identify drugs known to interact with remote protein targets by deciphering information encoded in the protein sequences rather than the structures of the target. The researchers from Indian Institute of Science say it can be used to find therapies for rare and neglected genetic diseases, including COVID-19.

Most existing tools don’t provide reliable structural data about the target proteins to which drugs bind. NOD could help overcome this drawback.

The researchers ran the NOD to identify drug molecules that bind to protein targets in pathogens such as Mycobacterium tuberculosis, Plasmodium falciparum, Candida albicans, the human immunodeficiency virus, the hepatitis C virus and the novel coronavirus. They also tested its efficiency in identifying drugs that bind to G-protein-coupled receptors and kinases, two major drug targets in humans.

NOD picked out 65 per cent of the protein targets in the pathogens, outperforming DrugBank, a popular open-access tool used for finding repurposed drugs. It identified several drugs with novel repurposing potential. Among them, diacerein, used for treating osteoarthritis, could be used against tuberculosis; afatinib, an anticancer agent, against candidiasis; and tranilast, an antiallergic drug, against malaria.