One of the most fruitful assets for drug repurposing is the large arsenal of potent protein kinases inhibitors that has been amassing over the last decade. With at least 538 human protein kinases now identified, and more than 400 diseases that have been linked with defects in kinase signalling pathways, there is tremendous opportunity to find existing drugs that may in fact be more efficacious for off-target kinases that may underlie many of these diseases. Under a hundred of the protein kinases have been seriously targeted for drug development so far. More than 70% of the approved applications of these kinase inhibitor drugs has been restricted for use in the treatment of cancer.

The open-access Kinase SARfari Database produced by the European Bioinformatics Institute in Hinxton, UK features collected data with over half a million measurements of the effects of over 50,000 compounds specifically on protein kinases. At Kinexus Bioinformatics Corporation, we are trying to link this kind of information to the primary and tertiary structures of protein kinases so that we can predict the sensitivities of individual protein kinases, so as to prioritize them for further in vitro testing with the most promising candidate kinase inhibitors. I envision that similar initiatives are underway in many other research institutes and companies as well.

While only about two dozen kinase inhibitors have presently received drug approvals from the US FDA, it seems highly likely that the approval rates for new kinase-based drugs will markedly escalate in the near future. More than 150 other kinase inhibitors are presently in human clinical trials, and in excess of 500 more are in pre-clinical animal studies. It has been estimated that about a third of total pharmaceutical drug development is currently kinase-focused, but based on the recent success and the potential for this class of drug targets, I expect this to increase to 50% over the coming decade.