The University of Oxford has now teamed up with a pharmaceutical company to run clinical trials of ebselen for bipolar disorder. The researchers are able to skip the phase I safety trials because the drug had already passed them, and are going straight to phase II: testing the drug’s efficacy against bipolar disorder. Churchill is well aware that ebselen could fail this trial, or the larger, more stringent ones needed to test whether the drug works better than lithium. But he is already proud of what his team has achieved. “As an academic group with no company money,” he says, “we were able to go from identification of the molecule to a human trial with a very limited budget.”
Such stories are becoming more and more common: taking drugs that have been developed for one disorder and ‘repositioning‘ them to tackle another is an increasingly important strategy for researchers in industry and academia alike. These efforts take inspiration from some classic success stories. One is sildenafil, an angina medication developed in 1989 that is now marketed as Viagra and used to treat erectile dysfunction. Another is azidothymidine, which failed as a chemotherapy drug but emerged in the 1980s as a therapy for HIV.
Increasingly, the serendipity responsible for those earlier discoveries is giving way to systematic searches for candidates. Partly, this is the result of advances in technology. These include big-data analytics that can now uncover molecular similarities between diseases; computational models that can predict which compounds might take advantage of those similarities; and high-throughput screening systems that can quickly test many drugs against different cell lines.