Complementary new approaches enable repositioning of failed drug candidates.

Until recently, safe drug candidates that failed in clinical trials were shelved as drug developers channelled resources to the next candidates in the pipeline. In the past few years, new technologies, improved genomic information and high-throughput methods have made it possible to quickly and economically re-examine advanced drug candidates for therapeutic activity against other diseases. This development arrives at an opportune time, as pharmaceutical companies strive to fill sparse late-stage pipelines at the same time as keeping costs down. Specialised companies are emerging with new methods and a fresh point of view to assist pharmaceutical developers in turning failed drug candidates from one therapeutic area into successful treatments in another. This editorial introduces a series of papers to be published in Expert Opinion on Investigational Drugs, discussing discontinued drugs from 2005.