The relationship between exploratory and confirmatory post-approval trials for pregabalin (Lyrica) has been recently analysed by Canadian researchers, who conducted a systematic review of all clinical trials testing the effectiveness of pregabalin in non-approved indications prior to January 2018. From 238 trials assessing pregabalin efficacy in at least 33 indications, 5 indications were granted marketing approval by the European Medicines Agency and/or US Food and Drug Administration. In addition, 17 of 27 indications (63%) with at least 5 years follow-up may have generated uncertainty not yet dealt with in confirmatory trials within 5 years. The study demonstrates the weakening relationship between exploratory and confirmatory trials as pregabalin use extended from regulatory approved indications to new indications, supporting the use of off-label prescription in clinical practice guidelines where confirmatory trial evidence is absent. The original research can be viewed here.