The management of interim analyses in drug development

The ethical need for interim analyses in long-term trials of life-threatening conditions is well established, but recently there has been increased enthusiasm for the use of interim analyses in other areas of clinical research. Interim analysis is seen as a powerful tool in drug development to help reduce 'time to market' by allowing key decisions to be made earlier on the basis of one or more ongoing clinical trials. However, this goal can only be achieved without serious penalties if interim analyses are properly designed and executed, so that the integrity of the whole drug development programme is maintained. The purpose of this paper is to define procedures for the design and management of clinical trials which involve interim analyses. These procedures are intended to incorporate good clinical and statistical practice, hence maintaining high scientific standards not only of individual trials but also of the overall development programme. Aspects of design, conduct, analysis and dissemination of results are considered, with particular focus on the effective use of data monitoring committees in confirmatory efficacy trials.