Validity and interpretation of meta-analyses and one pivotal study

The International Conference on Harmonization E9 guideline indicates that meta-analyses can be used not only for summarizing safety and efficacy in an application but also for providing pivotal evidence of efficacy. Furthermore, this guideline states that "in some circumstances" a single confirmatory trial may be sufficient to provide pivotal evidence of the efficacy of drug. However little guidance is given as to how these circumstances are defined. In this paper we will focus on the role of meta-analysis and one pivotal trial in clinical drug development to provide pivotal evidence of effectiveness of a drug.