Choosing Metrics Appropriate for Different Stages of Drug Development

In this chapter, we give an overview of metrics that are useful to evaluate designs for determining if a new drug is efficacious at each of the three premarketing clinical development stages. The three stages are to determine if the new drug exhibits a positive proof of concept, to explore a possible dose-response relationship, and to confirm a hypothesized drug effect. The focus on efficacy is due to the generally well-defined endpoints to decide the beneficial effect of a new drug. Nevertheless, the approach is equally applicable to safety endpoints if there are specific safety endpoints that can be used to anchor design considerations and decision rules. Deliberations of the metrics for each stage will be further elaborated in Chaps. 7– 9 respectively.