Abstract

There has been much recent interest in the development of clinical trial methods that enable adaptation of the study design during the course of the trial whilst maintaining statistical and scientific integrity through the control of type I error rate. One such adaptation of interest is the ability to select from multiple treatments during a trial. The simplest form of design is conducted in two stages. In the first stage, patients are randomised between a placebo and a number of experimental treatments. At the end of this stage, an interim analysis of the data observed so far, possibly on a short-term or surrogate endpoint, will be conducted. As a result of this, the trial could be stopped early, or one or more of the experimental treatments may be dropped from the trial. The trial then continues with further patients randomised between the placebo and the remaining experimental treatments. At the end of the trial, these experimental treatments are then compared with the placebo using the data from all patients randomised. The final statistical inference is conducted so as to maintain the overall type I error rate allowing for the treatment selection and interim analyses. This talk will describe the methodology which has been developed for these types of trials, exploring the different approaches which are documented in the literature. In addition, recent work in the areas of design and analysis is highlighted.