ABSTRACT
This chapter reviews commonly used adaptive trial design methods and adaptive trial simulations, and discusses the adaptive trial designs based on global optimization through a case study. An adaptive design is a clinical trial design that allows adaptations or modifications to aspects of the trial after its initiation without undermining the validity and integrity of the trial. Commonly used adaptive designs include group sequential design (GSD), sample-size re-estimation, and drop-loser design. GSD is probably one of the most commonly used adaptive designs in clinical trials. There are three different types of GSDs: early efficacy stopping design, early futility stopping design, and early efficacy or futility stopping design. An adaptive clinical trial design allows aspects of the trial to be modified without undermining the integrity and validity of the trial. Among different adaptive design options, power and average sample size are often the conventional criteria for selecting an adaptive design.
