PAREXEL - Definition of Adaptive Design Trials from Dr Sy Pretorius, Chief Scientific Officer
It is important to understand what adaptive design trials are, and there are several definitions. The one that I like most and prefer to use is the definition proposed in the FDA draft guidance document issued in 2010. It defines an adaptive trial as a study that includes a prospectively planned opportunity for modification of one or more of the specified aspects of the study design and hypotheses based on the analysis of data. The challenge here is to modify these elements without jeopardizing the validity and the integrity of the study data. An analogy I like to use is to think of the traditional way we conduct clinical trials as somewhat analogous to a cargo plane without windows; in other words there is no way from the outside to tell what is going on inside the plane while the plane is flying to its destination and we typically have to wait until the plane lands before we are able to look into the plane. The analogy of course is that in a traditional trial you need to wait until the end of the study to lock the database before we get a sense of what happened during the study. An adaptive trial is more like a passenger plane with windows – in other words, you have these opportunities / windows during the course of the trial to look at and evaluate the data and make some predefined changes or course adjustments. Examples of adaptive trial designs include: Designs where you stop the trial or an arm because the treatment or dose is not working; sample size re-estimation where we modify incorrect assumptions on effect size and population variance and seamless Phase I/II or Phase II/III trials where we combine studies in order to save time and cost. Our goal is to simplify the journey between science and new treatments and to help our clients bring new drugs to market for the patients who need them.