2012 年 33 巻 1 号 p. 77-99
Recently, it is becoming more challenging to cope with low success probabilities, much cost and severe competitions in a new drug development. An adaptive design is considered to be a promising tool for efficient development for its various types of adaptations and applications in multiple development stages. However, its flexibility does not necessarily make the development more efficient and it may always allow a risk of operational bias to use such a design. Thus, to consider the specific benefit and risk of each adaptive design using quantitative measures under a concrete setting, it is important to make intensive discussions and to share experiences between each side persons in charge. In this review, focusing on sample size re-estimation which is a relatively simple and basic adaptive design, I will give some outlines of methods and review statistical points to consider.