Adaptive clinical trials for new drug applications in Japan.

Adaptive design is regarded as an efficient method for clinical trials in order to increase the success rate of a new drug in development, and recently has been actively discussed among regulatory agencies, industry and academia. Since adaptive design involves interim analyses and is more complex than traditional fixed design, some points such as possibility of introducing statistical and operational bias should be considered when planning and implementing such trials. In this article, we share our perspectives in the consideration of adaptive design clinical trials based on our experiences discussing adaptive design in clinical trial consultation meetings in Japan.