2011 年 32 巻 Special_Issue_2 号 p. S133-S137
Multi-Regional Clinical Trials (MRCT) have increased for simultaneous new drug development in many therapeutic areas. Primary endpoint in oncology MRCT is usually survival time and two points to be considered should be taken into account in this case. One is different accrual periods among regions and the other is different responses in control treatment among regions. In this paper, we show how they affect actual power to overall result and assurance probabilities by simulation. We also deal with the difference of the approval institutions between Japan and the United States and discuss the issue derived from the difference.