Abstract

To speed up drug development to allow faster access to medicines for patients globally, the design of multiregional clinical trials incorporates subjects from many countries around the world under the same protocol. The aim of a multiregional clinical trial is to show the efficacy of a drug in various global regions, and concurrently to evaluate the possibility of applying the overall trial results to each region so that simultaneous drug development, submission, and approval in the world are possible. In this entry, we reviewed some recent developments for sample size determination for MRCT. In the first part, we reviewed the methods for sample size calculation based on the assumptions that the effect size is uniform across regions and treatment effect is heterogeneous across regions respectively. In the second part, we reviewed statistical criteria for assessing the consistency between the region of interest and overall results.