An Overview of Design and Evaluation of Multiregional Clinical Trials

In recent years, the design of multiregional clinical trials (MRCTs) has become a new strategy for global drug development. A MRCT is a clinical trial which incorporates subjects from many countries around the world under the same protocol. After showing the overall efficacy of a drug in all global regions, one can concurrently assess the chance of applying the overall trial results to each region and consequently support new drug approval in each region. To achieve the goal of conducting MRCT, several regulatory guidelines and statistical methods have been established. In this paper, we will briey describe the regulatory requirements for MRCTs. Also in this article, two statistical approaches for design and evaluation of MRCTs were reviewed. One assumes that the treatment effect is uniform across regions, while the other uses the random effect model to address the heterogeneous treatment effect across regions. Special consideration was also placed on the determination of the number of subjects in a specific region to establish the consistency of treatment effects between the specific region and the entire group.