ABSTRACT
With increasing globalization in the development of medicines, developing strategies for when and how to address geographic variations of ef‚cacy and safety for product development has become essential. To shorten the time for drug development and regulatory approval, it would be desirable to conduct a trial for simultaneous drug development, submission, and approval around the world. Recently, the number of clinical trials simultaneously conducted in Asian countries, Europe, and the United States has increased signi‚cantly. In particular, the Japanese government has the initiative to participate in global development and international clinical studies. The 11th Q&A for the ICH E5 (ICH, 2006) guideline described points to consider for evaluating the possibility of bridging among regions in a multiregional trial and stated that “it may be desirable in certain situations to achieve the goal of bridging by conducting a multi-regional trial under a common protocol that includes suf‚cient numbers of patients from each of multiple regions to reach a conclusion about the effect of the drug in all regions.” Basically, a multiregional clinical trial is designed for two objectives. The ‚rst objective is to assess the ef‚cacy of the test treatment over all regions in the trial. The second objective is to bridge the overall effect of the test treatment to each of the regions in the trial.
