Investigation of Characteristics of Japanese Clinical Trials in Terms of Data Variability

Background Because Asian countries have become involved in multiregional clinical trials, it is increasingly important to understand the characteristics of each country in terms of clinical trials to seek an appropriate strategy for worldwide drug development. Since variability of data is one of the important factors in clinical trials, variability of Japanese data, such as shown in coefficient of variation (CV) and standard deviation (SD) values, is an area of interest from which to consider an appropriate development strategy.Methods To characterize variability of Japanese data compared with non-Japanese data, the authors selected pharmaceutical products recently approved in Japan, reviewed their clinical trial data, and analyzed these data for efficacy response variables in Japan and Western countries. Twenty-nine products were selected for the examination.Results Japanese data are similar to non-Japanese data in terms of data variability, and the ratios of the Japanese to the non-Japanese values for CV and SD were within a relatively narrow range for most products.Conclusions Japanese clinical trial data showed variability similar to that of non-Japanese data for most cases. It is expected that further studies to characterize specific regions in terms of clinical trial data will be conducted to consider an appropriate strategy for worldwide drug development.