[Multinational clinical trial in Japan and Korea on detrusitol]

A randomized, double-blind, placebo- and active comparator-controlled study was conducted in 69 centers to compare detrusitol and oxybutynin with placebo in Japanese and Korean patients with an overactive bladder (OAB). Detrusitol had similar efficacy but was better tolerated than oxybutynin in Japanese and Korean patients with OAB. The study result was acknowledged as pivotal data in the clinical data package when NDA was filed and successfully approved both in Japan and Korea. Some differences were found in the efficacy and safety of the drug between the Japanese and Korean data, though. We therefore investigated the differences through stratified analysis; however exact causes could not be identified. This study is positioned as a first multinational clinical trial conducted in East Asia. From the aspects of utilization of interoperable data obtained from such multinational clinical trials for NDA filing and earliest possible registration of drugs in the participating countries, we believe it is important to accumulate more experiences in conducting multinational clinical trials. At this time, it is our prime task to minimize the "drug lag" in Japan; I think improving the speed of clinical trials is one of the factors to solve the issue. Global clinical trials involving Western and Asian countries make it possible to use the study data effectively and commonly in many countries. Moreover, from the viewpoint of revitalization of clinical trials, conducting global clinical trials is critically important; so we intend to continue accumulation of our experiences in global clinical trials.