ABSTRACT
As of April 2005, “Shihango-rinsyoushiken” defined in the GPMSP was renamed “Seizouhanbaigo-rinsyoushiken” in the revised regulations (GPSP). The relevant part of the GCP was also modified at the same time. Strictly speaking, therefore, post-approval clinical trials are not the same as postmarketing clinical trials. This report provides an explanation of post-approval clinical trials and the related regulations. It is generally considered that post-approval clinical trials, which help gather more clinical information, should be actively pursued for the further development of approved drugs in the post-marketing setting. However, the results of the questionnaire show that pharmaceutical companies are not willing to conduct them, mainly due to the high cost. To improve the economic efficiency of post-approval clinical trials, it is necessary to streamline monitoring activities that account for 40% of the cost.