Key Points of Clinical Trials in the Drug Development: Lessons Learned.

In the drug development, manufacturers or investigators need to demonstrate the effectiveness of their products through the conduct of adequate and well-controlled studies. On the other hand, the success probability of clinical trials is not high in some disease areas. This is because even for treatments that are expected to be effective, the method of conduct and study design may affect the outcome of clinical trials. For example, in clinical trials of neuropsychiatric disorders, there is substantial improvement and variability in placebo groups, and/or in which the effects of therapy are small or variable. In addition, efficacy evaluation is generally done by subjective evaluation using a symptom rating scale, which results in a certain degree of variability in the evaluation. This can lead to higher-than-expected response to placebo and failure to achieve the expected results in clinical trials. In other words, clinical trials present issues specific to disease areas. Therefore, in planning and conducting clinical trials, it is important to identify and control factors that influence efficacy and safety assessment. In this symposium, important points of clinical trials and how to examine factors affecting efficacy assessment will be introduced.