Yuji Kumagai, MD, PhD. Director, Clinical Trial Center Kitasato University East Hospital, Kanagawa, Japan

Information of pharmacokinetic data in human is essential in drug development. Failure rate of investigational drugs in phase I trials is still approximately 10%, and microdose clinical trials are started in EU, US and Japan. The microdose trials principally aim at revealing absorption characteristics of a drug and we noticed several factors which may affect kinetics of drugs in microdose trials.  We also have several experiences of interesting pharmacokinetic data of phase I clinical trials in healthy and diseased subjects. Although original data cannot be presented by the obligation of contracts for some drugs, I'd like to share some information with Asian colleagues for the future benefits o f Asian people.