Sample size considerations for Japanese patients in a multi-regional trial based on MHLW guidance

• Published in: Pharmaceutical statistics : the journal of the pharmaceutical industry 2010-04, Vol.9 (2), p.100-112
• Main Authors: Quan, Hui, Zhao, Peng-Liang, Zhang, Ji, Roessner, Martin, Aizawa, Kyo
• Format: Article
• Language: English
• Subjects: Asian Continental Ancestry Group; bridging study; Clinical Trials as Topic - methods; Clinical Trials as Topic - statistics & numerical data; Computer Simulation; delta method; Drug Approval - methods; Drug Approval - statistics & numerical data; ethnic effect; Guidelines as Topic; Humans; Models, Statistical; Multicenter Studies as Topic - methods; Multicenter Studies as Topic - statistics & numerical data; risk reduction; Sample Size; Survival Analysis; survival endpoint
• ISSN: 1539-1604; 1539-1612
• DOI: 10.1002/pst.380

Since the publication of the International Conference on Harmonization E5 guideline, new drug approvals in Japan based on the bridging strategy have been increasing. To further streamline and expedite new drug development in Japan, the Ministry of Health, Labour and Welfare, the Japanese regulatory authority, recently issued the ‘Basic Principles on Global Clinical Trials' guidance to promote Japan's participation in multi‐regional trials. The guidance, in a Q&A format, provides two methods as examples for recommending the number of Japanese patients in a multi‐regional trial. Method 1 in the guidance is the focus of this paper. We derive formulas for the sample size calculations for normal, binary and survival endpoints. Computations and simulation results are provided to compare different approaches. Trial examples are used to illustrate the applications of the approaches. Copyright © 2009 John Wiley & Sons, Ltd.