Use of a Bayesian approach in the design and evaluation of NCE2s

Taiwan's regulatory agency defines New Chemical Entity 2 (NCE2) as a compound drug that has been approved and marketed for ten years in a top-ten pharmaceutically-advanced country but which is new in Taiwan. To apply for registration of NCE2 in Taiwan, a clinical trial may be conducted in Taiwan to evaluate the efficacy and safety. Since the NCE2 has been approved in at least one of the top-ten pharmaceutically-advanced countries, we can borrow the information from all of the observed data from other countries to synthesize the data from both Taiwan and other countries to assess the NCE2 efficacy. In this paper, we propose a Bayesian approach that uses a mixture of prior information to help evaluate an NCE2's efficacy. Numerical examples illustrate applications of the proposed approach in different scenarios. A method for sample-size determination for such trials is also proposed.