Basic Considerations for Data Pooling Strategy in Multi-Regional Clinical Trials (MRCTs)

The National Medical Products Administration of China has been implementing ICH E17, which describes the general principles for planning and designing of multi-regional clinical trials (MRCTs), yet there are several ambiguities in the execution and conduct remains in China or East Asia. In specific, pooling strategy, effect modifiers (EMs), statistical analysis, sample size allocation and their impact in alignment with global trial remains a challenge. In this paper, we explore on the criteria mentioned above under the context of China. EMs need to be determined and identified from intrinsic and extrinsic factors which might have the impact to the drug on specific populations. If no EMs are found, we use pooling by regions to understand whether differences across East Asian population exists, and whether pooling by East Asian is necessary. Statistical models used in the analysis are also listed to estimate the drug effect in pooled populations. In summary, this paper outlines the details of the MRCTs practices in China and provides better insights in practice both domestically and internationally for any future improvements.