Influence Diagnostics of a Region of Interest in Multi-regional Clinical Trials

Multi-regional clinical trials (MRCTs) are an efficient way to enable recruitment of the planned number of subjects within a reasonable timeframe in drug development for rare diseases. One of the aim of MRCTs is to evaluate the applicability of overall trial results to a region of interest. Various statistical methods proposed for this purpose are primarily relying on regional estimates from subgroup analyses of a region of interest, thus they may not work well for studies with small sample size in rare diseases. This paper, instead, presented how to apply influence diagnostics to assessing influence of a region of interest on the overall results in MRCTs and showed this approach could be an analysis option for MRCTs in rare diseases through Monte Carlo simulation and analysis of an MRCT.