Abstract: Objective To encourage drug sponsors to optimize communication applications and to improve the efficiency of communication with the Center for Drug Evaluation (CDE) of National Medical Products Administration in China by summarizing the common questions about statistics encountered in communication between drug developers and technical reviewers, analyzing the flaws, and giving proposals for improvement. Methods The communication applications submitted by drug sponsors and handled by the author in the communication subsystem of the CDE drug technical review system between 2018 and 2020 were collected. Statistics-related questions were extracted from applications and categorized and then the commonly-asked questions were selected from categories. Finally, the inadequacies of these common questions were analyzed and regulatory considerations for improvement were elaborated. Results More than 400 communication applications were collected. The common questions related to statistics involved sample size estimations and margins of hypothesis tests, multiplicities, adaptive designs, interim analyses, bridging studies in clinical trials, and Chinese subgroup evaluations of global multi-regional clinical trials. The analysis results showed that there were such inadequacies as insufficient supporting information and misplaced or implicit questions. Accordingly, corresponding regulatory considerations were recommended. Conclusion Good communication requires the joint efforts of both sides. It is hoped that drug sponsors will optimize communication applications, ensure the sufficiency of supporting information and ask explicit questions so as to improve the efficiency of communication.

Key words: drug development, technical review, communication, statistics, regulatory considerations