Characteristics of Asian 4 countries on cancer clinical trials registered in the International Clinical Trials Registry Platform between 2005 and 2018.

Background: The characteristics and comparison of countries regarding clinical trials for cancer were unknown. The World Health Organization-International Clinical Trials Registry Platform (WHO-ICTRP) are providing data from various countries and releases them generally in a downloadable format. We aimed to examine and descriptively identify the number of cancer clinical trials registered in the world and the fundamental characteristics in Asian 4 countries of China, India, Japan and South Korea, focusing on study characteristics, e.g., phase or targeted size, using the WHO-ICTRP.

Methods: We extracted information on cancer clinical studies in the ICTRP database on September 20, 2019. Then, we performed a cross-sectional study on the annual number of registered studies and country, registered registry, phase, target sizes and sponsors.

Results: We identified 80,677 cancer clinical studies. The annual number of registered cancer clinical studies significantly increased between 2005 and 2018 (3,172 to 8,156, β =382.2, 95% CI: 329.6, 434.8). Among the Asian 4 countries, the numbers of trials were significantly increasing in 2005-2018 (P<0.001). The characteristics on interventional studies for cancer differed in those 4 countries, e.g., the registered registries, phase and sponsors, compared with the US.

Conclusions: This study descriptively clarified an increase and the characteristics of cancer clinical trials in Asian 4 countries. It suggests to take that characteristics into account and select a database or data source discreetly for analysis of clinical trials, according to the purpose of the research and the required data.