Registered clinical trial trends evolved differently in East Asia vs the United States during 2014–2023

ObjectivesEast Asia, including China, Japan, South Korea, and Taiwan, has become a major hub for clinical trials. However, comprehensive comparisons between ClinicalTrials.gov and local registries remain limited. This study analyzes registered clinical trial trends in East Asia over the past decade (2014-2023) and compares them to trends in the United States (US).Study design and settingWe extracted clinical trial data through the International Clinical Trials Registry Platform, including data from local registries and ClinicalTrials.gov for China, Japan, South Korea, Taiwan, and the US. We analyzed overall clinical trial trends and filtered randomized controlled trials (RCTs), categorizing them by location, target size, and disease category.ResultsChina experienced rapid growth in clinical trials, surpassing both Japan and the US in total trials and RCTs. By 2023, China led with 16,612 total trials (7798 RCTs), while the US registered 9100 (4619 RCTs). Except for China, all other countries showed some decline in recent years. Neoplastic diseases and cardiovascular and metabolic diseases were prominent in both regions, but the US showed growing focus on mental health. China's RCTs were predominantly domestic, while the United States maintained a higher proportion of international trials. Japan, South Korea, and Taiwan showed moderate growth, with fewer international trials than the US. We recorded some inconsistencies and missing information across existing registries.ConclusionThe study highlights the increasing prominence of East Asia, particularly China, in registered clinical trials, though with a primarily domestic focus. Improvements in existing trial registries covering East Asia are desirable.