Characteristics analysis of clinical trial registration for CDK4/6 inhibitors based on the ClinicalTrials.gov and ChiCTR databases

ZHANG Juan; LIU Xue-yan; YIN Gui-sen; YANG Si-tong

doi:10.20251/j.cnki.1003-3734.2026.13.010

Abstract：Objective:To investigate the registration status of clinical trials on CDK4/6 inhibitors in ClinicalTrials.gov and the Chinese Clinical Trial Registry(ChiCTR),analyze their registration characteristics and development trends,and provide a reference for clinical research.Methods:All clinical trials on CDK4/6 inhibitors registered in ClinicalTrials.gov and ChiCTR from the establishment of the database to April 17,2025 were retrieved.Information including registration date,clinical phase,sample size,indication,registration status,country/region,and study type was extracted.Descriptive statistical analysis was performed using Excel.Results:A total of 765 clinical trials on CDK4/6 inhibitors were registered in the two databases,including 698 in ClinicalTrials.gov and 67 in ChiCTR.These trials involved more than 40 countries,with the top three being the United States(397 trials),China(69 trials),and France(22 trials).The number of registrations peaked in 2020.Most trials were interventional studies,with breast cancer as the primary indication.The main endpoints were core clinical indicators of efficacy and safety.However,there were significant differences between the two databases in terms of coverage breadth and research depth.Conclusion:This study is the first to summarize the registration status of CDK4/6 inhibitor clinical trials and analyze the registration characteristics in ClinicalTrials.gov and ChiCTR.Internationally,research and development started early with wide coverage,while domestic research mainly focuses on follow-up innovation and post-marketing studies,providing a reference for the direction of clinical research and resource allocation related to CDK4/6 inhibitors.