Purpose: To examine the trends and characteristics of industry-sponsored drug clinical trials registered in the JapicCTI (Japan Pharmaceutical Information Center Clinical Trials Information) in 2010-2018.
Methods: A data set of 3116 clinical trials registered from Jan. 2010 to Dec. 2018 were analyzed. Fundamental characteristics of the clinical trials were analyzed by 3-year time periods. The analysis was also focused on 3 therapeutic areas: cardiovascular, mental health, and oncology.
Results: Of all the trials (2010-2018), 74.7% were conducted in Japan only; the rate decreased from 82.8 to 65.3% over the 3 time periods. Most trials were phase 3 trials, which comprised 44.1% of the trials. Small trials (anticipated number of 1000 or fewer participants) made up 94.0% of the trials. Oncology trials (29.5%) were the most common type and involved more phase 1 trials than mental health and cardiovascular trials (33.6% vs 14.5% and 11.5%, respectively). Oncology trials composed the smallest proportion of trials conducted in "Japan only" at 57.3% vs 81.0% and 83.1% for mental health and cardiovascular trials, respectively (p < 0.001). The median of the anticipated number of participants in mental health trials were larger than those in cardiovascular and oncology trials (p = 0.001). Mental health trials were more likely to permit children under age 15 (10.9% vs 4.9% for cardiovascular and 1.2% for oncology). Oncology trials were more likely not to set an upper age limit (89.8% vs 51.4% for cardiovascular and 41.7% for mental health). Cardiovascular and mental health trials were more likely to be conducted as "double blind" (42.4% and 47.1%, respectively vs 16.7% for oncology).
Conclusion: During this time, the majority of industry-sponsored trials in Japan were phase 3 trials, Japan only and small trials. There were differences in clinical trials among the 3 therapeutic areas: size of the trial, globalization, phase, age of participants, blinding.
Keywords: Clinical research design; Clinical trial registry; Industry-sponsored clinical trials; Japan Clinical trials; Therapeutic areas studied.