Quality evaluation of investigator-initiated trials using post-approval cancer drugs in Japan

Summary Investigator-initiated trials (IITs) are important aspects of medical research and have contributed substantially to modern oncology. IITs using post-approval drugs have been conducted by domestic institutions in Japan. Data from this study were obtained by all IITs registered clinical trials for five cancers (lung, colorectal cancer, gastric cancer, liver cancer, and breast cancer) using drugs approved from 1999 to 2009 in Japan. The Kaplan-Meier method, analysis of variance (ANOVA), and Kruskal-Wallis test were used to estimate time to enrolment completion (TTEC) and time to enrolment per patient (TTEP). Of 1,222 trials eligible for analysis, 465 trials (38%) completed enrolment to the studies, and 203 trials (17%) published results. In the distribution according to trial phase, 98 (8%) were phase I, 1,058 (87%) were phase I/II + II, and 66 (5%) were phase II/III + III. The accrual achievement and publication rates were higher in late-phase than in early-phase trials. The median TTEC was 1,387 days (95% confidence interval [CI], 1,302 to 1,472). The median TTEP was 38.5 days (95% CI, 34.5 to 42.5). The median TTEC and TTEP were significantly different in each trial phase (P < 0.01), funding source (P < 0.01), and publication status (median TTEC published trials vs. unpublished trial; 720 days vs. 1,672 days, median TTEP; 16 days vs. 55.8 days; P < 0.001). Many IITs using approved cancer drugs have been conducted; however, the quality of the clinical trials was low in terms of accrual achievement, publication rate, and time to publication of trial results. This article is protected by copyright. All rights reserved.