Inadequate Dissemination of Phase I Trials: A Retrospective Cohort Study

BACKGROUND: Drug development is ideally a logical sequence in which information from small early studies (Phase I) is subsequently used to inform and plan larger, more definitive studies (Phases II–IV). Phase I trials are unique because they generally provide the first evaluation of new drugs in humans. The conduct and dissemination of Phase I trials have not previously been empirically evaluated. Our objective was to describe the initiation, completion, and publication of Phase I trials in comparison with Phase II–IV trials. METHODS AND FINDINGS: We reviewed a cohort of all protocols approved by a sample of ethics committees in France from January 1, 1994 to December 31, 1994. The comparison of 140 Phase I trials with 304 Phase II–IV trials, showed that Phase I studies were more likely to be initiated (133/140 [95%] versus 269/304 [88%]), more likely to be completed (127/133 [95%] versus 218/269 [81%]), and more likely to produce confirmatory results (71/83 [86%] versus 125/175 [71%]) than Phase II–IV trials. Publication was less frequent for Phase I studies (21/127 [17%] versus 93/218 [43%]), even if only accounting for studies providing confirmatory results (18/71 [25%] versus 79/125 [63%]). CONCLUSIONS: The initiation, completion, and publications of Phase I trials are different from those of other studies. Moreover, the results of these trials should be published in order to ensure the integrity of the overall body of scientific knowledge, and ultimately the safety of future trial participants and patients.