 Inadequate Dissemination of Phase I Trials: A Retrospective Cohort StudyEvelyne Decullier, An-Wen Chan and François Chapuis PLOS Medicine, 2009, vol. 6, issue 2, 1-8 Abstract: 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. François Chapuis and colleagues examine a cohort of clinical trial protocols approved by French ethics committees, and show that Phase I trials are less frequently published than other types of trials. Background.: Before a new drug is used to treat patients, its benefits and harms have to be carefully investigated in clinical trials—studies that investigate the drug's effects on people. Because giving any new drug to people is potentially dangerous, drugs are first tested in a short “Phase I” trial in which a few people (usually healthy volunteers) are given doses of the drug likely to have a therapeutic effect. A Phase I trial evaluates the safety and tolerability of the drug and investigates how the human body handles the drug. It may also provide some information about the drug's efficacy that can guide the design of later trials. The next stage of clinical drug development is a Phase II trial in which the therapeutic efficacy of the drug is investigated by giving more patients and volunteers different doses of the drug. Finally, several large Phase III trials are undertaken to confirm the evidence collected in the Phase II trial about the drug's efficacy and safety. If the Phase III trials are successful, the drug will receive official marketing approval. In some cases, this approval requires Phase IV (postapproval) trials to be done to optimize the drug's use in clinical practice. Why Was This Study Done?: In an ideal world, the results of all clinical trials on new drugs would be published in medical journals so that doctors and patients could make fully informed decisions about the treatments available to them. Unfortunately, this is not an ideal world and, for example, it is well known that the results of Phase III trials in which a new drug outperforms a standard treatment are more likely to be published than those in which the new drug performs badly or has unwanted side effects (an example of “publication bias”). But what about the results of Phase I trials? These need to be widely disseminated so that researchers can avoid unknowingly exposing people to potentially dangerous new drugs after similar drugs have caused adverse side effects. However, drug companies are often reluctant to disclose information on early phase trials. In this study, the researchers ask whether the dissemination of the results of Phase I trials is adequate. What Did the Researchers Do and Find?: The researchers identified 667 drug trial protocols approved in 1994 by 25 French research ethics committees (independent panels of experts that ensure that the rights, safety, and well-being of trial participants are protected). In 2001, questionnaires were mailed to each trial's principal investigator asking whether the trial had been started and completed and whether its results had been published in a medical journal or otherwise disseminated (for example, by presentation at a scientific meeting). 140 questionnaires for Phase I trials and 304 for Phase II–IV trials were returned and analyzed by the investigators. They found that Phase I trials were more likely to have been started and to have been completed than Phase II–IV trials. The results of 86% of the Phase I studies matched the researchers' expectations, but the study hypothesis was confirmed in only 71% of the Phase II–IV trials. Finally, the results of 17% of the Phase I studies were published in scientific journals compared to 43% of the Phase II–IV studies. About half of the Phase I study results were not disseminated in any form. What Do These Findings Mean?: These findings suggest that the fate of Phase I trials is different from that of other clinical trials and that there is inadequate dissemination of the results of these early trials. These findings may not be generalizable to other countries and may be affected by the poor questionnaire response rate. Nevertheless, they suggest that steps need to be taken to ensure that the results of Phase I studies are more widely disseminated. Recent calls by the World Health Organization and other bodies for mandatory preregistration in trial registries of all Phase I trials as well as all Phase II–IV trials should improve the situation by providing basic information about Phase I trials whose results are not published in full elsewhere. Additional Information.: Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000034. Date: 2009 Downloads: (external link) Related works: Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text Persistent link: https://EconPapers.repec.org/RePEc:plo:pmed00:1000034 DOI: 10.1371/journal.pmed.1000034 Access Statistics for this article More articles in PLOS Medicine from Public Library of Science |
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