A Call for More Transparency of Registered Clinical Trials on Endometriosis. Ranked "Exceptional" by F1000

Shelley Reilly; Neil Johnson


Faculty of 1000 

Guo SW, Hummelshoj L, Olive DL, Bulun SE, D'Hooghe TM, Evers JL
Hum Reprod 2009 Jun 24(6):1247-54

Commentary from Shelley Reilly and Neil Johnson

This paper hits the nail on the head by highlighting an important point, as the title suggests. The need for exposure of important research findings to the medical and public eyes is long overdue. Endometriosis research needs to be encouraged and undertaken with results published for all to learn from, whether the results are positive or negative. The call for new and improved endometriosis medical treatments is out and the outcome long awaited for. Potential treatments need trialling in an effort to pursue the goal of finding a safe, effective, with minimal side effects, low cost, long-term alternative to those currently available. Many animal and in vitro studies have shown positive results on various compounds but not many have gone on to become phase II/III trials.

Traditionally, clinical trials have been kept hidden from the public. The US congress, concerned about this fact, created a publicly accessible internet site with information on trials by enacting Section 113 of the Food and Drug Administration Modernisation Act in November 1997 with the creation of ClinicalTrials.gov. In September 2004, the International Committee of Medical Journal Editors announced that its journals would not publish the results of trials that had not been registered at this or similar websites. The World Health Organisation gave the thumbs up to this approach by itself launching in May 2007 a website which allowed access to information on clinical trials. Guo et al. searched ClinicalTrials.gov website with the keyword ‘endometriosis’. They found 57 registered trials, 25 were listed as complete and 2 as suspended. Of the completed trials, 15 were phase II/III clinical trials. However, only 3 (20%) have published their results and the other 12 (80%) remain unpublished even though some of these trials had been completed several years ago. These three published trials showed no promising results. The phase II clinical trial[1] on the use of infliximab, an anti-TNF monoclonal antibody, to treat deep endometriosis found no difference in any of the outcome measures between the treatment and control groups. Another trial involving 104 patients found that post-operative pentoxifylline treatment (800mg/day) immediately after laparoscopy achieved a higher increase in cumulative probability of pregnancy within 6 months after surgery as compared with those receiving placebo post-operatively, but the difference failed to reach statistical significance.[2] The phase II clinical trial on raloxifene found that raloxifene treatment is associated, unexpectedly, with earlier return of pain symptoms as compared with placebo.[3] For this reason, the study was terminated early. Guo et al. argue that this apparent lack of transparency will actually not benefit the researchers or their audience with an overall detrimental effect on research. The huge gap between the number of clinical trials conducted and the number for which results were made public has been known for decades. It is suggested that this could be due to concern about publishing negative studies at all levels with an intention to conceal ‘inconvenient’ results which could be embarrassing or financially damaging. Trial registration appears to have only gone one step towards the attainment of transparency in clinical trials on endometriosis by highlighting the gap between research conducted and results reported; the next crucial step is to close this gap with faithful reporting of all results. There is a need for all those involved in endometriosis clinical trials, both investigator initiated and industry sponsored, to openly and voluntarily disclose their trial data to the public within 12 months of trial completion. Guo et al. conclude that "this would be the only correct thing to do, morally, ethically, scientifically and no doubt economically, if we are ever to crack the enigma that currently is endometriosis".

Faculty of 1000 Medicine Evaluations, Dissents and Author responses for: [Guo SW et al. A call for more transparency of registered clinical trials on endometriosis. Hum Reprod 2009 Jun 24(6):1247-54 ]. 2009 Jun 16 www.f1000medicine.com/article/id/1162102/evaluation


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