An overview of the current status of clinical trials on endometriosis: issues and concerns

To examine and compare differences, if any, between industry- and nonindustry-sponsored clinical trials on endometriosis and to evaluate the effect of prior published positive preclinical results, or lack thereof, on trial status.

Cross-sectional study of clinical trials on endometriosis that evaluate drugs/biologicals registered at ClinicalTrials.gov as of July 3, 2013.

University-affiliated hospital.

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Trial status, size, phase, and duration; use of comparator groups; drug classes, number of arms, targeting conditions; and presence or absence of prior positive preclinical results before the launch of the trial.

Eighty trials were identified. The trials sponsored by industry and non-industry have distinct features, differing in trial status, phase, comparator, drug classes, number of arms, trial size, and duration. The phase II/III trials are predominantly industry supported, but these trials frequently use placebo as the comparator. Trials launched without prior published preclinical results do not seem to fare well, although the presence of such studies is no guarantee for success.

Questions as to whether the drug on trial is truly superior to the best available drug or of its cost-benefit profile are overlooked in most cases. There seems to be a deluge of "me-too" drugs with equivocal superiority over existing drugs and cost-benefit profiles. Because clinical trials are time-consuming, no blockbuster drug for endometriosis seems to be on the horizon yet.