Ovarian cancer clinical trials: Study the studies to terminate the terminations.

6069 Background: Clinical trials safely expand the arsenal of treatments available to future patients while providing hope to current patients, particularly ovarian cancer patients who often have poor prognoses. Trial termination for lack of efficacy or unacceptable toxicity are consistent with the aim of protecting patients in the pursuit of knowledge, but those are not the only reasons trials terminate early. Understanding why some clinical trials do not achieve their stated goals may aid in the design of future trials. Methods: Data were gathered from clinical trials registered to ClinicalTrials.gov. Included trials were interventional (as opposed to observational), were closed between 2004 and 2019, enrolled ovarian cancer patients, had submitted results, and were open at one or more domestic sites. For each trial, data were captured regarding study completion, reason for non-completion (if applicable), sites, phase, sponsor (defined as the study initiator, not necessarily the funder), and intervention type. Results: A total of 313 trials were examined, of which 262 met inclusion criteria. Of the 262 evaluable trials, 189 (72%) were completed and 72 (27%) terminated early. The most common reasons for early termination were low accrual (27 trials, 38%), lack of efficacy (15 trials, 21%), or insufficient funding (9 trials, 13%). Five trials (7%) were terminated early due to toxicity. Early phase trials are less likely to complete enrollment, with 11 out of 16 (65%) phase 1 trials, 135 out of 180 (75%) phase 2 trials, and 15 out of 16 (94%) phase 3 trials completed. Trials initiated by an academic center were twice as likely to be terminated early (41/103, 40%) as those initiated by industry (16/80, 20%), with remaining trials initiated by consortia, NCI, or non-academic oncology practices. Terminated trials were open at an average of 11 sites (range 1-317), while completed trials were open at an average of 27 sites (range 1-632). Trials that had multiple types of interventions, for instance a drug and a procedure, had a 34% early termination rate which was higher than the rate for trials with any single type of intervention. Conclusions: More than one in four ovarian cancer clinical trials are terminated early, rarely due to treatment efficacy or tolerability. Trials terminated for reasons other than patient outcomes represent a misallocation of resources or a missed opportunity for innovation. Further research is needed to understand the circumstances that allow for clinical trial completion such that available resources maximize patient benefit.