Factors associated with non-completion of gynecological cancer clinical trials

Clinical trials are essential for advancing treatment, yet inefficiencies across the trial lifecycle may hinder progress. We evaluated trial-level characteristics associated with non-completion among gynecologic cancer clinical trials.

We conducted an analysis of interventional cervical, ovarian, and uterine cancer trials registered on ClinicalTrials.gov. Trials with at least one U.S. site initiated between 2008 and 2021 and classified as completed or not completed were included (n = 1033). Multivariable logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for factors associated with non-completion. Reasons for premature trial termination were categorized into predefined groups.

The majority of trials included ovarian cancer (68.3%), followed by uterine (25.8%), and cervical (24.7%) cancers. Overall, 30.3% of trials did not complete. In multivariable analyses, intervention type, year of initiation, and U.S. region were significantly associated with non-completion. Compared with drug/biologic trials, those evaluating multiple (OR 0.62, 95% CI 0.42-0.93) or other interventions (OR 0.49, 95% CI 0.25-0.98) had lower odds of non-completion. Trials initiated between 2018 and 2021 had substantially higher odds of non-completion compared with trials initiated 2008-2012 (OR 2.30, 95% CI 1.58-3.36). There was also heterogeneity of non-completion across region; however, no region was significantly different from the reference category of Northeast. Insufficient patient accrual was the most common reason for non-completion (28.8%).

Thirty percent of gynecologic cancer trials fail to complete, with temporal trends playing a role. Findings highlight the need for improved trial design and feasibility planning to enhance efficiency in gynecologic oncology.