Assessing Compliance to Reporting Mandates in Glioblastoma-related Clinical Trials

Introduction: Accurate and timely reporting of scientific knowledge is crucial to the ethical principles of clinical research. ClinicalTrials.gov is an online repository that allows researchers to register trials and report results. Unfortunately, despite reporting mandates issued by the FDA, compliance with the 12-month reporting window remains low across many sectors of clinical research. Given the aggressive nature of glioblastoma, timely reporting is especially important to advance research and benefit patients. In this study, we aimed to assess the reporting rates of glioblastoma-related trials on ClinicalTrials.gov and identify factors related to non-compliance.

Methods: We utilized a previously published algorithm for identifying studies on ClinicalTrials.gov that are highly likely to have been mandated to report. For each study, we obtained the titles, status, results, phases, type of funding, type of intervention, type of study, study design, location of the study, and all available dates related to the trial. We then used Kaplan-Meier analysis to evaluate reporting times and Cox regression models to identify factors associated with reporting within five years.

Results: Our algorithm identified 255 glioblastoma-related trials that were likely mandated to report. Only 13% of trials reported results within the 12-month deadline, while 82.7% reported within five years. Factors significantly associated with lower reporting rates at the five-year mark were biological interventions (HR 0.61, 95% CI: 0.37-1.00, p = 0.049), Phase 1-2 trials (HR 0.65, 95% CI: 0.46-0.91, p = 0.014), and studies with quadruple masking (HR 0.19, 95% CI: 0.04-0.93, p = 0.040).

Conclusion : For glioblastoma-related clinical trials, noncompliance with existing reporting mandates remains a major issue. With results similar to previous examinations of larger groups of trials, the reporting within 12 months was only at 13%. Interestingly, no factors influenced whether or not a study reported by 12 months, but multiple factors influenced reporting by the 5-year time frame. Further research is needed to better understand these potential associations and create targeted incentives and regulatory efforts to increase transparency through the timely reporting of glioblastoma-related clinical trials.