By: Mike Bassett
Situation steadily improving since passage of FDAAA, however
While fewer than 40% of completed oncology trials in 2017 reported their results in a timely fashion, that percentage was eight times higher compared with a decade ago, researchers reported.
Among more than 12,000 clinical trials registered in ClinicalTrials.gov, the percentage reporting results within 24 months of the primary completion date increased from 5.1% in 2007 to 39.1% in 2017 (adjusted HR 1.11 per year increase, 95% CI 1.10-1.13), according to Jun Ma, MD, of Sun Yat-sen University Cancer Center in Guangzhou, China, and colleagues.
The increase in results reporting was likely associated with recent joint efforts to promote results reporting, especially mandatory reporting requirements enforced by the FDAAA [Food and Drug Administration Amendments Act] in the U.S. and similar statutory regulations in Europe,” the authors wrote in JAMA Network Open.
Over the 10-year study period, 60.7% of oncology trials reported results, eventually, with 22.9% reporting their results only at ClinicalTrials.gov, 21.8% only in journal articles, and 15.9% in both.
Ma and colleagues pointed out that while researchers have an ethical obligation to report the findings of clinical trials, “numerous examples exist of potentially harmful data being withheld from the public and/or selective non-reporting.”
In a commentary accompanying the study, Vanessa Piechotta, MSc, and Nina Kreuzberger, MPH, both of the University of Cologne in Germany, observed that the inability of investigators to publish complete trial results “is a critical waste of resources that may lead to duplicate work and distortion of the perceived association between a treatment and the examined health outcomes.” They also suggested that it could encourage investigators to spin their results to increase the chance of publication.
To address this issue, the FDAAA of 2007 included a mandate that sponsors of trials meet specific criteria for reporting summary results on ClinicalTrials.gov, a database of private and publicly funded clinical studies conducted worldwide, and which is the largest public clinical trial registry in the world. Here, Ma and colleagues wanted to evaluate the status of clinical trial reporting in the decade following the passage of the FDAAA.
The authors identified 25,907 interventional oncology trials registered from 2007 to 2017. They included for analysis 12,240 that were completed or terminated and had a primary completion date on or before Sept. 30, 2017. Of these, 64.6% were phase II-IV trials, 27.2% were phase I, and the rest (8.2%) included trials of devices and behavioral interventions. About three-fourths of all trials were completed, while the remaining were terminated prematurely.
Overall, 10.6% of trials reported results at 1 year from the primary completion date, 27.7% after 2 years, and 51.1% at 5 years from the primary completion date.
Ma’s group also reported that there was a paradigm shift in the way trial results were reported during the study period. About three-fourths of trials completed in or before 2007 were reported in journal articles, but by 2017 most (64.4%) were reported through posting on ClinicalTrials.gov.
While the overall increase in the number of oncology trials reporting results is “promising,” wrote Ma and co-authors, there is room for improvement.
They noted that a previous study showed that oncology trials have the lowest rate of results reporting across all disease categories, with a likely explanation that these trials typically are small, not randomized or controlled, and have a high risk of adverse results, which has been a barrier to publication in peer-reviewed journals.
“Trial registries could serve as a convenient platform for results reporting and as an indispensable resource of data from clinical studies,” they suggested.
Piechotta and Kreuzberger noted that there will be some challenges involved in getting registries to be the primary means of posting data results. For example, they noted that while ClinicalTrials.gov may be the largest and most well-known trial registry in the world, other national and international registries exist. However, they also pointed out these registries don’t have the same functionality as ClinicalTrials.gov, and therefore can’t provide a similar infrastructure for posting results.
Barbara Jacoby is an award winning blogger that has contributed her writings to multiple online publications that have touched readers worldwide.