woman for radiotherapy
Photo by Rhoda Baer
TURIN, ITALY—Results from many phase 3 radiotherapy trials conducted in the US are not being published on ClincalTrials.gov, according to a study presented at ESTRO 35.
Since 2007, it has been mandatory to publish the results of clinical trials carried out in the US on ClinicalTrials.gov within 12 months of trial completion.
However, an analysis of more than 800 radiotherapy trials revealed that more than 80% did not meet this requirement.
Jaime Pérez-Alija, of Hospital Plató in Barcelona, Spain, and his colleagues presented these results at ESTRO 35 as abstract PV-0087.
In 2007, the Food and Drug Administration Amendments Act (FDAAA) mandated that sponsors of most US trials begin registering and reporting basic summary results on ClinicalTrials.gov so the American public could have access to the resulting data.
The requirement covers non-phase-1 trials of drugs, medical devices, or biologics that had at least 1 US research site. Trial results are to be reported by the sponsor within a year of completing data collection.
To investigate how well this mandate has been followed by sponsors of phase 3 radiotherapy trials, Pérez-Alija and his colleagues analyzed 802 trials with a primary completion date prior to January 1, 2013.
The team found that 81.7% of these trials (n=655) did not have even summary results published on ClinicalTrials.gov.
The researchers also looked specifically at those trials that began after the 2007 act was passed and found that 76.4% of these trials (422/552) did not have results published.
When the researchers looked at publication by cancer type, they found that 78% of lymphoma trial results were unpublished.
The most-published cancer type was glioblastoma, with 62.5% of results unpublished. And the least-published cancer types were anal and testicular cancers, for which 100% of trial results were unpublished.
“These findings came as a surprise for many reasons, not least of which was that many of the trials had been funded by the US National Institutes of Health,” Pérez-Alija said.
“Interestingly, we found that company-funded trials are far better at complying with the rules than academic trials—55% and 30% respectively. However, only one-third of all the trials we studied were company trials. Since we know that clinical trials produce the best data for decision-making in modern evidenced-based medicine, it is particularly worrying that the law is being ignored on such a wide scale.”
One possible reason for non-publication, according to the researchers, is that some of the trials may have been granted a deadline extension. However, if this is the case, it is not publicly known.
“Therefore, our first problem is that we do not know with any certainty whether a trial is truly overdue,” Pérez-Alija said. “The registry says clearly that all dates must be updated if an extension has been allowed, but it seems likely that this is not happening in many cases.”
The researchers are investigating the issue further to see, for example, how many of the trials registered in ClinicalTrials.gov or in other databases are being published in medical journals.
They intend to email principal investigators to ask why the mandatory deposition of results did not take place and to enquire about the reasons for non-publication in medical journals of those trials where there is a published deposition.
“We have shown that a large number of study participants are routinely exposed to the risks of trial participation without the benefits that sharing and publishing results would have for patients in the future,” Pérez-Alija said.
“Information about what was done and what was found in these trials could be lost forever, leading to bad treatment decisions, missed opportunities for good medicine, and trials being repeated unnecessarily. This situation should not be allowed to continue.”
