More than one-third of postmarket studies following drug approval that should be published are not, according to new research.
Investigators examined a Food and Drug Administration internal database to identify all postmarket drug studies between 2009 and 2013 identified by the agency as completed, with a follow-up search to find if/where the results of the studies were published.
“As of July 2016, 183 of the 288 postmarket studies (63.5%) meeting inclusion criteria were published in either the scientific literature or on the ClinicalTrials.gov website,” Marisa Cruz, MD, medical officer in the Food and Drug Administration’s Office of Public Health Strategy and Analysis, and her colleagues wrote in a researcher letter published online May 15 in JAMA Internal Medicine (doi: 10.1001/jamainternmed.2017.1313).
ClinicalTrials.gov
More studies were published in journals (175) than in the agency’s clinical trial registry (87), and the 183 interventional clinical trials had a higher overall publication rate (87.4%) than the other 105 studies combined (21.9%).
Of the 69 interventional clinical trials that were focused on efficacy, 86.2% were categorized as having results that were favorable to the trial sponsor. However, the 57 interventional clinical trials with positive results were no more likely to be published than the 12 trials with negative results, Dr. Cruz and colleagues noted.
The findings are consistent with previous research, the researchers noted, with the analysis demonstrating “that postmarket study results are not consistently disseminated, either through journal publication or trial registries.”
“Despite calls for data sharing and publication of all clinical trial results, publication rates for completed postmarket studies required by the FDA remain relatively low,” the researchers wrote.
While the FDA could publish the data itself, “this approach would likely require new regulations,” the authors noted. “Alternatively, increased sponsor commitment to submitting to journals and to publish all clinical trial results on trial registries, regardless of whether publication is legally required, may serve to promote dissemination of scientific knowledge.”
The researchers reported no conflicts of interest.
gtwachtman@frontlinemedcom.com