Industry-funded, phase 2 trials frequently unpublished after completion
Years after completion, a significant number of clinical trials — particularly industry-funded, phase 2 studies — go unreported to the public, according to recent results.
Researchers at the Boston University School of Public Health Pharmaceuticals evaluated 400 randomly selected studies registered at ClinicalTrials.gov that had been listed as completed for at least 4 years. Of the 400, 29.5% were still unpublished within 4 years of completion. Industry-backed research was significantly less likely to be published (HR=0.49; 95% CI, 0.36-0.66), and fewer than half of phase 2 studies were published. The researchers also noted that industry-funded studies that were published took longer to reach the public: The median number of days before phase 2, industry-funded studies were published was 1,462, compared with 736 for academic or blended studies of any phase (P<.001).
“I was quite surprised to see that the behavior for industry-funded studies really differed markedly, where the phase 3 trials rapidly went public and the phase 2 trials took a very long time,” study co-author Christopher Gill, MD, MS, director of the Boston University School of Public Health Pharmaceuticals program and an associate professor of global health, told Cardiology Today. “In fact, when you’re trying to do a survival analysis, and you’re trying to calculate the point in time when half of the cohort achieves the endpoint, we couldn’t report that, because half of the papers never got published.”
Gill added that the majority of clinical development and research is done in phase 2, so the inaccessibility of that data not only keeps scientific information unavailable, but may put future study participants at risk: If a drug is studied in phase 2 and shows negative consequences to participants, and that information is not published, it could expose another cohort of participants to risk if the compound is acquired by another company and analyzed to treat a different condition.
“The majority of sponsored research does not get published,” Gill said. “That’s a rather depressing thought to me, especially since the really interesting science is typically done in phase 2, and that is systematically being withheld.”
Gill said a potential solution could come, not from regulations, but from journals. If all top journals required phase 2 trials to be published before allowing phase 3 trials to be public, he said, industry may be more enthusiastic about publishing phase 2 data.
“There is no statutory requirement that a phase 2 trial be published,” Gill said, noting that such actions have worked in the past: In 2005, registration of studies increased significantly after the International Committee of Medical Journals required registration as a condition of publication.
“That non-regulatory penalty by the journals had a profound effect on compliance with [registering on] ClinicalTrials.gov,” Gill said. “The journals have enormous power in this.” — by Shirley Pulawski
For more information:
Disclosure: Gill reports no relevant financial disclosures.