Study: Most sponsors complete postmarketing trials, publish results

Postmarketing requirements and commitments were completed for nearly nine out of ten drugs approved by the US Food and Drug Administration, with such requirements or commitments assigned at the time of approval. Of those, the vast majority of study results were published in ClinicalTrials.gov or another publication, according to an article published Thursday in JAMA Network Open.

Despite these results, study authors Maximilian Siebert, of the Harvard-MIT Center for Regulatory Science, and colleagues said that more should be done to encourage sponsors to complete and publish their postmarketing studies.

The study consisted of a cross-sectional analysis of 370 FDA-approved drugs from 2016 to 2023. Of those drugs, 59 had at least one postmarketing requirement or commitment, with a total of 88 postmarketing safety or efficacy trials. Their analysis found that 76 of those trials (86.4%) were completed by the end of 2023. Furthermore, the results of 67 (88.2%) of the completed trials were published, with 58 (76.3%) published on www.ClinicalTrials.gov.

The study also found that the results of efficacy trials were much more likely to be published (94.4% vs. 75%) or published specifically on ClinicalTrials.gov (88.9% vs. 65%) compared to those of safety studies.

The researchers noted that postmarket trial requirements and commitments are mandated by several regulatory authorities, including accelerated approval, the Pediatric Research Equity Act (PREA), and section 505(o)(3) of the FDA Amendments Act (FDAAA), and each mandates specific requirements. They searched through ClinicalTrials.gov, PubMed, EMBASE, and Google Scholar to identify whether sponsors had submitted postmarket trial results by 31 December 2025.

Despite the significant number of trials completed and published, the researchers noted that many trials faced prolonged delays in publishing results, especially those required to publish under a Pediatric Research Equity Act (PREA) mandate.

"It is important to note that the observed time from approval to publication reflects multiple phases, including trial initiation, conduct, and dissemination," said the researchers. "Delays may arise from sponsor decisions as well as factors partly outside sponsor control, such as scientific complexity, recruitment challenges, and peer review timelines.

"Efforts to strengthen oversight or implement policy interventions should account for both modifiable operational delays and differences in trial burden," they added. "Nonetheless, our findings suggest that strengthening oversight and aligning incentives for timely reporting of results from clinical trials outlined in postmarketing requirements and commitments may be necessary to ensure postapproval evidence fulfills its intended role in promoting evidence-based clinical decision-making."