FDA Reminds More Than 2,200 Sponsors and Researchers to Report Clinical Trial Results

The FDA has contacted more than 2,200 medical product companies and researchers to remind them of their legal obligation to submit clinical trial results to ClinicalTrials.gov.¹

The outreach, issued on March 30, covered more than 3,000 registered clinical trials—including some that were publicly funded—where required results information either had not been submitted or had not completed the National Library of Medicine's quality control review process.

According to an internal FDA analysis, 29.6% of studies highly likely to fall under mandatory reporting requirements have no results information submitted to ClinicalTrials.gov. The figures exclude Phase I and device feasibility studies, covering instead interventional studies with a US nexus and an FDA-regulated product that are past their reporting deadline.

"Far too often, companies are suppressing unfavorable clinical trial results and keeping them secret from patients and the scientific community," said FDA Commissioner Marty Makary, MD, MPH, in an agency news release. "Those sponsoring clinical trials have an ethical obligation to make results public regardless of the data's influence on the company's share price."

Under federal law, certain clinical trial sponsors and researchers are required to submit results information to ClinicalTrials.gov within one year of trial completion.

The agency noted that companies and researchers often fail to disclose negative results, creating gaps in the public record and a publication bias that overrepresents successes and underrepresents failures—a distortion that can affect how clinicians and researchers assess the safety and efficacy of medical products.

The March 30 messages represent a voluntary compliance step ahead of potential regulatory action. The FDA noted it may also issue Pre-Notices of Noncompliance and Notices of Noncompliance as part of its broader, risk-based compliance efforts related to ClinicalTrials.gov reporting.

"We hope that the thousands of messages sent to sponsors and investigators reminding them to publicly report their findings will improve patient safety and keep researchers and the public better informed of benefits and risks of new and investigational products," added Tracy Beth Hoeg, MD, PhD, acting director of the Center for Drug Evaluation and Research, in the news release.

A year of active FDA engagement

So far this year, the FDA has moved on several fronts that carry direct implications for clinical trial sponsors and researchers.²

In a series of actions taken in the first months of 2026, the agency updated its evidentiary standards across multiple dimensions of drug development, signaling a broader shift toward flexibility, mechanism-based evidence, and human-centric science.

Among the most consequential changes: the agency clarified that a single adequate and well-controlled trial, supported by confirmatory evidence, can serve as the basis for new drug approval.

A new plausible mechanism framework opened a regulatory pathway for individualized therapies targeting ultra-rare diseases where traditional trial designs are not feasible. Draft guidance on new approach methodologies established formal validation principles for alternatives to animal testing, including organoids, organs-on-chips, and in silico models.

And updated Bayesian methodology guidance gave sponsors clearer direction on applying adaptive statistical methods and incorporating real-world evidence into regulatory submissions.

Taken together with the results reporting push, these actions reflect an FDA that is actively recalibrating how it engages with sponsors by raising expectations around transparency and evidence quality while offering more flexible tools for meeting them.

Earlier insight on FDA capacity constraints

At the turn of the new year, Applied Clinical Trials spoke with Charlie Paterson, partner at PA Consulting, on how reduced FDA capacity and significant staff turnover in 2025 have reshaped regulatory engagement and operational planning for clinical trials.

In an exclusive video interview, he noted that agency capacity constraints are creating uncertainty from initial submissions through late-stage approval, elongating timelines and influencing global development strategies.

“Further downstream, during tech transfer and the period between last patient last visit and approval, timelines are also elongating because capacity can’t meet volume. That’s driving concern and pushing activity outside the US,” Paterson explained. “Even with initiatives like the single pivotal trial concept, confidence requirements may still demand larger samples and longer timelines. As a result, organizations are delaying submissions, spending more time planning, or seeking guidance from other jurisdictions.”

References

1. FDA Reminds More Than 2,200 Sponsors and Researchers to Disclose Trial Results. News release. FDA. April 13, 2026. Accessed April 15, 2026. https://www.fda.gov/news-events/press-announcements/fda-reminds-more-2200-sponsors-and-researchers-disclose-trial-results

2. Four FDA Actions Reshaping Drug Development in 2026. Applied Clinical Trials. March 23, 2026. Accessed April 15, 2026. https://www.appliedclinicaltrialsonline.com/view/fda-actions-reshaping-drug-development-2026