Results May Vary, But Reporting Shouldn’t: FDA Sends a Not-So-Gentle Reminder on ClinicalTrials.gov Compliance

FDA has, once again, reminded sponsors that ClinicalTrials.gov results reporting is not optional.

In a March 30, 2026 outreach, the Agency contacted more than 2,200 sponsors and investigators associated with over 3,000 clinical trials that appear to be missing required results submissions to ClinicalTrials.gov or have not cleared the National Library of Medicine’s quality control process. As FDA put it, these communications were intended to prompt “voluntary compliance” with long-standing statutory and regulatory requirements.

This is not a new obligation, and FDA’s expectations are not ambiguous. Applicable clinical trials—generally interventional studies of FDA-regulated products with a U.S. nexus—must submit results information to ClinicalTrials.gov within one year of primary completion, absent a limited exception. Yet, FDA’s internal analysis indicates that roughly 30% of trials likely subject to these requirements have no results posted.

FDA Commissioner Makary suggested that some sponsors may be intentionally withholding unfavorable results. That may be true in a limited number of cases. But in our experience, reporting delays and failures typically reflect breakdowns in process rather than a nefarious strategy—missed deadlines, personnel turnover, unclear delegation of responsibility for reporting, or even situations in which the original sponsor no longer exists and no clear “responsible party” remains to complete the submission.

That does not make the issue insignificant. Failure to submit required results contributes to an incomplete public record and can skew the available evidence base. That concern is not new, but FDA’s latest outreach suggests that the Agency is taking a more active approach to addressing it.

Procedurally, FDA has several well-established enforcement tools available. The Agency may issue Pre-Notices of Noncompliance (as of the date of this blog, FDA has issued 232 such notices since 2013) and, if necessary, formal Notices of Noncompliance (of which FDA has issued 8 since 2021)  as part of its risk-based compliance efforts related to ClinicalTrials.gov reporting requirements. These actions can lead to additional enforcement consequences, including civil monetary penalties.

What is notable here is that FDA has taken an additional step before initiating those formal processes. The March 30 communications were directed to responsible parties whose trials appear to be out of compliance or delayed in quality control, providing an opportunity to come into compliance before the Agency considers whether to pursue further regulatory action.

This is not the first time FDA has signaled increased attention to ClinicalTrials.gov compliance. As discussed in our prior posts (see FDA Cracks Down on ClinicalTrials.gov Reporting Failures and Court Determines That Decades Worth of Missing Data Must Be Published on ClinicalTrials.gov), both FDA and the courts have, at various points, pushed to address persistent gaps in results reporting—though enforcement has historically been uneven and, at times, dependent on Agency discretion.

The latest outreach suggests that FDA may be taking a more active approach, at least at the front end of the compliance process.

So, what’s the takeaway? FDA seems to be signaling that it is actively reviewing ClinicalTrials.gov compliance and is willing to follow up. If you are listed as the “responsible party,” now is the time to confirm that results have been submitted, that any quality control comments have been addressed, and that responsibility for ongoing compliance is clearly assigned.