FDA warns it may reject foreign trial data it cannot inspect now

The US Food and Drug Administration has warned drug and device makers that clinical data it cannot verify may not count towards approval, wherever the trial was run. In an FDA Voices article published on 2 September 2026, the heads of the agency's drug, biologics, device and oncology centres said they would expand inspections of foreign trial sites, publish more about what those inspections find, and look harder at foreign studies run outside an Investigational New Drug (IND) application.

The article is titled "Good Clinical Practices Are Not Optional". It does not change the law. It sets out how the agency intends to apply existing rules as more of the evidence behind US approvals comes from trials with few or no American patients.

Who wrote it

The piece is signed by four senior officials:

• Michael Davis, acting director of the Center for Drug Evaluation and Research (CDER)
• Karim Mikhail, acting director of the Center for Biologics Evaluation and Research (CBER)
• Michelle Tarver, director of the Center for Devices and Radiological Health (CDRH)
• R. Angelo de Claro, director of the Oncology Center of Excellence

Having all four centre heads on one article signals that the position applies across drugs, biologics and devices.

The core message

Good Clinical Practice (GCP) is the international standard for how trials are designed and run, from day-to-day monitoring through to how the data are recorded and reported. Its purpose, the FDA writes, is to make sure trial data are "credible and accurate" and that participants' rights, safety and well-being are protected. All trials of investigational products submitted to the FDA must comply.

The officials argue that globalised research is testing that standard. They list three concerns with multi-regional trials that enrol few or no US patients:

• results may be harder to generalise to the American population the product is meant for
• Americans lose the chance to take part in trials of new treatments
• it is harder and more costly for the FDA to inspect foreign sites in the same way as domestic ones, including through unannounced inspections

The article focuses on the third point. The host country, it adds, "may not have the regulatory capacity or authority to provide oversight of clinical trials commensurate with the FDA's expectations."

Data the FDA cannot check

The agency's position rests on a simple requirement. For data to support a regulatory decision, the FDA must be able to validate it. That includes protecting participants, independent ethical review, informed consent, and the FDA's ability to inspect trial sites and audit records.

"This standard does not depend on geography," the officials write. "It holds whether a trial was conducted in Boston or Beijing."

If the FDA cannot confirm that data were collected under GCP, including at sites where in-person inspection is constrained or denied, its regulations allow it to refuse that evidence in support of a marketing application. If falsified, duplicated or otherwise invalid data are found during review or after a product reaches the market, the agency can remove those data from consideration. Where the remaining evidence cannot support the authorisation, it can deny, withhold or rescind it.

The article stresses that this is "not a new policy" but "the logical application of existing law to a rapidly evolving reality."

Denied or conditional access

The FDA says that for some foreign inspections it has been denied access, or told that an inspection would require it to sign agreements restricting the scope or conduct of the visit, or to attest to "geopolitical principles unrelated to the inspection". The article does not name countries.

"Before the FDA opens the door to let a product reach the American market, sponsors and clinical investigators must open their doors to the FDA," it says. That means access to sites, records, source data and consent documentation.

The agency says companies "should not assume that there is a lower probability of FDA inspection by conducting studies abroad."

What the FDA says it will do

The article lists concrete steps.

Expanding inspection coverage. The FDA is adding resources for foreign Bioresearch Monitoring (BIMO) inspections. It plans to inspect more phase 1 and early-stage trials abroad and to widen some assignments so that inspectors look at more of the trials running at a facility. It also plans to update the risk-based criteria it uses to pick sites, to reflect compliance risks in specific countries or regions.

Telling sponsors and the public. The agency says it is becoming more systematic about telling sponsors and the public when sites, staff or documents were not available for inspection, or when inspections were conditioned on agreements it could not sign.

Training reviewers. Medical product reviewers will get extra training to spot sites where there may be GCP concerns, including whether informed consent was "obtained, freely given, and documented", and to escalate data integrity problems.

Publishing more findings. When the FDA finds human subject protection or data integrity problems at sites outside the US, it will make more information from inspections public, as appropriate.

Engaging earlier. The FDA will discuss the origin and IND or device exemption status of foreign data with sponsors early in development, through pre-IND meetings, Type B meetings and device pre-submissions.

Foreign studies run without an IND

A large part of the article deals with foreign studies run outside a US IND or Investigational Device Exemption (IDE). Under 21 CFR 312.120, the FDA can accept such studies in support of an application if they followed GCP, including approval by an independent ethics committee and informed consent from every participant.

The agency says it is placing "greater scrutiny" on whether those data are "reliable, inspectable, and ethically derived." It is particularly concerned about early feasibility studies and phase 1 studies, and about sites in countries or regions where geopolitical conditions make informed consent difficult to ensure, or where documented human rights concerns create a higher risk that consent was not freely given.

The officials say audits across all trial phases "have revealed instances of fabricated participants, falsified health conditions, falsified laboratory results, and concealed adverse events." They will use requests for more information, reanalysis and inspection to satisfy themselves that GCP was met before accepting such data.

Not protectionism, the FDA says

The article anticipates the charge that this is about trade or politics. "This is not protectionism, and it is not a geopolitical statement about any particular country's scientific capacity," it says, adding that many foreign institutions produce data "of the highest quality" that the agency "actively welcomes and relies on."

The closing message to sponsors is direct. Plan development programmes in settings "where FDA access will not be impeded from day one". If a regulatory strategy depends on data from sites the FDA could not inspect, or from circumstances where ethical conditions are "in serious question", the officials write: "think again."

How it fits with other FDA moves

The article sits alongside a wider push by the agency and the Department of Health and Human Services to bring more early-stage research back to the United States. Two weeks later, on 15 September, the FDA opened applications for its Expedited IND Pilot under HHS's Operation TrialBlazer, which aims to shorten the time to first-in-human trials in the US. We report on that pilot in our article on the FDA Expedited IND Pilot.

The FDA's own press release for the pilot says first-in-human trials can take up to two years in the US and are completed "much faster in China and Australia". Taken together, the two announcements combine a stricter line on data the agency cannot verify with an effort to make early US trials quicker.

What it means for sponsors

For companies, the practical message is about risk. Industry commentary has focused on the warning that the FDA may decline data from sites it cannot inspect. In planning terms that means:

• Site choice for phase 1 and early-stage trials may need to weigh FDA inspection access as well as speed and cost.
• Programmes that rely heavily on non-IND foreign data should expect more questions, reanalysis requests or inspections.
• Sponsors should raise the source and status of foreign data at pre-IND or Type B meetings, before late-stage trials.
• Records, source data and consent documents need to be ready for inspection at every site.

The FDA has not published new guidance or a list of affected countries. Changes to its risk-based site selection criteria are described as planned.

What it means for patients

For people taking part in trials, the article is framed around protection. Informed consent that is freely given is central to GCP, and the agency's focus on consent in settings with human rights concerns speaks directly to participant safety.

For patients who rely on approved medicines, the point is reliability. The FDA says approval decisions are "only as good as the evidence underlying them." Stronger checks on foreign data aim to reduce the chance that an approval rests on data that later prove unreliable.

Our patient guide on how to find and join a clinical trial explains what consent should involve and the rights every participant has.

What happens next

The FDA has said it will add inspection resources, update its site selection criteria, and publish more inspection information. None of these has a public timetable in the article. Sponsors and investors will watch for any published examples of data being refused, any new transparency listings of sites that blocked access, and whether Congress acts on the concerns the article says policymakers have raised.

Related reading

• FDA launches Expedited IND Pilot under Operation TrialBlazer
• How new medicines get approved and reach patients

This article is for general information and is not medical advice. Please talk to your own doctor before joining a trial or changing any treatment.