Nearly 5,000 clinical trials, including more than 1,000 cancer treatment tests, face termination under proposed federal regulations, a new analysis by the science advocacy group Stand Up for Science finds. The potential cuts would also affect hundreds of pediatric, veteran health and heart disease trials, according to the report.
The trials are at risk because of rules proposed by the White House’s Office of Management and Budget (OMB) in May that would give political appointees the final word on federal research grants across agencies—a departure from decades of relying on scientific peer review to judge grants’ merits. The proposed rules are aimed to combat “a ‘woke’ policy agenda” and to curb international collaboration, according to a statement published in the Federal Register. The OMB is headed by Russell Vought, the lead architect of the Heritage Foundation’s Project 2025 plan for the Trump administration.
Clinical trials are the final stages for testing new medical treatments and interventions, and they can involve dozens to thousands of volunteer patients, depending on the trial’s aims. A 2025 JAMA Internal Medicine analysis of 383 clinical trials associated with grants that were terminated by the Trump administration found that as many as 74,000 participants were affected by the cuts.
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Applying the proposed rules to some 10,000 clinical trials currently being funded by the National Institutes of Health, Stand Up for Science found that nearly half would face termination. Many of these are international in nature or could trip a list of more than 350 “banned words”—phrases that PEN America, a free speech group, reports that federal agencies have either sought to prohibit or limit, according to the new analysis. Words on the list include “abortion,” “solar power” and “vaccines.”
“People’s lives are on the line. These are clinical trials of new drugs and interventions that could change people’s lives,” said Stand Up for Science founder Colette Delawalla in a statement.
In response to the new report, a Trump administration spokesperson told Scientific American, “The Trump Administration will ensure funding goes toward real science instead of promoting a far-left DEI [diversity, equity and inclusion] agenda with things like drag shows in Ecuador and transgender experiments on mice. This rule will bring much-needed transparency to the grantmaking process and ensure taxpayer dollars are spent wisely.” (The reference to “transgender” mice derives from a 2025 address to Congress in which Trump impugned studies of hormone effects on chronic wounds and in gender-affirming care.)
Outside experts were cautious about the estimated number of trials that may be canceled in the new report. “This seems like an analysis that is highly sensitive to the assumptions made by the analyst,” says Vishal Patel, a physician at Brigham and Women’s Hospital and lead author of the 2025 JAMA Internal Medicine study. The assumption that using a banned word will inevitably lead to termination might be too extreme, he says. “This might just be a little too crude of an estimate,” Patel adds.
Elizabeth Ginexi, a former NIH program officer, says that likely about a third of the clinical trials that the NIH has funded have had some foreign involvement, putting them at risk. And grants that the administration sought to kill last year over their diversity-related character (moves halted by courts, in some cases) might also face the chopping block. But the Stand Up for Science analysis was hard to evaluate without more details, she says. “In any case, I do expect mass grant cancellations at NIH if this new OMB rule is passed,” Ginexi adds. “It will be very ugly.”
The proposed OMB rules have received widespread condemnation from medical and scientific organizations, such as the American Heart Association and the American Association for the Advancement of Science. These groups see the rules as breaking the compact between the scientific enterprise and federal agencies to deliver research based on peer review by scientists inside and outside the government.
“The OMB proposal to permit political appointees to discontinue funding of ongoing grants at any time, without cause, would have serious adverse consequences for the research enterprise and for patients,” wrote the editorial board of the New England Journal of Medicine in an article published on Monday. “Can physician-investigators ethically enroll a patient in a trial if ongoing funding for the trial is uncertain?”
The public comment period for the OMB rules ends on July 13, with more than 28,000 comments submitted so far. If implemented, the new rules would take effect by October.
Editor’s Note (6/17/26): This story has been updated with comments from Vishal Patel and Elizabeth Ginexi.