U.S. FDA finds little evidence that a generic drug can help people with autism

President Donald Trump listens as Dr. Marty Makary, commissioner of the Food and Drug Administration, speaks in the Roosevelt Room of the White House, Monday, Sept. 22, 2025, in Washington. (AP Photo/Mark Schiefelbein, file)

WASHINGTON — The U.S. Food and Drug Administration on Tuesday approved a generic medication for a rare brain disorder, while walking back suggestions by U.S. President Donald Trump and other administration officials that the drug showed great promise for people with autism.

The agency said it approved leucovorin for children and adults with a genetic condition that limits delivery of folate, a form of vitamin B, to the brain. FDA officials estimate the ultrarare condition impacts fewer than 1 in a million people in the U.S.

It’s a major step back from statements made at a White House news conference in September, when Trump and FDA commissioner Marty Makary announced the drug was under review to benefit patients with autism, some of whom have a form of the vitamin brain deficiency.

“It might be 20, 40, 50% of kids with autism,” Makary said at the news conference.

The White House event followed promises from Health Secretary Robert F. Kennedy Jr. to determine the cause of autism by September.

But senior FDA officials told reporters Monday that their review was narrowed to focus on the strongest evidence, which only supported the drug’s use by patients with the rare mutation that impacts folate levels in the brain.

The FDA officials also pointed out that one study supporting the drug’s use for autism was retracted earlier this year.

Leucovorin is a synthetic metabolite of folate, which is essential for healthy pregnancies and is recommended for women before conception and during pregnancy. The drug’s current FDA label covers leucovorin’s use in reducing side effects of certain chemotherapy drugs and treating a rare blood disorder.

Patients affected by the condition targeted by Tuesday’s approval experience movement disorders, seizures and other neurological problems that can resemble symptoms of autism.

But professional medical societies say it’s far from clear whether the drug helps people with autism.

The American Academy of Pediatrics doesn’t recommend routine use of leucovorin for autistic children, including those with the brain condition known as cerebral folate deficiency. Some trials in that subset of patients “suggest potential benefit,” the group states, but the research comes from small-scale studies.

Unresolved questions about the drug haven’t stopped U.S. doctors from prescribing it.

A paper published in The Lancet last week found that leucovorin prescriptions for children aged 5 to 17 were 71% higher than normal in the three months immediately following Trump’s late September news conference. And families of children with autism have reported trouble getting prescriptions filled in recent weeks.

FDA officials told reporters the agency is allowing imports of the drug by foreign drugmakers to help boost supply. The drug’s original manufacturer, GSK, does not plan to relaunch its version of the drug.

Trump officials originally decided to review the drug after speaking with an Arizona-based neurologist who prescribes the drug for autism patients and runs an online education business focused on the experimental treatment.

The theory behind the drug’s use is that some people with autism have specific antibodies that block folate from entering the brain. But the Autism Science Foundation and other groups note that non-autistic relatives of people with the disorder often have the same antibodies, suggesting they’re not a factor in the condition.

While there is no single cause behind autism, most researchers say science points to genetic and environmental factors as playing a role.

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Matthew Perrone, The Associated Press