The Food and Drug Administration on Tuesday announced a new approved use of the drug leucovorin, a synthetic form of vitamin B9 that the Trump administration has touted as a treatment for autism symptoms.
But the new approval isn’t for autism – it’s for cerebral folate deficiency, a rare neurological condition characterized by low levels of vitamin B9 in the brain.
Contrary to the messages that President Donald Trump and FDA Commissioner Marty Makary gave in September when they announced the plan to rename the drug, a top FDA official said Monday that there is not enough data to support the use of leucovorin as an autism treatment.
“We don’t have enough data to say that we can establish the general efficacy of autism,” the official said. “It will be up to patients to talk to their doctors to see if that might be right for them.”
Leucovorin is mainly used to help reduce the side effects of chemotherapy or improve its effectiveness in cancer patients. But at a Sept. 22 briefing, Makary said the FDA is taking steps to change the drug’s label “so that it is available to children with autism,” adding that “hundreds of thousands of children, in my view, will benefit.”
Trump said at the time that the revised drug label would “show potential benefits in reducing some symptoms of autism.”
“This gives hope to many parents with children with autism that they can improve their lives,” she said.
Many experts who research or treat autism are skeptical of that talk, saying the drug needs more study before it can be applied to patients with autism.
Alycia Halladay, chief science officer at the Autism Science Foundation, said the FDA’s announcement Tuesday is “1,000% different” from the administration’s statement in September.
The original change proposed by the FDA nearly six months ago did not say the drug would be approved to treat autism. Instead, the agency said it is beginning to approve leucovorin tablets for patients with cerebral folate deficiency and described overlaps between symptoms of that condition and autism, such as challenges with social interaction, sensory processing and repetitive behaviors.
One in 1 million people is estimated to have cerebral folate deficiency, and although some researchers suspect that the condition may be linked to autism, it is thought to affect only a small minority of autism patients.
Even though leucovorin is not approved to treat autism, doctors may prescribe it off-label. Others were doing this before Trump’s comments in September, based on the findings of a handful of small trials conducted mostly outside the U.S. The results of one such study, published in the European Journal of Pediatrics, were retracted in January after the authors pointed out several errors in their data.
In the 2½ months following Trump’s announcement in September, pediatric leucovorin prescriptions increased by 71%, according to data published last week in the medical journal The Lancet.
“The bell has rung, and we’ve seen in the data that leucovorin prescriptions have increased dramatically,” Halladay said. “I don’t see that changing with this announcement is warranted solely for cerebral folate deficiency.”
David Mandell, a psychology professor at the University of Pennsylvania, said the FDA’s announcement this week amounts to mixed messages, given the Trump administration’s explanation for leucovorin in September.
“This is bad for families – this back and forth about what causes autism, what doesn’t cure autism, what causes autism, what doesn’t,” he said. “Families deserve better than that. They deserve more rigorous science. They need more accurate information.”
Still, Mandell said he was “relieved” that the FDA is not approving leucovorin for autism patients, “given the very weak data and my understanding that the current ongoing trials are not promising for autism.”
