FDA Approves Leucovorin for Rare Brain Disorder, Rejects Autism Claims
The United States Food and Drug Administration has granted approval for the generic medication leucovorin to treat an ultrarare genetic brain disorder, while simultaneously and explicitly walking back previous suggestions from President Donald Trump and administration officials that the drug held significant promise for treating autism spectrum disorders. This approval, announced on Tuesday, marks a substantial reversal from the optimistic rhetoric presented at a White House news conference in September.
A Narrowed Focus on Strong Evidence
Senior FDA officials clarified to reporters that their review was deliberately narrowed to focus on the most robust scientific evidence available. This evidence solely supported the use of leucovorin for patients diagnosed with cerebral folate deficiency, a genetic mutation that severely limits the delivery of folate, a crucial form of vitamin B, to the brain. The agency estimates this condition affects fewer than one in a million individuals in the United States.
The approval represents a major step back from statements made by President Trump and FDA Commissioner Marty Makary in September, who announced the drug was under review for potential benefits to autism patients. At that event, Makary speculated the drug might help "20, 40, 50% of kids with autism." This White House announcement followed pledges from Health Secretary Robert F. Kennedy Jr. to identify the cause of autism by that same month.
Disputed Science and Retracted Research
FDA officials pointedly noted that one key study which had been cited to support leucovorin's use for autism was formally retracted earlier this year. The theory behind the experimental treatment suggests some individuals with autism possess specific antibodies that block folate from entering the brain. However, organizations like the Autism Science Foundation counter that non-autistic relatives of autistic individuals often have the same antibodies, indicating they are not a definitive causal factor in the condition.
While leucovorin is a synthetic metabolite of folate—essential for healthy pregnancies and used to mitigate chemotherapy side effects—its new label is strictly for cerebral folate deficiency. Patients with this disorder experience severe neurological symptoms, including movement disorders and seizures, which can superficially resemble some aspects of autism.
Medical Community's Cautious Stance
Leading medical societies maintain a cautious position. The American Academy of Pediatrics does not recommend the routine use of leucovorin for autistic children, even those with cerebral folate deficiency. The academy acknowledges that small-scale studies in this specific patient subset "suggest potential benefit," but emphasizes the evidence remains preliminary and insufficient for broad recommendation.
Most researchers in the field assert that autism likely arises from a complex interplay of genetic and environmental factors, with no single identified cause. The initial push for the FDA review reportedly came after Trump officials consulted with an Arizona-based neurologist who prescribes the drug for autism patients and operates an online education business centered on this experimental treatment.
Surge in Prescriptions and Supply Issues
Despite these unresolved scientific questions, the political spotlight has significantly impacted prescribing patterns. A recent paper published in The Lancet found that leucovorin prescriptions for children aged 5 to 17 were 71% higher than normal in the three months immediately following President Trump's late September news conference. This surge in demand has led to reported difficulties for families of autistic children in getting prescriptions filled in recent weeks.
In response to potential supply constraints, FDA officials stated the agency is permitting imports of the drug from foreign manufacturers to bolster availability. Notably, the drug's original manufacturer, GSK, has indicated it does not plan to relaunch its version of leucovorin at this time.
