The U.S. Food and Drug Administration has approved a new use for leucovorin calcium tablets, allowing the drug to treat cerebral folate deficiency (CFD), an extremely rare neurological condition. The medication is a synthetic version of vitamin B9 and has long been used to lessen the toxic side effects of chemotherapy or boost its effectiveness in cancer care. The drug—sometimes sold under the name Wellcovorin—was originally marketed by GlaxoSmithKline beginning in 1983, though the company later stopped selling it when generic versions became available.
According to the FDA, the decision was based on “a systematic review of the published literature on the topic, including published case reports with patient-level information, as well as mechanistic data.” Cerebral folate deficiency disrupts the body’s ability to transport folate into the brain. People with the condition—particularly those with variants in the FOLR1 gene—often experience severe developmental delays, seizures, movement problems and other neurological complications. The disorder is extraordinarily uncommon; the National Organization for Rare Disorders reports that fewer than 20 cases have appeared in scientific literature, and its true prevalence remains unclear.
Health officials say the approval marks the first FDA-authorized therapy for this genetic condition. FDA Commissioner Marty Makary said in a statement: “Today’s approval represents a significant milestone for patients living with cerebral folate transport deficiency due to the FOLR1 variant, a rare genetic condition that has had no FDA-approved treatment options until today. This action may benefit some individuals with FOLR1-related cerebral folate transport deficiency who have developmental delays with autistic features.”
Leucovorin has also drawn attention recently as a possible treatment for autism symptoms, a claim that sparked debate after members of the Trump administration promoted the idea last year. At the time, officials suggested updating the drug’s label so it could be used for autistic children, with President Trump saying the change would “reflect potential benefits in reducing some autism symptoms.”
FDA officials said that they initially reviewed research on leucovorin’s potential role in autism, but ultimately narrowed their focus to patients with confirmed cerebral folate deficiency because that group showed the strongest treatment responses. FDA officials now say the evidence is not strong enough to support approving the drug for autism itself, noting that families should consult physicians if considering the medication. Despite the lack of formal approval for autism, doctors are allowed to prescribe leucovorin off-label. Interest in the drug has surged in recent months; one analysis found prescriptions for children increased 71% in the weeks after the administration highlighted it publicly.
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