FDA approves leucovorin – but not for autism
The FDA has approved the generic drug leucovorin as a treatment for an ultra-rare condition, with autism-like symptoms, known as cerebral folate deficiency.
The US regulator has not, however, cleared leucovorin for autism spectrum disorder (ASD) itself, stepping back from the furore that broke out last year when President Trump claimed it could be a treatment for speech-related deficits associated with the neurodivergent condition, prompting pushback from medical groups.
The FDA said it had approved GSK's Wellcovorin brand of leucovorin for the treatment of cerebral folate deficiency in adult and paediatric patients who have a confirmed variant in the folate receptor 1 gene (CFD-FOLR1), based on "a systematic review of the published literature on the topic."
The agency said it had narrowed the scope of its approval to the area where there was the strongest evidence of a clinical benefit, adding that it was not possible to run a clinical trial as CFD-FOLR1 is so uncommon. The review also spanned published case reports with patient-level information and "mechanistic data."
One of the biggest studies suggesting leucovorin was able to treat autism, published in 2024, was retracted from the European Journal of Paediatrics at the end of January, according to the publisher. Now, there is concern that the approval could further encourage off-label prescribing of leucovorin for ASD, with no evidence of efficacy and a risk of side effects.
Leucovorin was originally developed by GSK to prevent side effects in people treated with some forms of chemotherapy, and the company said last year that it would file for approval of the drug in the CFD indication, having withdrawn its brand from the market in the late 1990s. Generics of the drug, which are widely available in the US, will now be prescribable for the disorder, and GSK has indicated it will not be restarting production.
People with CFD-FOLR1 often have severe developmental delays, movement disorders, seizures, and other serious neurological complications, said the FDA. It is estimated that there are only a few dozen cases of the genetic disease worldwide.
The rise in autism diagnoses has been repeatedly held up by the Trump administration and HHS under Secretary Robert F Kennedy Jr as an epidemic caused by exposure to some environmental factor, although scientific experts have attributed it to increased awareness, broader diagnostic criteria, and improvements in screening and detection.
Earlier this year, Kennedy formed an Interagency Autism Coordinating Committee (IACC) to guide federal policy on autism, populating it with some members with ties to groups that promote claims linking vaccines to autism. In response, scientists and autism community advocates said they would form their own committee to provide a science-based response to any advice or information that may emerge from the IACC.
Photo by Annie Spratt on Unsplash
