Federal health officials say there is little scientific evidence that a drug promoted by President Donald Trump as a potential treatment for autism is effective for most people with the condition, according to a new review by the U.S. Food and Drug Administration.
The agency recently approved the drug leucovorin for a rare genetic disorder that prevents the brain from properly receiving folate, a form of vitamin B. The condition affects fewer than one in a million people in the United States and can cause neurological problems including seizures, movement disorders and symptoms that resemble autism.
The approval represents a significant narrowing of earlier claims made by administration officials who had suggested the medication could benefit a large share of people with autism. During a White House announcement last fall, officials indicated the drug might help a substantial percentage of children diagnosed with the disorder.
FDA officials now say their evaluation focused on the strongest available evidence, which only supported the drug’s use in patients with the rare folate-related brain condition. The agency also noted that a key study cited in support of leucovorin as an autism treatment was retracted earlier this year.
Researchers and autism specialists say there is currently no reliable evidence showing that the drug is safe or effective for the majority of people with autism. Medical organizations have also expressed caution about its use.
The American Academy of Pediatrics does not recommend routine use of leucovorin for autistic children, including those who may have cerebral folate deficiency, a brain disorder linked to impaired folate transport.
Despite those warnings, prescriptions for the drug increased sharply after the administration’s announcement last year. A study published recently in The Lancet found that prescriptions for leucovorin among children ages 5 to 17 rose 71 percent above expected levels during the three months following the September news conference.
The surge in demand has created confusion among families and physicians about whether the medication should be used to treat autism symptoms. Some parents have recently reported difficulty filling prescriptions as supply issues developed.
To address shortages, the FDA said it is allowing foreign manufacturers to import the medication into the United States. The drug’s original manufacturer, GlaxoSmithKline, does not plan to resume production of its version.
Leucovorin has long been used for other medical purposes, including reducing side effects from certain chemotherapy drugs and treating a rare blood disorder. The medication is a synthetic metabolite of folate, a nutrient considered essential for healthy fetal development during pregnancy.
Some doctors believe the drug may help a subset of autism patients whose immune systems produce antibodies that block folate from entering the brain. However, research has found that the same antibodies can also appear in relatives who do not have autism, casting doubt on their role in the condition.
Scientists generally agree that autism does not have a single cause and is likely influenced by a combination of genetic and environmental factors.
Source: FDA, AP