GSK discontinued Wellcovorin in 1999, but the FDA in September last year asked the pharma to refile an application, pointing to its potential to treat cerebral folate deficiency with “autistic features.”
GSK has withdrawn an approval application for Wellcovorin, a decades-old drug that late last year gained renewed attention after the members of the Trump administration publicly suggested it has the potential to treat autism symptoms.
The pharma requested to terminate the new drug application because “the drug products were no longer marketed,” according to a Federal Register notice on Thursday. The withdrawal of the application was procedural and not linked to any safety or efficacy issues, a GSK spokesperson told The Wall Street Journal on Thursday, noting that the company had never intended to revive the drug.
Wellcovorin (generic name: leucovorin) was first approved in 1983 as a treatment to counter the toxic side effects of methotrexate, a common chemotherapeutic agent. GSK eventually discontinued the drug in 1997, though generic versions are on the market.
These generics will be unaffected by the pharma’s petition to pull the approval application for Wellcovorin, a spokesperson for the Department of Health and Human Services confirmed to WSJ. “GSK’s action does not affect the availability of generic leucovorin . . . or the labeling of leucovorin products,” the spokesperson said.
Wellcovorin re-entered the public’s consciousness in September 2025 after the FDA asked GSK to refile an application for the drug as a potential medicine for cerebral folate deficiency (CFD)—a highly unusual move for the regulator. At the time, the agency linked the rare disorder to “developmental delays with autistic features” and positioned leucovorin as a treatment.
Shortly after, GSK said that it would comply with the FDA’s request and file an application to update the drug’s label. This led to an approval last month, allowing the drug’s use in CFD caused by certain genetic anomalies.
In a press call, however, the agency admitted that there is not enough evidence to support the approval of leucovorin for autism more broadly, WSJ reported on Thursday. The American Academy of Pediatrics notes that “current evidence is insufficient to support prescribing leucovorin for autism in the absence of CFD.”
In September, alongside FDA Commissioner Marty Makary’s effort to paint leucovorin as an autism treatment, the agency also updated the label of products containing acetaminophen, such as Tylenol, to reflect a purported link to autism in children when used during pregnancy. These drugs, the FDA claimed at the time, could lead to “increased risk of neurological conditions such as autism and ADHD in children.”
However, the agency itself at the time conceded that “a causal relationship has not been established,” pointing to “contrary studies in the scientific literature.” Indeed, scientists have many times over rejected a causal link between acetaminophen during pregnancy and autism in children. As recently as 2024, a population study looking at 2.5 million children born from 1995 to 2019 found no such link.
