FDA Revives Dormant Drug for Autism Treatment, Warns of Acetaminophen Risks in Pregnancy

In a significant move, the U.S. Food and Drug Administration (FDA) has initiated the reapproval process for GlaxoSmithKline's (GSK) Wellcovorin, a drug that has been off the market for 25 years, as a potential treatment for autism symptoms. Simultaneously, the agency has raised concerns about the use of acetaminophen during pregnancy, linking it to possible neurological and developmental defects in children.

Wellcovorin's Potential in Autism Treatment

The FDA has begun the approval process for Wellcovorin, a branded version of leucovorin, for the treatment of cerebral folate deficiency (CFD). This condition is characterized by low folate levels in the brain despite normal blood concentrations and has been associated with "developmental delays with autistic features," seizures, and motor problems.

According to George Tidmarsh, director of the FDA's Center for Drug Evaluation and Research, the agency is collaborating with GSK to "broaden" Wellcovorin's label. The pharmaceutical company has expressed its intention to file a supplemental application for the drug's use in CFD.

The FDA's decision is based on a "systematic analysis" of studies conducted from 2009 to 2024, which included patient-level information and "mechanistic data." However, the Department of Health and Human Services has cautioned that leucovorin "is not a cure for ASD [autism spectrum disorder] and may only lead to improvements in speech-related deficits for a subset of children."

Acetaminophen Use During Pregnancy: New Warnings

In a parallel development, the FDA has initiated a label update for Tylenol and other acetaminophen products. The new labeling will "reflect evidence" suggesting that the use of these medications during pregnancy could be linked to an "increased risk of neurological conditions such as autism and ADHD in children."

The FDA's decision is based on studies including the Nurses' Health Study II and the Boston Birth Cohort. However, the agency acknowledges that "a causal relationship has not been established" and that "there are contrary studies in the scientific literature."

To address these concerns, the FDA has issued a letter to physicians nationwide, warning about the potential link between acetaminophen use during pregnancy and adverse neurological outcomes in children. This action comes despite a 2024 study of 2.5 million children born between 1995 and 2019, which found no association between acetaminophen use and autism.

These developments occur as Health Secretary Robert F. Kennedy Jr.'s self-imposed deadline approaches. In April, Kennedy promised to direct the agency's resources towards a "massive testing and research effort" to identify the root cause of autism "by September."