FDA Takes Unusual Step to Repurpose Old GSK Drug for Autism Treatment

The U.S. Food and Drug Administration (FDA) has initiated an unconventional process to repurpose an old GlaxoSmithKline (GSK) drug as a potential treatment for autism-related symptoms. This move, part of the Trump administration's efforts to combat autism, involves the revival of leucovorin, a medication GSK hasn't marketed in over two decades.

FDA's Literature Review Prompts Action

The FDA's decision stems from a review of scientific literature published between 2009 and 2024. The agency found evidence suggesting that leucovorin, previously sold under the brand name Wellcovorin, may help address speech-related deficits in some patients with cerebral folate deficiency, a neurological condition associated with autism.

FDA Commissioner Marty Makary expressed optimism about the potential impact, stating, "Hundreds of thousands of kids, in my opinion, will benefit." However, the FDA acknowledged limitations in the available data and emphasized the need for further studies to fully assess the drug's safety and efficacy in this patient population.

GSK's Response and Regulatory Process

In response to the FDA's initiative, GSK has agreed to submit a supplemental new drug application to include cerebral folate deficiency in Wellcovorin's label. The British pharmaceutical company, which developed and sold the drug from 1983 to 1997, no longer manufactures the medicine. Leucovorin is currently available in generic forms in the U.S.

The regulatory process involves an unusual step: the FDA is approving GSK's previously withdrawn application and requesting the company to submit supplemental paperwork. This approach aims to change the official labeling of the medicine, which could potentially lead to insurance coverage for the new use.

Controversial Approach and Scientific Debate

The Trump administration's approach to repurposing leucovorin has sparked controversy within the scientific community. Critics argue that this method bypasses the rigorous clinical trials typically required for regulatory approvals of medicines in the U.S.

Leucovorin has been used off-label by doctors for patients with cerebral folate deficiency since the condition was identified about 20 years ago. The drug is commonly used in cancer patients to counteract side effects from chemotherapy and medicines that block the action of folic acid.

While some researchers have drawn connections between cerebral folate deficiency and autism, the exact prevalence of the condition remains unknown. A small study testing leucovorin in 48 patients with autism spectrum disorder found that approximately two-thirds of treated children experienced language improvements.

As the pharmaceutical industry watches this unconventional drug repurposing unfold, questions remain about the long-term implications of this regulatory approach and its potential impact on future drug development and approval processes.