Little-known drug Leucovorin explained as it’s announced FDA will approve it to ‘treat autism’

Donald Trump has made some shocking claims about autism in recent days - and everyone's a little bit confused.

Mid-tribute to his political ally Charlie Kirk on Sunday (21 September) the US president came out with: "I think you’re going to find it to be amazing. I think we found an answer to autism, how about that?"

And in a news conference yesterday (Monday 22 September) with Health Secretary Robert F. Kennedy Jr. and Dr Mehmet Oz, administrator of the Centers for Medicare and Medicaid Services, he went on to claim there is a link between autism and Tylenol, known elsewhere as paracetamol.

However, medical experts around the world have pushed back on the claims, with some even calling the president's comments dangerous.

While this was all going on, Trump has also hailed another medication, leucovorin, as 'the answer' to autism.

And the US Food and Drug Administration has seemingly followed suit, as yesterday it announced it's planning to approve a new use for the drug in the coming weeks to treat children with 'cerebral folate deficiency and autistic symptoms'.

US Health and Human Services Secretary Robert F. Kennedy Jr. and Donald Trump held a press conference yesterday (Andrew Harnik/Getty Images)

What is Leucovorin?

Leucovorin, which is also known as folinic acid, is a form of folate, an essential B vitamin, or B9, as per Reuters.

It's most often used in cancer treatment, alongside the chemotherapy drug fluorouracil, which stops cancer cells from making DNA and dividing.

In simple terms, leucovorin enhances and helps the effects of fluorouracil.

As reported by The Conversation, it also helps to reduce the toxic side effects of methotrexate, another chemotherapy drug.

Essentially, methotrexate blocks the body’s use of folate, which healthy cells need to make DNA.

So, leucovorin comes in to provide an active form of folate that healthy cells can use to make DNA, while the methotrexate continues to target cancer cells.

According to the US Food and Drug Administration website and Reuters, leucovorin is already made by more than half a dozen different companies.

Individuals with cerebral folate deficiency have reportedly been observed to have developmental delays with autistic features (Getty Stock Images)

Why is Leucovorin being considered as an autism treatment?

To break it down, the US Food and Drug Administration have now initiated the approval of leucovorin calcium tablets for patients with cerebral folate deficiency (CFD).

CFD is a neurological condition that affects folate - a vitamin essential for brain health - transport into the brain.

The FDA said in a press release that individuals with CFD have been observed to have developmental delays with autistic features, such as challenges with social communication, sensory processing, and repetitive behaviours, seizures, and problems with movement and coordination.

Some studies, but not all, have also found a link between low folate levels during early pregnancy with an increased risk of autism in children.

So, the FDA now want to relabel the drug as being able to treat CFD, which reportedly in turn would 'treat autism'.

What does the evidence say?

It's important to note that the Autism Science Foundation (ASF) said in a statement that the science regarding leucovorin and autism 'is still in very early stages, and more studies are necessary before a definitive conclusion can be reached'.

Reuters reported that researchers at SUNY Downstate Medical Center in New York, suggested that up to three-fourths of children with autism have 'genetic variations that impair their body's ability to process folate or autoimmune disorders that block folate transport to the brain'.

A handful of other small studies have linked these findings with more severe forms of the disorder and suggested that treatment with leucovorin can improve verbal skills, social skills and irritability in these children.

While some small studies provide evidence, more research is needed to confirm the link (Getty Stock Image)

However, as we say, there's a long way to go before any of these findings are concrete.

The ASF continued in it's statement: "The suggestion that folate may ameliorate some of the symptoms of autism comes from four randomized controlled trials investigating a drug called leucovorin, which is also known as folinic acid.

"Unlike regular folic acid, folinic acid can cross into the brain even when folate transport is impaired. Some studies suggest that folate transport is blocked in some children with autism, resulting in low brain levels of folate, but these findings have been inconsistent.

"Data suggesting that leucovorin may be effective come from four small randomized controlled trials, all using different doses and different outcomes, and in one case, reliant on a specific genetic variant. This science is still in very early stages, and more studies are necessary before a definitive conclusion can be reached."