FRIDAY, May 26, 2017 (HealthDay News) -- A drug first used in the early 1900s to treat sleeping sickness has shown promise in an early trial as a potential treatment for autism.
The study involved just 10 boys, aged 5 to 14, with autism. This was the first human trial to attempt to replicate encouraging results seen in work with mice, the researchers noted. The drug is called suramin.
"The main finding was that a single dose of suramin was safe and produced improvements in language, social interaction and restricted and/or repetitive behaviors in five children with ASD [autism spectrum disorder]," said study author Dr. Robert Naviaux. He is co-director of the Mitochondrial and Metabolic Disease Center at the University of California, San Diego's School of Medicine.
He added that no such improvements were observed among the five children not treated with suramin.
However, the gains from the one-dose treatment proved to be temporary, fading within a matter of weeks, the researchers said.
Naviaux stressed that the latest effort was just "a start." At the moment, suramin is not approved for any use in the United States, and much more follow-up research will be needed, he cautioned. The drug is used for sleeping sickness, which is caused by parasites.
Roughly 1 in every 68 children develops some form of autism, according to the U.S. Centers for Disease Control and Prevention.
Exactly what causes autism remains unclear. But this latest trial set out to test one specific theory known as the "cell danger hypothesis."
The theory suggests that at least some cases of autism arise when the body's normal reaction to stress and injury goes haywire.
In such a scenario, the usual healing process -- which involves the temporary halting of communication between cells -- ends up becoming permanent, causing cells to behave as if they're continually under assault. The theory suggests this dynamic might lead to autism, the researchers explained.
Suramin, however, has the ability to block a specific molecule known as ATP, which relentlessly triggers this abnormal healing process, the researchers said.
Essentially, explained Naviaux, "suramin is a molecular armistice therapy. It sends the message to the cell that the war is over."
Five of the 10 study patients were given one intravenous infusion of suramin, while the other five were treated with a placebo drug.
All the boys treated with suramin ended up showing significant -- and, in some cases, immediate -- improvements, with no serious side effects, researchers said.
The most notable changes involved improved socializing, communication and playing. Those in the suramin group also showed an increased ability to remain calm and focused, while displaying less repetitive behavior and better coping skills.
One parent said a son displayed more emotional range, improved eye contact, greater interest in socializing, and a new sense of calmness within hours following treatment, the researchers said.
And two children who had never spoken in their lives did so for the first time, within roughly one week after treatment, the researchers added.
Suramin also appeared to boost the ability to benefit from standard treatment, such as speech therapy and behavior therapy.
However, all the improvements from the one-dose treatment proved to be temporary, with gains ultimately fading over a matter of weeks.
"[But] we are cautiously optimistic," said Naviaux, while noting that it will be at least four to five years before follow-up research is complete. "The science," he said, "cannot be rushed."
The findings were published May 26 in the Annals of Clinical and Translational Neurology.
Dr. Matthew Lorber, a child and adolescent psychiatrist with Lenox Hill Hospital in New York City, reacted to the findings with caution.
"The improvement in the children studied was robust," he noted, "which is cause for hope, since we do not have any approved treatments for the root of autism.
"Unfortunately," Lorber added, "the study was so small -- only five children actually received the medication -- that we cannot come to any real conclusions."
The upshot, Lorber said, is that "until suramin is tested in a much larger group of people with autism, we cannot move ahead using it as a potential treatment. In addition, suramin in traditional doses can have serious side effects, and it is important that doctors do not start using it for children with autism because the data is scant, and we need much more scientific research."
HealthDay reached out to two advocacy groups, Autism Speaks and the Autism Society of America, but did not receive comment.
There's more on autism at the U.S. National Institutes of Health.