A quarterly publication of the Autism Research Institute

The Autism Research Review International is quarterly publication of the Autism Research Institute

Winter, 2021 | Number 1, Volume 35

Positive results reported in study of suramin

A new study adds to evidence that the drug suramin—a hundred-year-old drug used to treat sleeping sickness—may have significant positive effects on the symptoms of autism spectrum disorder (ASD). 

In earlier research (see ARRI 2017, No. 2), Robert Naviaux and colleagues administered a single IV infusion of suramin to five boys with ASD, while five boys in a matched placebo group received a single IV infusion of saline. The researchers reported that all five boys who received the suramin infusion showed improvements in language, social behavior, restricted or repetitive behaviors, and coping skills. 

In the new study, conducted by the pharmaceutical firm PaxMedica, 52 South African children with moderate to severe ASD were given one of two different doses of intravenous suramin or a placebo at baseline, week 4, and week 8. The researchers conducted a six-week follow-up study after the children received the last dose. 

Of the group, 43 children completed the study. One withdrew because of a side effect, and the others withdrew due to COVID-19-related issues or for other reasons. 

According to the company’s researchers, treatment with suramin led to “marked and sustained” improvement in measures including the Aberrant Behavior Checklist composite score of core symptoms (ABC Core), the Clinical Global Impression of Improvement scale, adapted for autism (CGI-I), and the Autism Treatment Evaluation Checklist (ATEC). They add that participants tolerated both doses of suramin well, although adverse events occurring during treatment included rashes, upper respiratory infection, and vomiting. One child experienced a serious adverse event that resolved with treatment. 

According to the researchers, the mechanism by which suramin may improve symptoms of autism is unknown. They speculate that the drug may act to reverse the effects of mitochondrial dysfunction and to reduce neuroinflammation. In the earlier study, Naviaux suggested that suramin works by inhibiting the signaling function of the nucleotide adenosine triphosphate, which is produced by the mitochondria and released from cells to signal danger. He hypothesized that this process can sometimes get “stuck,” and that suramin signals that “the cellular war is over, the danger has passed and cells can return to ‘peacetime’ jobs like normal neurodevelopment, growth and healing.”

Editor’s note: This research is unpublished. The researchers will present their full findings at an upcoming medical conference.


“Positive topline results for novel autism drug,” Megan Brooks, Medscape, February 9, 2021.