What is suramin?
Suramin is a drug that was developed about 100 years ago to treat parasite-borne illnesses such as African sleeping sickness and river blindness. The drug has been around since then, and is actually relatively cheap to manufacture and distribute. A single one-month dose to treat one of these parasite-born illnesses only costs about $27. But it wasn’t until recently that Dr. Robert K. Naviaux of the University of California San Diego’s School of Medicine began to theorize and then test what the drug could do for patients with autism.
The clinical trial
The trial was conducted by Dr. Naviaux and his team at UC San Diego. Due to meager funding, the trial was small, which, as we’ll discuss later, limits the application of its results a bit. Dr. Naviaux and his team tested the effects of suramin on 10 boys ages 5-14. The boys in the study were matched so that they all fit within the age range and had similar IQs and autism intensity. 5 of the boys were given a low dose of suramin, and the other 5 boys were given a placebo. The effects of the drug were then charted over a six-week period to determine what effect, if any, it had on the boys’ autism symptoms. To put it short, it did have an effect, and it was significant.
The promising trial results
The mother of one of the boys treated with the suramin reported that she saw improvements in her son within an hour of the infusion. She noted that her son started making more eye contact with medical personnel, developed a notably calmer demeanor, and took an interest in activities, such as playing with his older brother, that his parents had never seen before.
Two different sets of parents reported that their sons began speaking in complete sentences. This development was especially notable because in both cases the boys had not been using complete sentences to communicate in over a decade. Across the board, the 5 boys who were given suramin had remarkable improvements in their communication skills, social interactions, and coping abilities as well as their ability to remain calm and focused. Researchers also noted that any ongoing treatment such as speech therapy in which the boys were already involved had a drastically more significant effect while the boys were on the suramin than had been previously noted.
These results should be viewed in contrast to the control group of 5 boys given a placebo. As far as their symptoms go, no improvement was reported during the clinical trial.
At first glance, the results of this study seem overwhelmingly positive, and they seem to encourage a more serious look at the possibility of using suramin to treat autism. While the study’s results are startling, there are several reasons why the autism community is approaching the results with caution.
For starters, the clinical trial was very small. Suramin was tested for a relatively short period of time, only 6 weeks, on a very small sample of boys with autism. Only 10 total were in the group and only 5 were actually given a dose of suramin. Dr. Naviaux and his team at UC San Diego have noted that because of the small size of their clinical trial, their results can’t be considered authoritative at this point.
The length of the study poses an especially important problem at this point. As we’ve noted, suramin has been around for about a century and is commonly used to treat parasite born illnesses. When doses of suramin are given to patients with these diseases, physicians know what side effects to expect. Suramin can often cause nausea, diarrhea, low blood pressure and even kidney problems when used to treat parasite born illnesses over a long period of time. Researchers do note then when used for these diseases, patients are given a relatively high dose of the drug. In the clinical trial, the boys were all given a very low dose of suramin.
Still, because the trial only lasted 6 weeks and only included one infusion, Dr. Naviaux and his team don’t have any data on potential negative side effects which could occur due to long term use of the drug, even at a low dose. And the duration of dosage will be important to understand more fully. After the six-week trial, the effects of the suramin wore off and the boys went back to the level of functioning they had experienced before.
The theory behind how suramin works
Dr. Naviaux has theorized that the symptoms of autism have something to do with a problem in the communication of cells in the brain, gut, and immune system. While the cause of autism cannot be pinpointed to one specific thing, it has been hypothesized as having something to do with genetics and environmental factors. But Dr. Naviaux and other researchers believe that the symptoms may be related to this inhibited cell communication, called the cell danger hypothesis.
Essentially the cell danger hypothesis argues that the different cells in the brain, gut, and immune system are always in a danger mode. When cells receive signals that they are in danger, they tend to wall themselves up in order to protect themselves and encourage healing. Dr. Naviaux believes that some of the difficulties with development in children who have autism stems from these cells remaining in danger mode and therefore not communicating properly with each other.
Suramin may be able to alter these cells by turning off the danger signals and therefore convincing the cells that the danger has passed and allowing them to communicate normally, at least that’s the theory that Dr. Naviaux was trying to test in this clinical trial. Researchers have noted that it’s unclear at this point why this disruption in cell communication causes developmental problems, especially for functions like speech and social learning. Regardless of what validity the cell danger hypothesis holds, based on this trial, suramin appeared to have a positive impact on autism symptoms.
The bottom line
At this point, there aren’t any approved treatments for the core symptoms of autism. Researchers and caregivers alike would certainly like to see that change within the next few years. Dr. Naviaux is not alone in his research into the cell danger hypothesis, and with further study this theory may prove to hold some answers for scientists studying the condition. The effects of suramin on children who have autism aligns with expectations for the cell danger hypothesis, and the results were significantly positive. But, as Dr. Naviaux himself noted, the results of this study alone cannot be enough evidence to move forward with using suramin for the treatment of autism. Greater studies on larger samples sizes and for longer periods of time will need to be conducted in order to understand what side effects may occur and their seriousness.
Please note as well that while the results of this study did show drastic improvement in the 5 boys tested, the results do not warrant use of suramin for treatment at this time. Dr. Naviaux and his team specifically advised parents to be wary of black market treatments using suramin. Because the nature of possible side effects is still unknown, misuse of the drug could have terrible and even deadly consequences.