An experimental drug for autism did not improve levels of lethargy and social
withdrawal in children who took it, but it did show some other benefits, a new
Children on arbaclofen did improve on an overall measure of autism severity
when compared to kids taking an inactive placebo, said lead researcher Dr Jeremy
Veenstra-VanderWeele, an associate professor of psychiatry, paediatrics and
pharmacology at Vanderbilt University.
He is to present the findings at the International Meeting for Autism
Research (IMFAR) in Spain.
One of 88 children in the United States is now diagnosed with an autism
spectrum disorder, the umbrella term for complex brain development disorders
marked by problems in social interaction and communication.
Veenstra-VanderWeele focused on evaluating the social improvement with the
drug because earlier research had suggested it could help. However, one of the
earlier studies did not compare the drug to a placebo, but simply measured
improvement in those who took the drug.
In the new study, Veenstra-VanderWeele and his team assigned 150 people with
autism, aged 5 to 21, to take the medicine or a placebo, without knowing which
group they were in, for eight weeks. The participants had been diagnosed with
autistic disorder, Asperger's syndrome or another related condition known as
pervasive developmental disorder.
In all, 130 finished the study. When no differences were found in social
withdrawal or lethargy between the two groups, the researchers looked at a scale
that measures severity and improvement of autism with treatment.
Next phase of trials
Those on the drug improved more on that scale. A child, for instance, who
began the study evaluated as having marked severity might be described as
moderate by the study's end, Veenstra-VanderWeele said.
"This is the sort of improvement that would motivate us to start a medicine,"
The drug is believed to work, Veenstra-VanderWeele said, by increasing
inhibition, improving social functioning and interactions.
Right now, Veenstra-VanderWeele said, "there is no medication that has clear
evidence to improve social function in autism."
Those on the drug did report side effects, including suicidal thoughts
reported by one patient on the drug and one on the placebo. Some patients on the
drug became upset more easily; others reported sleepiness.
The next phase of trials of the drug are in the planning stages,
But more research is needed, said Dr Andrew Adesman, chief of developmental
and behavioural paediatrics at the Steven and Alexandra Cohen Children's Medical
Center of New York.
Even though the expected benefit did not materialise, Adesman sees a reason
to continue to study the medication. "There is [still] some suggestion of
benefit from the medicine," Adesman said. "It just didn't quite show up where
The drug may offer benefit to some children with autism, Adesman said. "But
it's unclear which children may be the best candidates."
The trial received funding from the drug's maker, Seaside Therapeutics. The
medication is not currently approved by the US Food and Drug Administration.
The data and conclusions of research presented at medical meetings should be
viewed as preliminary until published in a peer-reviewed journal.
To learn more about autism, visit
the US Centers for Disease Control and Prevention.