Authors of a new study claim that an experimental drug can improve sociability in patients with the rare genetic disorder Fragile X Syndrome and may be helpful as a treatment for autism. The drug, called STX209, or arbaclofen, is the first to treat one of the core symptoms of Fragile X Syndrome, which is one of the leading causes of intellectual disability and the most prevalent known cause of autism.
While only tested in a small number of patients, arbaclofen has not yet been approved by the Food and Drug Administration. But as about one-third of people with Fragile X have autism, it is the researchers' hope that it might also help many in the much broader autistic community, according to the study's lead author, Elizabeth Berry-Kravis of Rush University Medical Center in Chicago.
Robert Ring, vice president of translational research at Autism Speaks, an advocacy group, says: "This is groundbreaking work. The arbaclofen program is perhaps the most important medicine development program running in autism today."
"This is the first drug in the field of autism that directly reports on improving social symptoms, and we have no other drug that does that. I'm very, very excited that this is being published," commented Robert Schultz, director of the Center on Autism Research at Children's Hospital of Philadelphia.
Researchers tested STX209 in mice that were genetically engineered to have an animal version of fragile X. They found that it helped correct the biochemical abnormalities associated with the mutation and reduced seizures and repetitive behaviors in the mice, they reported Wednesday in the journal Science Translational Medicine.
In a related study, 46 children and 17 adults with fragile X syndrome took the drug for four weeks and a placebo for four weeks. Patients made bigger improvements on a "social avoidance" scale while they were taking the drug compared with when they were taking the placebo.
"They're willing to go out in public," study leader Elizabeth Berry-Kravis, a child neurologist at Rush University Medical Center in Chicago, said, describing reports from patients' parents. "They're willing to come downstairs. They're willing to stay at a birthday party. They're willing to go to a dentist."
Experts who were not involved in the study warned that the social impairments in fragile X may be unique to that disorder. "I would be cautious in concluding this drug is effective for the social deficits of autism on the basis of this study," said Larry Scahill, a drug researcher at Yale University.
Dr. Paul Wang, an executive at the Seaside Therapeutics that makes STX209 and funded the two studies, said the drug was being tested in two larger clinical trials for fragile X as well as a study involving 150 patients with autism.
He said: "We need to prove - which we have not done - that this drug can help people with autism."