Clinical trial begins in California to test enzyme to help autistic children digest proteins

From the San Francisco Chronicle:

UCSF researchers are kicking off a clinical trial to test whether certain children with autism can benefit from regular doses of an enzyme to help them digest proteins, which may in turn improve their brain function and ease some symptoms of their disease.

It's one of several treatments being explored that could address the root causes of autism - an incurable set of developmental problems that affects socialization, language and behavior - instead of just the symptoms of the disease. But the theory behind the enzyme is controversial, because there is little solid research demonstrating that the missing enzyme, or digestion problems in general, is a direct cause of autism.

Some studies have shown that autistic children are more likely than healthy children to have gastrointestinal problems, and that a certain subgroup of autistic kids have enzyme deficiencies. But whether those problems cause autism or are just another symptom of the disease isn't known for sure.

Still, some researchers say that even if there's no clear connection between the missing enzyme and autism, it's a treatment worth exploring.

"I think every avenue, every potential hypothesis, should be investigated in autism," said Dr. Antonio Hardan, a pediatric psychiatrist and an autism researcher at Lucile Packard Children's Hospital who is not involved in the enzyme trial. "This is one of them, and regardless what the results show, it will be helpful to look at what they find."

The trial is being paid for by Curemark, the New York-based drug company that developed the enzyme. UCSF is one of 15 sites around the country participating in the trial, which will involve 170 children ages 3 to 8. UCSF is planning to recruit up to 10 children.

The trial is double-blind, meaning that children will be randomly assigned to receive either the enzyme or a placebo, and the patients, their parents and the researchers will not know who is getting the treatment and who isn't.

Children will eat the enzyme three times a day - they sprinkle the tasteless powder over their food - for 90 days. After that time period, parents can opt to give their children the enzyme for up to a year, whether they were in the treatment group or the placebo group.

Researchers will use interviews with parents and other behavioral tests to assess whether there are any changes in the children's symptoms.

"The treatment is enormously simple, but finding it out wasn't simple at all," said Joan Fallon, chief executive of Curemark, who is a pediatric chiropractor who works with autistic children. "Is it theoretical? Yes. But we hope the trials will give some benefit to a subgroup of children. And we hope our trials will make other researchers look at the physiology of the disorder."

Fallon took an interest in enzyme replacement when she saw that many autistic children had diets heavy in carbohydrates - french fries and pastas and breads - but hardly any protein. These kids may avoid protein because they're missing the enzyme to help them digest it.

That enzyme helps the body break down proteins in a process that produces certain amino acids, which are important for brain development and communication between brain cells. So some autistic kids aren't eating enough protein to begin with, and what protein they do eat isn't being digested properly. The idea is that those missing amino acids may be a cause of autism.

At least anecdotally, doctors seem to agree that gastrointestinal problems are common among autistic children. And many parents have reported - again, anecdotally - that dietary changes help improve symptoms of autism.

So it's possible that giving the enzyme to children who are missing it will help some autistic kids, doctors say. At the very least, it's worth testing, especially since the enzyme itself is unlikely to have any side effects, some researchers say.

"I do think there is a subgroup of kids who have these gastrointestinal symptoms or some difficulty digesting proteins, who may have that relate somewhat to autism," said Dr. Robert Hendren, director of child and adolescent psychiatry at UCSF. "We're always thinking about what else we can try. What else we can do that might help these kids. We have a responsibility to leave no stone unturned."

Much of the research into treatments for autism is based on anecdotal evidence, Hardan said. Doctors often hear of reports from parents who try one trick or another to help ease symptoms in their children, and if something sounds promising, they'll test the treatment in a scientific study.

"I meet with a lot of parents, and they support our research. But some of them, they want something this afternoon, not tomorrow," Hardan said. "And I understand that, it's very frustrating. But that's science. It takes time."