thicker and less numerous. Just as significantly, the animals behaved much like normal mice.
Tonegawa speculated that PAK inhibitors might be an effective therapy in babies diagnosed with Fragile X; developmental delays typically emerge between ages 9-12 months, he noted in the paper published by PNAS.
Lichter told Luke that he was intrigued by Tonegawa’s research because the mouse model for Fragile X is biologically similar to the condition in humans. The FMR1 gene is affected in mice and humans, and they share the same anatomic changes in the brain. The mice are hyperactive and engage in repetitive behaviors, symptoms seen in some people with Fragile X.
PAK is a family of enzymes and the question for aFraxis was whether it could make an oral drug to block PAK1, the specific member of the PAK family believed responsible for the symptoms. Lichter told Luke that after two years of work, the company now has a library of several hundred compounds that can turn off PAK1.
In animal studies, the company’s experimental drugs have been able to produce changes in the brains of mice “in as little as a few hours,” Lichter said. He told Luke the company aims to begin human tests in 2012.
The company’s program sounds a lot like research conducted at another San Diego biotechnology company, Ambit Biosciences. Tonegawa and collaborators from Ambit are named as inventors on a patent that describes a method for treating Fragile X and other neurodevelopmental disorders with specific small molecule PAK inhibitors. Interestingly, Ambit is an owner of aFraxis according to this SEC filing. And like aFraxis, Ambit is backed by Avalon Ventures. I left messages with Ambit and its PR firm to find out if aFraxis is a spinout of Ambit, but didn’t get an answer by deadline.
Lichter told Luke that aFraxis sees opportunities in other disorders as well, including schizophrenia and Alzheimer’s disease. For neuropsychiatric conditions, the company is experimenting with drugs that turn on PAK, at least judging from this patent filing.
Advisers to aFraxis include Tonegawa, Gary Lynch of UC Irvine and Dennis Selko of Harvard Medical School, Lichter said. David Campbell, formerly of Phenomix, is chief scientific officer.