Seaside Therapeutics reported encouraging results from the largest randomized study conducted to date in patients with Fragile X syndrome, the most common cause of mental impairment and the most common known cause of autism. In the Phase II study of STX209, pediatric patients with severe sociability impairment showed a statistically significant improvement in behavior. The results were presented July 24th at the National Fragile X Foundation’s 12th International Fragile X Conference in Michigan.
Fragile X syndrome is caused by a genetic mutation on the X chromosome that prevents individuals from producing a protein required for brain development. Patients with Fragile X may have symptoms such as mental and developmental impairment, autism, poor sociability, and seizures. According to the National Fragile X Foundation, the disorder occurs in approximately 1 in 3,600 males and 1 out of every 4,000 to 6,000 females.
STX209 is formulated to inhibit the excessive protein synthesis associated with Fragile X syndrome. Many of the patients involved in the STX209 study are participating in an extension study, with positive results. According to an investigator involved in the study, a number of patients have successfully been taken off anti-psychotics and other drugs used to manage Fragile X symptoms. Seaside Therapeutics is currently testing another drug candidate, STX107, which may inhibit a molecular pathway believed to cause Fragile X symptoms. The company received $30 million in funding last year to advance its autism and Fragile X pipeline.
Other companies developing treatments for Fragile X syndrome include XenoPort, Novartis, and Roche.