A Randomized, Double-blind, 12-week, Parallel Group, Placebo-controlled Study of Efficacy and Safety of RO4917523 in Patients With Fragile X Syndrome.

This multi-center, randomized, double-blind, placebo-controlled, parallel-group study will investigate the efficacy and safety of RO4917523 in adolescent and adult patients with fragile X syndrome. Patients will be randomized to receive oral doses of 0.5 mg or 1.5 mg of RO4917523, or matching placebo once daily. The anticipated time on study treatment is 12 weeks.