Phase 2 Clinical Trial of SGS-742 Therapy in Succinic Semialdehyde Dehydrogenase Deficiency

Objective: To perform a clinical trial assessing the safety, tolerability and efficacy of the GABA(B) receptor antagonist SGS-742 in patients with SSADH deficiency. Study Population: Twenty-two children and adults with SSADH deficiency. Design: Double-blind, cross-over, phase II clinical trial. Outcome Measures: The primary outcome measures for drug efficacy will be performance on neuropsychological testing and responses to parent questionnaire. The secondary outcome measure will be TMS parameters of cortical excitation and inhibition. The outcome measures for safety will include clinical examination and neuropsychological tests.