In this study, we evaluated activity of SGE-516 on epilepsy phenotypes in the Scn1a+/− mouse model that recapitulates many features of Dravet syndrome, including spontaneous seizures, premature death and seizures triggered by hyperthermia. The gene discussed is SCN1A; the disease is encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy.