A Study With SAGE-547 for Super-Refractory Status Epilepticus

Inclusion Criteria: * Subjects two (2) years of age and older * Subjects who have: * Failed to respond to the administration of at least one first-line agent (e.g., benzodiazepine or other emergent initial anti-epileptic drug \[AED\] treatment), according to institution standard of care, and; * Failed to respond to at least one second-line agent (e.g., phenytoin, fosphenytoin, valproate, phenobarbital, levetiracetam or other urgent control AED), according to institution standard of care, and; * Not previously been administered a third-line agent but have been admitted to an intensive care unit with the intent of administering at least one third-line agent for at least 24 hours; or who have previously failed zero, one or more wean attempts from third-line agents and are now on continuous intravenous infusions of one or more third-line agent and in an EEG burst or seizure suppression pattern; or who have previously failed one or more wean attempts from third-line agents and are now either not on a continuous intravenous infusion of at least one third-line agent or are on a continuous intravenous infusion of one or more third-line agent but not in an EEG burst or seizure suppression pattern Exclusion Criteria: * Subjects with SRSE due to anoxic/hypoxic encephalopathy with highly malignant/ malignant EEG features * Children (subjects aged less than 17 years) with an encephalopathy due to a rapidly progressing underlying neurological disorder * Subjects who have any of the following: 1. a glomerular filtration rate (GFR) low enough to warrant dialysis but for whatever reason, dialysis is not planned or non-continuous dialysis planned (that would not adequately remove Captisol®); 2. severe cardiogenic or vasodilatory shock requiring two or more pressors that is not related to third-line agent use; 3. fulminant hepatic failure; 4. no reasonable expectation of recovery (for instance, a likely outcome is persistent vegetative state) or life-expectancy, in the experience of the investigator, is less than 30 days. * Subjects who are being administered more than three third-line agents concomitantly or in whom the qualifying wean cannot be completed per protocol