This is an open-label, expanded access protocol, designed to offer treatment with SAGE-547 to subjects in SRSE, and to evaluate the efficacy and safety of SAGE-547 administered as a continuous intravenous infusion to these subjects

Inclusion Criteria:

• Subjects six (6) months 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 AED treatment), according to the institution's 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 AEDs), according to the institution's 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 agents 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 at least one continuous infusion of a third-line agent or are on one or more continuous infusions of third-line agents 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 18 years) with an encephalopathy due to an underlying progressive neurological disorder

• Subjects who have any of the following:

  1. a GFR low enough to warrant dialysis for whatever reason, but dialysis is not planned or non-continuous dialysis is planned;
  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 or life-expectancy of 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