Study to Evaluate SAGE-547 Injection as Adjunctive Therapy for the Treatment of Super-Refractory Status Epilepticus

This is an open-label study consisting of a screening period (1 day), 4-day treatment period (96 hours) followed by a 1-day dose taper period (24 hours), a 2-day acute follow-up period, and a 3 week extended follow-up period. On Day 1 of treatment SRSE participants under seizure suppression or burst-suppression with a continuous intravenous (IV) anti-epileptic drug (AED) (third-line agent) were given a 1-hour IV loading infusion of SAGE-547 followed by a maintenance infusion. After 48 hours of SAGE-547 treatment, the continuous IV AED (third-line agent) was weaned while continuing SAGE-547 at the maintenance infusion for the remainder of the treatment period. After 96 hours (4 days) of therapy with SAGE-547, the dose was to be tapered and discontinued over 24 hours. The participants would have routine continuous electroencephalogram (EEG) monitoring during the screening period, and continuing until 48 hours after SAGE-547 treatment had completed. Participants would then have follow-up examinations weekly for the next 3 weeks (Days 8, 15, 22, and 29), during which safety and functional assessments would be obtained. Apart from treatment with SAGE-547, all participants would receive the standard of care for adults in SRSE along with ongoing treatment for all underlying medical conditions.