RENAISSANCE 2: SPN-817 Phase 2, Double-Blind, Placebo-Controlled Study in Adults With Focal Onset Seizures

This is a Phase 2 double-blind, randomized, placebo-controlled, multicenter, parallel-group study to evaluate the efficacy, safety, and tolerability of SPN-817 administered as an adjunctive treatment in adults with focal onset seizures that have previously failed at least 2 anti-seizure medication (ASM) regimens. Participants will be taking 1 to 4 ASMs, with at least 4 seizures during the 6-week Screening Period. Following the Screening Period, eligible participants will be randomized 2:1 to SPN-817 (3.0-4.0 mg BID) or placebo and begin the Titration Period (8-10 weeks). In both treatment groups, open-label ondansetron (or another concomitant medication to assess pharmacological approaches to managing cholinergic adverse events \[AEs\]) will be taken (8 mg oral \[PO\]) prophylactically approximately 30 minutes before each study medication (SM) dose (ie, BID) during the Titration Period as an antiemetic. After the target dose of 3.0-4.0 mg BID is reached, participants will enter the Maintenance Period (14 weeks). Ondansetron (or another concomitant medication to assess pharmacological approaches to managing cholinergic AEs) may be taken as needed as either a preventative or therapeutic antiemetic during the Maintenance Period. Participants who complete the Maintenance Period will have the opportunity to enroll in a separate open-label study for continued treatment with SPN-817. Participants who do not enroll in the open-label study will undergo a Tapering Period (up to 4 weeks) and a follow-up safety phone call.