Extension Study to Evaluate the Safety and Tolerability of NBI-921352 When Used With Anti-seizure Medications in Adults With Focal Onset Seizures

Prospective, Long-Term, Interventional, Active Extension Study to Evaluate the Safety and Tolerability of NBI-921352 as Adjunctive Therapy in Subjects With Focal Onset Seizures (FOS)

This Phase 2, prospective, interventional, active extension study was designed to evaluate the long-term safety and tolerability of NBI-921352 as adjunctive therapy in adult participants with focal onset seizures who completed 11 weeks of treatment in randomized, double-blind, placebo-controlled Study NBI-921352-FOS2021. Eligible participants may enroll directly following the completion of the Week 11 study visit of Study NBI-921352-FOS2021 or after a gap following completion of that study.

Key Inclusion Criteria:

• Provided informed consent.
• Completed 11 weeks of treatment in Study NBI-921352-FOS2021.
• Stable treatment with at least 1 but not more than 4 antiseizure medicines.

Key Exclusion Criteria:

• Have developed any other disorder for which the treatment takes priority over the treatment of focal onset seizure or is likely to interfere with study treatment or impair treatment compliance.