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)

Status

Terminated

Phases

Phase 2

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT05493293

Enrollment

Registered

2022-08-09

Start date

2022-11-09

Completion date

2024-03-11

Last updated

2024-04-12

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Focal Onset Epilepsy, Focal Onset Seizure

Keywords

epilepsy, focal seizure, sodium channel, voltage-gated, alpha subunit, Nav1.6 inhibitor, antiseizure medicine, ASM, antiepileptic drug, AED, partial seizure, partial onset epilepsy

Brief summary

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.

Interventions

DRUGNBI-921352

Tablets for oral administration

Study design

Allocation

Intervention model

SINGLE_GROUP

Primary purpose

TREATMENT

Masking

NONE

Masking description

For participants who enroll directly from Study NBI-921352-FOS2021, the study will include a Blinded Dose Conversion Period (1 week) before proceeding to the Open-Label Treatment Period.

Eligibility

Sex/Gender

ALL

Age

18 Years to 67 Years

Healthy volunteers

Inclusion criteria

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.

Design outcomes

Primary

Measure	Time frame
The occurrence of serious treatment-emergent adverse events (TEAEs)	Through Week 111

Countries

Australia, Belgium, Czechia, France, Hungary, Italy, Spain

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026