SPN-817 Open-Label Extension Study in Adults With Focal Onset Seizures

NCT07141329 | Recruiting Phase 2 FDA Drug

• 1 other identifier: 817P210
• Study Type: interventional
• Target: 100
• Locations: 1 country
• Sites: 1

Brief Summary

This is a Phase 2b open-label extension study to evaluate the long-term safety and efficacy of SPN-817.

Conditions

Focal Onset Seizures

Keywords

focal seizures; focal epilepsy; open-label extension; anti-seizure medication

Outcome Measures

Primary Outcomes (1)

• Incidence of treatment-emergent adverse events

  The percent of participants who took at least one dose of SPN-817 and reported at least one adverse event during the 1-year SPN-817 Treatment Period

  Week 1-Week 52

Secondary Outcomes (4)

• Percent change (PCH) from baseline in quantifiable focal onset seizure frequency per 28 days over the 1-year SPN-817 Treatment Period

  Baseline and Treatment Period (Week 1-52)

• Proportion of participants experiencing ≥50% reduction in focal seizure frequency per 28 days from baseline

  Baseline and Treatment Period (Week 1-52)

• Proportion of participants experiencing seizure freedom

  Baseline and Treatment Period (Week 1-52)

• Percentage of seizure-free days over the 1-year SPN-817 Treatment Period

  Week 1-Week 52

Study Arms (1)

SPN-817

EXPERIMENTAL

SPN-817, bid

Drug: SPN-817

Interventions

SPN-817 DRUG

SPN-817 starting at 0.25 mg bid up to 4.00 mg bid

SPN-817

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Completed antecedent SPN-817 double-blind study
• Taking a stable dosage regimen (maintained during the antecedent study) of at least one antiseizure medication (ASM) and no more than 4 ASMs

You may not qualify if:

• Has current nonepileptic events that could be confused by the participant and/or study staff as epileptic seizures
• Has any suicidal behavior or suicidal ideation related to Item 4 (active suicidal ideation with some intent to act without specific plan) or Item 5 (active suicidal ideation with specific plan and intent) based on the Columbia-Suicide Severity Rating Scale (C-SSRS) assessments in the antecedent study and at Visit 1 or more than one lifetime suicide attempt.

Sponsors & Collaborators

• Supernus Pharmaceuticals, Inc.: lead

Study Sites (1)

Medsol Clinical Research Center

Port Charlotte, Florida, 33952, United States

RECRUITING

MeSH Terms

Conditions

Seizures; Epilepsies, Partial

Condition Hierarchy (Ancestors)

Neurologic Manifestations; Nervous System Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Epilepsy; Brain Diseases; Central Nervous System Diseases

Study Officials

• Maciej Gasior, MD, PhD

  Supernus Pharmaceuticals, Inc.

  STUDY DIRECTOR

Central Study Contacts

Supernus Clinical Trials

CONTACT

240-403-5838; clinicaltrials@supernus.com

Navid Saeidi, MS

CONTACT

240-403-5328; nsaeidi@supernus.com

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: August 19, 2025
• First Posted: August 26, 2025
• Study Start: July 30, 2025
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): December 31, 2027
• Last Updated: October 10, 2025

Record last verified: 2025-10

Locations

US (1)