A Phase 2 interventional study of SPN-817 in Focal Onset Seizures, sponsored by Supernus Pharmaceuticals, Inc.. Recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-10-10.
Sponsored by Supernus Pharmaceuticals, Inc. · Phase 2, Interventional, and Treatment
This is a Phase 2b open-label extension study to evaluate the long-term safety and efficacy of SPN-817.
This is a Phase 2b, multicenter, open-label extension, one-year, safety, tolerability, and efficacy study in adults who previously completed an applicable double-blind SPN-817 clinical study. This study will include a double-blind Dose Titration/Bridging Period of 8-10 weeks in which SPN-817 will be titrated to the participant's maximum tolerated dose based on response. Following the Dose Titration/Bridging Period, participants will enter an Open Label Extension (OLE) Period of 42-44 weeks. When participants finish the OLE Period, they will initiate a Tapering Period (up to 4 weeks) followed by an End-of-Tapering Period video contact (VC) after the last dose of study drug. The duration of study treatment before starting the 4-week Tapering Period will be one year (52 weeks).
881 studies on the registry are indexed under Seizures; 143 are open to participants now.
This study's planned enrollment of 100 is above the median of 64 across 610 interventional studies indexed under Seizures.
Browse Seizures studies →Supernus Pharmaceuticals, Inc. is the lead sponsor of 61 studies on the registry; 6 are open to participants now.
Of its 31 completed or terminated interventional studies of FDA-regulated products, 25 (81%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
SPN-817, bid
Drug: SPN-817
SPN-817 starting at 0.25 mg bid up to 4.00 mg bid
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
Time frame: Week 1-Week 52
Percent change (PCH) from baseline in quantifiable focal onset seizure frequency per 28 days over the 1-year SPN-817 Treatment Period
Percent change in 28-day frequency of quantifiable focal seizures during the 1-year Treatment Period relative to baseline
Time frame: Baseline and Treatment Period (Week 1-52)
Proportion of participants experiencing ≥50% reduction in focal seizure frequency per 28 days from baseline
Greater than or equal to 50% reduction in 28-day frequency of focal seizures during the 1-year Treatment Period relative to baseline.
Time frame: Baseline and Treatment Period (Week 1-52)
Proportion of participants experiencing seizure freedom
100% reduction in 28-day frequency of focal seizures during the Treatment Period relative to baseline
Time frame: Baseline and Treatment Period (Week 1-52)
Percentage of seizure-free days over the 1-year SPN-817 Treatment Period
The number of seizure-free days reported for each participant divided by the total number of days with seizure data reported, multiplied by 100.
Time frame: Week 1-Week 52
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Supernus Pharmaceuticals, Inc.