NCT05716100

A Randomized Study of XEN1101 Versus Placebo in Focal-Onset Seizures (X-TOLE3)

A Randomized, Double-blind, Placebo-Controlled, Multicenter Phase 3 Study to Evaluate the Safety, Tolerability, and Efficacy of XEN1101 as Adjunctive Therapy in Focal-Onset Seizures

• Status: Recruiting
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 360 (estimated)
• Sponsor: Xenon Pharmaceuticals Inc. · Industry
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

The X-TOLE3 Phase 3 clinical trial is a randomized, double-blind, placebo-controlled study that will evaluate the clinical efficacy, safety and tolerability of XEN1101 administered as adjunctive therapy in focal-onset seizures.

Detailed description

Approximately 360 subjects will be randomized in a blinded manner to one of two active treatment groups or placebo in a 1:1:1 fashion (XEN1101 25 mg : 15 mg : Placebo). Eligible subjects will have up to 9.5 weeks of baseline to assess frequency of seizures, followed by 12 weeks of blinded treatment. In order to be included in the study, subjects must be treated with a stable dose of 1 to 3 allowable antiseizure medications (ASMs) for at least one month prior to screening, during baseline, and throughout the double-blind treatment period (DBP) of the study. During the DBP, subjects will be instructed to orally take XEN1101 or placebo once daily with an evening meal. Subjects who complete the 12-week DBP will have the opportunity to qualify and enroll in a separate open-label extension (OLE) study for continued treatment with XEN1101. Subjects who do not enroll in the OLE will enter a 8-week post treatment follow-up period.

Conditions

• Focal Onset Seizures

Interventions

Type	Name	Description
DRUG	XEN1101	XEN1101 Capsules
DRUG	Placebo	Placebo Capsules

Timeline

• Start date: 2023-05-09
• Primary completion: 2026-10-01
• Completion: 2026-12-01
• First posted: 2023-02-08
• Last updated: 2026-03-12

Locations

94 sites across 20 countries: United States, Argentina, Australia, Austria, Belgium, Bulgaria, Chile, Croatia, Czechia, Finland, France, Germany, Hungary, Israel, Italy, Mexico, Netherlands, Poland, Portugal, Spain

Regulatory

• FDA-regulated drug study