NCT05718817

An Open-label Study of XEN1101 in Epilepsy

A Multicenter, Open-label, Long-term, Safety, Tolerability, and Efficacy Study of XEN1101 in Subjects Diagnosed With Epilepsy

• Status: Enrolling By Invitation
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 880 (estimated)
• Sponsor: Xenon Pharmaceuticals Inc. · Industry
• Sex: All
• Age: 12 Years
• Healthy volunteers: Not accepted

Summary

This study will evaluate the long term safety, tolerability, pharmacokinetics (PK), and efficacy of XEN1101 in subjects with Focal Onset Seizures (FOS) or Primary Generalized Tonic-Clonic Seizures (PGTCS) for the treatment of seizures for up to 6 years.

Detailed description

This is an Open Label Extension study of the following Phase 3 clinical studies: XPF-010-301 (X-TOLE2), XPF-010-302 (X-TOLE3), and XPF-010-303 (X-ACKT). This study will evaluate the long-term safety, tolerability, PK, and efficacy of XEN1101 in subjects with FOS or PGTCS for the treatment of seizures for up to 6 years. Subjects who successfully completed and did not terminate early from one of the antecedent studies (X-TOLE2, X-TOLE3, or X-ACKT) are eligible to participate in X-TOLE4. Following enrollment into X-TOLE4, subjects will undergo a treatment period of up to 6 years, during which there will be a visit at 2-, 4-, and 13-weeks post-entry, with subsequent visits occurring at 13-week intervals during the first year, and then at 26-week intervals (with a telephone call in between) until dosing is completed. Subjects will be initially assigned to XEN1101 as follows: * 25 mg QD for subjects aged ≥18 years * For subjects aged ≥12 and \<18 years * 15 mg QD for those * who weigh \<45 kg at the start of the X-TOLE4 study * who weighed \<45 kg during the X-ACKT study * who weighed ≥45 kg at randomization in the X-ACKT study and had dose reduction(s) for intolerability * 25 mg QD for all others Subjects will be instructed to orally take XEN1101 once daily (QD) with an evening meal. Subjects will be expected to keep a daily seizure eDiary with a minimum of 80% compliance for the duration of the extension study (reporting on ≥80% of days between visits). Upon completion of dosing at the end of the treatment period, there will be an 8-week follow up period.

Conditions

• Focal Epilepsy
• Tonic-Clonic Seizures

Interventions

Type	Name	Description
DRUG	XEN1101	XEN1101 capsules

Timeline

• Start date: 2023-04-25
• Primary completion: 2033-04-01
• Completion: 2033-06-01
• First posted: 2023-02-08
• Last updated: 2026-04-13

Locations

146 sites across 23 countries: United States, Argentina, Australia, Austria, Belgium, Bulgaria, Canada, Chile, Croatia, Czechia, France, Georgia, Germany, Hungary, Ireland, Israel, Italy, Mexico, New Zealand, Poland, Portugal, Spain, United Kingdom

Regulatory

• FDA-regulated drug study