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

Sponsor
Xenon Pharmaceuticals Inc. (Industry)
Overall Status
Not yet recruiting
CT.gov ID
NCT05716100
Collaborator
Worldwide Clinical Trials (Other)
360
3
33.1

Study Details

Study Description

Brief 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.

Condition or Disease Intervention/Treatment Phase
Phase 3

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.

Study Design

Study Type:
Interventional
Anticipated Enrollment :
360 participants
Allocation:
Randomized
Intervention Model:
Parallel Assignment
Masking:
Double (Participant, Investigator)
Primary Purpose:
Treatment
Official Title:
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
Anticipated Study Start Date :
Mar 1, 2023
Anticipated Primary Completion Date :
Aug 1, 2025
Anticipated Study Completion Date :
Dec 1, 2025

Arms and Interventions

Arm Intervention/Treatment
Experimental: XEN1101 25 mg/day

XEN1101 25 mg/day

Drug: XEN1101
XEN1101 Capsules

Experimental: XEN1101 15 mg/day

XEN1101 15 mg/day

Drug: XEN1101
XEN1101 Capsules

Placebo Comparator: Placebo

Placebo

Drug: Placebo
Placebo Capsules

Outcome Measures

Primary Outcome Measures

  1. Median percent change (MPC) in focal seizure frequency from baseline to DBP for XEN1101 versus placebo. [From baseline through to the double blind period (week 12).]

Secondary Outcome Measures

  1. Proportion of subjects experiencing ≥50% reduction in focal seizure frequency from baseline through the DBP for XEN1101 versus placebo. [From baseline through to the double blind period (week 12).]

  2. MPC in weekly (7 days) focal seizure frequency from baseline to Week 1 for XEN1101 versus placebo. [From baseline through to the week 1.]

  3. Proportion of subjects experiencing "at least much improved" (including "much" and "very much improved") in Patient Global Impression of Change (PGI-C). [From baseline through to the double blind period (week 12).]

  4. To assess adverse events as criteria for safety and tolerability of XEN1101. [From screening through to 56 days post-final dose]

Eligibility Criteria

Criteria

Ages Eligible for Study:
18 Years and Older
Sexes Eligible for Study:
All
Accepts Healthy Volunteers:
No
Inclusion Criteria:
  • Be properly informed of the nature and risks of the study and give informed consent in writing, prior to entering the study

  • Diagnosis (≥2 years) of focal epilepsy according to the International League Against Epilepsy (ILAE) Classification of Epilepsy (2017). Subject must have had adequate trials of at least 2 ASMs, which were given (and tolerated) at adequate therapeutic doses, without achieving sustained seizure freedom.

  • Treatment with a stable dose of 1 to 3 allowable current ASMs for at least one month prior to screening, during baseline, and throughout the duration of the DBP

  • Able to keep accurate seizure diaries

Exclusion Criteria:
  • Previously documented electroencephalogram which shows any pattern not consistent with focal etiology of seizures.

  • History of focal aware non-motor seizures only, non-epileptic psychogenic seizure, primary generalized seizure, developmental and epileptic encephalopathy, including Lennox-Gastaut syndrome.

  • Seizures secondary to drug or alcohol use, ongoing infection, neoplasia, demyelinating disease, degenerative neurological disease, metabolic illness, progressive structural lesion, encephalopathy, or progressive central nervous system (CNS) disease.

  • History of status epilepticus or repetitive seizures within the 12-month period preceding Visit 1 where the individual seizures cannot be counted.

  • History of neurosurgery for seizures <1 year prior to Visit 1, or radiosurgery <2 years prior to enrollment.

  • Any medical condition or personal circumstance that, in the opinion of the investigator, exposes the subject to unacceptable risk by participating in the study or prevents adherence to the protocol.

Contacts and Locations

Locations

No locations specified.

Sponsors and Collaborators

  • Xenon Pharmaceuticals Inc.
  • Worldwide Clinical Trials

Investigators

  • Study Director: Xenon Medical Director, Xenon Pharmaceuticals Inc.

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.
Responsible Party:
Xenon Pharmaceuticals Inc.
ClinicalTrials.gov Identifier:
NCT05716100
Other Study ID Numbers:
  • XPF-010-302
First Posted:
Feb 8, 2023
Last Update Posted:
Feb 8, 2023
Last Verified:
Feb 1, 2023
Individual Participant Data (IPD) Sharing Statement:
No
Plan to Share IPD:
No
Studies a U.S. FDA-regulated Drug Product:
Yes
Studies a U.S. FDA-regulated Device Product:
No
Keywords provided by Xenon Pharmaceuticals Inc.
Additional relevant MeSH terms:

Study Results

No Results Posted as of Feb 8, 2023