X-TOLE4: An Open-label Study of XEN1101 in Epilepsy

Sponsor
Xenon Pharmaceuticals Inc. (Industry)
Overall Status
Not yet recruiting
CT.gov ID
NCT05718817
Collaborator
Worldwide Clinical Trials (Other)
880
1
50

Study Details

Study Description

Brief Summary

This study will evaluate the long term safety, tolerability, PK, and efficacy of XEN1101 25 mg QD taken orally in subjects with Focal Onset Seizures (FOS) or Primary Generalized Tonic-Clonic Seizures (PGTCS) for the treatment of seizures for up to 3 years.

Condition or Disease Intervention/Treatment Phase
Phase 3

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 25 mg QD taken orally once daily (QD) in subjects with FOS or PGTCS for the treatment of seizures for up to 3 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 3 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. All subjects will be initially assigned to receive 25 mg QD of XEN1101. Subjects will be instructed to orally take XEN1101 once daily 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.

Study Design

Study Type:
Interventional
Anticipated Enrollment :
880 participants
Allocation:
N/A
Intervention Model:
Single Group Assignment
Masking:
None (Open Label)
Primary Purpose:
Treatment
Official Title:
A Multicenter, Open-label, Long-term, Safety, Tolerability, and Efficacy Study of XEN1101 in Adults Diagnosed With Epilepsy
Anticipated Study Start Date :
Apr 1, 2023
Anticipated Primary Completion Date :
Jun 1, 2026
Anticipated Study Completion Date :
Jun 1, 2027

Arms and Interventions

Arm Intervention/Treatment
Experimental: XEN1101 25 mg/day

XEN1101 25 mg/day

Drug: XEN1101
XEN1101 capsules

Outcome Measures

Primary Outcome Measures

  1. The adverse events [From the start of treatment in the OLE study through 8 weeks after the last dose.]

    To assess the safety and tolerability of XEN1101

Secondary Outcome Measures

  1. Change in monthly seizure rate [From baseline through the active extension treatment (Week 156).]

    Percent change in monthly seizure rate recorded at baseline (in the antecedent studies) compared to each 4-week assessment period in the treatment period in X-TOLE4.

  2. Proportion of responders [From baseline through the active extension treatment (Week 156).]

    Proportion of responders (subjects experiencing ≥50% reduction in seizure frequency from baseline) in each consecutive 4-week assessment period of the treatment period of the OLE study.

  3. Change in Clinical Global Impression of Severity (CGI-S) [From baseline through the active extension treatment (Week 156).]

    Improvement in Clinical Global Impression of Severity (CGI-S) scores over time.

  4. Change in Patient Global Impression of Severity (PGI-S) [From baseline through the active extension treatment (Week 156).]

    Improvement in Patient Global Impression of Severity (PGI-S) scores over time.

  5. Change in Quality of Life in Epilepsy Inventory (QOLIE-31) [From baseline through the active extension treatment (Week 156).]

    Change in the 31-Item Quality of Life in Epilepsy Inventory (QOLIE-31) over time.

Eligibility Criteria

Criteria

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

  2. Subject must have successfully completed the DBP and have not terminated early from Study X-TOLE2, X-TOLE3, or X-ACKT, met all eligibility requirements, and had no important protocol deviations (in the opinion of the sponsor) or AEs (in the opinion of the investigator) that would preclude the subject's entry into the long-term extension study.

  3. In the opinion of the investigator, the subject is able to understand verbal and written instructions and will adhere to all study schedules and requirements.

  4. Subject is able to keep accurate seizure diaries.

Exclusion Criteria:
  1. Subject met any of the withdrawal criteria while in Study X-TOLE2, X-TOLE3, or X-ACKT.

  2. Subject has any medical condition, personal circumstance, or ongoing AE (from Study X-TOLE2, X-TOLE3, or X-ACKT) that, in the opinion of the investigator, exposes the subject to unacceptable risk by participating in the study, or prevents adherence to the protocol.

  3. Subject is planning to enter a clinical study with a different investigational drug or planning to use any experimental device for treatment of epilepsy or any other medical condition during the study and until 28 days after completion of this study.

Contacts and Locations

Locations

No locations specified.

Sponsors and Collaborators

  • Xenon Pharmaceuticals Inc.
  • Worldwide Clinical Trials

Investigators

  • Study Director: Medical Director, Xenon Pharmaceuticals Inc.

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.
Responsible Party:
Xenon Pharmaceuticals Inc.
ClinicalTrials.gov Identifier:
NCT05718817
Other Study ID Numbers:
  • XPF-010-304
First Posted:
Feb 8, 2023
Last Update Posted:
Feb 8, 2023
Last Verified:
Jan 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