An Open-label Study of XEN1101 in Epilepsy

Overview

Sponsor-declared trial summary

Key facts

Sponsor

Xenon Pharmaceuticals Inc.

Participant type

Pediatric, Patients

Age range

0-17 years, 18-64 years, 65+ years

Gender

Male and Female

Therapeutic area

Diseases [C] - Nervous System Diseases [C10]

Trial duration

14 Feb 2024 → ongoing

Decision date (initial)

2023-10-09

Transition trial

No

Low-intervention

No

Rare-disease indication

No

Vulnerable population

Yes

Funding sources

Xenon Pharmaceuticals Inc.

External identifiers

EU CT number

2022-502282-24-00

ClinicalTrials.gov

NCT05718817

Trial design

CTIS Part I — objectives, methods, condition coding

Main objective

Scope: Efficacy, Others, Safety

To assess the safety and tolerability of long-term therapy with XEN1101 in subjects with FOS or PGTCS who have completed Study XPF-010-301, XPF-010-302, or XPF-010-303.

Secondary objectives 3

1. To assess the efficacy of long-term treatment with XEN1101 on seizure frequency.
2. To assess the change in disease severity.
3. To assess the impact of long-term treatment with XEN1101 on quality of life in subjects aged ≥18 years at study entry.

Conditions and MedDRA coding

Primary generalized tonic-clonic seizures

Study design 1 period

Regulatory references

Scientific advice from competent authorities

European Medicines Agency, European Medicines Agency

Plan to share IPD

No

Eligibility criteria

Principal inclusion / exclusion criteria as submitted by sponsor

Inclusion criteria 6

1. Subject must have successfully completed the Double bling period (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.
2. Subject is able to keep accurate seizure diaries.
3. Subject must be properly informed of the nature and risks of the study and give informed consent in writing, prior to entering the study.
4. Subject must be willing to comply with the contraception requirements as defined in protocol Section 5.3.
5. Male subjects must agree not to donate sperm until 3 months after the last dose of study drug. Female subjects must agree not to donate ova until 6 months after the last dose of study drug.
6. 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.

Exclusion criteria 4

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. Female subject who is pregnant, breastfeeding, or planning to become pregnant prior to 6 months after the last dose of study drug.
4. 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.

Endpoints

Primary and secondary outcome measures (English text)

Primary endpoints 1

1. Severity and frequency of TEAEs, SAEs, AESIs, AEDCs, AEs leading to dose reduction, and ECIs; potentially clinically significant changes in vital signs, clinical laboratory findings, and/or 12-lead ECG; changes in ophthalmologic exams; increase in suicide risk as assessed by the C-SSRS; clinically significant changes in urological symptoms (including retention) as measured by the AUA-SI; and growth and development in adolescents assessed via physical exam and endocrine laboratory assessments.

Secondary endpoints 4

1. 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 (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 CGI‑S and PGI-S scores over time.
4. Change in the QOLIE-31 over time.

Investigational products

Investigational medicinal products (IMPs), comparators, placebo, auxiliary

Test 4

Sponsors and contacts

Sponsor organisations, regulatory contacts, third parties

Xenon Pharmaceuticals Inc.

Sponsor organisation

Xenon Pharmaceuticals Inc.

Address

3650 Gilmore Way

City

Burnaby

Postcode

V5G 4W8

Country

Canada

Scientific contact point

Organisation

Xenon Pharmaceuticals Inc.

Contact name

Daniela Nenciu

Public contact point

Organisation

Xenon Pharmaceuticals Inc.

Contact name

Xenon Medical Affairs

Third parties 14

Locations

16 EU/EEA countries · 75 investigational sites

By country

Investigational sites

Country notifications

Trial-start, recruitment-start, end and early-termination notifications submitted per Member State

Oversight and notifications

Regulatory notifications under CTR Articles 38, 52, 53, 54 and 77

Serious breaches 1 · Art. 52 CTR

Results and documents

Annex IV summary of results, Annex V layperson summary, and all documents registered in CTIS for this trial

Documents 278 files

Public protocol annexes, IB summaries, regulatory submissions and post-authorisation documents registered in CTIS.

Application history

41 submissions — initial application plus substantial / non-substantial modifications