A Study to Investigate the Long-Term Safety of ZX008 (Fenfluramine Hydrochloride) Oral Solution in Children and Adults With Epileptic Encephalopathy Including Dravet Syndrome and Lennox-Gastaut Syndrome

An Open-Label Extension Trial to Assess the Long-Term Safety of ZX008 (Fenfluramine Hydrochloride) Oral Solution as an Adjunctive Therapy for Seizures in Patients with Rare Seizure Disorders Such as Epileptic Encephalopathies Including Dravet Syndrome and Lennox-Gastaut Syndrome

Status

Active, not recruiting

Phases

Phase 3

Study type

Interventional

Source

EU CTR

Registry ID

EUCTR2019-001331-31-BE

Enrollment

650

Registered

2019-09-26

Start date

2019-11-18

Completion date

Unknown

Last updated

2025-09-15

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Dravet syndrome or Lennox-Gastaut syndrome MedDRA version: 20.1 Level: PT Classification code 10048816 Term: Lennox-Gastaut syndrome System Organ Class: 10029205 - Nervous system disorders MedDRA version: 20.0 Level: LLT Classification code 10073682 Term: Dravet syndrome System Organ Class: 100000004850

Interventions

Product Name: Fenfluramine hydrochloride (colorless) Product Code: ZX008 Pharmaceutical Form: Oral solution INN or Proposed INN: FENFLURAMINE HYDROCHLORIDE CAS Number: 404-82-0 Current Sponsor code: Z

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: • Male or nonpregnant, nonlactating female • Satisfactory completion of a core study • Has a rare seizure disorder, such as epileptic encephalopathy and has successfully completed another Zogenix-sponsored clinical trials with ZX008 • Subject's caregiver is willing and able to be compliant with study procedures, visit schedule and study drug accountability Are the trial subjects under 18? yes Number of subjects for this age range: 445 F.1.2 Adults (18-64 years) yes F.1.2.1 Number of subjects for this age range 205 F.1.3 Elderly (>=65 years) no F.1.3.1 Number of subjects for this age range

Exclusion criteria

Exclusion criteria: • Current cardiac valvulopathy or pulmonary hypertension that is clinically significant • Moderate or severe hepatic impairment • Receiving prohibited medication (please see protocol section 5.6.2) within 14 days of receiving ZX008

Design outcomes

Primary

Measure	Time frame
Main Objective: To assess the long-term safety and tolerability of ZX008;Secondary Objective: To assess the effect of ZX008 on the following effectiveness measures: - Investigator assessment of convulsive seizure response (<25%, =25%, =50%, =75%, or 100% [ie, seizure-free] improvement) - Clinical Global Impression – Improvement (CGI-I) rating, global and symptomatic, as assessed by the investigator - CGI-I rating, global and symptomatic, as assessed by the parent/caregiver;Primary end point(s): The safety endpoints of the study are: • AEs • Laboratory safety (hematology, chemistry) • Vital signs (blood pressure, heart rate, temperature, and respiratory rate) • Physical examination • Neurological examination • Electrocardiogram (ECGs) • Doppler echocardiogram (ECHOs) • Body weight/height • Chest x-ray (subjects in France and Netherlands only) • Electroencephalogram (EEG) (in Italy only);Timepoint(s) of evaluation of this end point: Up to 36 months	—

Measure

Time frame

Main Objective: To assess the long-term safety and tolerability of ZX008;Secondary Objective: To assess the effect of ZX008 on the following effectiveness measures: - Investigator assessment of convulsive seizure response (<25%, =25%, =50%, =75%, or 100% [ie, seizure-free] improvement) - Clinical Global Impression – Improvement (CGI-I) rating, global and symptomatic, as assessed by the investigator - CGI-I rating, global and symptomatic, as assessed by the parent/caregiver;Primary end point(s): The safety endpoints of the study are: • AEs • Laboratory safety (hematology, chemistry) • Vital signs (blood pressure, heart rate, temperature, and respiratory rate) • Physical examination • Neurological examination • Electrocardiogram (ECGs) • Doppler echocardiogram (ECHOs) • Body weight/height • Chest x-ray (subjects in France and Netherlands only) • Electroencephalogram (EEG) (in Italy only);Timepoint(s) of evaluation of this end point: Up to 36 months

—

Secondary

Measure	Time frame
Secondary end point(s): The effectiveness endpoints of the study are: • CGI-I, global and symptomatic, as assessed by parent/caregiver • CGI-I, global and symptomatic, as assessed by investigator (or designee) • Percent improvement in seizure burden as assessed by the investigator (or designee);Timepoint(s) of evaluation of this end point: Up to 36 months	—

Countries

Australia, Belgium, Canada, Denmark, France, Germany, Italy, Japan, Mexico, Netherlands, Poland, Spain, Sweden, United Kingdom, United States

Contacts

Public ContactClin Trial Reg & Results Disclosure

UCB BIOSCIENCES GmbH

clinicaltrials@ucb.com

Outcome results

None listed

Source: EU CTR (via WHO ICTRP) · Data processed: Feb 4, 2026