MedPath

An Open-Label Extension Trial to Assess the Long-Term Safety of ZX008 (Fenfluramine Hydrochloride HCl) Oral Solution in Children and Young Adults With Dravet Syndrome

Phase 3
Completed
Conditions
Dravet Syndrome
Interventions
Drug: ZX008 (Fenfluramine Hydrochloride)
Registration Number
NCT02823145
Lead Sponsor
Zogenix International Limited, Inc., a subsidiary of Zogenix, Inc.
Brief Summary

This is an international, multicenter, open-label, long-term safety study of ZX008 in subjects with Dravet syndrome.

Detailed Description

This is an international, multicenter, open-label, long-term safety study of ZX008 in pediatric and young adult subjects with Dravet syndrome who participated in one of the core studies (ZX008-1501 and ZX008-1502) and are candidates for continuous treatment for an extended period of time. This trial will consist of a 36-month Open-Label Extension (OLE) Treatment Period and a 2-week Post-Dosing Period.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
375
Inclusion Criteria
  • Male or non-pregnant, non-lactating female, age 2 to 18 years, inclusive as of the day of the core study Screening Visit.
  • Satisfactory completion of the core study in the opinion of the investigator and the sponsor.
  • Subjects who are >18 to ≤35 years of age at the time of screening and did not participate in one of the core studies may be eligible for participation.
  • A documented medical history to support a clinical diagnosis of Dravet syndrome, where convulsive seizures are not completely controlled by current antiepileptic drugs.
  • Parent/caregiver is willing and able to be compliant with diary completion, visit schedule and study drug accountability.
  • Subject's parent/caregiver has been compliant with diary completion during the core study, in the opinion of the investigator (eg, at least 90% compliant).

Key

Exclusion Criteria
  • Current or past history of cardiovascular or cerebrovascular disease, myocardial infarction or stroke.
  • Current cardiac valvulopathy or pulmonary hypertension that is clinically significant and warrants discontinuation of study medication.
  • Current or past history of glaucoma.
  • Moderate or severe hepatic impairment.
  • Receiving concomitant therapy with: centrally-acting anorectic agents; monoamineoxidase inhibitors; any centrally-acting compound with clinically appreciable amount of serotonin agonist or antagonist properties, including serotonin reuptake inhibition; atomoxetine, or other centrally-acting noradrenergic agonist; cyproheptadine, and/or cytochrome P450 (CYP) 2D6/3A4/2B6 inhibitors/substrates.
  • Currently taking carbamazepine, oxcarbamazepine, eslicarbazepine, phenobarbital, or phenytoin, or has taken any of these within the past 30 days, as maintenance therapy.
  • A clinically significant condition, or has had clinically relevant symptoms or a clinically significant illness at Visit 1, other than epilepsy, that would negatively impact study participation, collection of study data, or pose a risk to the subject.

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
ZX008ZX008 (Fenfluramine Hydrochloride)ZX008 is supplied as an oral solution in a concentration of 2.5 mg/mL. Subjects will be titrated to an effective dose beginning with 0.2 mg/kg/day (maximum: 30 mg/day).
Primary Outcome Measures
NameTimeMethod
Percentage of Participants With Treatment-emergent Adverse Events (TEAEs) During the Open-label Extension (OLE) Treatment PeriodFrom Day 1 to End of OLE Treatment Period - End of Study (EOS) Visit (Month 42)

Treatment-emergent adverse events (TEAE) were defined as any AEs that based on start date information occurs after the first intake of study treatment.

Percentage of Participants With Treatment-emergent Adverse Events (TEAEs) Leading to Withdrawal From Investigational Medicinal Product (IMP) During the OLE Treatment PeriodFrom Day 1 to End of OLE Treatment Period - EOS Visit (Month 42)

A TEAE was defined as any AE that based on start date information occurs after the first intake of study treatment. Percentage of participants with TEAEs leading to withdrawal from IMP during OLE Treatment Period were reported.

Percentage of Participants With Serious Treatment-emergent Adverse Events (TEAEs) During the OLE Treatment PeriodFrom Day 1 to End of OLE Treatment Period - EOS Visit (Month 42)

Serious Adverse event (SAE) was defined as any untoward medical occurrence that at any dose: • results in death, • is life-threatening threatening, • results in initial inpatient hospitalization or prolongation of hospitalization, •results in persistent or significant disability or incapacity, • results in a congenital anomaly/birth defect, • results in any medically significant event that did not meet any of the other 5 SAE criteria, but which was judged by a physician to potentially jeopardize the participant or require medical or surgical intervention to prevent one of the above outcomes listed as an SAE criterion.

Secondary Outcome Measures
NameTimeMethod
Convulsive Seizure Frequency (CSF) Per 28 Days During the OLE Treatment Period (to Month 36)At Month 1, Month 2, Month 3, Month 4-6, Month 7-9, Month 10-12, Month 13-15, Month 16-18, Month 19-21, Month 22-24, Month 25-27, Month 28-30, Month 31-33, and Month 34-36

Monthly (28 day) CSF was based on electronic diary data obtained for each participant. The total number of convulsive seizures in the ith interval (CSF in OLE, where, i=1, 2, 3, ... , 14 ) was divided by the total number of days in the ith interval with nonmissing diary data and the result was then multiplied by 28 to get a 28-day CSF of OLE.

Percentage of Participants With Changes in Antiepileptic Drug (AED) Medications During First 6 Months of OLE Treatment PeriodAt Month 1, 2, 3, 4 , 5, and 6 of OLE Treatment Period

Participants in the study were required to be on stable background therapy for the first 6 months of treatment, after which background AEDs could be reduced or withdrawn so long as one background AED remained. The percentage of participants who had changes in dose or type of concomitant AED medications during the first, second, third, fourth, fifth, and sixth months were analyzed and reported.

Convulsive Seizure Frequency (CSF) by Mean Daily Dose During the Overall OLE Treatment PeriodFrom Day 1 to End of OLE Treatment Period - End of Study (EOS) Visit (Month 42)

Convulsive seizure frequency over time, reported as per 28 days was analyzed by the actual dose administered. Participants were grouped into low (0.2 to \<0.4 mg/kg), medium (0.4 to \<0.6 mg/kg), and high dose (\>0.6 mg/kg) groups depending on their mean daily doses of ZX008 during the OLE Treatment period. For each participant, the seizure frequency per 28 days was calculated as the number of seizures recorded during the period, divided by the number of days in the period and multiplied by 28. The convulsive seizure frequency was calculated from all available data collected.

Change From Baseline (Core) in Convulsive Seizure Frequency Per 28 Days From Day 1 to End of Study (EOS) Visit (Month 42) in the OLE Treatment PeriodFrom Day 1 to End of OLE Treatment Period (EOS Visit - up to Month 42), compared to Baseline (Core)

Baseline (Core) was defined as Baseline prior to double-blind treatment in the core studies (ZX008-1501/ZX008-1502, and ZX008-1504 Cohort 2). Participants in 1504- Cohort 1 and de novo participants (who entered 1503 without having been in any of the core studies) did not have a Baseline (Core), and were not included in the analysis of this outcome measure. The total number of convulsive seizures from Day 1 to EOS was divided by the total number of days from Day 1 to EOS with nonmissing diary data and the result was then multiplied by 28 to get a 28-day convulsive seizure frequency (CSF). The change from Baseline for any individual participant was calculated by subtracting the Baseline (Core) from the post-baseline value. Monthly (28 day) CSF was based on electronic diary data obtained for each participant.

Change From Baseline (Core) in Convulsive Seizure Frequency Per 28 Days From Month 2 to EOS (Month 42) in the OLE Treatment PeriodFrom Month 2 to End of OLE Treatment Period (EOS Visit - up to Month 42), compared to Baseline (Core)

Baseline (Core) was defined as Baseline prior to double-blind treatment in the core studies. Participants in 1504-Cohort 1 and de novo participants did not have a Baseline (Core), and were not included in the analysis of this outcome measure. The total number of convulsive seizures from Month 2 to EOS was divided by the total number of days from Month 2 to EOS with nonmissing diary data and the result was then multiplied by 28 to get a 28-day CSF. The change from Baseline for any individual participant was calculated by subtracting the Baseline (Core) from the post-baseline value. Monthly (28 day) CSF was based on electronic diary data obtained for each participant.

Trial Locations

Locations (67)

Kempenhaeghe

🇳🇱

Heeze, Netherlands

Rady Children's Hospital San Diego

🇺🇸

San Diego, California, United States

Children's Hospital Of Michigan

🇺🇸

Detroit, Michigan, United States

University of Utah

🇺🇸

Salt Lake City, Utah, United States

Ospedale Fatebenefratelli e Oftalmico

🇮🇹

Milano, Italy

University Hospitals Cleveland Medical Center

🇺🇸

Cleveland, Ohio, United States

Massachusetts General Hospital

🇺🇸

Boston, Massachusetts, United States

Phoenix Children's Hospital

🇺🇸

Phoenix, Arizona, United States

Miami Children's Hospital Brain Institute

🇺🇸

Miami, Florida, United States

Clinical Integrative Research Center of Atlanta, Panda Neurology

🇺🇸

Atlanta, Georgia, United States

Institute of Neurology and Neurosurgery at St. Barnabus

🇺🇸

Livingston, New Jersey, United States

Neurology and Epilepsy Research Center

🇺🇸

Orlando, Florida, United States

NW FL Clinical Research Group, LLC

🇺🇸

Gulf Breeze, Florida, United States

Mayo Clinic

🇺🇸

Rochester, Minnesota, United States

CHU Amiens-Picardie Service De Neurologie Pediatrique

🇫🇷

Amiens, France

Danish National Epilepsy Centre

🇩🇰

Dianalund, Denmark

Universitaetsklinikum Freiburg Zentrum fuer Kinder- und Jugendmedizin

🇩🇪

Freiburg, Germany

The Children's Hospital Colorado

🇺🇸

Aurora, Colorado, United States

Children's Hospital of Philadelphia

🇺🇸

Philadelphia, Pennsylvania, United States

Melbourne Brain Centre Austin Hospital

🇦🇺

Heidelberg, Australia

Universitaetsklinikum Jena Klinik fuer Kinder- und Jugendmedizin Neuropaediatrie

🇩🇪

Jena, Germany

MultiCare Institute for Research & Innovation

🇺🇸

Tacoma, Washington, United States

Boston Children's Hospital

🇺🇸

Boston, Massachusetts, United States

Children's Health Queensland Hospital and Health Service at Lady Cilento Children's Hospital

🇦🇺

South Brisbane, Australia

Hôpital Robert Debré Pôle: Pédiatrie Médicale Service: Neurologie Et Maladies Métaboliques

🇫🇷

Paris, France

Universitair Ziekenhuis Antwerpen

🇧🇪

Edegem, Belgium

The Children's Hospital Westmead Dept. of Neurology and Neurosurgery

🇦🇺

Westmead, Australia

Hôpital Universitaire Necker-Enfants Malades Service de neurologie pédiatrique Centre de référence épilepsies rares (CReER)

🇫🇷

Paris, France

Universitaetsklinikum Schleswig-Holstein Campus Kiel Klinik fuer Neuropaediatrie

🇩🇪

Kiel, Germany

Krankenhaus Mara Epilepsie-Zentrum Bethel

🇩🇪

Bielefeld, Germany

A.O. Carlo Poma

🇮🇹

Mantova, Italy

Ospedale Civile Maggiore di Borgo Trento - Ospedale della Donna e del Bambino

🇮🇹

Verona, Italy

Schoen Klinik Vogtareuth Neuropaediatrie und Neurologische Rehabilitation, Epilepsiezentrum fuer Kinder und Jugendlische, Tagesklinik fuer Neuropaediatrie

🇩🇪

Vogtareuth, Germany

Policlinico A. Gemelli

🇮🇹

Roma, Italy

AOU Anna Meyer Clinica di Neurologia Pediatrica

🇮🇹

Firenze, Italy

Istituto Pediatrico Giannina Gaslini Dipartimento di Neurologia

🇮🇹

Genova, Italy

Istituto Neurologica Carlo Besta

🇮🇹

Milano, Italy

National Epilepsy Center Shizuoka Institute of Epilepsy and Neurological Disorders

🇯🇵

Shizuoka, Japan

Birmingham Children Hospital NHS Foundation Trust

🇬🇧

Birmingham, United Kingdom

Saitama Children's Medical Center

🇯🇵

Saitama, Japan

Tokyo Women's Medical University Hospital

🇯🇵

Tokyo, Japan

Hospital Sant Joan de Déu

🇪🇸

Barcelona, Spain

Alder Hey Hospital

🇬🇧

Liverpool, United Kingdom

Hospital Ruber Internacional Primera Planta Servicio de Neurologia

🇪🇸

Madrid, Spain

St. Thomas Hospital

🇬🇧

London, United Kingdom

Institute of Neurosciences Queen Elizabeth University Hospital

🇬🇧

Glasgow, United Kingdom

Clinica Universitaria de Navarra Fase 4. Segunda planta, Consulta de Pediatria

🇪🇸

Pamplona, Spain

Sheffield Children's Hospital

🇬🇧

Sheffield, United Kingdom

HOPITAL DEL LA TIMONE - HOPITAL HENRI GASTAUT Hôpital De La Timone Neurologie Pédiatrique Pneumologie Pédiatrique Et Médecine Infantile

🇫🇷

Marseille, France

Centre Hospitalier Universitaire Sainte-Justine

🇨🇦

Montréal, Canada

British Columbia Children's Hospital

🇨🇦

Vancouver, Canada

Minnesota Epilepsy Group, P.A.

🇺🇸

Saint Paul, Minnesota, United States

Ann and Robert H. Lurie Children's Hospital of Chicago

🇺🇸

Chicago, Illinois, United States

Cook Children's Medical Center

🇺🇸

Fort Worth, Texas, United States

Seattle Children's Hospital

🇺🇸

Seattle, Washington, United States

Children's Hospital of Orange County

🇺🇸

Orange, California, United States

University of California San Francisco

🇺🇸

San Francisco, California, United States

CHRU Lille Antenne Pédiatrique Du CIC - Hôpital Jeanne De Flandre

🇫🇷

Lille, France

CHU De Bordeaux Service De Pédiatrie Médicale

🇫🇷

Bordeaux, France

Kleinwachau Saechsisches Epilepsiezentrum Radeberg gemeinnuetzige GmbH

🇩🇪

Radeberg, Germany

Universitaetsklinik fuer Kinder- und Jugendmedizin Abteilung III

🇩🇪

Tübingen, Germany

Great Ormond Street Hospital for Children NHS Foundation Trust

🇬🇧

London, United Kingdom

Le Bonheur Children's Hospital

🇺🇸

Memphis, Tennessee, United States

Stichting Epilepsie Instellingen Nederland

🇳🇱

Zwolle, Netherlands

Center for Neurosciences - Tucson

🇺🇸

Tucson, Arizona, United States

DRK Kliniken Berlin - Westend Epilepsiezentrum / Neuropaediatrie

🇩🇪

Berlin, Germany

U.O. Neurologia Dipartimento di Neuroscienze Ospedale Pediatrico Bambino Gesù

🇮🇹

Roma, Italy

© Copyright 2025. All Rights Reserved by MedPath