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A 2-Part Study to Investigate the Dose-Ranging Safety and Pharmacokinetics, Followed by the Efficacy and Safety of ZX008 (Fenfluramine Hydrochloride) Oral Solution as an Adjunctive Therapy in Children ≥ 2 Years Old and Young Adults With Dravet Syndrome

Phase 3
Completed
Conditions
Dravet Syndrome
Interventions
Drug: ZX008 (Fenfluramine Hydrochloride)
Drug: Matching Placebo
Registration Number
NCT02926898
Lead Sponsor
Zogenix International Limited, Inc., a subsidiary of Zogenix, Inc.
Brief Summary

The primary purpose of this study is to evaluate the safety, tolerability, and efficacy of ZX008 (fenfluramine hydrochloride) when added to adjunctive antiepileptic stiripentol treatment in children and young adults with Dravet syndrome.

Detailed Description

This is a multicenter, 2-cohort trial to first assess the pharmacokinetic and safety profile of a single dose of ZX008 (fenfluramine hydrochloride) oral solution when added to a standard Dravet syndrome treatment regimen containing valproate (VPA) and clobazam (CLB), with or without stiripentol (STP) (Cohort 1), followed by a randomized, double-blind, placebo-controlled parallel group evaluation of the efficacy, safety, and tolerability of ZX008 as adjunctive therapy for seizures in children and young adults with Dravet syndrome (Cohort 2).

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
87
Inclusion Criteria
  • Subject must be male or non-pregnant, non-lactating female, aged 2 to 18 years (inclusive).
  • Subject must have documented medical history to support a clinical diagnosis of Dravet syndrome, where convulsive seizures are not completely controlled by current antiepileptic drugs.
  • Subject must be receiving a therapeutically relevant and stable dose of stiripentol (STP) plus clobazam (CLB) and/or valproate (VPA), and for at least 4 weeks prior to screening and be expected to remain stable throughout the study (Cohort 2 only).
  • Subject must be receiving a stable dose of CLB and VPA, administered twice daily (BID), to be eligible for Dose Regimen 1 and 2, or subject must be receiving a stable dose of CLB, VPA, and STP, administered BID, to be eligible for Dose Regimen 3 (Cohort 1 only).

Key

Exclusion Criteria
  • Subject has a known hypersensitivity to fenfluramine or any of the excipients in the study medication.
  • Subject has pulmonary arterial hypertension.
  • Subject has a current or past history of cardiovascular or cerebrovascular disease, such as cardiac valvulopathy, myocardial infarction, or stroke.
  • Subject has a current or recent history of anorexia nervosa, bulimia, or depression within the prior year that required medical treatment or psychological treatment for a duration greater than 1 month.
  • Subject has a current or past history of glaucoma.
  • Subject is receiving concomitant therapy with: centrally acting anorectic agents; monoamine-oxidase inhibitors; any centrally acting compound with clinically appreciable amount of serotonin agonist or antagonist properties, including serotonin reuptake inhibition; triptans, atomoxetine, or other centrally acting noradrenergic agonists; cyproheptadine, and/or cytochrome P450 (CYP) 2D6/3A4/2B6 inhibitors/substrates.
  • Subject is currently taking carbamazepine ,oxcarbazepine, eslicarbazepine, phenobarbital, or phenytoin, or has taken any of these within the past 30 days, as maintenance therapy.
  • Subject has a positive result on urine tetrahydrocannabinol (THC) panel or whole blood cannabidiol (CBD) at the Screening Visit.
  • Subject has a clinically significant condition, or has had clinically relevant symptoms or a clinically significant illness in the 4 weeks prior to the Screening Visit, 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
PARALLEL
Arm && Interventions
GroupInterventionDescription
Cohort 2: ZX008 0.5 mg/kg/dayZX008 (Fenfluramine Hydrochloride)ZX008 0.5 mg/kg/day (maximum 20 mg/day) dose supplied as an oral solution administered twice a day (BID) in equally divided doses with food.
Cohort 2: Matching PlaceboMatching PlaceboMatching placebo administered twice a day (BID) in equally divided doses with food.
Primary Outcome Measures
NameTimeMethod
Change in Convulsive Seizure Frequency (CSF) From the Baseline Period (Baseline) to the Combined Titration + Maintenance (T+M) Period15 weeks (combined Titration + Maintenance Period)

Monthly (28 day) convulsive seizure frequency (CSF) was based on electronic diary data obtained for each participant. Convulsive seizures included hemiclonic, focal with clear observable motor signs, generalized tonic clonic, secondarily generalized tonic clonic, tonic, clonic, and drop seizures (tonic/atonic). The number of convulsive seizures reported during the entire time interval was divided by the number of nonmissing diary days and the result was then multiplied by 28 to get a 28-day CSF.

Secondary Outcome Measures
NameTimeMethod
Percentage of Participants Who Achieved ≥ a 50% Reduction in Convulsive Seizure Frequency From Baseline to the Combined Titration + Maintenance Period15 weeks (combined Titration + Maintenance Period)

Percentage of participants who achieved ≥ a 50% reduction in convulsive seizure frequency from Baseline compared to the combined Titration + Maintenance Periods in the ZX008 0.5 mg/kg/day vs placebo groups.

Longest Convulsive Seizure-Free Interval (Days)15 weeks (combined Titration + Maintenance Period)

Comparison of the duration of the longest convulsive seizure-free interval (days) during the combined Titration + Maintenance Periods for the ZX008 0.5 mg/kg/day and placebo groups.

Trial Locations

Locations (28)

Evelina London Children'S Hospital, Paediatric Neurosciences

🇬🇧

London, United Kingdom

Ann & Robert H. Lurie Children'S Hospital of Chicago

🇺🇸

Chicago, Illinois, United States

University of California San Francisco

🇺🇸

San Francisco, California, United States

Royal Hospital For Children, Queen Elizabeth University, Institute of Neurosciences Hospital

🇬🇧

Glasgow, Scotland, United Kingdom

Chu Sainte-Justine Hospital Neurology Clinic

🇨🇦

Montréal, Quebec, Canada

Bc Children'S Hospital Division of Neurology

🇨🇦

Vancouver, British Columbia, Canada

Mayo Clinic

🇺🇸

Rochester, Minnesota, United States

Children'S Hospital of Michigan

🇺🇸

Detroit, Michigan, United States

Children'S Hospital Colorado

🇺🇸

Aurora, Colorado, United States

Chu de Bordeaux Hôpital Des Enfants

🇫🇷

Bordeaux, France

HÔPITAL FEMME-MÈRE-ENFANT Hôpital Service de Neurologie Pédiatrique

🇫🇷

Bron, France

Chu Amiens Picardie Service de Neurologie Pédiatrique

🇫🇷

Amiens, France

Hôpital Robert-Debré

🇫🇷

Paris, France

Hôpital D'Enfants Chur de Nancy

🇫🇷

Vandœuvre-lès-Nancy, France

Krankenhaus Mara, Epilepsie-Zentrum Bethel

🇩🇪

Bielefeld, Germany

Universitätsklinikum Schleswig-Holstein, Klinik Für Neuropädiatrie

🇩🇪

Kiel, Germany

Hôpital Necker-Enfants Malades

🇫🇷

Paris, France

Chu de Toulouse - Hôpital Des Enfants

🇫🇷

Toulouse, France

Chru de Lille Hôpital Roger Salengro

🇫🇷

Lille, France

Hôpital de La Timone, Service de Neuro-Métabolisme Pédiatrique

🇫🇷

Marseille, France

Epilepsiecentrum Kempenhaeghe

🇳🇱

Heeze, Netherlands

Kleinwachau Sächsisches Epilepsiezentrum Radeberg

🇩🇪

Radeberg, Germany

Cliníca Universidad de Navarra Nidad de Neuropediatría

🇪🇸

Pamplona, Spain

Stichting Epilepsie Instellingen Nederland

🇳🇱

Zwolle, Netherlands

Alder Hey Children'S Nhs Foundation Trust, Littlewood'S Neurosciences Unit

🇬🇧

Liverpool, United Kingdom

Hospital Sant Joan de Déu Barcelona

🇪🇸

Barcelona, Spain

Great Ormond Street Hospital For Children Nhs Foundation Trust

🇬🇧

London, United Kingdom

Hospital Ruber Internacional-Servicio de Neurología

🇪🇸

Madrid, Spain

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