A Study to Investigate the Efficacy and Safety of ZX008 (Fenfluramine Hydrochloride) as an Adjunctive Therapy in Children and Adults With Lennox-Gastaut Syndrome
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ClinicalTrials.gov Identifier: NCT03355209 |
Recruitment Status :
Active, not recruiting
First Posted : November 28, 2017
Last Update Posted : June 18, 2021
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Condition or disease | Intervention/treatment | Phase |
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Lennox Gastaut Syndrome | Drug: ZX008 0.2 or 0.8 mg/kg/day Drug: Matching Placebo | Phase 3 |
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 296 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Intervention Model Description: | Part 1: Double-Blind ZX008 - (0.2 mg/kg/day or 0.8mg/kg/day) or Placebo and Part 2: Open-Label |
Masking: | Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor) |
Masking Description: | Part 1: Double-Blind Part 2: Open-Label |
Primary Purpose: | Treatment |
Official Title: | A Two-Part Study of ZX008 in Children and Adults With Lennox-Gastaut Syndrome (LGS); Part 1: A Randomized, Double-blind, Placebo-controlled Trial of Two Fixed Doses of ZX008 (Fenfluramine Hydrochloride) Oral Solution as Adjunctive Therapy for Seizures in Children and Adults With LGS, Followed by Part 2: An Open-label Extension to Assess Long-Term Safety of ZX008 in Children and Adults With LGS |
Actual Study Start Date : | November 27, 2017 |
Estimated Primary Completion Date : | March 2024 |
Estimated Study Completion Date : | March 2024 |

Arm | Intervention/treatment |
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Experimental: ZX008 0.2 or 0.8 mg/kg/day
Part 1: ZX008 is supplied as an oral solution. Subjects will be randomized to receive 1 of 2 doses of ZX008 0.2 mg/kg/day or 0.8 mg/kg/day.
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Drug: ZX008 0.2 or 0.8 mg/kg/day
ZX008 drug product is an oral aqueous solution of fenfluramine hydrochloride. The product is sugar free and is intended to be compatible with a Ketogenic Diet. |
Placebo Comparator: Matching Placebo
Part 1: Matching ZX008 placebo is supplied as an oral solution.
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Drug: Matching Placebo
Placebo will be administered twice a day (BID) in equally divided doses.
Other Name: Placebo Comparator |
Experimental: Open-Label
Part 2: ZX008 is supplied as an oral solution. Study medication will be administered twice a day (BID) in equally divided doses.
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Drug: ZX008 0.2 or 0.8 mg/kg/day
ZX008 drug product is an oral aqueous solution of fenfluramine hydrochloride. The product is sugar free and is intended to be compatible with a Ketogenic Diet. |
- Part 1: Change from baseline in frequency of seizures that result in drops in subjects receiving ZX008 compared to placebo [ Time Frame: Up to 20 weeks maintenance and taper period (T+M) ]Parent/caregiver seizure diary record will be used to assess frequency, type and duration of seizure activity
- Part 2: Adverse events and related safety parameters in subjects receiving ZX008 compared to placebo [ Time Frame: Up to 12 months open label ]Safety and tolerability evaluated by reported adverse events, laboratory parameters, physical and neurological examination, vital signs, electrocardiograms, echocardiograms, and body weight

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Ages Eligible for Study: | 2 Years to 35 Years (Child, Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Key Inclusion Criteria:
- Male or non-pregnant, non-lactating female, age 2 to 35 years, inclusive as of the day of the Screening Visit.
- Clinical diagnosis of Lennox-Gastaut syndrome, where seizures that result in drops are not completely controlled by current antiepileptic treatments.
- Onset of seizures at 11 years of age or younger.
- Abnormal cognitive development.
- Must be receiving at least 1 concomitant AED and up to 4 concomitant anti-epileptic treatments.
Key Exclusion Criteria:
- Etiology of seizures is a degenerative neurological disease.
- History of hemiclonic seizures in the first year of life.
- Subject only has drop seizures in clusters, where individual seizures cannot be counted reliably.
- Pulmonary arterial hypertension.
- Current or past history of cardiovascular or cerebrovascular disease, such as cardiac valvulopathy, myocardial infarction or stroke.
- 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.
- Taking felbamate for less than 1 year prior to screening and/or does not have stable liver function and hematology laboratory tests, and/or the dose has not been stable for at least 60 days prior to the Screening Visit.
- Currently receiving an investigational product.
- Institutionalized in a general nursing home (ie, in a facility that does not specialize in epilepsy care).
- 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.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03355209

Responsible Party: | Zogenix International Limited, Inc., a subsidiary of Zogenix, Inc. |
ClinicalTrials.gov Identifier: | NCT03355209 |
Other Study ID Numbers: |
ZX008-1601 |
First Posted: | November 28, 2017 Key Record Dates |
Last Update Posted: | June 18, 2021 |
Last Verified: | June 2021 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
LGS |
Lennox Gastaut Syndrome Syndrome Disease Pathologic Processes Epileptic Syndromes |
Epilepsy Brain Diseases Central Nervous System Diseases Nervous System Diseases Genetic Diseases, Inborn |