Trial · NCT03355209
A Study to Investigate the Efficacy and Safety of ZX008 (Fenfluramine Hydrochloride) as an Adjunctive Therapy in Children and Adults With Lennox-Gastaut Syndrome
NCT03355209, Phase 3, Completed, Zogenix International Limited, Inc., a subsidiary of Zogenix, Inc.; results first posted 2025-07-03
3 sourcestrials-2026-11-12-0.5.0
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ConductScience Library. A Study to Investigate the Efficacy and Safety of ZX008 (Fenfluramine Hydrochloride) as an Adjunctive Therapy in Children and Adults With Lennox-Gastaut Syndrome. Trials, record NCT03355209. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT03355209
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Trial
As registered on ClinicalTrials.gov, in the graph's capture of the registry.
- Title
- A Study to Investigate the Efficacy and Safety of ZX008 (Fenfluramine Hydrochloride) as an Adjunctive Therapy in Children and Adults With Lennox-Gastaut Syndrome
- NCT number
- NCT03355209
- Status
- Completed
- Phases
- Phase 3
- Enrollment
- 296 participants, actual
- Lead sponsor
- Zogenix International Limited, Inc., a subsidiary of Zogenix, Inc.
- Conditions
- Lennox Gastaut Syndrome
- Interventions
- ZX008 0.2 or 0.8 mg/kg/day, Matching Placebo
- First posted
- 2017-11-28
- Last updated
- 2025-07-03
- Other registries' IDs
- eudract:2017-002628-26
- Results first posted
- 2025-07-03
Source ClinicalTrials.gov
Registered outcomes45
Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.
| List | Outcome | Time frame | Description |
|---|---|---|---|
| Primary | Part 1: Percent Change From Baseline in the Frequency of Seizures That Result in Drops (ESC-confirmed) in the Combined Titration and Maintenance Period (T+M) in the ZX008 0.8 mg/kg/Day Group Compared to the Placebo Group | From Baseline up to 14 weeks [Titration Period (2 weeks) + Maintenance Period (12 weeks)] | Percent change in frequency of seizures that result in drops (DSF: drop seizure frequency) per 28 days between the combined Titration and Maintenance (T+M) and Baseline. The percent change from Baseline DSF was calculated as the change in DSF between T+M and Baseline / DSF during Baseline\* 100. The seizure types included in the count were: atonic, tonic, tonic/atonic, generalized tonic-clonic, and secondarily generalized tonic-clonic seizures resulting in drops. |
| Primary | Part 2: Percentage of Participants With Treatment-emergent Adverse Events (TEAEs) | From Part 2 Baseline until end of the OLE Period (up to 72 months) | An Adverse event (AE) was defined as any unfavourable and unintended sign, symptom, or disease temporally associated with the use of investigational product, or whether considered related to the investigational product. A TEAE in Part 2 was defined as any AE with an onset on or after the first dose in Part 2. AEs with onset in Part 1 that are ongoing in Part 2 were not included in the count of AEs in Part 2. |
| Primary | Part 2: Percentage of Participants With Serious TEAEs | From Part 2 Baseline until end of the OLE Period (up to 72 months) | A serious adverse event (SAE) was defined as any untoward medical occurrence that at any dose: Results in death, is life-threatening, requires in-patient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability or incapacity, is a congenital anomaly or birth defect, or is medically significant. |
| Secondary | Part 1: Percent Change From Baseline in the Frequency of Seizures That Result in Drops (ESC-confirmed) in T+M in the ZX008 0.2 mg/kg/Day Group Compared to the Placebo Group | From Baseline up to 14 weeks [Titration Period (2 weeks) + Maintenance Period (12 weeks)] | Percent change in frequency of seizures that result in drops (DSF: drop seizure frequency) per 28 days between the combined Titration and Maintenance (T+M) and Baseline. The percent change from Baseline DSF was calculated as the change in DSF between T+M and Baseline / DSF during Baseline\* 100. The seizure types included in the count were: atonic, tonic, tonic/atonic, generalized tonic-clonic, and secondarily generalized tonic-clonic seizures resulting in drops. |
| Secondary | Part 1: Percentage of Participants Who Achieve a >=50% Reduction From Baseline in the Frequency of Seizures That Result in Drops Comparing the ZX008 0.8 mg/kg/Day and 0.2 mg/kg/Day Groups Independently Versus Placebo | From Baseline up to 14 weeks [Titration Period (2 weeks) + Maintenance Period (12 weeks)] | The seizure types included in the count were: atonic, tonic, tonic/atonic, generalized tonic-clonic, and secondarily generalized tonic-clonic seizures resulting in drops. Participants who achieved a \>=50% reduction from Baseline in the DSF, ie, a decrease in DSF of at least 50 percentage points per 28 days during Titration and Maintenance Period. |
| Secondary | Part 1: Percentage of Participants Who Achieve Improvement (Minimally, Much or Very Much Improved) in the CGI-I Scale as Assessed by Principal Investigator Comparing ZX008 0.8 and 0.2 mg/kg/Day Groups Independently Versus Placebo | At Day 99 (Visit 12) | Clinical Global Impression - Improvement (CGI-I) scale measures improvement in the participant's condition from Baseline. The severity of a participant's condition was rated on a 7-point scale ranging from 1 (very much improved) to 7 (very much worse), as follows: 1-very much improved,2-much improved, 3-minimally improved, 4- no change, 5-minimally worse, 6-much worse and 7-very much worse. |
| Secondary | Part 1: Percent Change From Baseline in Frequency of All Seizures That Typically Result in Drops in T+M, Whether ESC-confirmed as Drop or Not in the ZX008 0.8 mg/kg/Day and 0.2 mg/kg/Day Groups Independently Versus Placebo | From Baseline up to 14 weeks [Titration Period (2 weeks) + Maintenance Period (12 weeks)] | Seizures that typically result in drops included all: generalized tonic-clonic seizures \[GTC\], secondarily generalized tonic-clonic \[SGTC\], tonic seizures \[TS\], atonic seizures \[AS\], and tonic/atonic seizures \[TA\], whether confirmed by the ESC or not. Seizures that result in a drop were defined as seizures involving the entire body, trunk, or head that led to a fall, injury, slumping in a chair, or the participant's head hitting a surface or that could have led to a fall or injury, depending on the patient's position at the time of the seizure. |
| Secondary | Part 1: Percent Change From Baseline in the Frequency of All Countable Motor Seizures in T+M in the ZX008 0.8 mg/kg/Day and 0.2 mg/kg/Day Groups Independently Versus Placebo | From Baseline up to 14 weeks [Titration Period (2 weeks) + Maintenance Period (12 weeks)] | Countable motor seizures included: GTC, SGTC, TS, AS, TA, clonic seizures \[CS\], hemiclonic seizures \[HS\], and focal seizures \[FS\] with clearly observable signs. |
| Secondary | Part 1: Change From Baseline in the Frequency of All Countable Non-motor Seizures in T+M in the ZX008 0.8 mg/kg/Day and 0.2 mg/kg/Day Groups Independently Versus Placebo | From Baseline up to 14 weeks [Titration Period (2 weeks) + Maintenance Period (12 weeks)] | Countable non-motor seizures included: focal seizures \[FS\] without clear observable signs, myoclonic seizures \[MS\], absence/atypical absence, infantile spasms, epileptic spasms, and other seizures. 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. |
| Secondary | Part 1: Percent Change From Baseline in the Frequency of All Countable Seizures (Motor and Non-motor) in T+M in the ZX008 0.8 mg/kg/Day and 0.2 mg/kg/Day Groups Independently Versus Placebo | From Baseline up to 14 weeks [Titration Period (2 weeks) + Maintenance Period (12 weeks)] | Countable motor seizures included: GTC, SGTC, TS, AS, TA, CS, HS, and FS with clearly observable signs. Countable non-motor seizures included: FS without clear observable signs, MS, absence/atypical absence, infantile spasms, epileptic spasms, and other seizures. |
1 to 10 of 45Source ClinicalTrials.gov
See all 45 registered outcomesOutcomes45
Each outcome the trial posted results for, in ClinicalTrials.gov's words.
| Type | Outcome | Time frame | Population | Units | Measured as |
|---|---|---|---|---|---|
| PRIMARY | Part 1: Percent Change From Baseline in the Frequency of Seizures That Result in Drops (ESC-confirmed) in the Combined Titration and Maintenance Period (T+M) in the ZX008 0.8 mg/kg/Day Group Compared to the Placebo Group | From Baseline up to 14 weeks [Titration Period (2 weeks) + Maintenance Period (12 weeks)] | The Modified Intent-to-Treat (mITT) Population included all randomized participants who received at least 1 dose of ZX008 or placebo and for whom at least 1 week of diary data were available. | percent change | MEDIAN |
| PRIMARY | Part 2: Percentage of Participants With Treatment-emergent Adverse Events (TEAEs) | From Part 2 Baseline until end of the OLE Period (up to 72 months) | The OLE Safety Population included all participants who received at least 1 dose of ZX008 during the OLE. As pre-specified in study design, participants in Part 2 received individualized optimized treatment (0.2 mg/kg/day to 0.8 mg/kg/day) based on Investigator discretion. Hence overall data for Part 2 is reported. | percentage of participants | NUMBER |
| PRIMARY | Part 2: Percentage of Participants With Serious TEAEs | From Part 2 Baseline until end of the OLE Period (up to 72 months) | The OLE Safety Population included all participants who received at least 1 dose of ZX008 during the OLE. As pre-specified in study design, participants in Part 2 received individualized optimized treatment (0.2 mg/kg/day to 0.8 mg/kg/day) based on Investigator discretion. Hence overall data for Part 2 is reported. | percentage of participants | NUMBER |
| SECONDARY | Part 1: Percent Change From Baseline in the Frequency of Seizures That Result in Drops (ESC-confirmed) in T+M in the ZX008 0.2 mg/kg/Day Group Compared to the Placebo Group | From Baseline up to 14 weeks [Titration Period (2 weeks) + Maintenance Period (12 weeks)] | The mITT population included all randomized participants who received at least 1 dose of ZX008 or placebo and for whom at least 1 week of diary data were available. | percent change | MEDIAN |
| SECONDARY | Part 1: Percentage of Participants Who Achieve a >=50% Reduction From Baseline in the Frequency of Seizures That Result in Drops Comparing the ZX008 0.8 mg/kg/Day and 0.2 mg/kg/Day Groups Independently Versus Placebo | From Baseline up to 14 weeks [Titration Period (2 weeks) + Maintenance Period (12 weeks)] | The mITT population included all randomized participants who received at least 1 dose of ZX008 or placebo and for whom at least 1 week of diary data were available. | percentage of participants | NUMBER |
| SECONDARY | Part 1: Percentage of Participants Who Achieve Improvement (Minimally, Much or Very Much Improved) in the CGI-I Scale as Assessed by Principal Investigator Comparing ZX008 0.8 and 0.2 mg/kg/Day Groups Independently Versus Placebo | At Day 99 (Visit 12) | The mITT population included all randomized participants who received at least 1 dose of ZX008 or placebo and for whom at least 1 week of diary data were available. Here, number of participants analyzed included those participants who were evaluable for the assessment. | percentage of participants | NUMBER |
| SECONDARY | Part 1: Percent Change From Baseline in Frequency of All Seizures That Typically Result in Drops in T+M, Whether ESC-confirmed as Drop or Not in the ZX008 0.8 mg/kg/Day and 0.2 mg/kg/Day Groups Independently Versus Placebo | From Baseline up to 14 weeks [Titration Period (2 weeks) + Maintenance Period (12 weeks)] | The mITT population included all randomized participants who received at least 1 dose of ZX008 or placebo and for whom at least 1 week of diary data were available. | percent change | MEDIAN |
| SECONDARY | Part 1: Percent Change From Baseline in the Frequency of All Countable Motor Seizures in T+M in the ZX008 0.8 mg/kg/Day and 0.2 mg/kg/Day Groups Independently Versus Placebo | From Baseline up to 14 weeks [Titration Period (2 weeks) + Maintenance Period (12 weeks)] | The mITT population included all randomized participants who received at least 1 dose of ZX008 or placebo and for whom at least 1 week of diary data were available. | percent change | MEDIAN |
| SECONDARY | Part 1: Change From Baseline in the Frequency of All Countable Non-motor Seizures in T+M in the ZX008 0.8 mg/kg/Day and 0.2 mg/kg/Day Groups Independently Versus Placebo | From Baseline up to 14 weeks [Titration Period (2 weeks) + Maintenance Period (12 weeks)] | The mITT population included all randomized participants who received at least 1 dose of ZX008 or placebo and for whom at least 1 week of diary data were available. | seizure frequency per 28 days | MEDIAN |
| SECONDARY | Part 1: Percent Change From Baseline in the Frequency of All Countable Seizures (Motor and Non-motor) in T+M in the ZX008 0.8 mg/kg/Day and 0.2 mg/kg/Day Groups Independently Versus Placebo | From Baseline up to 14 weeks [Titration Period (2 weeks) + Maintenance Period (12 weeks)] | The mITT population included all randomized participants who received at least 1 dose of ZX008 or placebo and for whom at least 1 week of diary data were available. | percent change | MEDIAN |
1 to 10 of 45Source ClinicalTrials.gov
See all 45 outcomesResults by group1,108
Each measurement the trial posted, group by group, in the words and numbers it posted.
| Outcome | Group | Category | Value | Spread | Units |
|---|---|---|---|---|---|
Part 1: Percent Change From Baseline in the Frequency of Seizures That Result in Drops (ESC-confirmed) in the Combined Titration and Maintenance Period (T+M) in the ZX008 0.8 mg/kg/Day Group Compared to the Placebo Group | Cohort A: Placebo | -7.59 | Full Range -100.0 to 557.1 | percent change | |
Part 1: Percent Change From Baseline in the Frequency of Seizures That Result in Drops (ESC-confirmed) in the Combined Titration and Maintenance Period (T+M) in the ZX008 0.8 mg/kg/Day Group Compared to the Placebo Group | Cohort A: ZX008 0.8 mg/kg/Day | -26.49 | Full Range -95.2 to 402.1 | percent change | |
Part 1: Percent Change From Baseline in the Frequency of Seizures That Result in Drops (ESC-confirmed) in the Combined Titration and Maintenance Period (T+M) in the ZX008 0.8 mg/kg/Day Group Compared to the Placebo Group | Cohort B: Placebo | -17.89 | Full Range -97.3 to 61.8 | percent change | |
Part 1: Percent Change From Baseline in the Frequency of Seizures That Result in Drops (ESC-confirmed) in the Combined Titration and Maintenance Period (T+M) in the ZX008 0.8 mg/kg/Day Group Compared to the Placebo Group | Cohort B: ZX008 0.8 mg/kg/Day | -34.52 | Full Range -69.4 to 45.5 | percent change | |
| Part 2: Percentage of Participants With Treatment-emergent Adverse Events (TEAEs) | Part 2: Cohort A- Overall | 83.0 | percentage of participants | ||
| Part 2: Percentage of Participants With Treatment-emergent Adverse Events (TEAEs) | Part 2: Cohort B- Overall | 96.9 | percentage of participants | ||
| Part 2: Percentage of Participants With Serious TEAEs | Part 2: Cohort A- Overall | 16.6 | percentage of participants | ||
| Part 2: Percentage of Participants With Serious TEAEs | Part 2: Cohort B- Overall | 18.8 | percentage of participants | ||
| Part 1: Percent Change From Baseline in the Frequency of Seizures That Result in Drops (ESC-confirmed) in T+M in the ZX008 0.2 mg/kg/Day Group Compared to the Placebo Group | Cohort A: Placebo | -7.59 | Full Range -100.0 to 557.1 | percent change | |
| Part 1: Percent Change From Baseline in the Frequency of Seizures That Result in Drops (ESC-confirmed) in T+M in the ZX008 0.2 mg/kg/Day Group Compared to the Placebo Group | Cohort A: ZX008 0.2 mg/kg/Day | -14.16 | Full Range -100.0 to 3307.3 | percent change |
1 to 10 of 1,108Source ClinicalTrials.gov
See all 1,108 results by groupParticipant flow36
How many started, completed or left each group, period by period.
| Period | Milestone | Group | Participants | Units counted |
|---|---|---|---|---|
| Part 1: Double-Blind Period | STARTED | Cohort A: Placebo | 87 | |
| Part 1: Double-Blind Period | STARTED | Cohort A: ZX008 0.2 mg/kg/Day | 89 | |
| Part 1: Double-Blind Period | STARTED | Cohort A: ZX008 0.8 mg/kg/Day | 87 | |
| Part 1: Double-Blind Period | STARTED | Cohort B: Placebo | 11 | |
| Part 1: Double-Blind Period | STARTED | Cohort B: ZX008 0.2 mg/kg/Day | 11 | |
| Part 1: Double-Blind Period | STARTED | Cohort B: ZX008 0.8 mg/kg/Day | 11 | |
| Part 1: Double-Blind Period | COMPLETED | Cohort A: Placebo | 86 | |
| Part 1: Double-Blind Period | COMPLETED | Cohort A: ZX008 0.2 mg/kg/Day | 83 | |
| Part 1: Double-Blind Period | COMPLETED | Cohort A: ZX008 0.8 mg/kg/Day | 81 | |
| Part 1: Double-Blind Period | COMPLETED | Cohort B: Placebo | 11 |
1 to 10 of 36Source ClinicalTrials.gov
See all 36 participant flowAdverse events848
Each adverse event the trial posted, group by group: the participants affected out of those at risk.
| Type | Event | Organ system | Group | Affected | At risk | Events |
|---|---|---|---|---|---|---|
| other | Mitral valve incompetence | Cardiac disorders | Part 1: Cohort A- Placebo | 0 | 87 | 0 |
| other | Mitral valve incompetence | Cardiac disorders | Part 1: Cohort A- ZX008 0.2 mg/kg/Day | 0 | 89 | 0 |
| other | Mitral valve incompetence | Cardiac disorders | Part 1: Cohort A- ZX008 0.8 mg/kg/Day | 0 | 87 | 0 |
| other | Mitral valve incompetence | Cardiac disorders | Part 2: Cohort A- Overall | 0 | 247 | 0 |
| other | Mitral valve incompetence | Cardiac disorders | Part 1: Cohort B- Placebo | 0 | 11 | 0 |
| other | Mitral valve incompetence | Cardiac disorders | Part 1: Cohort B- ZX008 0.2 mg/kg/Day | 1 | 11 | 1 |
| other | Mitral valve incompetence | Cardiac disorders | Part 1: Cohort B- ZX008 0.8 mg/kg/Day | 0 | 11 | 0 |
| other | Mitral valve incompetence | Cardiac disorders | Part 2: Cohort B- Overall | 0 | 32 | 0 |
| other | Hyperprolactinaemia | Endocrine disorders | Part 1: Cohort A- Placebo | 0 | 87 | 0 |
| other | Hyperprolactinaemia | Endocrine disorders | Part 1: Cohort A- ZX008 0.2 mg/kg/Day | 0 | 89 | 0 |
1 to 10 of 848Source ClinicalTrials.gov
See all 848 adverse eventsAdverse event totals24
The totals the trial posted for each group.
| Total | Group | Affected | At risk |
|---|---|---|---|
| Total, all-cause mortality | Part 1: Cohort A- Placebo | 0 | 87 |
| Total, all-cause mortality | Part 1: Cohort A- ZX008 0.2 mg/kg/Day | 0 | 89 |
| Total, all-cause mortality | Part 1: Cohort A- ZX008 0.8 mg/kg/Day | 1 | 87 |
| Total, all-cause mortality | Part 2: Cohort A- Overall | 1 | 247 |
| Total, all-cause mortality | Part 1: Cohort B- Placebo | 0 | 11 |
| Total, all-cause mortality | Part 1: Cohort B- ZX008 0.2 mg/kg/Day | 0 | 11 |
| Total, all-cause mortality | Part 1: Cohort B- ZX008 0.8 mg/kg/Day | 0 | 11 |
| Total, all-cause mortality | Part 2: Cohort B- Overall | 0 | 32 |
| Total, other adverse events | Part 1: Cohort A- Placebo | 60 | 87 |
| Total, other adverse events | Part 1: Cohort A- ZX008 0.2 mg/kg/Day | 64 | 89 |
1 to 10 of 24Source ClinicalTrials.gov
See all 24 adverse event totalsPapers1
The papers the trial lists on ClinicalTrials.gov.
| PMID | Listed as |
|---|---|
| 35499850 | DERIVED |
Source PubMed
Grants0
The grants NIH RePORTER links to the trial, newest funded first: NIH's, and some of AHRQ's, CDC's, FDA's and VA's. Each shows its title, principal investigators, organization and funder in its newest year.
None in this release.
Trial comparisons0
Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.
None in this release.
Tests0
The ConductCognition tests this trial's registered outcomes name, as ScienceGraph matched them in trial-tests-2026-11-12-0.2.1.
None in this release.
Data dates
The day each source was copied for this release.
Sources 3
- ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
- ClinicalTrials.govNo license stated
- NIH RePORTER's clinical studies and project filesPublic domain
Each source's terms
- ClinicalTrials.gov's posted results, through CTTI's AACTClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299
- ClinicalTrials.govnone stated
- NIH RePORTER's clinical studies and project filesPublic domain (NIH RePORTER)
ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.
For software
Read this trial from software.
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GET https://conductscience.org/api/trials/v1/NCT03355209
GET https://conductscience.org/api/trials/v1/NCT03355209/registered?page=2