Treatment of Sunflower Syndrome With ZX008 (Fenfluramine Hydrochloride) in Children and Young Adults (Ages 4-25).

Summary

Sunflower Syndrome (also referred to as Self-induced Photosensitive Epilepsy) is a rare epileptic disorder characterized by a distinctive seizure that manifests itself in a highly stereotyped physical behavior. Seizure types associated with Sunflower Syndrome include absence seizures and generalized tonic-clonic seizures. Individuals with Sunflower Syndrome obsessively seek out a light source, stare at the light source, and wave one hand in front of their eye(s). Electroencephalogram (EEG) features include generalized spike and wave discharges interictally, and typically strong photoparoxysmal response during photic stimulation.

Currently, Sunflower syndrome is poorly characterized in medical literature and is often misunderstood at the clinical level. The name self-induced photosensitive epilepsy may be a misnomer as research concerning the neurochemical and neuropsychological pathways cannot conclusively determine that it is self-induced (conscious behavior) as the name implies. Although some reports have concluded that the hand waiving induces the seizure, these findings are not consistent throughout scientific literature. In fact, an EEG report found that the seizures can begin simultaneously with the hand waving. This suggests that the hand waving may in fact be part of the seizure, not the cause.

There are no treatments specifically approved for the treatment of Sunflower Syndrome in the United States. Broad spectrum anticonvulsant medications, including sodium valproate, lamotrigine, levetiracetam, and clobazam, have not shown full efficacy in seizure prevention in patients with Sunflower Syndrome. Accordingly, there remains a significant unmet need for an approved treatment for children and adults with Sunflower Syndrome.

Because this epilepsy typically does not respond to anticonvulsant medications, and because Aicardi described the successful treatment with fenfluramine of at least one child with this syndrome, the investigators of this study will investigate if fenfluramine is an effective, safe and well tolerated treatment for Sunflower Syndrome.

The primary objective of this study is to determine the efficacy of ZX008 on seizure frequency in children and young adults with Sunflower Syndrome. The goal of treatment is to provide a 30 percent or greater reduction of generalized tonic-clonic seizures and/or hand waving associated with absence seizures.

Secondary objectives of the study include evaluation of the effect of ZX008 (fenfluramine hydrochloride) on EEG patterns and quality of life. Patients with Sunflower Syndrome often experience low self-esteem, bullying due to the unusual motor movements associated with their seizures, school performance issues, anxiety, and depression.

The study population will include pediatric and young adult patients seen by Elizabeth A. Thiele, M.D., Ph.D. at MGH's Pediatric Epilepsy Clinic who were identified as candidates. The Principal Investigator (PI) will follow up to 20 patients with Sunflower Syndrome who will be taking ZX008.

Conditions

• Photosensitive Epilepsy

Interventions

DRUG

Fenfluramine Hydrochloride

Fenfluramine Hydrochloride will be supplied to the treatment group as an oral solution in a concentration of 2.5 mg/mL. Subjects will receive their daily dose of Fenfluramine Hydrochloride in two doses (one in the morning and one in the evening). After a four week baseline, subjects that meet enrollment criteria will enter a titration period. The starting dose will be 0.2 mg/kg/day for the first 14 days. The dose will be increased every 2 weeks as tolerated by 0.2 mg/kg/day, to a maximum dose of 0.7 mg/kg/day, or a total maximum dose of 26 mg/day. The subject will remain on a dose of 0.7 mg/kg/day, 26 mg/day, or maximum tolerated daily dose through the end of the core study period.

Sponsors & Collaborators

• Zogenix International Limited, Inc., a subsidiary of Zogenix, Inc.

  collaborator INDUSTRY

• Elizabeth Anne Thiele

  lead OTHER

Principal Investigators

• Elizabeth Thiele, M.D., Ph.D. · Director, Pediatric Epilepsy Program

Study Design

Allocation

NA

Purpose

TREATMENT

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

4 Years

Max Age

25 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2019-05-31

Primary Completion

2021-11-25

Completion

2024-07-19

FDA Drug

Yes

Countries

• United States

Study Locations