Zogenix Announces New Efficacy Data from Long-Term Study of Low-Dose Fenfluramine for Treatment of Dravet Syndrome

Zogenix, Inc. ZGNX, a pharmaceutical company developing and commercializing unique therapies for the treatment of central nervous system (CNS) disorders, today announced new data demonstrating sustained efficacy and tolerability for patients treated with low-dose fenfluramine as an adjunctive therapy for Dravet syndrome. The data was authored by world-renown experts in the field of Dravet syndrome, Berten Ceulemans, M.D., Ph.D. and Lieven Lagae, M.D., Ph.D., from the Universities of Antwerp and Leuven in Belgium, and was presented at the European Paediatric Neurology Society meeting taking place this week in Vienna, Austria (see study data here). Zogenix intends to initiate Phase 3 clinical studies for ZX008, the Company's investigational proprietary pediatric formulation of low-dose fenfluramine, during the second half of 2015. ZX008 is designated as an orphan drug in both the U.S. and Europe for the treatment of Dravet syndrome. Clinical Efficacy Data Patients with Dravet syndrome experience frequent, severe and potentially life-threatening seizures that typically start in the first year of life. These seizures do not respond to standard anti-epileptic medications and current treatment options are very limited. "The most important element of treating patients with Dravet syndrome is to reduce the frequency of all seizures and to prevent status epilepticus, which is a continuous state of seizure," said Prof. Berten Ceulemans. "As this most recent data analysis demonstrates, in our experience, we have been able to achieve major seizure control for Dravet syndrome patients using a low-dosage form of fenfluramine as adjunctive therapy. It is my hope that these outcomes will be replicated in the Phase 3 program to be undertaken by Zogenix." "We continue to be encouraged by the results of the ongoing open-label study of the use of low-dose fenfluramine in patients with Dravet syndrome. It is very exciting to observe a reduction of greater than or equal to 75% in seizure frequency for at least 80% of patients over the latest 5-year follow-up period with the use of fenfluramine as an add-on treatment. In addition, there continues to be a majority of Dravet patients who experience sustained periods of seizure-freedom. We believe these data represent the most robust, long-term data set of any investigational treatment for Dravet syndrome, especially since some of these patients have been treated for well over 20 years," said Stephen Farr, Ph.D., Chief Executive Officer of Zogenix. Farr continued, "Our current focus is to finalize the Phase 3 study protocol, based on recent feedback received from the U.S. Food and Drug Administration, and initiate the studies of ZX008 in the U.S. and Europe." The results presented are from the latest 5-year follow-up period (2010-2014) in a group of Dravet syndrome patients being treated with low-dose fenfluramine (10 mg to 20 mg per day). This analysis, which includes ten patients from the original study group (as published in 20121) and two patients who began treatment in 2011, demonstrated that during any given year of the follow-up period, at least 80% of patients achieved a greater than or equal to 75% reduction in the frequency of seizures. In addition, three patients (25%) were seizure-free for all 5 years and five patients (42%) were seizure-free for 2 to 4 years. The use of low-dose fenfluramine in this group of patients was shown to be generally well tolerated, with the most common adverse events being transient loss of appetite and fatigue/somnolence. No clinically meaningful cardiac adverse events were noted. No patient discontinued treatment due to adverse events. In addition, a recently published translational research study2 to elucidate fenfluramine's mechanism of action in Dravet syndrome demonstrated the ability of fenfluramine to significantly reduce locomotion and eliminate epileptiform EEG activity in a gene knockdown zebrafish model of Dravet syndrome. These data support the clinical results obtained in the Belgium cohort of patients.