A Trial of Two Fixed Doses of ZX008 (Fenfluramine HCl) in Children and Young Adults With Dravet Syndrome

Summary

Study 1 and Study 3 are the prospective, merged analyses of 2 identical double-blind, placebo-controlled studies, ZX008-1501 and ZX008-1502, to assess the efficacy, safety, and pharmacokinetics of ZX008 when used as adjunctive therapy in pediatric and young adult subjects with Dravet syndrome. Study 1501 and Study 1502 were conducted in parallel; Study 1501 was conducted at approximately 30 study sites in North America; Study 1502 was conducted at approximately 30 study sites in Europe, Asia and Australia. Upon completion of the Baseline Period after initial Screening and Baseline charting of seizure frequency, subjects who qualified for the studies were randomized (1:1:1) in a double-blind manner to receive either 1 of 2 doses of ZX008 (0.2 mg/kg/day or 0.8 mg/kg/day; maximum dose: 30 mg/day) or placebo. Randomization was stratified by age group (\< 6 years, ≥6 to 18 years) to achieve balance across treatment arms, with the target of 25% of subjects in each age group. All subjects were titrated to their randomized dose over a 14-day Titration Period. Following titration, subjects continued treatment at their randomly assigned dose over a 12-week Maintenance Period. Subjects exiting the study underwent a 2-week taper, unless they enrolled in a follow-on study. Subjects were followed for post-study safety monitoring.

Timeline

Start

2016-01-15

Primary completion

2020-07-29

Completion

2020-07-29

Publications

• Results Sullivan J, Lagae L, Cross JH, Devinsky O, Guerrini R, Knupp KG, Laux L, Nikanorova M, Polster T, Talwar D, Ceulemans B, Nabbout R, Farfel GM, Galer BS, Gammaitoni AR, Lock M, Agarwal A, Scheffer IE; FAiRE DS Study Group. Fenfluramine in the treatment of Dravet syndrome: Results of a third randomized, placebo-controlled clinical trial. Epilepsia. 2023 Oct;64(10):2653-2666. doi: 10.1111/epi.17737. Epub 2023 Aug 17.
• Cross JH, Galer BS, Gil-Nagel A, Devinsky O, Ceulemans B, Lagae L, Schoonjans AS, Donner E, Wirrell E, Kothare S, Agarwal A, Lock M, Gammaitoni AR. Impact of fenfluramine on the expected SUDEP mortality rates in patients with Dravet syndrome. Seizure. 2021 Dec;93:154-159. doi: 10.1016/j.seizure.2021.10.024. Epub 2021 Nov 2.
• Sullivan J, Specchio N, Devinsky O, Auvin S, Perry MS, Strzelczyk A, Gil-Nagel A, Dai D, Galer BS, Gammaitoni AR. Fenfluramine significantly reduces day-to-day seizure burden by increasing number of seizure-free days and time between seizures in patients with Dravet syndrome: A time-to-event analysis. Epilepsia. 2022 Jan;63(1):130-138. doi: 10.1111/epi.17106. Epub 2021 Oct 22.
• Sullivan J, Perry MS, Wheless JW, Galer B, Gammaitoni A. Fenfluramine responder analyses and numbers needed to treat: Translating epilepsy trial data into clinical practice. Eur J Paediatr Neurol. 2021 Mar;31:10-14. doi: 10.1016/j.ejpn.2021.01.005. Epub 2021 Jan 22.
• Lagae L, Sullivan J, Knupp K, Laux L, Polster T, Nikanorova M, Devinsky O, Cross JH, Guerrini R, Talwar D, Miller I, Farfel G, Galer BS, Gammaitoni A, Mistry A, Morrison G, Lock M, Agarwal A, Lai WW, Ceulemans B; FAiRE DS Study Group. Fenfluramine hydrochloride for the treatment of seizures in Dravet syndrome: a randomised, double-blind, placebo-controlled trial. Lancet. 2019 Dec 21;394(10216):2243-2254. doi: 10.1016/S0140-6736(19)32500-0. Epub 2019 Dec 17.

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