Zogenix, Inc. announced that the last patient has been randomized into the treatment period of Study 1504, its second Phase 3 clinical trial evaluating ZX008 (low-dose fenfluramine) as an adjunctive treatment for seizures in children and young adults with Dravet syndrome. Previously, in the third quarter of 2017, the Company announced positive top-line data from its first global Phase 3 trial of ZX008, Study 1, that met the primary efficacy endpoint, as well as all prespecified key secondary efficacy endpoints. Study 1504 is a double-blind, randomized, two arm Phase 3 trial with approximately 40 subjects per treatment group being conducted in the U.S., France, Spain, the Netherlands, U.K., Canada, and Germany, in which all subjects are taking stiripentol as part of their baseline standard of care. Randomized subjects are titrated to an active dose of 0.5 mg/kg/day ZX008 (maximum of 20 mg/day) or placebo, over three weeks and then held at that fixed dose for 12 weeks of maintenance treatment. The study dose of ZX008 accounts for the established drug-drug interaction between stiripentol and ZX008 and provides the same systemic exposure of ZX008 as the dose of 0.8 mg/kg/day (maximum 30 mg/day) previously evaluated in Study 1, where concomitant use of stiripentol was excluded. As in Study 1, the primary efficacy measure in Study 1504 is a comparison of the change in monthly convulsive seizure frequency between ZX008 and placebo during the treatment period compared with the baseline observation period. Study 1 results were announced in fall 2017. The trial met its primary objective of demonstrating that ZX008, at a dose of 0.8 mg/kg/day, is superior to placebo as adjunctive therapy in the treatment of Dravet syndrome in children and young adults based on change in the frequency of convulsive seizures between the 6-week baseline observation period and the 14-week treatment period (p<0.001). ZX008 0.8 mg/kg/day also achieved statistically significant improvements versus placebo in all key secondary measures, including the proportion of patients with clinically meaningful reductions in seizure frequency and longest seizure-free interval. The same analyses comparing a 0.2 mg/kg/day ZX008 dose versus placebo also demonstrated significant improvement compared with placebo. Both doses of ZX008 were safe and well-tolerated during the study, and most adverse events were mild or moderate in severity, and consistent with the known profile of the compound. ZX008 is designated as an orphan drug in both the U.S. and Europe, and has received Fast Track designation in the U.S. for the treatment of Dravet syndrome. ZX008 is an investigational treatment and is not approved for use in any country.