Zogenix Reports Positive Results in Late-Stage Study of Therapy for Rare Epilepsy

Rare Daily Staff

Zogenix reported positive top-line results from its first late-stage study of its experimental drug ZX008 for the treatment of Dravet syndrome, a rare form of epilepsy.

The Emeryville, California-based company said ZX008 at a dose of 0.8 mg/kg/day met its primary endpoint of being 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.

ZX008 also demonstrated 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 lower dose of 0.2 mg/kg/day of ZX008 versus placebo also demonstrated statistically significant improvement compared with placebo.

“Dravet syndrome is a rare, but catastrophic form of epilepsy that can be devastating for patients and their families,” said Joseph Sullivan, director of the Pediatric Epilepsy Center in UCSF Benioff Children’s Hospital San Francisco, and Principal Investigator of the study in the United States. He said the results demonstrate “impressive efficacy” of ZX008 and that it “could play an important role in treating this devastating condition.”

The randomized, double blind, placebo controlled, late-stage study enrolled 119 patients across sites in the United States, Canada, Europe, and Australia. The median age of patients was 8 years (range, 2-18 years). Following a six-week baseline observation period, patients were randomized to one of three treatment groups: 0.8 mg/kg/day, 0.2 mg/kg/day, or placebo

The study found ZX008 was generally well-tolerated. The incidence of treatment emergent adverse events was higher in the treatment groups as compared to the placebo group, with 95 percent of patients in the 0.8mg/kg/day group and 94.9 percent of patients in the 0.2 mg/kg/day group experiencing at least one treatment emergent adverse event compared to 65 percent of patients in the placebo group. Five patients in the 0.8 mg/kg/day group had an adverse event leading to study discontinuation compared to none in the other treatment groups.

ZX008 is designated as an orphan drug in both the United States and Europe, and has received Fast Track designation in the United States for the treatment of Dravet syndrome.

Zogenix is conducting a second double-blind, randomized, two-arm pivotal late-stage tria in which all patients will be taking stiripentol, valproate, and clobazam as part of their baseline standard care. The company expects to have topline results from that study in the first half of 2018. It said it is on track to submit applications for regulatory approvals in the United States and Europe in the second half of 2018.

September 29, 2017