Zogenix Soars on Late-Stage Trial of Dravet Syndrome Drug

The final trading day of September 2017 is a memorable one for drugmaker Zogenix, Inc. (NASDAQ: ZGNX) following the release of positive top-line data from the Emeryville, California-based company’s phase 3 clinical trial of ZX008 for boys with Dravet syndrome, a rare type of epilepsy characterized by frequent and/or prolonged seizures that usually presents in the first year of life. Currently, there are very few treatment options for the disease, with patients requiring constant care.

Zogenix has provided a glimpse of hope by meeting the primary endpoint in the trial of ZX008, a low-dose fenfluramine liquid solution, by demonstrating a dose of 0.8 mg/kg daily is superior to placebo after 14 weeks of treatment as adjunctive therapy in controlling seizures for children and young adults with Dravets. The drug also met all the important secondary endpoints, touching on things like reducing seizure frequency and improving seizure-free intervals.

A lower dose of 0.2 mg/kg of ZX008 daily also showed a statistically meaningful improvement versus placebo.

The trial enrolled 119 patients across the U.S., Canada, Australia and Europe, with the median age of eight years. Patients were randomized to receive one of the two doses of ZX008 in addition to their standard of care antiepileptic drugs or the antiepileptic drug plus placebo.

Patients taking the higher dose of ZX008 saw their mean monthly seizures reduced by 63.9% compared to baseline established before initiating therapy versus those in the placebo arm. Median seizure frequency each month dropped 72.4%, compared to 17.4% for those on placebo.

Zogenix said that adverse events aligned with the established safety profile of fenfluramine and that the incidence of serious adverse events was comparable across all three treatment groups.

As the company looks ahead to data from a second phase 3 study, expected in the first half of 2018, management believes it remains on track to seek commercialization of the drug in the U.S. and Europe in the second half of next year.

Shares of ZGNX ballooned three-fold at one point during pre-market activity. During market hours, the stock is up 116.3% at $27.85 about 90 minutes into the session, making it the top performing NASDAQ-listed stock.