Zogenix Epilepsy Data Sets Up Market Battle With GW’s Cannabis Drug

Xconomy San Francisco — 

Just weeks ago, the FDA approved the first ever medicine made from a derivative of marijuana, a drug from GW Pharmaceuticals for a rare form of epilepsy. Yet competition already looms from Zogenix, thanks to new data the Emeryville, CA, company reports this morning.

Zogenix (NASDAQ: ZGNX) said that its experimental drug ZX008 succeeded in the second of two Phase 3 trials in patients with Dravet Syndrome. The 43 patients on ZX008 had an average of 54.7 percent fewer convulsive seizures, per month, than the 44 on a placebo. The median reduction in seizures per month for ZX008 was 62.7 percent for ZX008 patients, compared to a 1.2 percent median reduction for placebo patients. Patients had an average of 25 seizures per month before the study. Those who got ZX007 were on a fixed dose of the Zogenix drug for at least 12 weeks and then evaluated.

The drug also met two key secondary study measures. Zogenix reported 53.5 percent of patients treated with ZX008 had at least 50 percent fewer seizures per month, compared to 6.8 percent of placebo patients. Those on the Zogenix drug had a median of 22 days without a seizure, compared to a median of 13 days for placebo patients.

Zogenix shares surged about 21 percent in pre-market trading Thursday morning.

ZX008 is a low dose form of the appetite suppressant fenfluramine, which was famously part of the “Fen-Phen” weight loss drug combination that was pulled from the U.S. and other markets in the 1990s due to an association with heart problems and other issues like pulmonary hypertension. Importantly, in both Zogenix Phase 3 studies, no patients had pulmonary hypertension or cardiac side effects. (Zogenix reported positive results from the first Phase 3 trial in September.)

The most common side effects seen were low appetite, diarrhea, fatigue, colds, and fever. The rates of these side effects were similar between placebo and ZX008 patients.

Dravet Syndrome is a rare disease that affects an estimated one in every 15,700 babies born in the U.S., according to the nonprofit Dravet Syndrome Foundation. The disease starts in infancy and is characterized by severe, long-lasting seizures that can cause cognitive impairment, developmental delays and other problems. The seizures can be fatal. Several drugs are used to try to prevent seizures or rescue patients from them when they happen, but they don’t work for everyone. The Epilepsy Foundation of Greater Chicago reports, for instance, that 20 percent of all epilepsy patients don’t respond to current medications.

On June 25, the FDA approved cannabidiol (Epidiolex) from GW Pharmaceuticals (NASDAQ: GWPH) for both Dravet Syndrome and Lennox-Gastaut Syndrome, another rare type of epilepsy. It was the first-ever approved marijuana derivative, and the first treatment ever approved specifically for Dravet patients. It is meant to be used by patients two years and older who don’t respond to other drugs.

ZX008 could be next. Zogenix said it aims to file for approval in the U.S. and Europe later this year. GW Pharma shares dipped about 4 percent Thursday morning.