Phase 3 Trial of Low-Dose Fenfluramine for Lennox-Gastaut Syndrome Is Enrolling Patients
In a phase 2 open-label study of the orphan drug fenfluramine (ZX008; Zogenix, Emeryville, CA) for treatment of patients with Lennox-Gastaut Syndrome (LGS) refractory to treatment, the majority of patients who took low-dose fenfluramine sustained clinically meaningful seizure reduction and tolerated the medicine well. In this 20-week core study and long-term extension option for responders to treatment, patients started on a dose of .2 mg/kg/day of fenfluramine twice per day. Those who responded with >50% reduction in seizures maintained this dose; other subjects had their dose titrated up to .8 mg/kg/day over a 4-week period.
The 13 patients enrolled had baseline median seizure frequency of 61 per month (range: 21-1360) with multiple seizure types and achieved a 53% median reduction in convulsive seizure frequency during the 20-week treatment period of the core study. After 15 months in the long-term extension study (n=9), patients achieved a 58% median reduction in convulsive seizure frequency (Epilepsia. 2018;00:1-8).
“The compelling results of this study supported commencing a global Phase 3 pivotal trial to evaluate the efficacy and safety of ZX008 for the treatment of seizures associated with LGS,” said Bradley S. Galer, MD, Executive Vice-President and Chief Medical Officer at Zogenix. “We are especially pleased with the long-term robustness of seizure control given the highly refractory nature of these patients. We believe the publication of these data underscores the significance of these findings for this patient population with a major unmet medical need.”
A phase 3 trial (NCT03355209) is currently enrolling at sites in North America, Europe and Australia.