Fintepla Led to ‘Profound’ Reduction in Seizure Frequency in Young Dravet Patients, Extension Study Shows
Study findings were presented by Zogenix, the therapy’s developer, in a poster titled “Long-Term (2-Year) Safety and Efficacy of Adjunctive ZX008 (Fenfluramine HCl) for Dravet Syndrome: Interim Results of an Ongoing Open-Label Extension Study,” at the Child Neurology Society and International Child Neurology Congress (CNS/ICNA) 2020.
Fintepla, formerly known as ZX008, is an oral solution of low-dose fenfluramine hydrochloride; it is currently approved in the U.S. as an anti-seizure therapy to treat people with Dravet age 2 and older.
Although its exact mechanism of action is still being investigated, Fintepla has been shown to reduce the frequency of seizures in children and adolescents with Dravet in three Phase 3 clinical trials (NCT02682927, NCT02826863, and NCT02926898), all of which were sponsored by Zogenix.
Patients who completed these placebo-controlled trials were allowed to enroll in an open-label extension study (NCT02823145) to continue treatment with Fintepla for up to three years. For the first month of the study, Fintepla was administered at a stable daily dose of 0.2 mg/kg. In the following months, the therapy was given at a flexible daily dose of up to 0.7 mg/kg.
Zogenix now presented updated, two-year interim data from the extension study. As of February 2019 — the cut-off date for the analysis — a total of 330 people had enrolled in the extension study.
Participants had a mean age of 9, were mostly white (74.2%), and more than half (54.5%) were males. At the time of this analysis, patients had been receiving Fintepla for a median of 445 days (about one year and three months).
Over this period of time, the average number of convulsive seizures participants experienced in a month dropped by a median of 63% — a statistically significant decrease relative to the seizure frequency observed before treatment.
“In addition to the significant convulsive seizure reductions seen in all three multi-national Phase 3 studies of Fintepla in Dravet syndrome, we are proud to collaborate with expert clinician investigators to show the durability of the clinically meaningful seizure reduction that Fintepla provided for patients treated for up to two years,” Bradley S. Galer, MD, said in a press release. Galer is executive vice president and chief medical officer at Zogenix.
Most trial participants (61.7%) experienced a clinically meaningful decrease in seizure frequency, defined as a decrease of at least 50% since the study’s start (baseline). More than a third (37.1%) experienced a decrease in seizure frequency of 75% or higher since baseline, which was deemed “profound.”
“For every two to three patients treated with Fintepla, one patient achieved [more than] 75% (profound) convulsive seizure reduction,” Galer said.
Safety analyses showed Fintepla was well-tolerated. The most common adverse side effects included fever, the common cold, decreased appetite, and diarrhea. None of the trial participants developed heart problems or pulmonary arterial hypertension.
“We believe these new data analyses further showcase the clinical value that Fintepla provides for many Dravet syndrome patients and their families,” Galer said.