Zogenix said the FDA determined that the NDA, which was submitted in February, was not “sufficiently complete to permit a substantive review.”
Shares of California-based Zogenix have plunged more than 30 percent in premarket trading after the company announced late Monday that the U.S. Food and Drug Administration (FDA) has refused to accept the company’s New Drug Application (NDA) for the epilepsy medication, Fintepla (fenfluramine hydrochloride)
The FDA issued a Refusal to File letter for the medication aimed at treating seizures associated with Dravet syndrome. Also known as Severe Myoclonic Epilepsy of Infancy, Dravet Syndrome is a rare form of epilepsy that is characterized by frequent and prolonged seizures.
In a brief announcement, Zogenix said the FDA determined that the NDA, which was submitted in February, was not “sufficiently complete to permit a substantive review.” The FDA cited two primary reasons for refusing to accept the NDA. The first reason regarded non-clinical studies that were not submitted to allow assessment of the chronic administration of fenfluramine, the active ingredient in Fintepla. The second reason cited, according to the Zogenix announcement, is the application contained an “incorrect version of a clinical dataset, which prevented the completion of the review process that is necessary to support the filing of the NDA.”
Zogenix said that the FDA did not request any additional clinical studies in its RTF and plans to seek a Type A meeting with the regulatory agency in order to clarify the issues and address them accordingly.
Stephen J. Farr, president and chief executive officer of Zogenix, said the company remains “highly confident” in the clinical profile that Fintepla achieved in its Phase III study. He said the company is committed to advancing the medication as a potential treatment for the rare “and often catastrophic epileptic encephalopathies.”
“We are fully committed to working with the FDA as quickly as possible to address the open issues and clarify the path to successfully re-filing our application,” Farr said in a statement.
Fintepla, previously known as ZX008, has successfully cleared two Phase III studies. In 2017, ZX008, a low-dose of fenfluramine hydrochloride, was able to reduce the frequency of convulsive seizures in trial patients. In that trial, ZX008 proved superior to placebo as an adjunctive therapy based on change in the frequency of convulsive seizures between the 6-week baseline observation period and the 14-week treatment period. Patients in the trial experienced approximately 40 seizures per month. The results of a second Phase III trial completed in July 2018 were similar to the first. The second trial showed that patients receiving the drug had a 54.7 percent greater decrease in mean monthly convulsive seizures compared to those taking placebo.
Over the course of its development, Fintepla has received orphan drug designation in both the U.S. and Europe. Also, Fintepla received Breakthrough Therapy designation for Dravet syndrome from the FDA.
While Zogenix was hit with the setback of the RTF and the significant decline in stock prices, a drop from Monday’s close of $51.85 to $38.30 in early trading, rival Dravet syndrome drugmaker GW Pharmaceuticals has seen a bump in its stock this morning. Shares of GW, which won approval in 2018 for Epidiolex, a cannabis-based epilepsy drug approved for treatment of Dravet and Lennox-Gastaut syndrome.
While Zogenix must now wait for potential approval in the U.S., the company anticipates regulatory action for Fintepla in Europe in the first quarter of 2020.
