Zogenix on Monday announced the receipt of a refuse-to-file letter from the FDA regarding its filing seeking approval of Fintepla (fenfluramine) for the treatment of seizures associated with Dravet syndrome, sending shares in the company down more than 30 percent. The drugmaker indicated that it will seek immediate guidance and respond to the issues identified by the FDA. Zogenix CEO Stephen Farr stated "we remain highly confident in Fintepla's clinical profile demonstrated in the Phase III programme in Dravet syndrome and are committed to advancing the product candidate as a potential new treatment option for this and other rare and often catastrophic epileptic encephalopathies."
In its preliminary review, the FDA found that Zogenix's filing was not sufficiently complete to allow a substantial review. Specifically, the agency stated that the absence of certain non-clinical studies from the filing would prevent an assessment of chronic Fintepla administration. In addition, the FDA noted that the submission included an incorrect version of a clinical dataset, precluding the completion of the review process.
Zogenix noted that the FDA has not asked to conduct additional clinical efficacy or safety studies. In trial results unveiled in 2017, Fintepla, also known as ZX008, was shown to significantly reduce seizure frequency versus placebo.
The company indicated that its European filing seeking authorisation of Fintepla for the treatment of seizures associated with Dravet syndrome was previously accepted by the European Medicines Agency, with a decision expected by the first quarter of next year.
Meanwhile, the news comes after Zogenix inked a deal granting Nippon Shinyaku exclusive commercialisation rights to Fintepla in Japan.
