FDA Rejects Regulatory Filing For Zogenix Epilepsy Drug; GW Pharma Moves In Sympathy

Zogenix, Inc. ZGNX, which develops therapies for rare diseases, said Monday afternoon the FDA issued a refusal to file letter regarding its NDA for Fintepla, chemically fenfluramine hydrochloride, which is being evaluated for the treatment of seizures associated with Dravet syndrome.

The FDA determined the NDA wasn't sufficiently complete to permit a substantive review, primarily due to two reasons: non-submission of certain non-clinical studies for assessing chronic administration of the pipeline asset and an incorrect version of a clinical dataset, which prevented the completion of the review process required to support the filing.

Why It's Important

Fintepla, previously codenamed ZX008, is Zogenix's lead asset and was touted to be a multi-billion-dollar opportunity for the company. The adverse development suggests a serious setback to the small-cap biotech.

Bank of America analyst Tazeen Ahmad said last September ZX008's worldwide, risk-adjusted peak sales is estimated to be $1.5 billion in 2029, comprising a $604-million opportunity in Dravet syndrome, $503 million in Lennox-Gastaut syndrome and $386 million in other pediatric epilepsy conditions.

What's Next

Zogenix will seek immediate guidance, including a Type A meeting with the FDA to clarify and respond to the issues.

"We remain highly confident in FINTEPLA's clinical profile demonstrated in the Phase 3 program 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," said Zogenix CEO Stephen Farr.

The company expects an approvability decision from the European Medicines Agency in the first quarter of 2020. It has a Marketing Authorization Approval pending before the agency for the same indication.

Zogenix stock slumped 27.21 percent to $37.74 early Tuesday morning.

GW Pharmaceuticals PLC- ADR GWPH is moving in sympathy. GW Pharma, which markets Epidiolex for treating Dravet syndrome, was trading up up 4.15 percent to $174.5 per share.

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