- Zogenix will apply for Food and Drug Administration approval of its Dravet syndrome drug Fintepla by the end of September, the company said Thursday after meeting with regulators.
- The FDA had issued a "refuse to file" letter to Zogenix in April, pointing to an incorrect data table and arguing that the company needed to conduct a non-clinical toxicology study. The company said today that regulators will accept the submission with corrected data, and will not require the toxicology study.
- Zogenix shares rose 21% to $47.65 apiece following the news, taking them near to their levels before the initial FDA rejection.
An FDA rejection can set back an experimental drug by years, and for a company without any commercial product it is a devastating event. Because the agency's initial rejection of Fintepla (fenfluramine) raised the need for additional chronic toxicity studies, analysts assumed it might be another 12 to 15 months before Zogenix could resubmit its application.
Notably, fenfluramine was part of the now-banned Fen-Phen weight-loss combination, which was linked to heart-valve disease. Stifel analyst Paul Matteis said Zogenix executives pointed to extensive animal toxicology data in medical journals as one reason additional work may not need to be done for this submission.
Zogenix executives said they have begun conducting chronic animal toxicology studies to bolster the data package, even though the FDA no longer will require them.
Meanwhile, the FDA is satisfied with Zogenix's plan to resubmit its application with the corrected version of the data at the center of the refuse-to-file letter, according to the company.
Less positive news, however, is that the agency has withdrawn its Breakthrough Therapy designation for Fintepla because two products are now on the market for Dravet syndrome: GW Pharma's Epidiolex (cannabidiol) and Biocodex's Diacomit (stiripentol).
Loss of the designation may not affect Fintepla's timeline because it also has Priority Review status with the agency, which requires an approval decision within six months.
Epidiolex had sales of $4.7 million in 2018 following its November approval and $33.5 million in the first quarter of 2019.
Should the drug be approved, SVB Leerink analyst Marc Goodman forecasts $1.1 billion in eventual peak sales for Fintepla in Dravet syndrome and the related Lennox-Gastaut syndrome.