- The Food and Drug Administration has approved Fintepla, a drug developed by Zogenix that's meant to reduce the frequency of seizures in patients with a rare, chronic form of epilepsy called Dravet syndrome.
- Fintepla is now cleared for use in Dravet patients two years or older, and has been shown to help patients within three to four weeks of starting treatment. But the approval comes with a boxed warning about the risk of possible heart issues, and the drug's label requires patient monitoring.
- The approval marks the end of a tumultuous year-plus ride for Zogenix, during which the FDA initially refused its application and then delayed its decision on approval twice. Fintepla will compete with several drugs, among them GW Pharmaceuticals' Epidiolex, which in 2018 became the first-ever cannabis-based drug cleared for use in the U.S.
Zogenix can rest easier with Fintepla's approval, a decision that was by no means certain.
The FDA cleared the drug on the night of its June 25 deadline, and did so after first rejecting a Fintepla application in 2019, citing two problems with the filing. Two subsequent delays further pushed back the FDA's consideration of Zogenix's resubmitted application.
In the meantime, a study of Fintepla in another rare epilepsy, Lennox-Gastaut syndrome, though positive, fell short of expectations. At roughly less than $30 apiece, Zogenix shares are worth half what they were in February.
Dravet syndrome affects one out of every 15,700 babies born in the U.S., according to the nonprofit Dravet Syndrome Foundation. The disease, which starts in infancy, causes long-lasting and potentially fatal seizures that can lead to developmental delays and other health problems.
Though there is no cure for Dravet, several drugs are used to rescue patients from those seizures or prevent them from happening. Two more were approved since 2018 — GW's Epidiolex and Diacomit, from Biocodex.
Seizure medicines don't work for everyone, however, and more treatment options are needed. Fintepla was shown in two placebo-controlled studies of patients between ages two and 18 to reduce the rate of convulsive seizures within thee to four weeks, with the effects remaining consistent for 14 to 15 weeks. The drug's prescribing information notes a 60% to 70% reduction in seizures, which could make for a "best-in-class product," wrote Stifel analyst Paul Matteis.
Still, patients will require monitoring while on treatment. Fintepla is a low-dose form of the appetite suppressant fenfluramine, half of the "Fen-Phen" weight loss drug combination that was pulled from the market in the 1990s because it was tied to potential heart problems and pulmonary hypertension. The fenfluramine dose that was used for weight loss is significantly higher than what Zogenix uses for Fintepla.
Zogenix hasn't reported heart problems in its Phase 3 studies, in which patients got Fintepla for up to three years. The most common side effects were drowsiness, lack of sleep and loss of appetite, among others.
An abnormal echocardiogram — described by the FDA as trace and physiologic — was observed in more than 10% of patients in one of Zogenix's studies. In Fintepla's label, the FDA flagged the risk of pulmonary hypertension and valvular heart disease, and requires patients to get an echocardiogram before treatment to assess their risk of either.
Patients must also get an echocardiogram every six months while on the medicine, then once between three and six months after stopping treatment.
Stifel's Matteis, citing discussions with doctors over the past several years, wrote that such monitoring "doesn't pose a material barrier for most epileptologists."
Fintepla's price, however, could be a challenge. The drug costs $1,278 per 30 milliliter bottle, tying the total price to a patient's weight.
For the patients treated in Zogenix's clinical trial, for example, the drug's average cost would have worked out to $96,000 per year, Ashish Sagrolikar, the company's chief commercial officer, said on a conference call. That's roughly triple the $32,500 list price for Epidiolex.
Sagrolikar said the price is reflective of the benefit Fintepla can provide patients based on "rapid and profound" seizure reductions, and expects the drug to receive broad coverage from payers.
By comparison, GW's Epidiolex dropped seizure frequency by a median of 39% after four weeks in the study cited in its label.
Correction: A previous version of this article incorrectly described the unit by which Fintepla is priced.