The Food and Drug Administration (FDA) has approved the supplemental New Drug Application (sNDA) for Fintepla® (fenfluramine) oral solution for the treatment of seizures associated with Lennox-Gastaut syndrome (LGS) in patients 2 years of age and older. 

An amphetamine derivative, fenfluramine was initially developed as an appetite suppressant and is believed to work through serotonergic mechanisms. The approval was based on data from a global randomized, double-blind, placebo-controlled phase 3 trial ( Identifier: NCT03355209) that evaluated the efficacy and safety of Fintepla in 263 patients aged 2 to 35 years with LGS. Patients were randomly assigned 1:1:1 to receive Fintepla 0.2mg/kg/day, 0.7mg/kg/day, or placebo.

Findings showed that treatment with Fintepla 0.7mg/kg/day met the primary endpoint achieving a 23.7% median reduction from baseline in the frequency of drop seizures per 28 days compared with an 8.7% median reduction for the placebo arm (P =.0037). A reduction in drop seizures was observed within 2 weeks of initiating treatment with Fintepla, and the effect remained generally consistent over the 14-week treatment period. Moreover, a statistically significant improvement in the proportion of patients with a clinically meaningful reduction (50% or greater) in drop seizure frequency (secondary efficacy endpoint) was also observed with Fintepla. 

The safety profile of Fintepla was found to be consistent with that observed in previous studies for Dravet syndrome. The most common adverse reactions (incidence at least 10% and greater than placebo) for Fintepla in patients with LGS were diarrhea, decreased appetite, fatigue, somnolence, and vomiting. Fintepla also carries a Boxed Warning regarding valvular heart disease and pulmonary arterial hypertension. 

Fintepla, a Schedule IV controlled substance, was also granted pediatric exclusivity by the FDA for the LGS indication and is only available through a restricted distribution program.

“LGS is one of the most challenging epileptic encephalopathies to treat, and the vast majority of patients are not well controlled, despite a regimen of multiple antiepileptic drugs,” said Kelly Knupp, MD, MSCS, FAES, Associate Professor, Children’s Hospital Colorado. “As a complementary therapy, Fintepla offers a different mechanism of action and demonstrated ability to significantly reduce the number of seizures associated with a drop, a critical measure for managing this severe form of epilepsy.”

Fintepla is already approved for the treatment of seizures associated with Dravet syndrome. The product is available as a cherry-flavored oral solution containing 2.2mg/mL of fenfluramine. 


  1. Fintepla® (fenfluramine) oral solution now FDA approved for treatment of seizures associated with Lennox-Gastaut syndrome (LGS). News release. UCB, Inc. Accessed March 28, 2022.
  2. Fintepla. Package insert. UCB, Inc.; 2022. Accessed March 28, 2022.