FDA Okays New Med for Lennox-Gastaut Syndrome

Megan Brooks

March 29, 2022

The US Food and Drug Administration (FDA) has approved fenfluramine (Fintepla) oral solution, a Schedule IV controlled substance, for the treatment of seizures associated with Lennox-Gastaut syndrome (LGS) in children aged 2 years and older, the company has announced.

As reported by Medscape Medical News, fenfluramine is already approved in the US to treat seizures associated with Dravet syndrome. LGS is a relatively rare type of epilepsy that typically develops in early childhood and is often drug resistant.

Beyond seizures, LGS may contribute to intellectual disability and impairments in motor control, behavior, and cognition and is associated with an increased risk of sudden unexpected death in epilepsy.

The FDA approval of fenfluramine for LGS was supported by safety and efficacy data from a global, randomized, placebo-controlled phase 3 clinical trial in 263 patients with LGS.

The study showed that fenfluramine at a dose of 0.7/mg/kg/day significantly reduced the frequency of drop seizures compared to placebo (P = .0037), the company says in a news release.

Nearly 25% of children taking this dose experienced at least a 50% reduction in drop seizure frequency over 28 days; 18% had a greater than 50% to less than 75% reduction, and 6% had a greater than 75% reduction.

The common adverse reactions in children treated with fenfluramine (incidence at least 10% and greater than placebo) were diarrhea, decreased appetite, fatigue, somnolence, and vomiting.

"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," Kelly Knupp, MD, with Children's Hospital Colorado, Aurora, says in the news release.

"As a complementary therapy, fenfluramine 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," said Knupp.

LGS "impacts every aspect of daily life and puts great strain on the entire family. There is a desperate need for more effective treatment options," adds Tracy Dixon-Salazar, PhD, executive director, LGS Foundation, and mother to an adult daughter with LGS.

"The potential for fenfluramine to make a difference in the daily, horrific seizures we are dealing with in LGS cannot be understated. We are so grateful for the researchers who have worked so hard to help all of us suffering at the hands of LGS," said Dixon-Salazar.

In the United States, fenfluramine oral solution for LGS is available only through a risk evaluation and mitigation strategy program.

Full prescribing information is available online.

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