New drug for Epilepsy
The US Food and Drug Administration (FDA) has approved fenfluramine (Fintepla, Zogenix) oral solution, a Schedule IV controlled substance, for the treatment of seizures associated with Dravet syndrome in children age 2 years and older.
Dravet syndrome is a rare childhood-onset epilepsy characterized by frequent, drug-resistant convulsive seizures that may contribute to intellectual disability and impairments in motor control, behaviour, and cognition, as well as an increased risk of sudden unexpected death in epilepsy (SUDEP).
The FDA approved fenfluramine for Dravet syndrome based on the results of two randomized, double-blind, placebo-controlled phase 3 trials involving children aged 2 to 18 years with Dravet syndrome.
In both studies, children treated with fenfluramine experienced significantly greater reductions in the frequency of convulsive seizures than their peers who received placebo. These reductions occurred within 3 to 4 weeks, and remained generally consistent over the 14- to 15-week treatment periods, the FDA said.
Fenfluramine is an anorectic agent that was used to treat obesity until it was removed from the market in 1997 over reports of increased risk of valvular heart disease when prescribed in higher doses and most often when prescribed with phentermine. The combination of the two drugs was known as fen-phen.
In the clinical trials of Dravet syndrome, the most common adverse reactions were decreased appetite; somnolence, sedation, lethargy; diarrhea; constipation; abnormal echocardiogram; fatigue, malaise, asthenia; ataxia, balance disorder, gait disturbance; increased blood pressure; drooling, salivary hypersecretion; pyrexia; upper respiratory tract infection; vomiting; decreased weight; fall; and status epilepticus.
The Fintepla label has a boxed warning stating that the drug is associated with valvular heart disease (VHD) and pulmonary arterial hypertension (PAH). Due to these risks, patients must undergo echocardiography before treatment, every 6 months during treatment, and once 3 to 6 months after treatment is stopped.
If signs of VHD, PAH, or other cardiac abnormalities are present, clinicians should weigh the benefits and risks of continuing treatment with Fintepla.
Fintepla is available only through a risk evaluation and mitigation strategy (REMS) program, which requires physicians who prescribe the drug and pharmacies that dispense it to be certified in the Fintepla REMS and that patients be enrolled in the program.
As part of the REMS requirements, prescribers and patients must adhere to the required cardiac monitoring to receive the drug.
Fintepla will be available to certified prescribers in the United States in July.