The U.S. Food and Drug Administration has approved Fintepla (fenfluramine) to treat seizures associated with Dravet syndrome in patients age 2 and older.
Dravet syndrome is a rare neurological condition that usually appears during the first year of life as frequent fever-related (febrile) seizures. As the condition progresses, other types of seizures typically occur, including myoclonus and status epilepticus. Moderate to severe cognitive impairment is also common. Other symptoms issues associated with Dravet syndrome include:
- Prolonged seizures
- Frequent seizures
- Behavioral and developmental delays
- Movement and balance issues
- Orthopedic conditions
- Delayed language and speech issues
- Growth and nutrition issues
- Sleeping difficulties
- Chronic infections
- Sensory integration disorders
Fenfluramine is an indirect serotonin agonist that was previously marketed as an appetite suppressant, either alone or in combination with phentermine.
The new drug approval comes with a boxed warning stating that the drug is associated with valvular heart disease and pulmonary arterial hypertension (PAH).
The approval of fenfluramine to treat children with Dravet syndrome was largely based on two clinical studies in 202 patients, aged 2 – 18 years, with Dravet syndrome. In both studies, children treated with fenfluramine had significant reductions in the frequency of convulsive seizures compared to those receiving placebo. These reductions were seen within 3-4 weeks, and remained generally consistent over the 14- to 15-week study period.
The most common adverse events were decreased appetite; drowsiness, sedation and lethargy; diarrhea; constipation; abnormal echocardiogram; fatigue or lack of energy; ataxia; balance disorder, gait disturbance; increased blood pressure; drooling, salivary hypersecretion; pyrexia; upper respiratory tract infection; vomiting; decreased weight; risk of falls; and status epilepticus.
Because of the risks of valvular heart disease and PAH, the drug is available only through a restricted drug distribution program, under a risk evaluation and mitigation strategy (REMS).