PP07.2 – 2774: Five-year follow-up of Fenfluramine as add-on treatment in Dravet syndrome

Objective Further evaluation of efficacy of fenfluramine in Dravet syndrome. Methods Dravet syndrome remains, notwithstanding the introduction of newer anti-epileptic drugs, a therapy resistant epilepsy syndrome. Fenfluramine is an amphetamine-like drug used in the past as part of anti-obesity treatment. Because of possible cardiac side effects (valve thickening, pulmonary hypertension), it has been withdrawn from the market in the US and Europe. In Belgium, it was allowed to study its potential anti-convulsive effect and possible side effects in a small group of well-defined patients with Dravet syndrome. Results Twelve patients, seven girls and five boys, with a genetically proven (11/12) diagnosis of Dravet syndrome received add-on therapy with fenfluramine. The retrospective data were published in 2012 (Ceulemans et al, Epilepsia 2012). We present here the results of 5 years (10 patients) and 4 years (2 patients) prospective follow-up. Overall, looking at the prospective period only, 50% (29/58) of the patient-years were seizure free years, and in 21% (12/58) were only rare seizures ( Conclusion These five-year prospective follow-up data confirms the promising results of fenfluramine as add on in Dravet syndrome. Patients were seizure free or only had rare seizures for at least one year in 71%. Valve thickening never seems a progressive problem and is never clinically significant.