Ingrid Scheffer (Melbourne / AU), Rima Nabbout (Paris / FR), Lieven Lagae (Leuven / BE), Orrin Devinsky (New York, NY / US), Stéphane Auvin (Paris / FR), Elizabeth Thiele (Boston, MA / US), Elaine Wirrell (Rochester, NY / US), Tilman Polster (Bielefeld / DE), Nicola Specchio (Rome / IT), Milka Pringsheim (Salzburg / AT), Katsumi Imai (Shizuoka / JP), Michael Lock (Haiku, HI / US), Mélanie Langlois (Colombes / FR), Amélie Lothe (Colombes / FR), Joseph Sullivan (San Francisco, CA / US)
Introduction: Phase 3 and interim open-label extension (OLE) studies have shown profound, durable reductions in median monthly convulsive seizure frequency (MCSF) in patients with Dravet syndrome (DS) treated with fenfluramine (FFA). We report results from the final OLE analysis of FFA use in a large cohort of patients with DS.
Objectives: To describe the long-term safety and effectiveness of FFA in patients with DS treated for 3 years
Materials & Methods: Safety was reported for patients who received ≥1 dose FFA. Key effectiveness endpoint in the modified intent-to-treat (mITT) group (from core study with baseline seizure frequency measured) was change in MCSF from core baseline vs overall OLE. Caregivers and investigators rated patients on the Clinical Global Impression-Improvement (CGI-I) scale. Descriptive statistics and Wilcoxon test for MCSF percent change from baseline were used.
Results: As of 27-Jan-2023, 375 patients had enrolled; 374 received >=1 dose FFA. Table 1 shows demographics and exposure. In the mITT population (n=324), median percent MCSF change from baseline over the entire OLE was -66.8%, P
Conclusions: This final analysis of patients with DS treated with FFA (median 2.3y) demonstrates sustained and clinically meaningful reduction in seizures and known safety profile.
Supported by: UCB Pharma.