Treatment of Adults with Lennox–Gastaut Syndrome: Further Analysis of Efficacy and Safety/Tolerability of Rufinamide

Introduction: Management of Lennox–Gastaut syndrome (LGS) in adulthood can be particularly challenging. Published reports describing the use of rufinamide specifically in adult patients with LGS are scarce. A post hoc subgroup analysis of data from a phase III trial was conducted to investigate the efficacy and safety/tolerability of rufinamide in adults with LGS. Methods: A randomized, double-blind, placebo-controlled trial was conducted in patients with LGS, aged 4 years and above. During an 84-day, double-blind treatment period, patients received either adjunctive rufinamide therapy or placebo. Efficacy and safety/tolerability were assessed in a post hoc subgroup analysis of adult patients (≥18 years). Efficacy was assessed as change from baseline in 28-day seizure frequency, 50% responder rate, and seizure freedom rate; each calculated for total seizures and drop attacks. Safety/tolerability assessments included the evaluation of adverse events (AEs). Results: Thirty-one adults aged 18–37 years with LGS received treatment with either rufinamide (n = 21) or placebo (n = 10). Three patients in the rufinamide group did not complete the trial. The median change from baseline in seizure frequency was −31.5% for rufinamide versus +22.1% for placebo (P = 0.008) for all seizures and −54.9% versus +21.7% (P = 0.002) for drop attacks. Responder rates were 33.3% for rufinamide versus 0% for placebo (P = 0.066) for all seizures and 57.1% versus 10.0% (P = 0.020) for drop attacks. No patient achieved freedom from all seizures but two rufinamide-treated patients (9.5%) became free of drop attacks. Overall, 71.4% of patients treated with rufinamide and 60.0% of patients treated with placebo experienced AEs; most commonly, somnolence (33.3% vs. 20.0%) and vomiting (19.0% vs. 0%). Most AEs were of mild or moderate intensity. Conclusion: Rufinamide demonstrated favorable efficacy and was generally well tolerated when used as adjunctive treatment for adults with LGS. Funding: Eisai.