Perampanel as First Adjunctive Treatment in Patients with Focal-Onset Seizures in the FAME Study: Post hoc Analyses of Dose-Related Efficacy, Safety and Clinical Factors Associated with Response.

Background and purpose: Perampanel is approved for the adjunctive treatment of focal-onset seizures (FOS) with or without secondary generalized seizures. The FAME (Fycompa^® as first Add-on to Monotherapy in patients with Epilepsy; NCT02726074) study evaluated the efficacy and safety of perampanel added to monotherapy in patients with FOS with or without secondary generalized seizures (SGS). Post hoc analyses of the FAME study assessed potential predictors of response and an in-depth evaluation of the safety and efficacy of perampanel.

Methods: Efficacy was assessed by reduction of total seizure frequency by ≥50%, ≥75% or 100%, and safety by incidence of treatment-emergent adverse events (TEAEs) and TEAEs leading to discontinuation. Univariate and multivariate logistic regression analyses for treatment response were performed.

Results: Most patients (82/85) received perampanel doses of 4-8 mg/day during maintenance therapy and the highest efficacy rates were achieved with 4 mg/day, irrespective of efficacy outcome. Doses of 4 or 6 mg/day in patients with FOS with SGS (n=16) produced comparable efficacy outcomes. In multivariate analysis, total perampanel dose was predictive of 50% and 75% response rates; longer total perampanel administration period with 50% response; and concomitant non-anti-seizure medication with a 100% response. Patients developed a TEAE more frequently during the 12-week titration period (60.2%) than the 24-week maintenance period (28.4%), including dizziness (45.5% vs. 9.1%), somnolence (10.2% vs. 0%), and headache (4.5% vs. 3.4%).

Conclusions: Post hoc analyses show that even low doses of perampanel may be effective and TEAEs are usually self-limited or well-tolerated.