Efficacy, safety, and tolerability of adjunctive perampanel in patients from China with focal seizures or generalized tonic-clonic seizures: Post hoc analysis of phase III double-blind and open-label extension studies

Aims: This post hoc analysis assessed the efficacy and safety/tolerability of adjunctive perampanel in patients from China (aged >= 12 years) with focal seizures (FS), with/without focal to bilateral tonic-clonic seizures (FBTCS), or generalized tonic-clonic seizures (GTCS). Methods: Study centers in China were identified using data from five double-blind, randomized, phase III studies of adjunctive perampanel (2-12 mg/day) and their open-label extensions (OLEx). Efficacy assessments included median percent reduction in seizure frequency per 28 days, and 50% and 75% responder and seizure-freedom rates. Safety/tolerability assessments included monitoring of treatment-emergent adverse events (TEAEs). Results: Overall, 277 patients (placebo, n = 79; perampanel, n = 198) were included in the double-blind safety analysis set. The full analysis set comprised 274 patients (FS, n = 238 [placebo, n = 60; perampanel, n = 178]; FBTCS, n = 120 [placebo, n = 31; perampanel, n = 89]; GTCS, n = 36 [placebo, n = 18; perampanel, n = 18]). Median percent reductions in seizure frequency for placebo vs perampanel were as follows: 16.6% vs 32.4% (FS; P < 0.05) and 39.1% vs 48.2% (FBTCS; not significant [NS]) at 4-12 mg/day, and 37.9% vs 82.6% (GTCS; NS) at 8 mg/day; 50% responder rates were 31.7% vs 37.4% (FS; NS), 48.4% vs 51.9% (FBTCS; NS), and 33.3% vs 61.1% (GTCS; NS), respectively. Seizure-freedom rates were 1.7% vs 9.2%, 16.1% vs 25.3%, and 16.7% vs 44.4%, respectively (all NS). Overall, 262 patients entered the OLEx (FS, n = 228; GTCS, n = 34). Perampanel was efficacious for up to four years for FS and FBTCS and up to two years for GTCS. Across the double-blind and OLEx studies, TEAEs were reported in 65.7% and 81.3% of perampanel-treated patients, respectively; the most common was dizziness. Efficacy and safety/tolerability outcomes were generally similar between Chinese and non-Chinese patients. Conclusion: Adjunctive perampanel (up to 12 mg/day) may be a suitable treatment for Chinese patients with FS, with/without FBTCS, or GTCS, with similar efficacy and safety/tolerability compared to non-Chinese patients.

Automated summary

The post hoc analysis evaluated the efficacy and safety of adjunctive perampanel in Chinese patients with focal seizures, showing good efficacy in reducing seizure frequency, particularly in focal seizures and generalized tonic-clonic seizures. The safety and tolerability of perampanel were similar between Chinese and non-Chinese patients.