Add-on perampanel safe, effective in patients with secondarily generalized seizures
Long‐term treatment with perampanel in the adjunctive setting appears to provide improved seizure control without raising new safety/tolerability signals in patients with epilepsy, particularly those with secondarily generalized seizures (SGS) at baseline, according to the results of an open-label extension of phase III trials.
The open-label extension included 1,218 patients, of which 838 were previously randomized to perampanel and the remaining 380 to placebo. Safety/tolerability (median percent reduction in seizure frequency per 28 days) and seizure (50 percent responder and seizure freedom rates) outcomes were evaluated for all focal seizures and SGS.
Majority of patients (65.4–80.9 percent) received a last daily dose of perampanel 12 mg and completed long‐term assessment on the same, or one fewer, concomitant antiepileptic drug.
Long-term safety/tolerability profile of perampanel was consistent with previous reports. Treatment‐emergent adverse events (TEAEs) resulted in treatment discontinuation in >1 percent of patients. Commonly reported TEAEs included dizziness, irritability and fatigue, with TEAEs of clinical interest being stable for 4 years.
Improvements in seizure outcome improvements were sustained over time. Median percent seizure reductions per 28 days reached 62.0 percent in patients with ≥3 years of perampanel exposure (n=436) and 70.6 percent in patients with ≥4 years of exposure (n=78). The respective 50-percent responder rates were 59.6 percent and 67.9 percent.
The largest median percent seizure reduction per 28 days was seen in SGS, specifically in patients with SGS at baseline: 88.0 percent with ≥3 years of perampanel exposure (n=190) and 100.0 percent with ≥4 years of exposure (n=28). Freedom from SGS occurred in 40.0 percent and 53.6 percent of patients in the ≥3- and ≥4-year exposure groups.
Median percent seizure reductions per 28 days did not significantly differ when early dropouts were accounted for.