Long-Term Efficacy of Perampanel Monotherapy in Patients with Newly Diagnosed/Currently Untreated Recurrent Focal-Onset Seizures: FREEDOM Study 342 Extension Phase Analysis by Seizure Type
Sung Chul Lim1, Anna Patten2, Marcia Morita-Sherman3, Stella Ngo3, Takamichi Yamamoto4
1The Catholic University of Korea, St. Vincent’s Hospital, 2Eisai Europe Ltd., 3Eisai Inc., 4Seirei Hamamatsu General Hospital
Objective:
To assess efficacy of perampanel monotherapy by seizure type in a post hoc analysis of the FREEDOM Study (Study 342; NCT03201900).
Background:
FREEDOM demonstrated long-term (52 weeks) efficacy and tolerability of perampanel monotherapy (4–8mg/day) in patients aged ≥12 years with newly diagnosed or currently untreated recurrent focal-onset seizures (FOS), with or without focal to bilateral tonic-clonic seizures (FBTCS) in Japan and Korea.
Design/Methods:
The Core Study comprised a 4-week Pretreatment Phase and a 32-week Treatment Phase (6-week Titration; 26‑week Maintenance) during which patients received perampanel 4mg/day. Patients who experienced seizure(s) during the 4-mg/day Maintenance Period could be transitioned to an additional 30-week 8-mg/day Treatment Phase (4-week Titration; 26-week Maintenance). Patients could also enter a 26‑week Extension Phase to continue treatment with perampanel monotherapy after completion of the Core Study. The 52‑week seizure-freedom rates were stratified by prior history of the following subtypes of FOS: focal impaired awareness seizures (FIAS), FBTCS, and FIAS plus FBTCS.
Results:
Overall, 89 patients received ≥1 dose of perampanel (Safety Analysis Set [SAS]) and 73 patients entered the 4-mg/day Maintenance Period (modified Intent-to-Treat [mITT] Analysis Set), of whom 21 patients transitioned to the 8-mg/day Treatment Phase. In the SAS, the mean (standard deviation [SD]) duration of perampanel exposure was 66.5 (52.0) weeks across the Core Study and Extension Phase. In the mITT population, the mean (SD) age was 41.7 (18.5) years, and most patients had newly diagnosed epilepsy (95.9% [n=70/73]). The 52-week seizure-freedom rates were 34.1% for FIAS, 31.3% for FBTCS, and 32.9% for FIAS plus FBTCS; these rates at last evaluated dose (4 or 8mg/day) were 41.5% (FIAS), 43.8% (FBTCS), and 42.9% (FIAS plus FBTCS).
Conclusions:
These results suggest that seizure freedom can be achieved and sustained with perampanel monotherapy treatment (4–8mg/day) long-term (≤52 weeks) regardless of seizure type.