Long-term efficacy and safety of perampanel as a first add-on therapy in patients with focal epilepsy: Three-year extension study

• Published in: Epilepsy & behavior Vol. 125; p. 108407
• Main Authors: Im, Kayeong, Lee, Sang-Ahm, Kim, Ji Hyun, Kim, Dong Wook, Lee, Sang Kun, Seo, Dae Won, Lee, Ji Woong
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.2021
• Subjects: Anticonvulsants - therapeutic use; Drug Therapy, Combination; Efficacy; Epilepsies, Partial - drug therapy; Epilepsy; Humans; Male; Nitriles; Perampanel; Prospective Studies; Pyridones - adverse effects; Responder rate; Retention rate; Retrospective Studies; Safety; Treatment Outcome; Retention rate; Efficacy; Safety; Responder rate; Epilepsy; Perampanel
• ISSN: 1525-5050; 1525-5069
• DOI: 10.1016/j.yebeh.2021.108407

•The 50% responder rate was 84.8% during the 3rd year and 71.7% during the 3 years.•The seizure-free rate was 58.7% during the 3rd year and 32.6% during the 3 years.•The 1-, 2-, and 3-year retention rates were 62.5%, 53.1%, and 52.1%, respectively.•Efficacies were higher in patients receiving ≤4 mg of perampanel.•No new safety signals were identified during the long-term follow-up period. We investigated the long-term efficacy and safety of perampanel as a first add-on therapy in patients with focal epilepsy. This retrospective study represented the 3-year extension phase of a multicenter, open-label, phase 4, prospective study of perampanel as a first add-on therapy in patients with focal epilepsy. Seizure and safety outcomes were assessed annually from the start of the extension study, and the retention rate was calculated from the start of perampanel exposure in the original study. The 50% responder and seizure freedom rates were 84.8% and 58.7%, respectively, during the third year and 71.7% and 32.6%, respectively, during the entire 3-year period of the extension study. The 1-, 2-, and 3-year retention rates were 62.5%, 53.1%, and 52.1%, respectively. Efficacies were higher in patients that were aged >55 years, male, and receiving ≤4 mg of perampanel. Perampanel was generally well tolerated; 47.3% of patients experienced at least one adverse event during the 3 years of extension (46 adverse events (AEs) in 35 patients). The most common AEs were dizziness (33.8%), somnolence (5.4%), anger (4.1%), and irritability (4.1%). AEs were resolved with perampanel dose reduction or discontinuation in 10 (13.5%) and 12 (16.2%) patients, respectively. Long-term treatment with perampanel as a first add-on therapy did not raise new safety signals in patients with focal epilepsy. Especially at low perampanel doses (≤4 mg/day), sustained improvement in seizure control was achieved, which could potentially avoid adverse drug reactions.