Real-World Data on Perampanel Shows High Mediciation Adherence

Robert T. Wechsler, MD, PhD

Interim analysis of perampanel, an α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor agonist, has shown that more than half of patients on the epilepsy therapy remain on the treatment after 24 months.

According to other recent data, poor adherence to antiepileptic medicines is common, despite the efficacy of the therapies. Some data have suggested that up to 70% of patients with epilepsy could be seizure-free if adherence were better, making perampanel’s higher rate of adherence a welcome sign.

Led by Robert T. Wechsler, MD, PhD, of the Idaho Comprehensive Epilepsy Center in Boise, the ongoing, multicenter, noninterventional trial, dubbed Study 506, examined 187 patients with epilepsy (mean age, 26.7 years [SD, 14.3]) who initiated therapy with perampanel after January 1, 2014.

Patients were assessed for retention rates at months 3, 6, 12, 18, and 24 following their initial treatment.

“Currently, there is limited information regarding real-world use of perampanel in the [United States] as an antiepileptic drug, and such clinical data may inform patient management,” the authors wrote. “Here, we report interim results from a phase 4 retrospective study to assess retention rate, safety, and dosing experience with perampanel administered during routine clinical care.”

The patient cohort was 51.3% female, with a mean time since diagnosis of 17.5 years (SD, 11.8). They were examined for antiepileptic drug history (82.4% received 1-3 concomitant therapies), seizure frequency, perampanel titration and dosage information, and both adverse events (AEs) and serious AEs.

Dosing amounts varied from patient to patient, ranging from 1.5-mg to 20.0-mg doses. The majority of patients were on 8.0-mg (n = 46; 24.6%), 6.0-mg (n = 41; 21.9%), and 4.0-mg (n = 40; 21.4%) doses. Additionally, 32 patients (17.1%) were on a 10.0-mg dose, and 13 (7.0%) were on a 12.0-mg dose.

At month 3, a total of 157 patients (of 185; 84.9%) were still on the therapy, followed by 128 (of 169; 75.7%) at the 6-month mark, 91 (of 143; 63.6%) at the 12-month mark, and 68 (of 116; 58.6%) at month 18. Overall, 58.5% of patients (n = 48) were still taking perampanel after 24 months.

Treatment was discontinued by 75 patients (40.1%)—25.1% because of AEs, 10.2% because of inadequate therapeutic effect, 3.2% for other reasons, and 1.1% for unknown reasons. Only 0.5% of patients discontinued treatment solely because of patient choice. The most common treatment-emergent AEs were dizziness (9.1%), somnolence (5.3%), and aggression (4.3%).

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