The impact of perampanel on cognition: A systematic review of studies employing standardized tests in patients with epilepsy

Three phase III studies (304 [ClinicalTrials.gov identifier: NCT00699972], 305 [NCT00699582], 306 [NCT00700310]) evaluated perampanel, an α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonist, as adjunctive therapy for refractory partial seizures. We report post hoc analyses of pooled study data by randomized dose. Patients with partial seizures despite receiving 1-3 antiepileptic drugs were randomized to once-daily placebo, perampanel 8 or 12 mg (studies 304, 305), or placebo, perampanel 2, 4, or 8 mg (study 306). Studies included a 6-week baseline period and double-blind treatment phase (6-week titration; 13-week maintenance). Primary end points were median change in partial seizure frequency (baseline vs. double-blind phase) and percentage of patients achieving ≥ 50% reduction in seizure frequency (baseline vs. maintenance). Here, these end points, together with secondary, exploratory, and safety end points, were assessed using pooled study data. The pooled intent-to-treat analysis set (randomized, treated patients with any seizure data) included 1,478 patients. Median changes in partial seizure frequency were greater with perampanel than placebo (perampanel 4 mg, -23.3%; 8 mg, -28.8%; 12 mg, -27.2%; placebo, -12.8%; p < 0.01, each dose vs. placebo), as were 50% responder rates (perampanel 4 mg, 28.5%; 8 mg, 35.3%; 12 mg, 35.0%; placebo, 19.3%; p < 0.05, each dose vs. placebo). In addition, median changes in complex partial plus secondary generalized seizure frequency were also greater with perampanel than placebo (perampanel 4 mg, -31.2%; 8 mg, -35.6%; 12 mg, -28.6%; placebo, -13.9%). Perampanel was generally well tolerated. The most frequent treatment-emergent adverse events (TEAEs) were dizziness, somnolence, and headache. Most TEAEs were mild/moderate; relatively few patients experienced severe TEAEs (placebo, 5.4%; perampanel, 8.9%) or serious TEAEs (placebo, 5.0%; perampanel, 5.5%). There were no deaths and no clinically important mean changes in laboratory values, electrocardiography (ECG) findings, or vital signs. Perampanel reduced partial seizure frequency and improved responder rates compared with placebo, with an acceptable tolerability profile. Wiley Periodicals, Inc. © 2013 International League Against Epilepsy.

The study was set up to evaluate the impact of the total drug load of antiepileptic pharmacotherapy on cognition. Retrospective analyses were based on 834 patients with epilepsy who underwent a brief routine assessment of executive function and verbal memory (EpiTrack Plus) at our department. The total drug load was quantified in two ways: (1) number of concurrent antiepileptic drugs (AEDs) and (2) total drug load according to the defined daily dose (DDD) provided by the World Health Organization. The cognitive measures showed higher inverse correlations with the number of AEDs (executive function: r=-0.35, p<0.001; memory: r=-0.22, p<0.001) than with the total DDD (executive function: r=-0.27, p<0.001; memory: r=-0.17, p<0.001). Reanalysis with statistical control for disease severity hardly changed the aforementioned results. With each additional drug in polytherapy, we observed a significantly lower performance in executive function. In this regard an additional explorative approach revealed that regimens combining AEDs with favorable cognitive profiles were associated with higher cognitive performance. Correlations between indicators of disease severity and drug load indices were low: altogether explaining only up to 9% of the observed variance in drug load. The findings demonstrate a considerable adverse effect of a higher drug load on cognition, especially on executive functions. Simply counting the number of drugs may be sufficient as a rough estimate of the risk of side effects. However, the combination of AEDs with favorable cognitive profiles may attenuate the negative effect of the total drug load.

Summary Objective Perampanel, a selective, noncompetitive α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid (AMPA) glutamate receptor antagonist, is indicated for adjunctive treatment of partial seizures in patients ≥12 years based on three phase III clinical studies. The perampanel U.S. Prescribing Information includes a boxed warning for serious psychiatric and behavioral adverse reactions. To provide context for this warning, detail on psychiatric and behavioral safety data from perampanel clinical studies is presented. Methods An analysis of pooled safety data from three phase III studies in patients with partial seizures is presented. Data from phase I and phase II studies in patients with and without epilepsy were also analyzed. Psychiatric and behavioral treatment‐emergent adverse events (TEAEs) were evaluated according to Medical Dictionary for Regulatory Activities (MedDRA) terms, using “narrow” and “narrow‐and‐broad” standardized MedDRA queries (SMQs) for TEAEs suggestive of hostility/aggression. Results From the three phase III partial‐seizure studies, the overall rate of psychiatric TEAEs was higher in the 8 mg (17.2%) and 12 mg (22.4%) perampanel groups versus placebo (12.4%). In the “narrow” SMQ, hostility/aggression TEAEs were observed in 2.8% for 8 mg and 6.3% for 12 mg perampanel groups, versus 0.7% of placebo patients. “Narrow‐and‐broad” SMQs for hostility/aggression TEAE rates were 12.3% for 8 mg and 20.4% for 12 mg perampanel groups, versus 5.7% for placebo; rates for events resulting in discontinuation were perampanel = 1.6% versus placebo = 0.7%. For events reported as serious AEs (SAEs), rates were perampanel = 0.7% versus placebo = 0.2%. In nonepilepsy patients, psychiatric TEAEs were similar between patients receiving perampanel and placebo. In phase I subjects/volunteers, all psychiatric TEAEs were mild or moderate. These analyses suggest that psychiatric adverse effects are associated with use of perampanel. Significance Patients and caregivers should be counseled regarding the potential risk of psychiatric and behavioral events with perampanel in patients with partial seizures; patients should be monitored for these events during treatment, especially during titration and at higher doses.