Perampanel outcomes at different stages of treatment in people with focal and generalized epilepsy treated in clinical practice: Evidence from the PERMIT study

Efficacy and safety of perampanel in genetic generalized epilepsy: A retrospective, single-center study in China

Perampanel (PER) is a selective non-competitive AMPA receptor antagonist approved for treating focal and generalized seizures. However, its efficacy in genetic generalized epilepsy (GGE) has not been extensively studied in Chinese populations. This retrospective, single-center study enrolled 54 patients with GGE treated with PER between March 2021 and November 2023. To ensure data quality and minimize bias, we implemented standardized data collection procedures including: (1) systematic documentation using standardized seizure diaries, (2) regular follow-up assessments at predefined intervals, and (3) rigorous application of inclusion/exclusion criteria. Efficacy was assessed by seizure freedom rate, responder rate (≥50 % seizure reduction) and retention rate at 3, 6, 12 months and last follow-up. Safety was evaluated by monitoring adverse events. At last follow-up (mean 14 ± 4.95 months), the overall seizure freedom rate was 53.7 % and responder rate was 70.4 %. Idiopathic generalized epilepsy (IGE) patients showed better outcomes compared to non-IGE patients (seizure freedom: 63.6 % vs 10 %; responder rate: 79.5 % vs 30 %). PER demonstrated highest efficacy in generalized tonic-clonic seizures (80.4 % responder rate), followed by myoclonic (70.8 %) and absence seizures (50 %). Among epilepsy syndromes, GTCA showed the best response (100 % responder rate), followed by JME (83.3 %). The mean effective dose was 3.86 mg/day in the seizure-free group. Treatment-emergent adverse events occurred in 18.5 % of patients, with dizziness (18.5 %) being most common, leading to discontinuation in 3.7 % of cases. PER demonstrated favorable efficacy and tolerability in Chinese patients with GGE, particularly in IGE patients and those with generalized tonic-clonic seizures. Lower doses were associated with better outcomes, suggesting careful dose titration may optimize therapeutic benefits.

A Phase 4, multicenter, prospective, non-interventional, observational study to investigate the effectiveness and safety/tolerability of perampanel when used as first adjunctive therapy in routine clinical practice in people with epilepsy: Study 512

Introduction

Study 512 aimed to assess the efficacy and safety of perampanel (PER) as the first add-on therapy.

Methods

In this 12-month, prospective, observational, multicenter study, people with epilepsy (PWE) aged ≥12 years with focal-onset seizures or generalized tonic-clonic seizures (GTCS) associated with idiopathic generalized epilepsy received PER as the first add-on therapy to antiseizure medication (ASM) monotherapy. The primary efficacy endpoint was the retention rate at 12 months. Other endpoints included change in seizure frequency from baseline; pragmatic seizure freedom rate (proportion of PWE in the full analysis set achieving freedom from all seizures); responder rate (≥50% seizure frequency reduction from baseline), changes from baseline in the 10-item Quality of Life in Epilepsy questionnaire (QOLIE-10) total score, the Epworth Sleepiness Scale (ESS), and the age-corrected EpiTrack and EpiTrack Junior total score; safety/tolerability (treatment-emergent adverse events [TEAEs]); and PER dose.

Results

Of 184 PWE (Safety Set, n = 182; Full Analysis Set, n = 174), 135 (73.4%) completed the 12-month study. The mean PER dose was 4.7 mg/day. Retention rate at 12 months was 74.2% in the overall population, 81.8% in the 12 to <18 years age group, 74.3% in the 18 to <65 years age group, and 66.7% in the ≥65 years age group. Retention rates were similar between PWE with focal-onset seizures (74.5%) and GTCS (75.0%). The median reduction in monthly seizure frequency per 28 days from baseline to 12 months was 78.6% in the overall population, 92.3% in the 12 to <18 age group, 75.0% in the 18 to <65 years age group, and 87.5% in the ≥65 years age group. In the overall population, pragmatic seizure freedom rates at 12 months were 36.2% (all seizures), 34.1% (all focal seizures), and 45.5% (GTCS); the responder rate at 12 months was 64.4% in the overall population. In total, 52.7% of PWE experienced TEAEs, and 12.1% discontinued due to TEAEs. No significant changes were identified from baseline to 12 months in QOLIE-10, ESS, and the age-corrected EpiTrack and EpiTrack Junior scores.

Conclusion

PER was efficacious for focal and generalized seizures across all age groups and was generally well-tolerated, as demonstrated by the high retention rates at 12 months.

Post-marketing Experience with Cenobamate in the Treatment of Focal Epilepsies: A Multicentre Cohort Study

BACKGROUND

In randomised controlled trials, adjunctive cenobamate (CNB) has been shown to reduce seizure frequency in patients with drug-resistant focal epilepsy. Studies conducted in real-world settings provide valuable complementary data to further characterise the drug's profile.

OBJECTIVE

To assess the efficacy, retention and tolerability of adjunctive cenobamate (CNB), and to identify factors that might predict these outcomes in the clinical treatment of focal epilepsies.

METHODS

This multicentre, retrospective cohort study included all patients who began CNB treatment between October 2020 and April 2023 at seven participating epilepsy centres. Baseline and follow-up data were collected from patients' medical records, covering clinical characteristics and outcome data such as seizure frequency, dosing of CNB, physician-assessed Clinical Global Impression of Change, treatment-emergent adverse events (TEAEs), CNB retention and reasons for discontinuation.

RESULTS

A total of 234 patients [mean age 40.7 ± 14 years, median 40 years, range 11-82 years; five adolescents under 18 years; 99 (42.3%) males] were analysed. The mean epilepsy duration at study entry was 23.2 ± 14.5 years (median 21 years, range 0.75-63 years), with the average age of epilepsy onset being 17.5 ± 13.0 years (median 17 years, range 0.1-71 years). The patients were taking a mean of 2.6 ± 0.8 (median 3) anti-seizure medications (ASMs) before starting CNB, and had failed a mean of 6 ± 3.3 (median 6) of further ASMs in the past. CNB exposure ranged from 5 to 1162 days, amounting to a total exposure time of 264.7 years. The retention rate was 92.6% at 3 months, 87.2% at 6 months and 77.8% at 12 months. At 3 months, 52.6% achieved a 50% seizure reduction, with 14.5% reporting seizure freedom; by 12 months, 47.7% maintained a 50% response rate and 11.9% were seizure-free. No significant differences in responder rates were observed based on sex, aetiology, seizure localisation, number of ASMs or target dose. The mean maximum CNB dose was 236.7 ± 97.4 mg (median 200 mg, range 12.5-450 mg), with 28 patients (12.0%) titrated up to 400 mg or above. During CNB treatment, 43.6% of patients were able to discontinue, and a further 24.4% were able to reduce the dose of a concomitant ASM. During CNB treatment, 144 patients (61.5%) experienced TEAEs. The most common TEAEs were sedation (n = 84, 35.9%), dizziness (n = 58, 24.8%) and ataxia (n = 23, 9.8%).

CONCLUSIONS

CNB showed a relatively high and clinically useful 50% responder rate of 47.7% and an overall retention of 77.8% at 1 year. We were unable to identify specific predictors for response and retention, indicating that CNB may be beneficial for patients with a history of multiple failed ASMs, a high number of concomitant ASMs and any localisation or aetiology of focal epilepsy.

Relationship between anti-seizure medication and behaviors that challenge in older persons with intellectual disability and epilepsy: a review

INTRODUCTION

There is increased focus on the negative impact of the overprescribing of medication, specifically psychotropic medication, including anti-seizure medications (ASM), in people with Intellectual Disability (ID). This is particularly important for the older adult population, where multi-morbidity and polypharmacy are more common. ASMs are associated with psychiatric and behavioral adverse effects. Furthermore, there is growing awareness of the anticholinergic burden for older adults with epilepsy and ID and the relationship with behaviors that challenge (BtC).

AREAS COVERED

This review defines the older adult population and outlines the relationship between epilepsy and ID. BtC is outlined in the context of the population and the relationship with ASMs. The evidence base to guide prescribing and de-prescribing for newer ASMs is also presented, including pragmatic data.

EXPERT OPINION

Polypharmacy, particularly psychotropics, are a mortality risk factor for older adults with epilepsy and ID. Therefore, any BtC requires a holistic assessment with a multi-disciplinary approach. This includes specific consideration of all prescribed medicines in the context of polypharmacy. There should be routine reviews, at least annually, for those aged 40 years and over particularly focused on anticholinergic burden and/or polypharmacy.

The cenobamate KORK study-A prospective monocenter observational study investigating cenobamate as an adjunctive therapy in refractory epilepsy, with comparisons to historical cohorts treated with add-on lacosamide, perampanel, and brivaracetam

OBJECTIVE

In Europe, cenobamate has been approved for use as an adjunctive therapy in adult patients with epilepsy (PWE) with focal-onset seizures (FOS) who have not responded satisfactorily to treatment with at least two antiseizure medications (ASMs). Pivotal trials and real-world observational studies have demonstrated a high efficacy of cenobamate, even in very difficult-to-treat epilepsies. Our aim was to investigate the efficacy of add-on cenobamate in adult PWE who were prospectively monitored. We compared these results with those previously obtained for add-on lacosamide, perampanel, and brivaracetam therapy.

METHODS

Patients were enrolled from the CENKORK study, which is a prospective, non-interventional, open-label, monocenter cohort study of adult PWE experiencing FOS. The titration of cenobamate was performed according to the guidelines outlined in the summary of product characteristics. The primary outcome measure was the retention rate at 6 months and 1 year. In addition, we assessed seizure-free rates, the proportion of patients achieving at least a 50% seizure reduction, adverse events, and the reasons for treatment discontinuation. These outcome measures were compared with historical controls treated with adjunctive lacosamide, perampanel, or brivaracetam at our center.

RESULTS

Between June 2021 and 2022, 172 PWE with ongoing FOS were included. 22 cases were lost to follow-up, leaving 150 cases for the 1-year assessment. The retention rates at 6 months and 1 year were 88.7% and 80%, respectively. Seizure freedom was achieved in 14% of patients at both the 6-month and 1-year marks, while the ≥50% responder rates were 50% and 61%, respectively. The 6-month retention rate was significantly higher in cenobamate than in other ASMs (p < 0.001 for each comparator). Adverse events were significantly more common with perampanel (p < 0.001).

SIGNIFICANCE

Add-on cenobamate proved to be particularly efficacious compared to our experience with other recently introduced ASMs.

PLAIN LANGUAGE SUMMARY

This observational study was carried out in 172 adult patients with difficult-to-treat epilepsy who were treated with adjunctive cenobamate. After 1 year, the data of 150 patients could be analyzed. Seizure freedom, in the preceding 3 months, was achieved in 14%. The rate of PWE continuing cenobamate was 80%. In our hands, cenobamate showed promising efficacy and tolerability even when compared to other recently introduced antiseizure medications.

Perampanel in post-stroke epilepsy: Clinical practice data from the PERampanel as Only Concomitant antiseizure medication (PEROC) study

INTRODUCTION

Post-stroke epilepsy (PSE) is one of the most common causes of acquired epilepsy. Nevertheless, there is limited evidence regarding the clinical profile of antiseizure medications (ASMs) in PSE. This study aims to evaluate the 12-month effectiveness and tolerability of perampanel (PER) used as only add-on treatment in patients with PSE in a real-world setting.

METHODS

We performed a subgroup analysis of PSE patients included in a previous retrospective, longitudinal, multicentre observational study on adults. Treatment discontinuation, seizure frequency and adverse events were collected at 3, 6 and 12 months. Sub-analyses by early (≤1 previous ASM) or late PER add-on were also conducted.

RESULTS

Our analysis included 56 individuals with PSE, characterized by varying initial treatment modalities and timeframes relative to disease onset. We found notable retention rates (92.8%, 83.7%, and 69% at 3, 6, and 12 months), with treatment withdrawal mainly due to poor tolerability. One year after PER introduction, seizure frequency significantly reduced, with a responder rate (≥50% reduction) of 83.9% and a seizure-free rate of 51.6%. Adverse events occurred in 25 (46.3%) patients, mainly dizziness, irritability, and behavioural disorders. No major statistical differences were found between early (30 patients, 53.6%) and late add-on groups, except for a higher 6-month responder rate in the early add-on group.

CONCLUSION

Adjunctive PER was effective and well-tolerated in patients with PSE in a real-world setting. Perampanel demonstrated good efficacy and safety as both early and late add-on treatment, making it a compelling option for this unique patient population.

Long-term efficacy and safety of perampanel as an add-on therapy in patients with epilepsy

BACKGROUND

Perampanel (PER) is a newly developed amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptor antagonist that has been globally approved for the treatment of both focal and generalized seizures. The efficacy and safety of PER have only been reported over short periods of treatment so far. This study aims to clarify the long-term efficacy and safety of PER as an add-on therapy.

METHOD

This retrospective observational study investigated 176 epilepsy patients who received PER as add-on medical therapy in two Japanese epilepsy centers between June 2016 and July 2022. The adherence, seizure frequency, and plasma concentration of PER were evaluated at three time points: 6 months, 12 months, and 24 months or longer after the start of adjunctive PER treatment.

RESULTS

112 patients undergoing PER treatment were evaluated at 6 months, 86 were evaluated at 12 months, and 52 were evaluated at 24 months or longer. Overall, 42.9 % (48/112), 45.4 % (40/86), and 44.2 % (23/52) of the patients were seizure-free at 6, 12, and 24 months or longer, respectively. The rate of PER tolerance was 78.3 %, 69.9 %, and 54.7 % at 6, 12, and 24 months or longer, respectively. At the latest timepoint, the seizure-free group was taking a significantly lower dose of PER than the seizure-remnant group, and the number of anti-seizure medications (ASMs) was associated with seizure outcomes. In addition, the seizure-free rate was significantly higher in patients who received PER as a first add-on than in those who received it as a late add-on. No significant difference was found in the plasma concentration of PER between the seizure-free and seizure-remnant groups at 24 months or longer. Among the patients receiving PER at dose of 2 mg, however, the plasma concentrations were significantly higher in the seizure-free group than in the seizure-remnant group (282.7 ± 109.8 μg/ml vs 94.7 ± 54.9 μg/ml, p = 0.0024).

CONCLUSION

This long-term retrospective observational study provides evidence of the efficacy and safety of PER over 2 years treatment period in Japan. Notably, patients who started on PER as the first add-on showed a better seizure outcome than those who received it as a late add-on over the long term. Measured plasma concentrations may provide valuable guidance for the management of patients. Higher plasma concentration at low dose PER may suggest the better seizure control.

Perampanel as only add-on epilepsy treatment in elderly: A subgroup analysis of real-world data from retrospective, multicenter, observational study

INTRODUCTION

Drug management of epilepsy in the elderly presents unique but data on this population are scarce. This study aimed to assess the effectiveness and tolerability of perampanel (PER) used as only add-on to a background anti-seizure medication (ASM) in the elderly in a real-world setting.

METHODS

We performed a subgroup analysis of patients aged ≥65 years included in a previous 12-month multicenter study on adults. Treatment discontinuation, seizure frequency, and adverse events were recorded at 3, 6 and 12 months after PER introduction. Sub-analyses by early (≤1 previous ASM) or late PER add-on were also conducted.

RESULTS

The sample included 65 subjects (mean age: 75.7 ± 7.2 years), with mainly focal (73.8%) epilepsy. The mean PER daily dose was ≈4 mg during all follow-up. Retention rates at 3, 6, and 12 months were 90.5%, 89.6%, and 79.4%ly. The baseline median normalized per 28-day seizure number significantly decreased at 3-, 6- and 12-month visits. One year after PER introduction, the responder rate (≥50% reduction in baseline seizure frequency) was 89.7%, with a seizure freedom rate of 72.4%. Adverse events occurred in 22 (34.9%) patients with dizziness and irritability being the most frequent. No major differences between early (41 patients, 63.1%), and late add-on groups were observed.

CONCLUSION

Adjunctive PER was effective and well-tolerated when used as only add-on treatment in elderly people with epilepsy in clinical practice, thus representing a suitable therapeutic option in this age category.

Efficacy and safety of perampanel as early add-on therapy in Chinese patients with focal-onset seizures: a multicenter, open-label, single-arm study

Background

No interventional study has been conducted in China to assess efficacy and safety of perampanel in treating Chinese patients with epilepsy, nor has there been any study on perampanel early add-on therapy in China. This interventional study aimed to assess efficacy and safety of perampanel as an early add-on treatment of focal-onset seizures (FOS) with or without focal-to-bilateral tonic-clonic seizures (FBTCS) in Chinese patients.

Methods

In this multicenter, open-label, single-arm, phase 4 interventional study, Chinese patients ≥ 12 years old with FOS with or without FBTCS who failed anti-seizure medication (ASM) monotherapy from 15 hospitals in China were enrolled and treated with perampanel add-on therapy (8-week titration followed by 24-week maintenance). The primary endpoint was 50% responder rate. Secondary endpoints included seizure-freedom rate and changes in seizure frequency from baseline. Treatment-emergent adverse events (TEAEs) and drug-related TEAEs were recorded.

Results

The full analysis set included 150 patients. The mean maintenance perampanel dose was 5.9 ± 1.5 mg/day and the 8-month retention rate was 72%. The 50% responder rate and seizure-freedom rate for all patients during maintenance were 67.9 and 30.5%, respectively. Patients with FBTCS had higher 50% responder rate (96.0%) and seizure-freedom rate (76.0%) during maintenance. Patients on concomitant sodium valproate had a significantly higher seizure-freedom rate than those on concomitant oxcarbazepine. Eight-six (55.1%) patients experienced treatment-related TEAEs, and the most common TEAEs were dizziness (36.5%), hypersomnia (11.5%), headache (3.9%), somnolence (3.2%), and irritability (3.2%). Withdrawal due to TEAEs occurred to 14.7% of the patients.

Conclusion

Perampanel early add-on was effective and safe in treating Chinese patients≥12 years old with FOS with or without FBTCS.Clinical trial registrationwww.chictr.org.cn, Identifier ChiCTR2000039510.

Adverse Event Profiles of Antiseizure Medications and the Impact of Coadministration on Drug Tolerability in Adults with Epilepsy

BACKGROUND

Antiseizure medication (ASM) as monotherapy or in combination is the treatment of choice for most patients with epilepsy. Therefore, knowledge about the typical adverse events (AEs) for ASMs and other coadministered drugs (CDs) is essential for practitioners and patients. Due to frequent polypharmacy, it is often difficult to clinically assess the AE profiles of ASMs and differentiate the influence of CDs.

OBJECTIVE

This retrospective analysis aimed to determine typical AE profiles for ASMs and assess the impact of CDs on AEs in clinical practice.

METHODS

The Liverpool AE Profile (LAEP) and its domains were used to identify the AE profiles of ASMs based on data from a large German multicenter study (Epi2020). Following established classifications, drugs were grouped according to their mode of action (ASMs) or clinical indication (CDs). Bivariate correlation, multivariate ordinal regression (MORA), and artificial neural network (ANNA) analyses were performed. Bivariate correlation with Fisher's z-transformation was used to compare the correlation strength of LAEP with the Hospital Anxiety and Depression Scale (HADS) and Neurological Disorders Depression Inventory for Epilepsy (NDDI-E) to avoid LAEP bias in the context of antidepressant therapy.

RESULTS

Data from 486 patients were analyzed. The AE profiles of ASM categories and single ASMs matched those reported in the literature. Synaptic vesicle glycoprotein 2A (SV2A) and voltage-gated sodium channel (VGSC) modulators had favorable AE profiles, while brivaracetam was superior to levetiracetam regarding psychobehavioral AEs. MORA revealed that, in addition to seizure frequency, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) modulators and antidepressants were the only independent predictors of high LAEP values. After Fisher's z-transformation, correlations were significantly lower between LAEP and antidepressants than between LAEP and HADS or NDDI-E. Therefore, a bias in the results toward over interpreting the impact of antidepressants on LAEP was presumed. In the ANNA, perampanel, zonisamide, topiramate, and valproic acid were important nodes in the network, while VGSC and SV2A modulators had low relevance for predicting relevant AEs. Similarly, cardiovascular agents, analgesics, and antipsychotics were important CDs in the ANNA model.

CONCLUSION

ASMs have characteristic AE profiles that are highly reproducible and must be considered in therapeutic decision-making. Therapy using perampanel as an AMPA modulator should be considered cautiously due to its relatively high AE profile. Drugs acting via VGSCs and SV2A receptors are significantly better tolerated than other ASM categories or substances (e.g., topiramate, zonisamide, and valproate). Switching to brivaracetam is advisable in patients with psychobehavioral AEs who take levetiracetam. Because CDs frequently pharmacokinetically interact with ASMs, the cumulative AE profile must be considered.

TRIAL REGISTRATION

DRKS00022024, U1111-1252-5331.