Perampanel and childhood absence epilepsy: A real life experience

Care of pharmaco-resistant absence seizures in childhood

In childhood absence epilepsy, pharmaco-resistance occurs in 20-30% of patients. In that situation, glucose transporter type 1 deficiency has to be ruled out, especially if absences started before the age of four years and if neurological signs are present. If ethosuximide, valproate and lamotrigine have failed in monotherapy or in association, there are currently no valuable therapeutic options. The same rules apply for epilepsy with myoclonic absences. Importantly, arguments supporting that making the patient seizure-free will improve eventual associated cognitive deficits such as attention deficit are very weak. Therefore, limiting the cognitive side effects of the anti-epileptic drugs has always to be a priority when faced with typical refractory absences in childhood. In epilepsy with eyelid myoclonia, the majority of patients are pharmaco-resistant. However, absence seizures, if present, tend to be very brief, and seizures are limited in many patients to eyelid myoclonia that eventually do not affect their quality of life and are well attenuated by wearing blue lenses. Atypical absences occurring in the course a developmental and/or epileptic encephalopathy are often pharmaco-resistant. In that situation, characterizing the type of epilepsy syndrome and searching for a specific genetic or structural etiology are needed to offer the best therapeutic options to the patient.

Role of Perampanel in the Management of Pediatric Epilepsies in Asia: Expert Opinion

Management of pediatric epilepsies poses unique challenges around diagnosis, treatment options, comorbidities, and the potential for these factors to interact with processes in the developing brain. In pediatric patients, broad-spectrum antiseizure medications (ASMs) with minimal potential for adverse events (AEs) and limited impact on cognition and behavior are preferred. Perampanel is a first-in-class ASM with broad-spectrum efficacy, a tolerable safety profile, minimal negative impact on cognitive function, and other features that make it a viable treatment option in this patient population. However, evidence and experience of its use in pediatric patients are less extensive than in adult patients. Experts in pediatric epilepsy across the region convened at a series of meetings to discuss the use of perampanel in pediatric patients, including dose optimization, AE prevention and management, and considerations in particular groups. This article summarizes key evidence for perampanel in the pediatric population and consolidates the experts' recommendations for using the ASM in managing pediatric epilepsies.

Whole Exome Sequencing as a First-Line Molecular Genetic Test in Developmental and Epileptic Encephalopathies

Developmental and epileptic encephalopathies (DEE) are severe neurodevelopmental disorders characterized by recurrent, usually early-onset, epileptic seizures accompanied by developmental impairment often related to both underlying genetic etiology and abnormal epileptiform activity. Today, next-generation sequencing technologies (NGS) allow us to sequence large portions of DNA quickly and with low costs. The aim of this study is to evaluate the use of whole-exome sequencing (WES) as a first-line molecular genetic test in a sample of subjects with DEEs characterized by early-onset drug-resistant epilepsies, associated with global developmental delay and/or intellectual disability (ID). We performed 82 WESs, identifying 35 pathogenic variants with a detection rate of 43%. The identified variants were highlighted on 29 different genes including, 3 new candidate genes (KCNC2, STXBP6, DHRS9) for DEEs never identified before. In total, 23 out of 35 (66%) de novo variants were identified. The most frequently identified type of inheritance was autosomal dominant de novo (60%) followed by autosomal recessive in homozygosity (17%) and heterozygosity (11%), autosomal dominant inherited from parental mosaicism (6%) and X-linked dominant de novo (6%). The most frequent mutations identified were missense (75%) followed by frameshift deletions (16%), frameshift duplications (5%), and splicing mutations (3%). Considering the results obtained in the present study we support the use of WES as a form of first-line molecular genetic testing in DEEs.

Comparison of the effectiveness and safety of perampanel and oxcarbazepine as monotherapy in children and adolescents with newly diagnosed focal epilepsy

Objective: This study aims to compare the effectiveness and safety of perampanel and oxcarbazepine as monotherapy in children with focal epilepsy (FE). Methods: This is an ambispective, single-center, non-inferiority study comparing the effectiveness and safety of perampanel (PER) monotherapy and oxcarbazepine (OXC) monotherapy in children with newly diagnosed FE. The primary endpoint was a six-month seizure freedom rate. The secondary endpoints included retention, responder, and seizure freedom rates at 3, 6, and 12 months, respectively. Adverse events (AEs) were also recorded for both groups. Results: One hundred and thirty children and adolescents aged from 4 to 18years newly diagnosed with FE between May 2020 and November 2022 in Wuhan Children's Hospital were included. There were 71 patients in the PER group and 59 patients in the OXC group. In the per protocol set (PPS), 50 (78.1%) in the PER group and 43 (78.2%) in the OXC group completed six months of treatment without seizures. The lower 95% CI (66.0%-87.5%) limit of PER was higher than the non-inferiority margin of 62.4% (80% of the 6-month seizure freedom rate in the OXC group); PER was non-inferior to OXC. The 3-month and 12-month seizure freedom rates were 77.1% and 82.9% for the PER group, respectively, while they were 80.4% and 75.8% for the OXC group. There were no serious adverse events in both groups. Conclusion: PER showed comparable effectiveness and safety compared with OXC in children with newly diagnosed focal epilepsy, which might be an effective and safe treatment for children and adolescents with newly diagnosed FE. Clinical Trial Registration: Identifier ChiCTR2300074696.

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.

Perampanel for the treatment of people with idiopathic generalized epilepsy in clinical practice

OBJECTIVE

This study was undertaken to evaluate perampanel (PER) when used under real-world conditions to treat people with idiopathic generalized epilepsy (IGE) included in the PERaMpanel pooled analysIs of effecTiveness and tolerability (PERMIT) study.

METHODS

The multinational, retrospective, pooled analysis PERMIT explored the use of PER in people with focal and generalized epilepsy treated in clinical practice across 17 countries. This subgroup analysis included PERMIT participants with IGE. Time points for retention and effectiveness measurements were 3, 6, and 12 months (last observation carried forward, defined as "last visit," was also applied to effectiveness). Effectiveness was evaluated by seizure type (total seizures, generalized tonic-clonic seizures [GTCS], myoclonic seizures, absence seizures) and included ≥50% responder rate and seizure freedom rate (defined as no seizures since at least the previous visit). Safety/tolerability was monitored throughout PER treatment and evaluated by documenting the incidence of adverse events (AEs), including psychiatric AEs and those leading to treatment discontinuation.

RESULTS

The Full Analysis Set included 544 people with IGE (51.9% women, mean age = 33.3 years, mean epilepsy duration = 18.1 years). At 3, 6, and 12 months, 92.4%, 85.5%, and 77.3% of participants were retained on PER treatment, respectively (Retention Population, n = 497). At the last visit, responder and seizure freedom rates were, respectively, 74.2% and 54.6% (total seizures), 81.2% and 61.5% (GTCS), 85.7% and 66.0% (myoclonic seizures), and 90.5% and 81.0% (absence seizures) (Effectiveness Population, n = 467). AEs occurred in 42.9% of patients and included irritability (9.6%), dizziness/vertigo (9.2%), and somnolence (6.3%) (Tolerability Population, n = 520). Treatment discontinuation due to AEs was 12.4% over 12 months.

SIGNIFICANCE

This subgroup analysis of the PERMIT study demonstrated the effectiveness and good tolerability of PER in people with IGE when administered under everyday clinical practice conditions. These findings are in line with clinical trial evidence, supporting PER's use as broad-spectrum antiseizure medication for the treatment of IGE.

An In Vivo Electroencephalographic Analysis of the Effect of Riluzole against Limbic and Absence Seizure and Comparison with Glutamate Antagonists

BACKGROUND

Riluzole (RLZ) has demonstrated neuroprotective effects in several neurological disorders. These neuroprotective effects seem to be mainly due to its ability to inhibit the excitatory glutamatergic neurotransmission, acting on different targets located both at the presynaptic and postsynaptic levels.

METHODS

In the present study, we evaluated the effects of Riluzole (RLZ) against limbic seizures, induced by AMPA, kainate, and NMDA receptor agonists in Sprague-Dawley rats, and in a well-validated genetic model of absence epilepsy, the WAG/Rij rat. Furthermore, in this latter model, we also studied the effect of RLZ in co-administration with the competitive NMDA receptor antagonist, CPP, or the non-competitive AMPA receptor antagonist, THIQ-10c, on spike-wave discharges (SWDs) in WAG/Rij rats, to understand the potential involvement of AMPA and NMDA receptors in the anti-absence effect of RLZ.

RESULTS

In Sprague-Dawley rats, RLZ pretreatment significantly reduced the limbic seizure severity induced by glutamatergic agonists, suggesting an antagonism of RLZ mainly on NMDA rather than non-NMDA receptors. RLZ also reduced SWD parameters in WAG/Rij rats. Interestingly, the co-administration of RLZ with CPP did not increase the anti-absence activity of RLZ in this model, advocating a competitive effect on the NMDA receptor. In contrast, the co-administration of RLZ with THIQ-10c induced an additive effect against absence seizure in WAG/Rij rats.

CONCLUSIONS

these results suggest that the antiepileptic effects of RLZ, in both seizure models, can be mainly due to the antagonism of the NMDA glutamatergic receptors.

The Efficacy and Cognitive Impact of Perampanel Monotherapy in Patients with Self-Limited Epilepsy with Centrotemporal Spikes: A Retrospective Analysis

Objective

The third generation of antiepileptic medication (ASM) perampanel (PER), is mostly used as an add-on treatment for refractory epilepsy patients, and rarely used as a monotherapy. This study aims to observe the efficacy and assess the cognitive effects of PER monotherapy in patients with self-limited epilepsy with centrotemporal spikes (SeLECTS).

Patients and Methods

Through screening, 86 patients who were first diagnosed with SeLECTS and treated with PER monotherapy were included in this study. All patients were followed up at least 12 months, and Evaluated the efficacy and safety of PER by observing the seizures of patients. At the same time, we used the P300 event-related potential (ERP) component and Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) to evaluate the cognitive changes in children before and after treatment with PER.

Results

Ten percent of the children experienced adverse effects, such as dizziness, gait instability, and irritability. The drug retention rate at the last follow-up was 98.83%. Further more, the P300 ERP component and WISC-IV tests were performed no significant difference before and 12 months after PER monotherapy in SeLECTS children.

Conclusion

The third-generation of ASM PER monotherapy had a clear effect in children with SeLECTS. A small dose of PER can control seizures well and has no obvious effect on cognitive development.

Efficacy, tolerability and safety of perampanel in children and adolescents with epilepsy: Systematic review and meta-analysis

OBJECTIVE

Perampanel (PER) is a novel antiepileptic drug. The efficacy, tolerability and safety of PER in children and adolescents with epilepsy are still unclear. We aimed to study the efficacy and safety of PER in children and adolescents with epilepsy.

METHODS

We searched PubMed, Embase and Cochrane Library for relevant literature up to November 2022. Then we extracted the relevant data from eligible literature for systematic review and meta-analysis.

RESULT

Twenty-one studies involving 1968 children and adolescent patients were included. A reduction in seizure frequency of at least 50 percent occurred in 51.5% (95% confidence interval [CI] [47.1%, 55.9%]) of patients. Complete seizure cessation occurred in 20.6% (95%CI [16.7%, 25.4%]). The incidence of adverse events was 40.8% (95%CI [33.8%, 48.2%]). The most common adverse events were drowsiness 15.3% (95% CI [13.7%, 16.9%]), irritability 9.3% (95%CI [8.0%, 10.6%]), dizziness 8.4% (95% CI [7.2%, 9.7%]). The incidence of drug discontinuation due to adverse events was 9.2% (95% CI [7.0%, 11.5%]).

CONCLUSION

PER is generally well tolerated and effective in the treatment of epilepsy in children and adolescents. Larger studies are still needed to explore the application of PER in children and adolescents.

RISK OF BIAS AND LIMITATION

The funnel plot suggests that there may be publication bias in our meta-analysis, and most of the included studies were Asian, so there may be some racial differences.