Open-label study to investigate the safety and efficacy of adjunctive perampanel in pediatric patients (4 to <12 years) with inadequately controlled focal seizures or generalized tonic-clonic seizures

Efficacy and safety of perampanel as the first add-on therapy for children with epilepsy: A real-world multicenter prospective observational study

OBJECTIVE

Perampanel (PER) is a new anti-seizure medication (ASM) with a novel mechanism of action. This study aimed to determine the efficacy and safety of PER when added to monotherapy in children and adolescents (age, 4-18 years) with epilepsy.

METHOD

A multicenter prospective observational study was performed on children and adolescents (age, 4-18 years) with epilepsy who did not respond to ASM monotherapy between July 2021 and October 2022. PER was used as the first add-on therapy for the enrolled patients. Seizure-free rate, response rate, inefficacy rate, and drug retention rate were the main observation indicators during the 6 months of treatment. The patients were grouped based on treatment efficacy, and factors affecting efficacy were statistically analyzed. Adverse reactions were also recorded.

RESULTS

In this study, 93 patients with epilepsy were enrolled; among them, 9 patients were lost to follow-up (attrition rate, 9.7 %), and 84 were included in the analysis. Five patients with unknown efficacy discontinued taking PER early due to intolerable adverse reactions, and 79 patients (48 males, 31 females; mean age, 11.0 ± 3.9 years) finally remained. Genetic epilepsy and structural epilepsy were found in 22 patients and 36 patients, respectively. The mean duration of epilepsy history at the time of PER initiation was 4.0 ± 3.8 years, and the mean maintenance dosage of add-on PER was 4.5 ± 1.8 mg/day (equivalent to 0.14 ± 0.07 mg/kg/day). Among the 79 patients, 28 patients were diagnosed with epilepsy syndrome, including 13 patients having self-limited epilepsy with centrotemporal spikes, among whom 9 patients were seizure-free after adding PER during the 6-month follow-up (seizure-free rate, 69.2 %). For these 79 patients, the seizure-free, response, and retention rates at the end of follow-up were 45.6 %, 74.7 %, and 82.1 %, respectively. Among the 84 patients included in the analyses, adverse reactions occurred in 20 patients, mainly dizziness (8 patients), somnolence (6 patients), and irritability (4 patients), and 4 patients developed two adverse reactions simultaneously. Univariate analyses revealed statistically significant differences in efficacy between groups with structural and non-structural epilepsy and between groups with different baseline concomitant ASMs, suggesting that these factors affected the efficacy of PER as the first add-on therapy.

CONCLUSION

The overall response rate of PER as the first add-on therapy for children and adolescents with epilepsy who were followed up for 6 months was 74.7 %, indicating a relatively favorable safety and tolerability profile. The group of the baseline concomitant ASM administered and the etiological classification of epilepsy as either structural or non-structural were the factors influencing the efficacy of PER as the first add-on therapy.

Effectiveness and safety of mono- and add-on perampanel in pediatric patients with epilepsy: Experience from a single-center retrospective study

OBJECTIVE

To evaluate the effectiveness and safety of perampanel (PER) monotherapy (MT) or add-on therapy (AT) in Chinese children with epilepsy, as well as to evaluate the data from routine therapeutic drug monitoring (TDM) of PER for these pediatric patients.

METHODS

This retrospective and observational study was carried out on children with epilepsy (n = 340) from 2020 to 2022 at the Children's Hospital of Nanjing Medical University. Outcome measures were the responder rate (50% or greater seizure reduction), long-term efficacy, and tolerability (number and types of adverse events) in MT and AT groups. Concentrations of plasma PER obtained from these patients, if available, were analyzed too.

RESULTS

A total of 279 patients achieved at least 3 months of therapy, and 58.1% responded to PER therapy. 53 of the responders were seizure-free (32.7%). The retention rate dropped from 88.0% at 3 months to 40.6% at 12 months after treatment. Patients with MT achieved better seizure control than those with AT (P < 0.001). Intriguingly, PER exerted a very weak effect on patients who took more than 2 ASMs or were diagnosed with drug-resistant epilepsy. There were no significant differences in tolerability between the two groups. In addition, 179 patients were routinely monitored for PER, and the trough concentrations (C0 ) for these patients ranged from 30.0 to 992.0 ng/mL. However, no significant difference in C0 was observed between responders and nonresponders (333 ng/mL vs 325.5 ng/mL, P = 0.264).

SIGNIFICANCE

This study provides effectiveness and safety data on Chinese children with epilepsy treated with PER either as MT or as AT. The efficacy of patients receiving MT was much better than cases administered with more than 2 ASMs or diagnosed with drug-resistant epilepsy. In addition, no association was found between the plasma PER concentration and efficacy or safety.

PLAIN LANGUAGE SUMMARY

The study reports the effects of perampanel on seizures and adverse effects in Chinese patients with epilepsy younger than 18 years. Seizures decreased in 58.1% of patients (responders); in a third of these responders, seizures stopped. After treatment was started, 88% of patients were still on perampanel at 3 months and 40.6% at 12 months. People who were treated with perampanel only were more likely to respond than those who received perampanel and other antiseizure treatments, although perampanel was tolerated equally well in these groups. Plasma perampanel concentration did not predict seizure response or adverse effects.

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.

Plasma Concentration, Efficacy, and Tolerability of Perampanel in Chinese Pediatric Patients with Epilepsy: Real-World Clinical Experience

BACKGROUND

Information on the efficacy and plasma concentration of perampanel (PER) in Chinese pediatric patients with epilepsy is limited. Therefore, this real-world retrospective study aimed to assess the efficacy, tolerability, and plasma concentration of the maximum dose of PER for epilepsy treatment in Chinese pediatric patients.

METHODS

A total of 107 pediatric patients from 2 hospitals in China were enrolled in this study. The plasma concentration of PER was determined using ultrahigh-performance liquid chromatography. The primary efficacy endpoint was the seizure reduction rate after PER treatment at the last follow-up.

RESULTS

The response rate to PER therapy was 59.8% (64/107). The authors observed that patients younger than 6 years of age (n = 49) showed a significantly lower concentration-to-dose ratio than patients with ages between 6 and 14 years (n = 58) (2.2 ± 1.7 vs. 3.0 ± 1.8 mcg·mL -1 ·kg·mg -1 , respectively; P < 0.05). Patients who received enzyme-inducing antiseizure medication had significantly lower concentration-to-dose ratios than those who did not receive enzyme-inducing antiseizure medication (EIASM) (2.1 ± 1.8 vs. 3.1 ± 2.0 mcg·mL -1 ·kg·mg -1 , P < 0.05). A total of 37 patients (34.6%) reported treatment adverse events. Patients with somnolence and irritability had a significantly higher PER plasma concentration than the "no treatment-emergent adverse effect" groups ( P < 0.05).

CONCLUSIONS

PER is an effective and well-tolerated treatment option for patients with epilepsy. To ensure the clinical efficacy and safety of PER in pediatric patients, it is necessary to monitor its plasma concentrations.

The Cognitive and Behavioural Effects of Perampanel in Children with Neurodevelopmental Disorders: A Systematic Review

In children and adolescents with epilepsy, neurodevelopmental comorbidities can impair the quality of life more than seizures. The aim of this review was to evaluate the cognitive and behavioural effects of perampanel (PER) in the paediatric population. We performed a systematic search of the literature, selecting studies published in English including children and adolescents with epilepsy treated with PER. Cognitive and behavioural outcomes were assessed through validated neuropsychological standardised scales. Eighteen studies involving 3563 paediatric patients were included. Perampanel did not impair general cognitive functions and visuospatial skills, whereas a slight improvement in verbal memory and a decline in attentional power were detected. In adolescents with refractory epilepsies, high doses and/or rapid titration of PER and an underlying psychiatric disorder were risk factors for developing or worsening psychiatric outcomes such as anger, aggressiveness, and irritability. Data on children and adolescents treated with new antiseizure medications are scant, and neuropsychiatric effects are tricky to be detected during developmental age. According to the currently available evidence, PER showed an overall favourable risk-benefit profile. Pharmacodynamics, co-administration of other antiseizure medications, and family and personal history of neuropsychiatric disorders should be considered before PER treatment.

Pathophysiology to Risk Factor and Therapeutics to Treatment Strategies on Epilepsy

Epilepsy represents a condition in which abnormal neuronal discharges or the hyperexcitability of neurons occur with synchronicity, presenting a significant public health challenge. Prognostic factors, such as etiology, electroencephalogram (EEG) abnormalities, the type and number of seizures before treatment, as well as the initial unsatisfactory effects of medications, are important considerations. Although there are several third-generation antiepileptic drugs currently available, their multiple side effects can negatively affect patient quality of life. The inheritance and etiology of epilepsy are complex, involving multiple underlying genetic and epigenetic mechanisms. Different neurotransmitters play crucial roles in maintaining the normal physiology of different neurons. Dysregulations in neurotransmission, due to abnormal transmitter levels or changes in their receptors, can result in seizures. In this review, we address the roles played by various neurotransmitters and their receptors in the pathophysiology of epilepsy. Furthermore, we extensively explore the neurological mechanisms involved in the development and progression of epilepsy, along with its risk factors. Furthermore, we highlight the new therapeutic targets, along with pharmacological and non-pharmacological strategies currently employed in the treatment of epileptic syndromes, including drug interventions employed in clinical trials related to epilepsy.

Long-term safety and efficacy of adjunctive brivaracetam in pediatric patients with epilepsy: An open-label, follow-up trial

OBJECTIVE

This study was undertaken to evaluate the long-term safety, tolerability, and efficacy of adjunctive brivaracetam (BRV) treatment in pediatric patients with epilepsy.

METHODS

A phase 3, open-label, multicenter, long-term follow-up trial (N01266; NCT01364597) was conducted on patients (aged 1 month to <17 years at core trial entry; direct enrollers aged 4 to <17 years) treated with BRV. Outcomes included treatment-emergent adverse events (TEAEs), behavior assessments (Achenbach Child Behavior Checklist [CBCL], Behavior Rating Inventory of Executive Function [BRIEF]/BRIEF-Preschool version [BRIEF-P]), and efficacy outcomes (percent change in focal seizure frequency, 50% responder rate for all seizure types for patient subgroups <2 years and ≥2 years of age using daily record card data).

RESULTS

Of 257 patients with ≥1 dose of BRV (141 [54.9%] male; mean age = 8.0 years [SD = 4.5]), 36 patients were <2 years of age, and 72.0% of patients had a history of focal seizures. Mean BRV exposure was 3.2 patient-years. At least one TEAE occurred in 93.4% patients, and 32.3% had serious TEAEs. Seven patients died during the trial; no deaths were considered treatment-related. Patients ≥2 years of age had a median decrease in 28-day adjusted focal seizure frequency of 62.9%, and 50.9% had a ≥50% response in all seizures. Patients <2 years of age had a median decrease in 28-day adjusted focal seizure frequency of 96.9%, and 68.2% had a ≥50% response in all seizures. Kaplan-Meier estimated treatment retention was 72.7%, 64.5%, 57.8%, 53.3%, 50.1%, and 44.8% at 1, 2, 3, 4, 5, and 6 years, respectively. Mean changes (baseline to last evaluation) for all Achenbach CBCL and BRIEF-P/BRIEF subscale scores were negative, reflecting stability/slight improvement.

SIGNIFICANCE

Long-term adjunctive BRV treatment was generally well tolerated and efficacious in reducing seizure frequency, and had high retention rates, with generally stable cognitive/behavioral scores in pediatric patients with epilepsy.

Effectiveness, safety and tolerability of perampanel by age group when used to treat people with focal and generalized epilepsy in clinical practice: The PERMIT Extension study

OBJECTIVE

To assess the effectiveness and safety/tolerability of perampanel (PER) in people with epilepsy (PWE) treated in everyday clinical practice for focal and generalized seizures, both in the total cohort and by age group.

METHODS

The PERMIT Extension study was a pooled analysis of data from PWE included in two large previous clinical practice studies (PERMIT and PROVE). Retention was assessed over 12 months. Effectiveness was assessed based on total seizures and by seizure type (focal and generalized) after 3, 6, and 12 months of PER treatment and at final follow-up (last observation carried forward; "last visit"); assessments included responder rate (≥50% seizure frequency reduction from baseline) and seizure freedom rate (no seizures since at least the previous visit). Safety/tolerability was assessed throughout PER treatment by evaluating adverse events (AEs). All assessments were conducted for the total population and by age category (<12, ≥12 to <18, ≥18 to <65, and ≥65 years at baseline).

RESULTS

Full Analysis Set included 6,822 PWE (51.1% female; mean age, 36.9 years; mean duration of epilepsy 21.4 years) with 6,433, 4,648, and 6,233 PWE assessed for retention, effectiveness, and safety/tolerability, respectively. The majority of PWE (81.1%) were aged 18-64 at baseline, with 4.5% aged <12 years, 8.4% aged 12-17 years, and 5.9% aged ≥65 years. In the overall population, retention rates at 3, 6, and 12 months were 88.0%, 77.6%, and 61.4%, respectively; responder rates at 12 months were 58.5% for total seizures, 54.6% for focal seizures, and 77.7% for generalized seizures, and corresponding seizure freedom rates were 23.6%, 19.0%, and 51.3%, respectively. PER was effective regardless of age category, although effectiveness was greatest in PWE aged ≥65 years, for both focal and generalized seizures. In the overall population, the incidence of AEs was 49.2% and the most frequent AEs (≥5% of PWE) were dizziness/vertigo (13.4%), somnolence (8.8%), irritability (7.3%), and behavioral disorders (5.3%); AEs led to treatment discontinuation in 18.3% of PWE over 12 months. The incidence of AEs and the discontinuation rate due to AEs increased with increasing age (55.0% and 23.9%, respectively, in PWE aged ≥65 years).

CONCLUSION

In this study, the largest pooled analysis of PER clinical practice data conducted to date, PER was shown to be effective and generally well tolerated when used to treat people with focal or generalized epilepsy in everyday clinical practice, regardless of age category. No new or unexpected side effects emerged following long-term use in the real-world setting.

Long-term efficacy and safety of adjunctive perampanel in pediatric patients aged 4-19 years with epilepsy: a real-world study

This study determined the 24-month outcomes of perampanel treatment in children and adolescents with epilepsy. The percentage of ≥ 50% responders was 47.3% (139/294) at 12 months and 49.0% (144/294) at 24 months. A 100% reduction in seizures for more than 12 months was observed in 12.2% (36/294). Discontinuation occurred in 39.8% (117/294). The most common reason for discontinuation was adverse events (29.1%, 34/117). Baseline seizure frequency was higher in children aged < 12 years than in patients aged ≥ 12 years; however, the percentage of seizure reduction and ≥ 50% responders did not significantly differ between the two groups. The rate of early discontinuation was higher (p < 0.001) and the duration of perampanel treatment was shorter in children aged < 12 years (p = 0.001). Most children aged < 12 years discontinued PER due to inadequate effectiveness, while adverse event was the most common reason in patients aged ≥ 12 years (p = 0.045). Only slow titration was significantly associated with ≥ 50% of responders. In conclusion, this study showed that perampanel can be utilized effectively and safely for a prolonged period in pediatric patients aged 4 to < 12 years, as well as in patients aged 12 years and older.

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.

Efficacy of perampanel in pediatric epilepsy with known and presumed genetic etiology

OBJECTIVE

The efficacy of perampanel (PER) in pediatric epilepsy with specific etiologies has not been well established. Here, we investigated outcome and predictors of PER treatment in a pediatric cohort with known and presumed genetic etiology.

METHODS

We included pediatric patients with potential genetic epilepsy who received PER treatment and underwent whole-exome sequencing (WES) from January 2020 to September 2021. All patients were followed up for >12 months.

RESULTS

A total of 124 patients were included. Overall response rates were 51.6% and 49.6% at 6 months and 12 months, respectively. Pathogenic or likely pathogenic variants in 27 multiple genes were detected among 58 patients (46.8%) by WES. On performing multivariate logistic regression analysis, only developmental delay (OR = 0.406, P = 0.042) was a negative predictor of treatment response. However, the seizure onset age, positive WES results, and number of ASMs before PER administration were not significantly. Thirteen carriers with variants in the SCN1A gene showed a better response compared to eight patients with other sodium channels (P = 0.007), and to the other 45 patients with positive WES results (OR = 7.124, 95% CI = 1.306-38.860, P = 0.023). Adverse events were only reported in 23 patients, the most common being emotional problems.

INTERPRETATION

PER is safe and efficacious in pediatric patients with known and presumed genetic etiology. The response rate is comparable to that reported in other pediatric populations, and lower among those with developmental delay. A gene-specific response to PER is found along with better efficacy links to pathogenic variants in the SCN1A gene.

The broad-spectrum activity of perampanel: state of the art and future perspective of AMPA antagonism beyond epilepsy

Glutamate is the brain's main excitatory neurotransmitter. Glutamatergic neurons primarily compose basic neuronal networks, especially in the cortex. An imbalance of excitatory and inhibitory activities may result in epilepsy or other neurological and psychiatric conditions. Among glutamate receptors, AMPA receptors are the predominant mediator of glutamate-induced excitatory neurotransmission and dictate synaptic efficiency and plasticity by their numbers and/or properties. Therefore, they appear to be a major drug target for modulating several brain functions. Perampanel (PER) is a highly selective, noncompetitive AMPA antagonist approved in several countries worldwide for treating different types of seizures in various epileptic conditions. However, recent data show that PER can potentially address many other conditions within epilepsy and beyond. From this perspective, this review aims to examine the new preclinical and clinical studies-especially those produced from 2017 onwards-on AMPA antagonism and PER in conditions such as mesial temporal lobe epilepsy, idiopathic and genetic generalized epilepsy, brain tumor-related epilepsy, status epilepticus, rare epileptic syndromes, stroke, sleep, epilepsy-related migraine, cognitive impairment, autism, dementia, and other neurodegenerative diseases, as well as provide suggestions on future research agenda aimed at probing the possibility of treating these conditions with PER and/or other AMPA receptor antagonists.

Open-label study to investigate the safety and efficacy of adjunctive perampanel in pediatric patients (aged 4 to <12 years) with inadequately controlled focal-onset seizures: Japanese subgroup analysis

PURPOSE

To evaluate the safety and tolerability of adjunctive perampanel in a Japanese subpopulation of Study 311 (NCT02849626), which was a global, multicenter, open-label, single-arm study of children (aged 4 to <12 years) with inadequately controlled focal-onset seizures (FOS), with or without focal to bilateral tonic-clonic seizures (FBTCS) or generalized tonic-clonic seizures (GTCS).

METHODS

Study 311 comprised a Core Study, Extension A, and Extension B; this report focuses on the Japanese patient subgroup in the Core Study only. In the Core Study, Japanese patients (FOS only) received adjunctive perampanel ≤12 mg/day in a 23-week Treatment Phase. Endpoints included safety/tolerability (primary) and median percent change in seizure frequency per 28 days from baseline. Patients were stratified by age and concomitant enzyme-inducing anti-seizure medication (EIASM) use.

RESULTS

Of 65 enrolled Japanese patients, 56 completed the Core Study and nine withdrew. The most common reason for discontinuation was adverse events (AEs) (n = 4 [6.2%]). The mean (standard deviation) daily dose of perampanel in Japanese FOS patients was 5.8 (2.2) mg/day. During the Core Study, treatment-emergent AEs (TEAEs) were reported by 89% of Japanese patients, most commonly nasopharyngitis (28%) and somnolence (28%). The median percent reduction in seizure frequency per 28 days from baseline was 37% and the lower limit of the 95% CI was greater than 10.5%, satisfying the pre-defined efficacy criteria. Perampanel was effective regardless of age or concomitant EIASM use.

CONCLUSION

Perampanel as adjunctive therapy is generally safe, well-tolerated, and efficacious in Japanese children aged 4 to <12 years with FOS (with/without FBTCS).

Efficacy, Tolerability, and Safety of Treatment With Perampanel in Pediatric Patients With Epilepsy Aged ≥4 Years: A Real-Life Observational Study

Purpose: The safety and effectiveness of perampanel in clinical settings involving Chinese pediatric patients are limited, as perampanel has only recently been approved for use in China, in September 2019. We aimed to evaluate the efficacy and tolerability of perampanel as an adjunctive therapy for pediatric patients with epilepsy aged ≥ 4 years in Xinjiang, Northwest China. Methods: Efficacy was assessed by measuring changes in seizure frequency at 3-, 6-, and 12-month follow-up compared with baseline. The baseline was 3 months before the addition of perampanel, and the seizure frequency was based on the patients' seizure diary. The safety and tolerability depended on the type and frequency of any adverse event during epilepsy treatment across all pediatric patients. Results: Overall, 67 pediatric patients from 2 different hospitals were enrolled in the study. Among the pediatric patients with seizures during the baseline period, the effective rates for all seizure types at 3, 6, and 12 months were 59.1%, 58.7%, and 57.4%, respectively. During perampanel treatment, 34 patients (50.7%) experienced at least 1 adverse reaction. Conclusion: Overall, this real-world retrospective study of pediatric patients validated that perampanel is an effective treatment option as an adjunctive therapy among pediatric patients with epilepsy aged ≥4 years.

Anti-seizure efficacy of perampanel in two established rodent models of early-life epilepsy

Early-life seizures can be refractory to conventional antiseizure medications (ASMs) and can also result in chronic epilepsy and long-term behavioral and cognitive deficits. Treatments targeting age-specific mechanisms contributing to epilepsy would be of clinical benefit. One such target is the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) subtype of excitatory glutamate receptor, which is upregulated in the developing brain. Perampanel is a non-competitive, selective AMPAR antagonist that is FDA-approved for focal onset seizures (FOS) or primary generalized tonic-clonic seizures (PGTC) in children and adults. However, the efficacy of perampanel treatment in epilepsy patients younger than 4 years has been less documented. We thus tested the efficacy of perampanel in two early-life seizure models: (1) a rat model of hypoxia-induced neonatal seizures and (2) a mouse model of Dravet syndrome with hyperthermia-induced seizures. Pretreatment with perampanel conferred dose-dependent protection against early-life seizures in both experimental models. These findings suggest that AMPAR-mediated hyperexcitability could be involved in the pathophysiology of early-life seizures, which may be amenable to treatment with perampanel.

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

Introduction

The PERMIT study is the largest pooled analysis of perampanel (PER) clinical practice data conducted to date.

Methods

This post-hoc analysis of PERMIT investigated the effectiveness, safety and tolerability of PER when used as early add-on therapy (after failure of one or two previous antiseizure medications) in comparison with late add-on therapy (after failure of three or more previous antiseizure medications). Retention and effectiveness were assessed after 3, 6, and 12 months, and at the last visit (last observation carried forward). Effectiveness was assessed by seizure type (total seizures, focal seizures, generalized tonic-clonic seizures [GTCS]) and assessments included seizure freedom rate and responder rate. Safety and tolerability were assessed by evaluating adverse events (AEs) and discontinuation due to AEs.

Results

The Full Analysis Set included 1184 and 2861 PWE treated with PER as early and late add-on therapy, respectively. Compared to the late add-on subgroup, the early add-on subgroup was characterized by later mean age at epilepsy onset, shorter mean duration of epilepsy, lower rates of intellectual disability and psychiatric comorbidity, and lower frequency of seizures per month, suggesting a less severe form of epilepsy in this subgroup. After 12 months, retention was significantly higher in the early versus late add-on subgroup (67.7% vs. 62.4%; p = 0.004). At the last visit, responder rates in the early versus late add-on subgroup were significantly higher for total seizures (68.2% vs. 39.3%; p &lt; 0.001), focal seizures (65.0% vs. 36.8%; p &lt; 0.001) and GTCS (83.7% vs. 67.2%; p &lt; 0.001), as were seizure freedom rates (total seizures, 35.9% vs. 11.9% [p &lt; 0.001]; focal seizures, 29.4% vs. 8.7% [p &lt; 0.001]; GTCS, 69.0% vs. 48.1% [p &lt; 0.001]). Incidence of AEs was significantly lower in the early versus late add-on subgroup (42.1% vs. 54.7%; p &lt; 0.001), as was the rate of discontinuation due to AEs over 12 months (15.0% vs. 18.1%; p = 0.031).

Discussion

This study demonstrated that PER was effective and generally well tolerated when initiated as early or late add-on therapy, but it was significantly more effective and better tolerated when initiated early. These findings support PER's use as a broad-spectrum, early add-on therapy for use in PWE with focal and generalized seizures.

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.

Kainate Receptor Antagonists: Recent Advances and Therapeutic Perspective

Since the 1990s, ionotropic glutamate receptors have served as an outstanding target for drug discovery research aimed at the discovery of new neurotherapeutic agents. With the recent approval of perampanel, the first marketed non-competitive antagonist of AMPA receptors, particular interest has been directed toward 'non-NMDA' (AMPA and kainate) receptor inhibitors. Although the role of AMPA receptors in the development of neurological or psychiatric disorders has been well recognized and characterized, progress in understanding the function of kainate receptors (KARs) has been hampered, mainly due to the lack of specific and selective pharmacological tools. The latest findings in the biology of KA receptors indicate that they are involved in neurophysiological activity and play an important role in both health and disease, including conditions such as anxiety, schizophrenia, epilepsy, neuropathic pain, and migraine. Therefore, we reviewed recent advances in the field of competitive and non-competitive kainate receptor antagonists and their potential therapeutic applications. Due to the high level of structural divergence among the compounds described here, we decided to divide them into seven groups according to their overall structure, presenting a total of 72 active compounds.

Current Status of Pharmacokinetic Research in Children: A Systematic Review of Clinical Trial Records

BACKGROUND

Many medications have different pharmacokinetics in children than in adults. Knowledge about the safety and efficacy of medications in children requires research into the pharmacokinetic profiles of children's medicines. By analysing registered clinical trial records, this study determined how frequently pharmacokinetic data is gathered in paediatric drug trials.

METHODS

We searched for the pharmacokinetic data from clinical trial records for preterm infants and children up to the age of 16 from January 2011 to April 2022. The records of trials involving one or more drugs in preterm infants and children up to the age of 16 were examined for evidence that pharmacokinetic data would be collected.

RESULTS

In a total of 1483 records of interventional clinical trials, 136 (9.17%) pharmacokinetic data involved adults. Of those 136 records, 60 (44.1%) records were pharmacokinetics trials involving one or more medicines in children up to the age of 16. 20 (33.3 %) in America, followed by 19 (31.6 %) in Europe. Most trials researched medicines in the field of infection or parasitic diseases 20 (33.3%). 27 (48.2%) and 26 (46.4%) trials investigated medicines that were indicated as essential medicine.

CONCLUSION

The pharmacokinetic characteristics of children's drugs need to be better understood. The current state of pharmacokinetic research appears to address the knowledge gap in this area adequately. Despite slow progress, paediatric clinical trials have experienced a renaissance as the significance of paediatric trials has gained international attention. The outcome of paediatric trials will have an impact on children's health in the future. In recent years, the need for greater availability and access to safe child-size pharmaceuticals has received a lot of attention.

Effectiveness and safety of perampanel as adjunctive therapy among Chinese patients with focal-onset epilepsy: A real-world prospective observational study

OBJECTIVE

Perampanel (PER) has previously been shown to be effective and tolerable when used as an adjunctive therapy for patients with focal-onset seizures (FOS). This study aimed to evaluate the effect of PER as adjunctive therapy for patients with FOS in the Chinese population under real-world conditions for 1 year.

METHODS

A prospective, single-center, 1-year observational study was conducted at Huashan Hospital, enrolling both under age (≥4 years old) and adult patients with FOS. Response to PER was assessed at 3-, 6-, and 12-month checkpoints by analyzing the 50 % responder rate, the seizure-free rate, and reduction in seizure frequency.

RESULTS

One hundred and eight patients (mean age: 26.6 years, 56.5 % males) with FOS were included, with seventy-six patients finishing the 1-year follow-up (retention rate: 70.4 %, mean PER dose: 4.3 mg/day). The seizure frequency was reduced significantly at 3, 6, and 12 months relative to baseline (p < 0.001 for each seizure type). At 12 months, the responder rate was 65.8 %, and the seizure-free rate was 39.5 %. A significantly higher responder rate was found in patients with focal to bilateral tonic-clonic seizures (p = 0.024), among which the percentage of patients with sleep-related epilepsy was significantly high (p = 0.045). Responders had a lower number of concomitant anti-seizure medications (ASMs) than the non-responders (p = 0.009). Drug-related adverse events (AEs) were reported in 37 % of patients, mostly mild or moderate, and the patients who experienced AEs had a higher daily dose of PER than those who did not (p = 0.026).

CONCLUSION

Perampanel, an add-on therapy for focal-onset seizures, was found to be effective and tolerable in Chinese patients at 12 months.

Safety evaluation of perampanel as monotherapy or first adjunctive therapy in patients with epilepsy

INTRODUCTION

There is a need for anti-seizure medications (ASMs) that are well tolerated and effective as monotherapy or first adjunctive therapy to reduce the need for adjunctive ASMs to treat newly diagnosed epilepsy, and to reduce the number of concomitant ASMs in patients with refractory epilepsy. Although the pivotal trials of perampanel evaluated its adjunctive use in patients with refractory seizures, open-label/real-world studies support its use in first/second-line settings.

AREAS COVERED

This paper reviews the pharmacology, efficacy, and safety/tolerability of perampanel, focusing on its use as monotherapy or first adjunctive therapy. The safety of perampanel in special populations and its safety/tolerability compared with that of other ASMs is also discussed.

EXPERT OPINION

Perampanel is a favorable candidate for initial or first adjunctive therapy due to its favorable efficacy and safety/tolerability as monotherapy and adjunctive therapy, its long half-life and ease of use, and its limited drug-drug interactions. The proposed mitigation strategies for managing the risk of serious psychiatric adverse events are appropriate patient selection, use of low doses, and slow titration. The growing body of evidence might shift current treatment strategies towards the early use of perampanel and its use at a low dose (4 mg/day).

The real-world effectiveness and safety of perampanel in Europe: A scoping review

In order to characterize the real-world effectiveness and safety of perampanel during clinical use in Europe, we conducted a structured literature search and scoping review of real-world studies conducted in Europe in adolescents (aged ≥ 12 years) or adults who were prescribed perampanel for focal epilepsy or primary generalized tonic-clonic seizures in the context of idiopathic generalized epilepsy, published between January 2016 and July 2021. We identified 29 relevant studies (20 retrospective and 9 prospective) in 3608 patients; median study duration was 12 months. Most patients (76.1%) were receiving two or more antiseizure drugs (ASDs) when perampanel was initiated. The maintenance perampanel dose ranged from 2 to 16 mg/day (most commonly 6 mg/day). Retention rate at 12 months ranged from 46% to 90.5% (median 71.1%). The proportion of patients who were free of seizures during perampanel ranged from 1.8% to 84.6%, but were consistently below 20% in studies where patients had received an average of ≥5 prior ASDs and above 20% where patients had received an average of <5 prior ASDs. The proportion of patients who achieved ≥50% reduction in seizures during perampanel ranged from 20.0% to 85.7%. Across all studies, the incidence of adverse events (AEs) ranged from 18.2% to 67.4% (median 37.1%) and discontinuation due to AEs from 6.2% to 56% (median 12.5%). Discontinuation rates tended to be higher in UK studies than in studies from Italy or Spain. The most commonly reported individual AEs were dizziness/vertigo (median incidence 13.7%), somnolence (median 11.9%), aggression (median 9.8%), irritability (median 9.1%), and cognitive deficits (median 7.0%). There was no relationship between the overall rate of AEs and perampanel dose, perampanel plasma levels, or number of concomitant medications. Our global overview of European observational studies with perampanel provides evidence that this agent is effective and safe in clinical practice in a range of countries, patients, and settings.

Intranasal delivery of lipid-based nanosystems as a promising approach for brain targeting of the new-generation antiepileptic drug perampanel

Perampanel (PER), a new-generation antiepileptic drug effective against different types of seizures, has already demonstrated a potential in status epilepticus therapy. Considering the growing interest of intranasal (IN) administration for nose-to-brain delivery, PER could be envisioned as a good candidate for this route, especially if formulated in a lipid-based nanosystem. With that purpose, a hydrophobic formulation (FO1.2) and a self-microemulsifying drug delivery system (SMEDDS) (FH5) loaded with PER were developed and characterized. Following PER IN administration (1 mg/kg) to mice, its pharmacokinetics was characterized and compared with intravenous and oral routes. Histopathological toxicity was also examined after a 7-day repeated dose study. FH5 homogeneously formed nanodroplets upon dispersion (20.07 ± 0.03 nm), showing a sustained in vitro PER release profile up to 4 h. By IN route, PER brain delivery was more extensive with FH5 (C_max and AUC of 52.32 ng/g and 190.35 ng.h/g for FO1.2; 93.87 ng/g and 257.75 ng.h/g for FH5). Maximum brain concentration and total brain exposure were higher than those obtained after oral dosage, with maximum PER concentrations reached significantly faster than post-oral administration (15 min vs 2 h). An improvement in PER plasmatic concentration was also obtained, demonstrated by high relative bioavailability values (134.1% for FH5 and 107.8% for FO1.2). PER absolute plasma bioavailability after IN delivery was 55.5% for FH5 and 44.6% for FO1.2, ensuring a somewhat improved targeting of PER to the brain by the IN route compared to the IV route. No signs of toxicity were found by histopathologic evaluation. Results suggest that IN administration of PER might be a feasible and safe approach for acute and chronic epilepsy management, especially using delivery systems as SMEDDS.

Movement Disorders Secondary to Novel Antiseizure Medications in Pediatric Populations: A Systematic Review and Meta-analysis of Risk

Novel antiseizure medications are thought to be safer than their conventional counterparts, though no dedicated analysis of movement disorder risk among pediatric populations using novel antiseizure medications has been completed. We report a systematic review with meta-analysis describing the relationship between novel antiseizure medications and movement disorders in pediatrics.MEDLINE, EMBASE, and the World Health Organization's International Clinical Trials Registry Platform were searched up to October 2020 for randomized controlled trials investigating novel antiseizure medications in pediatric populations. Antiseizure medications included lacosamide, perampanel, eslicarbazepine, rufinamide, fenfluramine, cannabidiol, and brivaracetam. Outcomes were pooled using random effects models; risk difference (RD) and 95% confidence intervals (CIs) were calculated.Twenty-three studies were selected from 1690 nonredundant manuscripts (n = 1912 total). There was a significantly increased risk of movement disorders associated with perampanel (RD 0.07, 95% CI 0.01-0.13; n = 133), though only 1 relevant trial was found. No increased risk of movement disorders was found with other antiseizure medications.Our findings indicate most novel antiseizure medications are safe to use in pediatric populations with respect to movement disorders. However, findings were limited by quality of adverse event reporting.

Cost-effectiveness of perampanel as an adjunctive treatment for uncontrolled focal seizures in pediatric patients: a Chinese perspective

Background

The incidence of epilepsy is 41-187 per 100,000 person-year in children. The health care costs for children with uncontrolled epilepsy is a huge burden. Perampanel (PER) was effective, safety and well-tolerated as add-on therapy in pediatric patients aged 4 to <12 years with uncontrolled focal seizures. However, there is still limited evidence on cost-effectiveness of PER in pediatric patients. We aimed to evaluate the cost-effectiveness of PER as an add-on therapy for pediatric patients with uncontrolled focal seizures.

Methods

A Markov model was established to conduct an analysis from the perspective of the Chinese health system and society. The incremental cost-effectiveness ratio (ICER) of patients using PER and conventional therapy versus patients using conventional therapy alone were estimated and compared. The transition probability of the response level, health state utility values, and costs were derived from clinical trials and the literature. Costs, including medical, drug, transportation and indirect costs, were calculated. We performed 1-way sensitivity analyses and probabilistic sensitivity analyses. A subgroup analysis of different ages was also conducted.

Results

The base-case analysis indicated that compared to maintaining conventional therapy, adding PER as an adjuvant drug therapy had an increased cost of $3,449.85 over 5 years, with an incremental quality-adjusted life years (QALY) value of 0.40, resulting in an ICER of $8,582.58 per additional QALY. The health state utility value had the greatest effect on the ICER. The probabilistic sensitivity analyses showed that the probability of PER being cost-effective was 76.72% at a willingness-to-pay of $11,293/QALY. The ICER of the subgroup ranged from $7,167.95/QALY to $19,710.96/QALY.

Conclusions

Our study demonstrated that PER is a cost-effective add-on therapy for pediatric patients.

A post-approval observational study to evaluate the safety and tolerability of perampanel as an add-on therapy in adolescent, adult, and elderly patients with epilepsy

OBJECTIVE

Perampanel is a once-daily oral anti-seizure medication for focal-onset seizures, with or without focal to bilateral tonic-clonic seizures (FBTCS), and generalized tonic-clonic seizures. Study 402 (NCT02033902) collected safety information on clinically important treatment-emergent adverse events (TEAEs) from real-world clinical practice in patients aged ≥12 years with refractory epilepsy who were receiving perampanel as an add-on therapy.

METHODS

Study 402 was a multicenter, observational, 52-week cohort study conducted in Austria, Belgium, Czech Republic, Denmark, France, Israel, Sweden, and the United Kingdom. Safety data were gathered prospectively from patients at clinic visits. The primary endpoint was the incidence of clinically important TEAEs defined as dizziness; blurred vision; somnolence; aggression; balance disorders (including ataxia and falls); weight gain; suicidality; drug abuse, misuse, dependence, and withdrawal; skin photosensitivity; and unintended pregnancy while taking levonorgestrel-containing contraceptives. Off-label use of perampanel and outcomes associated with any suspected drug-drug interaction were also monitored and recorded. Secondary endpoints included the Hospital Anxiety and Depression Scale (HADS) and Clinical Global Impression of Change.

RESULTS

Of 483 patients in the Safety Analysis Set, mean (standard deviation [SD]) age was 38.3 (15.1) years, 48.4% were female, mean (SD) time since diagnosis was 23 (14.8) years, 56.5% had focal impaired awareness seizures, and 48.7% had FBTCS. Overall, 243 (49.3%) patients treated with perampanel completed the study and 227 (46.0%) patients discontinued. The most common primary reason for discontinuation was adverse events (n = 130 [26.4%]). A total of 301 (62.3%) patients reported at least one TEAE, of which 45 (15.0%) patients had severe TEAEs and 256 (85.0%) patients had TEAEs judged as mild to moderate in severity. Overall, 51 (10.6%) patients had serious TEAEs, including two deaths that were judged as not related to perampanel, and 136 (28.2%) patients experienced a TEAE that led to treatment discontinuation. Clinically important TEAEs were reported by 153 (31.7%) patients, with the most common being dizziness (13.9%), balance disorders (5.6%), aggression (5.4%), and weight gain (5.4%). In general, the frequencies of clinically important TEAEs were lower in this study compared with previous interventional clinical studies, except for the incidence of suicidality (2.1% vs 1.0%) and aggression (5.4% vs 5.1%). Mean total HADS scores were similar at the end of the study compared with baseline; at the end of treatment, most (>60%) patients had no shift in HADS score category; ∼15% of patients moved to a worse category vs baseline and ∼20% of patients moved to an improved category vs baseline for both anxiety and depression. Based on investigator assessment, disease severity was improved in 185/415 (44.6%) patients. A subanalysis in elderly patients aged ≥65 years showed similar results to the overall population.

CONCLUSIONS

The data from this observational study are consistent with the known safety profile of perampanel derived from previous interventional phase II and III clinical studies. No unusual or unexpected TEAEs were observed in this real-world clinical practice setting.

Perampanel as first add-on antiseizure medication: Italian consensus clinical practice statements

Background

When use of a single antiseizure medication (ASM) fails to induce seizure remission, add-on therapy is justified. Perampanel (PER) is approved in Europe as adjunctive therapy for focal, focal to bilateral tonic-clonic seizures and generalized tonic-clonic seizures. Aim of the study was to establish whether PER is suitable for first add-on use.

Methods

A Delphi methodology was adopted to assess consensus on a list of 39 statements produced by an Expert Board of 5 epileptologists. Using an iterative process, statements were finalized by a Delphi Panel of 84 Italian pediatric and adult neurologists. Each statement was rated anonymously to determine level of agreement on a 9-point Likert scale. Consensus was established as agreement by at least 80% of the panelists. The relevance of each statement was also assessed on a 3-point scale.

Results

Consensus was achieved for 37 statements. Characteristics of PER considered to justify its use as first add-on include evidence of a positive impact on quality of life based on long term retention data, efficacy, tolerability, and ease of use; no worsening of cognitive functions and sleep quality; a low potential for drug interactions; a unique mechanism of action. Potential unfavorable factors are the need for a relatively slow dose titration; the potential occurrence of behavioral adverse effects; lack of information on safety when used in pregnancy; limited access to plasma PER levels.

Conclusion

Perampanel has many features which justify its use as a first add-on. Choice of an ASM as first add-on should be tailored to individual characteristics.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-021-02450-y.

PERMIT study: a global pooled analysis study of the effectiveness and tolerability of perampanel in routine clinical practice

The PERaMpanel pooled analysIs of effecTiveness and tolerability (PERMIT) study was a pooled analysis of data from 44 real-world studies from 17 countries, in which people with epilepsy (PWE; focal and generalized) were treated with perampanel (PER). Retention and effectiveness were assessed after 3, 6, and 12 months, and at the last visit (last observation carried forward). Effectiveness assessments included 50% responder rate (≥ 50% reduction in seizure frequency from baseline) and seizure freedom rate (no seizures since at least the prior visit); in PWE with status epilepticus, response was defined as seizures under control. Safety and tolerability were assessed by evaluating adverse events (AEs) and discontinuation due to AEs. The Full Analysis Set included 5193 PWE. Retention, effectiveness and safety/tolerability were assessed in 4721, 4392 and 4617, respectively. Retention on PER treatment at 3, 6, and 12 months was 90.5%, 79.8%, and 64.2%, respectively. Mean retention time on PER treatment was 10.8 months. The 50% responder rate was 58.3% at 12 months and 50.0% at the last visit, and the corresponding seizure freedom rates were 23.2% and 20.5%, respectively; 52.7% of PWE with status epilepticus responded to PER treatment. Overall, 49.9% of PWE reported AEs and the most frequently reported AEs (≥ 5% of PWE) were dizziness/vertigo (15.2%), somnolence (10.6%), irritability (8.4%), and behavioral disorders (5.4%). At 12 months, 17.6% of PWEs had discontinued due to AEs. PERMIT demonstrated that PER is effective and generally well tolerated when used to treat people with focal and/or generalized epilepsy in everyday clinical practice.

Optimal Use of Perampanel in Asian Patients with Epilepsy: Expert Opinion

Perampanel is a once-daily, first-in-class AMPA receptor antagonist approved for the treatment of epilepsy and exhibits broad-spectrum efficacy in a range of seizure types when used as both monotherapy and adjunctive therapy. Clinical studies and real-world evidence have demonstrated the advantages of initiating perampanel at low doses and utilizing a slow titration strategy. Initiating perampanel at an early stage has also been shown to be associated with better patient outcomes. However, the optimal use and place of perampanel in clinical practice has not yet been clearly defined for the Asian patient population. Use of perampanel in clinical practice varies markedly across the Asia region because of variation in knowledge, attitudes, and practice. There is currently no specific guidance on best practices for prescribing perampanel in Asian patients or how to optimize treatment strategies to maximize adherence. A group of epilepsy experts attended a virtual meeting in September 2020 to discuss their experience with using perampanel in the Asian practice setting, including their views regarding appropriate patient populations, optimal starting and maintenance doses, optimal titration regimens, key barriers to adherence, and prevention and management of adverse events. This article summarizes key clinical and real-world evidence for perampanel and consolidates the experts’ opinions on optimization of perampanel prescribing and adherence in real-world practice, providing practical strategies for clinicians to implement to improve outcomes for people with epilepsy in Asia.

Perampanel and Visuospatial Skills in Children With Epilepsy

Introduction: Perampanel (PER) is a non-competitive AMPA glutamate receptor antagonist approved for focal and generalized seizures as add-on therapy. PER does not seem to negatively affect the cognitive profile in children and adolescents, but its influence on visuospatial abilities is still to be assessed. The aim of our study was to assess visuospatial skills through a standardized neuropsychological evaluation in adolescents taking PER for 12 months.

Methods: Our sample included 46 adolescents aged 12–18 years with focal and generalized drug-resistant epilepsy already in therapy with one or two antiseizure medications. Changes in visuospatial perception and memory were assessed by the Rey–Osterrieth Complex Figure Test at baseline (before taking PER) and after 12 months of pharmacological treatment. Executive functions and non-verbal intelligence were also assessed at baseline.

Results: After 12 months of PER therapy, the mean scores on the Rey–Osterrieth Complex Figure Test remained almost unchanged for both visuospatial perception and visuospatial memory skills. At baseline, visuospatial memory was related to executive function, and visuospatial perception was related to executive function and non-verbal intelligence.

Conclusions: Adjunctive treatment with PER did not negatively affect visuospatial skills. No adverse event effects have been reported after 12 months of follow-up, and this suggests a good tolerability in the middle-to-long term.

X-linked neonatal-onset epileptic encephalopathy associated with a gain-of-function variant p.R660T in GRIA3

The X-linked GRIA3 gene encodes the GLUA3 subunit of AMPA-type glutamate receptors. Pathogenic variants in this gene were previously reported in neurodevelopmental diseases, mostly in male patients but rarely in females. Here we report a de novo pathogenic missense variant in GRIA3 (c.1979G>C; p. R660T) identified in a 1-year-old female patient with severe epilepsy and global developmental delay. When exogenously expressed in human embryonic kidney (HEK) cells, GLUA3_R660T showed slower desensitization and deactivation kinetics compared to wildtype (wt) GLUA3 receptors. Substantial non-desensitized currents were observed with the mutant but not for wt GLUA3 with prolonged exposure to glutamate. When co-expressed with GLUA2, the decay kinetics were similarly slowed in GLUA2/A3_R660T with non-desensitized steady state currents. In cultured cerebellar granule neurons, miniature excitatory postsynaptic currents (mEPSCs) were significantly slower in R660T transfected cells than those expressing wt GLUA3. When overexpressed in hippocampal CA1 neurons by in utero electroporation, the evoked EPSCs and mEPSCs were slower in neurons expressing R660T mutant compared to those expressing wt GLUA3. Therefore our study provides functional evidence that a gain of function (GoF) variant in GRIA3 may cause epileptic encephalopathy and global developmental delay in a female subject by enhancing synaptic transmission.

Glutamate is the excitatory neurotransmitter in brain, abnormality of which causes excitotoxicity and diseases. Here we identified a pathogenic missense variant in GRIA3 gene in a female patient with severe epilepsy and global developmental delay. The X-linked GRIA3 gene encodes GLUA3, a subunit of glutamate receptors. Through electrophysiological analysis of the mutant GLUA3 in a cell line and mouse neurons, we found this mutant makes strengthened glutamate receptors. This study thus indicates that the variant causes epileptic encephalopathy and global developmental delay by enhancing glutamate signaling in brain.

A multivariable prediction model of a major treatment response for focal-onset seizures: A post-hoc analysis of Phase III trials of perampanel

OBJECTIVE

Although 50 % reduction in seizure frequency is a common efficacy endpoint in clinical trials of antiepileptic drugs (AEDs), 75 % or greater reductions may be required to improve patients' health-related quality of life. Identification of clinical factors that are associated with high responder rates may help to inform clinicians on which patients may optimally benefit from treatment. We evaluated potential predictive factors for achieving major treatment responses (≥75 % reduction in seizure frequency per 28 days from study baseline) in patients with drug-resistant focal-onset seizures, with/without focal to bilateral tonic-clonic (FBTC) seizures in perampanel trials designed for regulatory approval.

METHODS

Univariate analyses using logistic regression were performed using data from three double-blind, placebo-controlled Phase III studies of adjunctive perampanel (Studies 304 [NCT00699972], 305 [NCT00699582], 306 [NCT00700310]), and their open-label extension study (OLEx; Study 307 [NCT00735397]). For the double-blind studies, baseline seizure frequency, number of baseline AEDs, baseline seizure type, baseline concomitant enzyme-inducing AEDs (EIAEDs), baseline carbamazepine, lamotrigine, or valproic acid, age at diagnosis, time since diagnosis, etiology, and perampanel plasma concentration were included individually with study treatment. The same factors were included for the OLEx analysis except for plasma concentration and treatment. Variables found to be significant predictors for a major treatment response in univariate analyses were subsequently included in multivariable analyses using backwards and forwards selection.

RESULTS

In the double-blind studies, 175/1374 patients had a major response to placebo (n = 25) or perampanel (n = 150). The best predictors of a major treatment response in multivariable models with forwards and backwards selection were: the presence of FBTC seizures during baseline (P = 0.0002), higher perampanel plasma concentration (P < 0.0001), older age at diagnosis (P = 0.0024 and 0.0045, respectively), and lower baseline seizure frequency (P = 0.0364 and 0.0127, respectively). In the OLEx, 217/1090 patients had a major treatment response. The best predictors of a major treatment response in the final multivariable model, regardless of backwards or forwards selection, were a lower baseline seizure frequency (P = 0.0022), the absence of focal impaired awareness seizures during baseline (P = 0.0011), the presence of FBTC seizures during baseline (P = 0.0164), lower number(s) of baseline AEDs (P = 0.0002), the absence of EIAEDs during baseline (P = 0.0059), an older age at diagnosis (P = 0.0054), and absence of structural etiologies (P = 0.0138).

SIGNIFICANCE

These analyses of placebo-controlled and long-term extension trial data identified a number of potential predictive factors for patients with focal-onset seizures achieving a major treatment response. These factors may help guide clinicians when predicting a patient's response to treatment and optimizing individual treatment regimens.

Neurocognitive Effects of Antiseizure Medications in Children and Adolescents with Epilepsy

Impairments in cognition are common in epilepsy and may be caused or exacerbated by antiseizure medications (ASMs). Positive effects on cognition may also be seen with some ASMs. Cognitive outcomes are of particular concern in children who may be at an increased risk of cognitive adverse effects of treatment. A comprehensive literature search was conducted in PubMed in order to evaluate the evidence for cognitive changes associated with treatment with ASMs in paediatric epilepsy patients. The ASMs considered were those in the current edition of the British National Formulary (BNF). For most ASMs, remarkably few studies providing robust data on cognitive effects in paediatric patients were identified. The available evidence suggests cognitive impairments may be associated with treatment with phenobarbital. Topiramate and phenytoin are also associated with negative effects on cognition, in particular word-finding difficulties and other language deficits with topiramate, but there are few data available specifically on children. Lamotrigine, levetiracetam and fenfluramine are associated with improvements in some cognitive domains, although it is unclear whether these effects are directly attributable to the medications or are a result of improvements in seizures. Neutral effects on cognition (no substantial evidence of worsening) were suggested for carbamazepine, everolimus, lacosamide, oxcarbazepine, perampanel and valproate. There is limited data for cannabidiol, clobazam, eslicarbazepine acetate, ethosuximide, rufinamide, vigabatrin and zonisamide, although the available evidence suggests these drugs are not associated with severe cognitive impairment. There was too little information to reach conclusions about the effects of brivaracetam, felbamate, gabapentin, pregabalin, retigabine, stiripentol or tiagabine.

Health-related quality of life in pediatric patients with partial onset seizures or primary generalized tonic-clonic seizures receiving adjunctive perampanel

RATIONALE

Study 311 (E2007-G000-311; NCT02849626) was a Phase 3, multicenter, open-label single-arm study of adjunctive perampanel oral suspension in pediatric patients (aged 4 to <12 years) with partial-onset seizures (POS) (with/without secondarily generalized tonic-clonic seizures [SGTCS]) or primary generalized tonic-clonic seizures (PGTCS). Health-related quality of life (HRQoL) was an exploratory endpoint initially analyzed through simple descriptive summaries. The aim of this post hoc analysis was to provide a more thorough assessment of HRQoL.

METHODS

This analysis focused on EQ-5D-Y data collected at Baseline, Week 23, and Week 52. Individual dimensions, visual analog scale (VAS) and summed misery index (MI) were evaluated at all visits and compared by seizure type (POS versus SGTCS versus PGTCS), age (4 to <7 versus 7 to <12), and use of concomitant enzyme-inducing antiepileptic drugs (EIAEDs) (yes versus no). Paretian Classification of Health Change (PCHC) analysis summarized the proportion of patients who showed improvement or deterioration in HRQoL. Waterfall plots assessed changes in EQ-5D-Y scores by treatment-emergent adverse events (TEAEs) and by reduction in seizure frequency. Health state utility values associated with differing seizure frequency states were estimated using a linear mixed model.

RESULTS

One hundred and fifteen patients completed EQ-5D-Y at relevant study visits (Seizure type: POS n = 84 [of which 21 had SGTCS], PGTCS n = 31; Age: 4 to <7 years n = 30, 7 to <12 years n = 85; Concomitant EIAEDs: Yes n = 35, No n = 80). Completion rates out of those expected to complete EQ-5D-Y were high at both timepoints (84.4% at Week 23 and 97.2% at Week 52). Overall, VAS/MI remained stable over time (did not exceed minimal important difference); this was similar according to seizure type, age, and EIAED usage. In patients with 'no problems' on any EQ-5D-Y dimension at Baseline, nearly all retained their full health at Week 23 (94.7%), and all retained it at Week 52 (100.0%). PCHC analysis showed fewer patients with POS experienced deterioration in EQ-5D-Y than patients with PGTCS at Week 23 (24.1% versus 42.1%). Not experiencing a TEAE, or remaining seizure-free, was associated with improvements in VAS score at Week 23 compared to those experiencing TEAEs or seizures, respectively. Health state utility values (HSUVs) were estimated as follows: seizure free (LS Mean 0.914 [95% CIs 0.587, 1.240]), ≥1 seizure per year (0.620 [0.506, 0.734]), ≥1 seizure per month (0.596 [0.338, 0.855]), ≥1 seizure per week (0.284 [-0.014, 0.582]).

CONCLUSIONS

An in-depth analysis of EQ-5D-Y data allowed for a more nuanced exploration of HRQoL than previous descriptive summaries. Our findings provide evidence that perampanel as adjunctive therapy did not result in deterioration of patient HRQoL. The association between TEAEs or remaining seizure-free and HRQoL warrants further exploration. Increasing seizure frequency was associated with decreasing HSUVs; these can inform cost-effectiveness modeling of perampanel and other therapies aiming to reduce seizure frequency in pediatric patients.

[Efficacy and tolerability of perampanel as adjunctive treatment of focal and generalized tonic-clonic epileptic seizures in children over 4 years of age]

The article is a short review of an observational study that proves the good efficacy and tolerability of perampanel suspension in the adjunctive treatment of epilepsy in children over 4 years of age. The study demonstrated a high level of 50% responders: 47% with focal seizures, 65% with transition of focal seizures to bilateral tonic-clonic seizures, 65% with primary generalized tonic-clonic seizures. Cessation of seizures was achieved in 12%, 19% and 55% of patients, respectively. The most common side-effects were fatigue (26%), nasopharyngitis (19%), lightheadedness, irritability, fever (13% each), and vomiting (11%). There were no significant clinical negative changes in cognitive functions according to the assessment on the Aldenkamp-Baker scale, both on the total score and subscales. Also, there were no significant changes in laboratory data, vital functions and ECG parameters.

Exploring the Evidence for Broad-Spectrum Effectiveness of Perampanel: A Systematic Review of Clinical Data in Generalised Seizures

BACKGROUND

The effectiveness of adjunctive perampanel has not been systematically assessed in seizure types other than its approved indications of focal seizures and primary generalised tonic-clonic seizures (PGTCS) in idiopathic generalised epilepsies (IGEs).

OBJECTIVE

We aimed to identify and review available evidence on outcomes with perampanel in generalised seizures and epilepsies to examine its potential as a broad-spectrum anti-seizure medication.

METHODS

Bibliographic databases of publications, clinical trials, and conference abstracts were searched up to August 2020 to identify studies reporting seizure or safety outcomes in patients of any age, with any type of epilepsy-associated generalised seizures treated with perampanel. Data extracted from selected records were tabulated by seizure type and syndrome, and analysed qualitatively (PROSPERO protocol CRD42020201564).

RESULTS

Ninety-one reports met inclusion criteria and were selected: 15 reports of 1 randomised controlled trial (RCT), 8 reports of 4 non-randomised interventional studies, 37 reports of observational studies, 21 case reports and 10 systematic reviews and meta-analyses. Extracted data included 359 patients with PGTCS of any aetiology, 251 with myoclonic seizures, 112 with absence seizures, 50 with tonic seizures and 32 children with epileptic spasms. The most commonly reported epilepsy type was IGE (N = 378) and the most common syndromes were juvenile myoclonic epilepsy (N = 92), progressive myoclonic epilepsies (N = 59) and absence epilepsies (N = 43). The RCT provided Class I evidence of the efficacy and tolerability of adjunctive perampanel for PGTCS in patients aged ≥ 12 years with IGE. Data from other studies provides weaker (observational) evidence of its effectiveness in multiple generalised seizure types, including myoclonic, absence and tonic seizures. There were no patterns suggesting seizure worsening or aggravation in any seizure or epilepsy type.

CONCLUSIONS

The identified studies suggest the potential of perampanel as a broad-spectrum antiseizure medication. Much of the available data, however, come from non-randomised, non-controlled studies and are open to high risk of bias. Further studies are warranted to provide more robust evidence.

Alternatives to valproate in girls and women of childbearing potential with Idiopathic Generalized Epilepsies: state of the art and guidance for the clinician proposed by the Epilepsy and Gender Commission of the Italian League Against Epilepsy (LICE)

Following recent European Medication Agency restrictions on valproate (VPA) use in girls and women of childbearing potential (WOCP), the Commission on Epilepsy and Gender of the Italian League against Epilepsy integrated current literature and legislative data in order to provide clinicians with guidance on antiseizure medication (ASM) prescription for Idiopathic Generalized Epilepsies (IGEs) in this population, avoiding VPA. We reviewed the updated literature on ASMs and examined the teratogenicity of those showing efficacy in IGEs. For all relevant ASMs, we considered the indications for use and the pregnancy and contraception-related recommendations given in the Italian Summary of Product Characteristics (SmPC) and on the websites of the European Medicines Agency (EMA) and other European Union (EU) countries' regulatory agencies. With the exception of absence seizures, the literature lacks high quality studies on ASMs in IGEs. In girls and WOCP, levetiracetam and lamotrigine should be considered the first-choice drugs in Generalized Tonic-Clonic Seizures Alone and in Juvenile Myoclonic Epilepsy, lamotrigine in Juvenile Absence Epilepsy, and ethosuximide in Childhood Absence Epilepsy. Although supported by the literature, several ASMs are off label, contraindicated or burdened by special warnings in pregnancy. Some discrepancies emerged between the various SmPC warnings for different brands of the same active principle. We provided a therapeutic algorithm for each IGE syndrome and highlighted the need for revised prescription rules, consistent with the latest literature data, uniformity of SmPC warnings for the same active principle, and more data on the efficacy of new ASMs in IGEs and their safety in pregnancy.

Open-label study to investigate the safety and efficacy of adjunctive perampanel in pediatric patients (4 to <12 years) with inadequately controlled focal seizures or generalized tonic-clonic seizures

Objective

Study 311 (NCT02849626) was a global, multicenter, open‐label, single‐arm study that assessed safety, tolerability, pharmacokinetics, and pharmacokinetics/pharmacodynamics of once‐daily adjunctive perampanel oral suspension in pediatric patients (aged 4 to <12 years) with focal seizures (FS) (with/without focal to bilateral tonic‐clonic seizures [FBTCS]) or generalized tonic‐clonic seizures (GTCS).

Methods

In the 311 Core Study, a 4‐week Pre‐treatment Period (Screening/Baseline) preceded a 23‐week Treatment Period (11‐week Titration; 12‐week Maintenance) and 4‐week Follow‐up. Endpoints included safety/tolerability (primary endpoint), median percent change in seizure frequency per 28 days from Baseline (Treatment Period), and 50% responder and seizure‐freedom rates (Maintenance Period). Patients were stratified by age (4 to <7; 7 to <12 years) and concomitant enzyme‐inducing anti‐seizure drug (EIASD) use.

Results

One hundred eighty patients were enrolled (FS, n = 149; FBTCS, n = 54; GTCS, n = 31). The Core Study was completed by 146 patients (81%); the most common primary reason for discontinuation was adverse event (AE) (n = 14 [8%]). Mean (standard deviation) daily perampanel dose was 7.0 (2.6) mg/day and median (interquartile range) duration of exposure was 22.9 (2.0) weeks. The overall incidence of treatment‐emergent AEs (TEAEs; 89%) was similar between patients with FS (with/without FBTCS) and GTCS. The most common TEAEs were somnolence (26%) and nasopharyngitis (19%). There were no clinically important changes observed for cognitive function, laboratory, or electrocardiogram (ECG) parameters or vital signs. Median percent reductions in seizure frequency per 28 days from Baseline were as follows: 40% (FS), 59% (FBTCS), and 69% (GTCS). Corresponding 50% responder and seizure‐freedom rates were as follows: FS, 47% and 12%; FBTCS, 65% and 19%; and GTCS, 64% and 55%, respectively. Improvements in response/seizure frequency from Baseline were seen regardless of age or concomitant EIASD use.

Significance

Results from the 311 Core Study suggest that daily oral doses of adjunctive perampanel are generally safe, well tolerated, and efficacious in children age 4 to <12 years with FS (with/without FBTCS) or GTCS.