Tolerability and efficacy of perampanel in children with refractory epilepsy

Efficacy and safety of perampanel for the treatment of epilepsy in adolescents: a meta-analysis

BACKGROUND

In the present meta-analysis, the efficacy and safety of perampanel (PER) for the treatment of adolescents with epilepsy were assessed.

METHODS

Keyword searches were performed in Embase, PubMed, Cochrane Library, Web of Science, EBSCO and CNKI from 1 January 2020 to 10 October 2020. The randomized controlled trials (RCTs) and case-control studies in which PER was compared with other Anti-seizure drugs (ASDs) and/or placebo in children with epilepsy, were considered eligible studies. Odds ratio (OR) with 95% confidence interval (95% CI) for the dichotomous outcome statistic was calculated using a fixed-effects or random-effects model.

RESULTS

Three RCTs with a total of 372 adolescents' patients were included in this meta-analysis. Placebo was used as a control in these studies. Compared with placebo, PER showed better efficacy in median seizure frequency reduction from baseline per 28 days (OR = 2.49, 95% CI: 1.25-4.96, p = 0.009) and in responder rate (OR = 1.87, 95% CI: 1.15-3.05, p = 0.01); both were considered statistically increased in PER group. Regarding adverse effects (AEs), significant differences between PER and placebo (OR = 1.47, 95% CI: 0.92-2.41, p = 0.11) were not found, and the most common AEs of PER were dizziness (24.0%), somnolence (15.9%), headache (11.2%), nasopharyngitis (9.7%), upper respiratory tract infection (7.0%) and aggression (7.0%).

CONCLUSION

Based on the results in this study, PER showed better efficacy than placebo therapy in children with epilepsy and the AEs were similar in PER group and placebo group. PER showed good efficacy and a low risk of AEs, and might be a promising medication for the treatment of pediatric epilepsy. In the future, well-designed and large-scale RCTs are necessary to validate the present findings.

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.

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.

Perampanel as precision therapy in rare genetic epilepsies

OBJECTIVE

Perampanel, an antiseizure drug with α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor antagonist properties, may have a targeted effect in genetic epilepsies with overwhelming glutamate receptor activation. Epilepsies with loss of γ-aminobutyric acid inhibition (e.g., SCN1A), overactive excitatory neurons (e.g., SCN2A, SCN8A), and variants in glutamate receptors (e.g., GRIN2A) hold special interest. We aimed to collect data from a large rare genetic epilepsy cohort treated with perampanel, to detect possible subgroups with high efficacy.

METHODS

This multicenter project was based on the framework of NETRE (Network for Therapy in Rare Epilepsies), a web of pediatric neurologists treating rare epilepsies. Retrospective data from patients with genetic epilepsies treated with perampanel were collected. Outcome measures were responder rate (50% seizure reduction), and percentage of seizure reduction after 3 months of treatment. Subgroups of etiologies with high efficacy were identified.

RESULTS

A total of 137 patients with 79 different etiologies, aged 2 months to 61 years (mean = 15.48 ± 9.9 years), were enrolled. The mean dosage was 6.45 ± 2.47 mg, and treatment period was 2.0 ± 1.78 years (1.5 months-8 years). Sixty-two patients (44.9%) were treated for >2 years. Ninety-eight patients (71%) were responders, and 93 (67.4%) chose to continue therapy. The mean reduction in seizure frequency was 56.61% ± 34.36%. Sixty patients (43.5%) sustained >75% reduction in seizure frequency, including 38 (27.5%) with >90% reduction in seizure frequency. The following genes showed high treatment efficacy: SCN1A, GNAO1, PIGA, PCDH19, SYNGAP1, POLG1, POLG2, and NEU1. Eleven of 17 (64.7%) patients with Dravet syndrome due to an SCN1A pathogenic variant were responders to perampanel treatment; 35.3% of them had >90% seizure reduction. Other etiologies remarkable for >90% reduction in seizures were GNAO1 and PIGA. Fourteen patients had a continuous spike and wave during sleep electroencephalographic pattern, and in six subjects perampanel reduced epileptiform activity.

SIGNIFICANCE

Perampanel demonstrated high safety and efficacy in patients with rare genetic epilepsies, especially in SCN1A, GNAO1, PIGA, PCDH19, SYNGAP1, CDKL5, NEU1, and POLG, suggesting a targeted effect related to glutamate transmission.

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.

Perampanel monotherapy for the treatment of epilepsy: Clinical trial and real-world evidence

Perampanel, a selective, non-competitive α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor antagonist, is a once-daily oral anti-seizure medication (ASM) for focal-onset seizures (FOS) and generalized tonic-clonic seizures (GTCS). In the US, perampanel is approved for the treatment of FOS (adjunctive and monotherapy), with or without focal to bilateral tonic-clonic seizures (FBTCS), in patients aged ≥4 years, and as adjunctive treatment of GTCS in patients aged ≥12 years. The monotherapy approvals in the US were based on the Food and Drug Administration's (FDA's) policy allowing extrapolation of adjunctive data to the monotherapy setting in the absence of randomized controlled monotherapy trials; since then, perampanel monotherapy has received approvals in approximately 48 countries. As there are key differences in clinical evidence of perampanel as adjunctive therapy vs monotherapy, we review the clinical outcomes of perampanel when administered as primary or secondary monotherapy. Eight publications reporting the efficacy and safety outcomes of perampanel monotherapy in clinical trial and real-world settings were selected during our literature search and are included; these comprise three Eisai-sponsored studies in patients with epilepsy: one prospective, open-label, Phase III clinical trial of patients with newly diagnosed epilepsy (Study 342 [FREEDOM]) and two retrospective, real-world Phase IV studies of patients with epilepsy who received perampanel during routine clinical care (Studies 504 and 506 [PROVE]); and five retrospective, real-world studies in patients with epilepsy who were prescribed perampanel during routine clinical care. Results from these studies demonstrated that seizure freedom may be achieved following treatment with perampanel monotherapy (either primary or secondary), with favorable retention rates and safety profiles. Overall, the clinical evidence supports the use of perampanel monotherapy both in newly diagnosed patients and in those who have been unable to control their seizures with other ASMs.

Therapeutic drug monitoring of perampanel in children diagnosed with epilepsy: Focus on influencing factors on the plasma concentration-to-dose ratio

OBJECTIVE

This study aimed to investigate the efficacy and tolerability of perampanel (PER) therapy and to optimize a specific plasma reference range for PER in children. Another major aim was to evaluate the potential determinators of PER concentration.

METHODS

Concentrations obtained from 80 children were analyzed for routine therapeutic drug monitoring (TDM) between 2021 and 2022. We retrospectively reviewed the clinical data of these patients and assessed the efficacy at 3 months after treatment initiation. Trough concentration-to-dose ratio (C₀ /Dose ratio) of PER was compared among patients on various potential influencing factors.

RESULTS

A 3-month PER therapy produced a ≥50% reduction in seizure frequency in 58.8% of patients. Twelve patients reported at least one adverse effect (AE), mainly dizziness. The monitoring data showed that the median C₀ was 325.5 ng/mL. Under maintenance dosages, approximately 75% of the C₀ values were 180.0-610.0 ng/mL. The C₀ /Dose ratio in patients aged 1 to <4 was significantly lower by twofold than in those aged 4 to ≤12 years (P = 0.001). Enzyme-inducing ASMs (EIASMs) decreased the C₀ /Dose ratio of PER by 25.9% (P = 0.165). In addition, seizure frequency reduction in responders was achieved at a median PER C₀ value of 357 ng/mL, which was similar to the value of 314 ng/mL found in nonresponders (P = 0.288). No significant difference was found in PER C₀ values between patients with and without AEs (P = 0.082).

SIGNIFICANCE

In this study, PER treatment showed acceptable efficacy and tolerance in Chinese children with epilepsy. Contributing factors like age to variable C₀ /Dose ratios were identified, and complex PER-ASMs interactions were observed. Notably, the reference range, that is, 180.0-610.0 ng/mL, for routine PER monitoring may be more applicable for them. Routine TDM should be considered a positive attempt to manage the effectiveness and safety of PER.

Psychobehavioural and Cognitive Adverse Events of Anti-Seizure Medications for the Treatment of Developmental and Epileptic Encephalopathies

The developmental and epileptic encephalopathies encompass a group of rare syndromes characterised by severe drug-resistant epilepsy with onset in childhood and significant neurodevelopmental comorbidities. The latter include intellectual disability, developmental delay, behavioural problems including attention-deficit hyperactivity disorder and autism spectrum disorder, psychiatric problems including anxiety and depression, speech impairment and sleep problems. Classical examples of developmental and epileptic encephalopathies include Dravet syndrome, Lennox-Gastaut syndrome and tuberous sclerosis complex. The mainstay of treatment is with multiple anti-seizure medications (ASMs); however, the ASMs themselves can be associated with psychobehavioural adverse events, and effects (negative or positive) on cognition and sleep. We have performed a targeted literature review of ASMs commonly used in the treatment of developmental and epileptic encephalopathies to discuss the latest evidence on their effects on behaviour, mood, cognition, sedation and sleep. The ASMs include valproate (VPA), clobazam, topiramate (TPM), cannabidiol (CBD), fenfluramine (FFA), levetiracetam (LEV), brivaracetam (BRV), zonisamide (ZNS), perampanel (PER), ethosuximide, stiripentol, lamotrigine (LTG), rufinamide, vigabatrin, lacosamide (LCM) and everolimus. Bromide, felbamate and other sodium channel ASMs are discussed briefly. Overall, the current evidence suggest that LEV, PER and to a lesser extent BRV are associated with psychobehavioural adverse events including aggressiveness and irritability; TPM and to a lesser extent ZNS are associated with language impairment and cognitive dulling/memory problems. Patients with a history of behavioural and psychiatric comorbidities may be more at risk of developing psychobehavioural adverse events. Topiramate and ZNS may be associated with negative effects in some aspects of cognition; CBD, FFA, LEV, BRV and LTG may have some positive effects, while the remaining ASMs do not appear to have a detrimental effect. All the ASMs are associated with sedation to a certain extent, which is pronounced during uptitration. Cannabidiol, PER and pregabalin may be associated with improvements in sleep, LTG is associated with insomnia, while VPA, TPM, LEV, ZNS and LCM do not appear to have detrimental effects. There was variability in the extent of evidence for each ASM: for many first-generation and some second-generation ASMs, there is scant documented evidence; however, their extensive use suggests favourable tolerability and safety (e.g. VPA); second-generation and some third-generation ASMs tend to have the most robust evidence documented over several years of use (TPM, LEV, PER, ZNS, BRV), while evidence is still being generated for newer ASMs such as CBD and FFA. Finally, we discuss how a variety of factors can affect mood, behaviour and cognition, and untangling the associations between the effects of the underlying syndrome and those of the ASMs can be challenging. In particular, there is enormous heterogeneity in cognitive, behavioural and developmental impairments that is complex and can change naturally over time; there is a lack of standardised instruments for evaluating these outcomes in developmental and epileptic encephalopathies, with a reliance on subjective evaluations by proxy (caregivers); and treatment regimes are complex involving multiple ASMs as well as other drugs.

Utility and Safety of Perampanel in Pediatric FIRES and Other Drug-Resistant Epilepsies

Perampanel is a novel antiepileptic drug, which antagonises AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) glutamate receptor. We describe perampanel as an adjunctive treatment for FIRES (febrile infection-related epilepsy syndrome) and other drug-resistant epilepsies. A single-centre, observational, retrospective study involving 20 pediatric patients was conducted. Perampanel was started for three patients with FIRES, achieving seizure cessation in two patients within a day and on days 19 and 32 of illness. Doses used ranged from 4 to 12 mg/day, without any adverse effects reported or discontinuation of therapy. Responder-rate for other drug-resistant epilepsies is 25%. Median time to achieve ≥50% seizure reduction was 80 days (range: 26-326 days). Adverse effect reported in 47% of the patients includes central nervous system-related, and thrombocytopenia. Eight patients discontinued perampanel, because of ineffectiveness or adverse effects. The median time on perampanel before discontinuation was 179 days (range: 94-345 days). Perampanel may be of benefit in pediatrics FIRES and is of utility in other drug-resistant epilepsies.

Perampanel treatment in highly drug-resistant epilepsies including nonsurgical candidates and failed surgery

OBJECTIVE

To evaluate the effectiveness and tolerability of perampanel (PER) treatment for patients with highly drug-resistant epilepsies (HDRE) including nonsurgical candidates and failed surgery in real-world setting.

METHODS

All patients who were treated with PER during June 2015 to August 2019 were selected. Primary outcomes were percentage of seizure reduction, responder rate, and seizure freedom rate. Seizure frequency after taking PER at 3 and 12 months were compared with baseline seizure frequency within the same time period prior to starting PER. Secondary outcomes were retention rate, side effects, and predictors for a response to PER. Descriptive statistics and the Kernel regression model were employed.

RESULTS

Forty-one patients received PER treatment during the study period. Six patients who had no baseline seizure frequency recordings were excluded, for a total of 35 patients included for analysis. Mean age was 40.06 years (SD 12.34). All were highly resistant to several antiseizure drugs (ASDs) with a median number of previously failed ASDs of 8 items. Eleven, 16, 5, and 3 patients were lesional, nonlesional focal epilepsy, nonsurgical candidate, and failed surgery, respectively. At 3 months after PER treatment, the median percentage of seizure reduction was 20 % (-35.71, 100), the responder rate was 22.86 % (8/35), and the seizure freedom rate was 17.14% (6/35). At 12 months after PER treatment, the corresponding outcomes were 25% (-20.57, 91.60), 22.58% (7/31), and 9.68% (3/31), respectively. Retention rates at 3 and 12 months were 100% and 91.43% (32/35), respectively. Nineteen patients (54.29%) experienced side effects from PER. Side effects were somnolence (6/35), dizziness (3/35), irritability (2/35), and ataxia (2/35), and one each for weight loss, nausea, headache, insomnia, verbal aggressivity, and depression. Median duration for 2-mg dose increment was 2.2 months.

CONCLUSIONS

In real-world practice, slow-titration PER regimen is well-tolerable and shows benefit in helping control seizures in patients with very difficult-to-treat HDRE.

Real-Life Effectiveness and Tolerability of Perampanel in Pediatric Patients Aged 4 Years or Older with Epilepsy: A Korean National Multicenter Study

Background and Purpose

The US Food and Drug Administration approval for perampanel has only recently been expanded to patients as young as 4 years, and so there have been few real-life studies of the effects of perampanel in pediatric patients. The aim of this study was to determine the long-term efficacy, factors affecting treatment response, and tolerability of perampanel as an add-on therapy in pediatric patients aged 4 years or older with epilepsy.

Methods

This multicenter retrospective observational study collected data from pediatric epilepsy centers of four Korean national universities. Changes in the seizure frequency from baseline, adverse events, and retention rates were obtained at 3, 6, and 12 months. Adverse events and discontinuation profiles were obtained to assess tolerability.

Results

This study included 220 children and adolescents (117 males and 103 females) aged 4 to 20 years. The overall response rate was 43.6%, and the seizure-freedom rate was 17.7%. Factors affecting a good treatment response were the absence of intellectual disability, small number of concomitant antiepileptic drugs, and low baseline seizure frequency. Eighty-eight patients (40%) experienced adverse events, but they mostly were of mild severity and resolved after the dose reduction or discontinuation of perampanel. The retention rates at 3, 6, and 12 months were 85.0%, 71.8%, and 50.5%, respectively.

Conclusions

Adjunctive treatment with perampanel was efficacious and tolerated in pediatric patients aged 4 years or older with epilepsy. Early perampanel treatment may help to reduce the burden of their seizures and improve their quality of life.

Efficacy and serum concentrations of perampanel for treatment of drug-resistant epilepsy in children, adolescents, and young adults: comparison of patients younger and older than 12 years

PURPOSE

Perampanel (PER) is a selective, non-competitive antagonist of the alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptor. In Japan, PER is approved for patients with epilepsy who are at least 12 years old for the adjunctive treatment of primary generalised tonic-clonic seizures and partial-onset seizures (with or without secondary generalization). We surveyed the efficacy, adverse effects, and serum concentrations of PER, focusing especially on patients younger than 12 years of age.

METHODS

We retrospectively surveyed the clinical information of patients treated with PER and assessed the efficacy at 6 months after treatment initiation. We compared efficacy, adverse effects, and serum concentration in patients younger or older than 12 years of age. Responders were defined as those who experienced a ≥50% seizure reduction.

RESULTS

Eighty-four patients were enrolled. The average age of the younger group was 7.1 ± 3.3 (standard deviation) years compared to 16.4 ± 3.7 years in the older group. The responder rate was 42.9% (36/84). The responder rate did not differ between the two age groups (<12 years, 20/44, 45.4%; >12 years, 16/40, 40.0%; p = 0.78). The younger age group had a significantly lower concentration-to-dose (CD) ratio than the older age group (<12 years, 1849.8 ± 2209.3; >12 years, 3076.3 ± 3352.2, p = 0.02). Treatment-emergent adverse events (TEAEs) were observed in 22.6% (19/84) of patients, with the most common being somnolence (8/84, 9.5%).

CONCLUSION

PER may be an alternative to treat seizures in paediatric drug-resistant epilepsy. Serum concentrations of PER might be lower in patients younger than 12 years than in older patients.

Successful treatment of intractable life-threatening seizures with perampanel in the first case of early myoclonic encephalopathy with a novel de novo SCN1A mutation

PURPOSE

Early myoclonic encephalopathy (EME) is a form of developmental and epileptic encephalopathy with myoclonic seizures and a suppression burst on electroencephalogram, which occurs during the neonatal or early infantile period and is characterized by highly intractable seizures and severe development impairment. Although multiple genetic aetiologies of EME have been identified, no SCN1A mutation has been reported.

METHODS

We described a female patient with EME due to an SCN1A mutation.

RESULTS

She developed frequent myoclonic and apnoeic seizures during the neonatal period. As her seizures were refractory to many antiepileptic drugs, she underwent a tracheotomy and has since been treated with continuous mechanical ventilation. Eventually, perampanel was added, which resulted in the cessation of the apnoeic seizures. Genetic analysis revealed a heterozygous de novo missense mutation in the SCN1A gene (c.2588 T > C:p.Leu863Ser).

CONCLUSION

This is the first patient with EME due to anSCN1A mutation to be successfully treated with perampanel. Recently, perampanel was reported to be effective in treating Dravet syndrome, including cases with an SCN1A mutation. Perampanel may contribute to seizure reduction in patients with intractable epilepsy carrying the SCN1A mutation.

Clinical profiles associated with serum perampanel concentrations in children with refractory epilepsy

BACKGROUND

Perampanel (PER) is a new antiepileptic drug (AED) with a novel mechanism of action. Investigations of the efficacy and safety of PER in pediatric and adult patients have increased recently. Although the clinical usefulness and pharmacokinetics of PER have been investigated in adolescent and adult populations, similar studies have not been performed in children.

PATIENTS AND METHODS

We retrospectively reviewed the medical records of patients treated with PER for more than 6 months in the Department of Pediatrics, Hiroshima University Hospital, between September 2016 and November 2018. We obtained demographic and clinical data including age, sex, epilepsy type, seizure type, seizure frequency before and after treatment initiation, adverse events, reasons for discontinuing PER treatment, doses at evaluation points, serum concentrations, concomitant AEDs, intellectual status, and epilepsy etiology. Seizure types and epilepsy syndromes were classified according to the criteria of the International League Against Epilepsy.

RESULTS

The study included 44 patients (22 males) between the ages of 6 months and 16 years. Of those, 10 patients discontinued PER therapy. The 50% response rate was 52.3% in patients treated with PER, and four patients achieved complete seizure control. Perampanel was highly effective in patients with generalized and focal epilepsy (50% responder rates, 52.9% and 50.0%, respectively). Favorable response rates were observed for tonic-clonic, focal nonmotor, and absence seizures with 50% response rates of 54.5%, 50.0%, and 66.7%, respectively. The 50% responder rate was 31.3 for epileptic spasms (ES). Treatment-emergent adverse events (TEAEs) included somnolence (n = 8), irritability (n = 2), ataxia (n = 2), and one case each of dizziness, compulsiveness, and enuresis. Serum concentrations of PER were compared in patients taking concomitant enzyme-inducing antiepileptic drugs (EIAEDs; carbamazepine, phenytoin, and phenobarbital) and those taking concomitant non-EIAEDs. Serum PER concentrations were correlated with dose per body weight in both groups (EIAED: r = 0.765, p = 0.00000212; non-EIAED: r = 0.71, p = 0.0000158). The mean concentration-to-dose (CD) ratio was 2398.4 ng mL^-1 mg^-1 kg^-1 (range: 800-4524.7) in the non-EIAED group and 693.7 ng mL^-1 mg^-1 kg^-1 (range: 344-1309.7) in the EIAED group. Serum PER levels were lower in the EIAED group than in the non-EIAED group. All patients with serum PER concentrations above 400 ng/mL experienced somnolence.

CONCLUSIONS

Perampanel is effective against various types of seizures, including ES, in pediatric patients with refractory epilepsy. Furthermore, PER has good tolerability when the dose is adjusted based on serum concentrations. The PER CD ratio was lower in pediatric patients than in adolescents and adults; therefore, clinicians must consider the CD ratio when treating children with PER.

An Evidence-Based Review On The Use Of Perampanel For The Treatment Of Focal-Onset Seizures In Pediatric Patients

Perampanel, a non-competitive AMPA receptor antagonist, is a once-daily oral antiepileptic drug approved for the treatment of focal seizures and primary generalized tonic-clonic seizures in children 12 years of age and over. We conducted a systematic review of the data on perampanel in children and adolescents with focal-onset seizures. We found 21 published papers on the pediatric use of perampanel for focal-onset seizures, including 9 papers on clinical trials and ancillary studies of these trials, of which 2 focused on pharmacokinetics, 1 was a meta-analysis, and 9 were real-life studies (1 was prospective). Perampanel, as an adjunctive treatment for uncontrolled focal-onset seizures, results in an improvement of seizure control with a generally good safety profile. Evidence-based data are currently available for children 12 years of age and over. Higher amounts of perampanel might be required in patients taking enzyme-inducing antiepileptic drugs. The most common adverse events are somnolence, dizziness and behavioral adverse events. The latter seems more frequent in adolescents than in adults and in adolescents with preexisting behavioral comorbidities. Current studies did not identify any short-term impact of perampanel on cognitive functions. Its long half-life allows once-daily administration. Real-life studies further established that a decrease of the dose frequently resolves adverse events, as demonstrated in pivotal studies. Pharmacokinetic and safety studies are still ongoing in the younger population, down to 4 years of age, in order to apply for approval in this age group.

Clinical Experience with Perampanel in Intractable Focal Epilepsy Over 12 Months of Follow-Up

Background and Purpose

There are only limited studies on perampanel (PER), one of the latest antiepileptic drug. This study aimed to evaluate the long-term efficacy and tolerability of perampanel as an add-on therapy in patients with intractable focal epilepsy.

Methods

The medical records of 97 patients (age, 12-30 years) were retrospectively reviewed and analyzed. The patients had been diagnosed with focal epilepsy, treated with PER, and regularly followed up over 12 months.

Results

All patients had uncontrolled seizures despite treatment with two or more antiepileptic drugs. The mean age of seizure onset was 5.2 years (range, 0-17.0). PER was first prescribed at an average age of 15.7 years (range, 12.0-25.3), and mean follow-up duration after PER initiation was 15.9 months (range, 12-20). The responder rate was 41.7%, with over 75% seizure reduction obtained in 11 cases (15.3%), including three seizure-free cases (4.2%). The retention rates at 3, 6, 12, and 18 months of follow-up were 82.5% (80/97), 72.1% (70/97), 60.8% (59/97), and 37.5% (6/16), respectively. Forty-four patients (44/97, 45.4%) discontinued PER, because of treatment-related adverse events in 20 (20.6%) and no efficacy in 24 (24.7%). Treatment-related adverse events were reported by 52 patients (53.6%). The most common adverse event was somnolence or lethargy, reported by 17 patients (17/97, 23%), followed by dizziness (15/97, 20%) and psychological problems such as aggressiveness or irritability (15/97, 20%). Thirty-three patients (33/52, 63.4%) showed their first adverse symptom for 2 or 4 mg/day of PER.

Conclusions

PER would be an effective therapeutic option for patients with intractable focal epilepsy. However, careful monitoring of adverse events is essential from treatment initiation, with particular attention to psychological problems in adolescents and young adults.

Efficacy and tolerability of adjunctive perampanel treatment in children under 12 years of age with refractory epilepsy

Purpose

There is limited data on the use of perampanel in children under 12 years of age. We evaluated the efficacy and tolerability of adjunctive perampanel treatment in children under 12 years of age with refractory epilepsy.

Methods

This retrospective observational study was performed in Kyungpook National University Hospital from July 2016 to March 2018. A responder was defined as a patient with ≥50% reduction in monthly seizure frequency compared with the baseline. Adverse events and discontinuation data were obtained to evaluate tolerability.

Results

Twenty-two patients (8 males, 14 females) aged 3.1–11.4 years (mean, 8.0±2.5 years) were included in this study. After an average of 9.2 months (range, 0.5–19 months) of follow-up, 15 patients (68%) showed a reduction in seizure frequency, including 5 patients (23%) with seizure freedom. The age at epilepsy onset was significantly lower (P=0.048), and the duration of epilepsy was significantly longer (P=0.019) in responders than in nonresponders. Nine patients (41%) experienced adverse events, including somnolence (23%), respiratory depression (9%), violence (4.5%), and seizure aggravation (4.5%). The most serious adverse event was respiratory depression, which required mechanical ventilation in 2 patients (9%). Eight patients (36%) discontinued perampanel due to lack of efficacy or adverse events. Three out of 4 patients (75%) who discontinued perampanel due to adverse events had an underlying medical condition.

Conclusion

Perampanel offers a treatment option for refractory epilepsy in children. Adjunctive treatment with perampanel requires special consideration in those with underlying medical conditions to prevent serious adverse events.

Safety and tolerability profile of new antiepileptic drug treatment in children with epilepsy

INTRODUCTION

Treatment of pediatric epilepsy requires a careful evaluation of the safety and tolerability profile of antiepileptic drugs (AEDs) to avoid or minimize as much as possible adverse events (AEs) on various organs, hematological parameters, and growth, pubertal, motor, cognitive and behavioral development.

AREAS COVERED

Treatment-emergent AEs (TEAEs) reported in the literature 2000-2018 regarding second- and third-generation AEDs used in the pediatric age, with exclusion of the neonatal period that exhibits specific peculiarities, have been described on the basis of their frequency, severity/tolerability, and particular association with a given AED.

EXPERT OPINION

Somnolence/sedation and behavioral changes, like irritability and nervousness, are among the most commonly observed TEAEs associated with almost all AEDs. Lamotrigine, Gabapentin, Oxcarbazepine, and Levetiracetam appear to be the best-tolerated AEDs with a ≤2% withdrawal rate, while Tiagabine and Everolimus are discontinued in up to >20% of the patients because of intolerable TEAEs. For some AEDs, literature data are scanty to draw a high-level evidence on their safety and tolerability profile. The reasons are: insufficient population size, short duration of treatments, or lack of controlled trials. A future goal is that of identifying clearer, easier, and more homogeneous methodological strategies to facilitate AED testing in pediatric populations.

Efficacy and tolerability of perampanel in children and adolescents with pharmacoresistant epilepsy: The first real-world evaluation in Asian pediatric neurology clinics

AIM

This study investigated the efficacy and safety of perampanel (PER) adjunctive therapy in pediatric patients with epilepsy whose seizures are pharmacoresistant to existing antiepileptic drugs.

METHODS

A clinical retrospective study was conducted from 2016 to 2017 in the pediatric neurology clinic at a tertiary children's hospital. We reviewed the data obtained from 66 children whose seizures were pharmacoresistant to more than two antiepileptic drugs, and could be followed up for a minimum of 3 months after PER adjunctive therapy initiation. The efficacy was estimated by the PER response rate at 3-, 6-, and 12-month follow-up evaluations, and adverse events were also recorded.

RESULTS

The rate of seizure reduction of >50% was 30.3%, 37.5%, and 34.7% for all seizure types at 3, 6, and 12 months, in which 7.6%, 8.9%, and 14.3% of the patients became seizure-free at these time points, respectively. No significant differences were found between enzyme-inducing and nonenzyme-inducing antiepileptic drugs in combination with PER with regard to the responder rate. Five patients with Dravet syndrome were included in the study. Four of them (80%) exhibited 50% seizure reduction at the last visit, at which point, two patients (40.0%) were seizure-free. The retention rate was 51% at 12 months. Adverse events were documented in 25 patients (35.7%) and led to PER discontinuation in eight patients (12.1%). The most common adverse events comprised irritability, skin rash, dizziness, and somnolence; however, all were transient and successfully managed after PER dose reduction or discontinuation.

CONCLUSION

The current data support the value of adjunctive PER in child and adolescent patients with pharmacoresistant epilepsy in daily clinical practice. Perampanel was efficacious and generally well-tolerated as an add-on treatment for epilepsy.

Perampanel, an AMPA receptor antagonist: From clinical research to practice in clinical settings

Epileptic seizures are refractory to treatment in approximately one-third of patients despite the recent introduction of many newer antiepileptic drugs (AEDs). Development of novel AEDs therefore remains a high priority. Perampanel is a first-in-class non-competitive selective AMPA receptor antagonist with a unique mechanism of action. Clinical efficacy and safety of perampanel as adjunctive treatment for focal seizures with/without secondary generalization (±SG) and primary generalized tonic-clonic (PGTC) seizures have been established in five phase 3 randomized controlled trials (RCTs), and a long-term extension study, and perampanel is approved as monotherapy for focal seizures ±SG in the USA. In patients with focal seizures ±SG, add-on perampanel resulted in median percent reduction in seizure frequency 23.3%-34.5% and ≥50% responder rate 28.5%-37.6%; in PGTC seizures, these results were 76.5% and 64.2%, respectively. Efficacy among adolescents (reduction in seizure frequency 34.8%-35.6%; ≥50% responder rate 40.9%-45.0%) and elderly people (reduction in seizure frequency 12.5%-16.9%; ≥50% responder rate 22.2%-42.9%) is similar to those in adults, and results remain comparable between Asian (reduction in seizure frequency 17.3%-38.0%) and global populations. Perampanel has been extensively studied in real-world clinical practice, with similar efficacy and safety results to the RCTs (≥50% responder rate 12.8%-75.0%; adverse events of somnolence/sedation, dizziness, ataxia, and behavioral changes). Real-world observational studies suggest that perampanel tolerability can be improved by slow titration (2 mg every 2-4 weeks), and bedtime administration can mitigate somnolence and dizziness. Counseling about the potential for behavioral changes and close monitoring are recommended.

Adverse Events During Perampanel Adjunctive Therapy in Intractable Epilepsy

Background and Purpose

Perampanel is the first α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA)-receptor antagonist developed to treat epilepsy. The effects of either rapid or slow dose titration on adverse events remain to be elucidated.

Methods

Eighty-five patients received perampanel between March 2016 and August 2016. Patients were divided into two groups according to their dosing schedule: rapid dose titration (2-mg increments at intervals of 1 to 2 weeks) and slow dose titration (2-mg increments at intervals of at least 3 weeks). Seizure frequency and adverse events were analyzed over 3 months.

Results

Adverse events were reported by 47 (58%) of the 81 patients analyzed, with 12 (15%) patients discontinuing perampanel due to adverse events. Common adverse events included dizziness (n=30, 37%), aggressive mood and behavior (n=19, 24%), gait disturbance (n=16, 20%), and sleep problems (n=10, 12.4%). The overall adverse events were similar in the slow-titration group (38 of 61 patients) and the rapid-titration group (8 of 20 patients, p=0.081). However, none of the 20 patients in the slow-titration group experienced gait disturbance, compared with 16 of the 61 patients in the rapid-titration group (p=0.009), while appetite change was experienced by 4 patients in the slow-titration group but only 1 in the rapid-titration group (p=0.003). No relationship was noted between adverse events and the maximum dose of perampanel (p=0.116). Sex differences were observed, with the response to perampanel being better and the rate of adverse events being higher in females (p=0.015 and p=0.046, respectively).

Conclusions

Slow titration of perampanel may reduce perampanel-related adverse events.

Spotlight on perampanel in the management of seizures: design, development and an update on place in therapy

Purpose

Perampanel is a first-in-class antiepileptic medication approved for the treatment of partial (focal) seizures, and as adjunctive treatment for primarily generalized tonic–clonic seizures. The pharmacology, efficacy data, adverse-effect profile, pharmacokinetics and place in therapy are reviewed.

Summary

Perampanel is indicated for use in patients with epilepsy who are 12 years of age or older. It is the first medication designed specifically to be a non-competitive antagonist at post-synaptic α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptors. Efficacy in refractory seizures has been established, and ongoing efficacy demonstrated by post-marketing data. The drug is completely absorbed, and exhibits a half-life that allows for once-daily administration in doses up to 12 mg/day. Drug interactions are minimal, but increased doses may be necessary when given with strong inducers of cytochrome P450 enzymes, including when perampanel is co-administered with other antiepileptics that exhibit this property. The most common adverse effects noted in both clinical trials and post-marketing are dizziness and somnolence. Psychiatric and behavioral adverse events have been documented in both adult and pediatric patients, including those with no corresponding diagnostic history.

Conclusion

Perampanel is a novel adjunctive antiepileptic medication that is an effective option for adolescents and adults with partial seizures, and primarily generalized tonic–clonic seizures uncontrolled with other medications.

Effectiveness and tolerability of Perampanel in children, adolescents and young adults with refractory epilepsy: A UK national multicentre study

PURPOSE

Perampanel is one of the latest antiepileptic drugs (AEDs) approved for the treatment of focal and generalised epilepsy in individuals with epilepsy aged 12 years and older. There is sparse data on the use of Perampanel in children under 12. We conducted a study amongst paediatric neurologists in the United Kingdom to investigate its effectiveness and tolerability as an adjunctive therapy in children of all ages with refractory epilepsy.

METHODS

Data was collected via an online questionnaire sent to paediatric neurologists in the UK. Data gathered, prospective in 62 (64.5%) and retrospective in 34 (35.5%) patients, included changes in seizure frequency from baseline and unwanted effects at 3, 6 and 12 months follow-up. Only patients with a minimum follow-up of six months were included.

RESULTS

Ninety six patients (48 females) with refractory epilepsy from 11 of 29 tertiary centres were included. Median [IQR] (range) age was 14 years 11 months [12 years, 16 years 6 months] (11 months-24 years 5 months). Seventy three (76%) had focal epilepsy, sixteen (17%) generalised, and seven (7%) patients both generalised and focal epilepsy. The responder rate, ≥50% seizure reduction from baseline, was 19% for all seizure types at both 6 and 12 months, 19% and 24% for focal seizures, and 25% and 7% for generalised seizures at these time points respectively. The retention rate was 42% at 12 months. Treatment was discontinued due to unwanted effects in 29 (36.7%) of the 79 patients with follow-up data available up to 12 months: 30% due to challenging behaviour, 14% dizziness, and 7.6% somnolence.

CONCLUSION

Perampanel was fairly effective in a heterogeneous group of 96 children and adolescents with very refractory epilepsy. The rate of adverse events leading to discontinuation was considerable in this group.

Current role of perampanel in pediatric epilepsy

Perampanel is among the latest AEDs approved, indicated for the treatment of partial-onset seizures with or without secondary generalization, and for primary generalized tonic-clonic seizures, in patients aged 12 years and older. This paper summarizes the clinical recommendations on the current role of perampanel in the treatment of pediatric epilepsies and future directions for research. The optimal dosage should be comprised between 4 and 12 mg/day, with 8 mg/day being the most common dosage used. The rate and severity of adverse events, including psychiatric symptoms, can be decreased by starting at low doses, and titrating slowly. Overall, perampanel presents an acceptable risk/benefit ratio, but special caution should be made to the risk of seizure aggravation and behavioral problems. The favorable cognitive profile, the ease of use of the titration scheme and the once-daily formulation offer advantage over other AEDs and make this drug particularly suitable for adolescent population. Perampanel is a welcome addition to the armamentarium of the existing AEDs, as it represents a new approach in the management of epilepsy, with a novel mechanism of action and a potential to have a considerable impact on the treatment of adolescents with epilepsy.