Adjunctive Perampanel Oral Suspension in Pediatric Patients From ≥2 to <12 Years of Age With Epilepsy: Pharmacokinetics, Safety, Tolerability, and Efficacy

Effects of CYP3A5*3 genetic polymorphisms on the pharmacokinetics of perampanel in Chinese pediatric patients with epilepsy

PURPOSE

This study was the first to evaluate the effect of CYP3A5*3 gene polymorphisms on plasma concentration of perampanel (PER) in Chinese pediatric patients with epilepsy.

METHODS

We enrolled 98 patients for this investigation. Plasma PER concentrations were measured using liquid chromatography-tandem mass spectrometry. Leftover samples from standard therapeutic drug monitoring were allocated for genotyping analysis. The primary measure of efficacy was the rate of seizure reduction with PER treatment at the final checkup.

RESULTS

The plasma concentration showed a linear correlation with the daily dose taken ( r  = 0.17; P  < 0.05). The ineffective group showed a significantly lower plasma concentration of PER (490.5 ± 297.1 vs. 633.8 ± 305.5 μg/ml; P  = 0.019). For the mean concentration-to-dose (C/D) ratio, the ineffective group showed a significantly lower C/D ratio of PER (3.2 ± 1.7 vs. 3.8 ± 2.0; P  = 0.040). The CYP3A5*3 CC genotype exhibited the highest average plasma concentration of PER at 562.8 ± 293.9 ng/ml, in contrast to the CT and TT genotypes at 421.1 ± 165.6 ng/ml and 260.0 ± 36.1 ng/ml. The mean plasma PER concentration was significantly higher in the adverse events group (540.8 ± 285.6 vs. 433.0 ± 227.2 ng/ml; P  = 0.042).

CONCLUSION

The CYP3A5*3 gene's genetic polymorphisms influence plasma concentrations of PER in Chinese pediatric patients with epilepsy. Given that both efficacy and potential toxicity are closely tied to plasma PER levels, the CYP3A5*3 genetic genotype should be factored in when prescribing PER to patients with epilepsy.

Effects of CYP3A4 genetic polymorphisms on the pharmacokinetics and efficacy of perampanel in Chinese pediatric patients with epilepsy

OBJECTIVE

This study was the first to evaluate the effect of CYP3A4 gene polymorphisms on the plasma concentration and effectiveness of perampanel (PER) in Chinese pediatric patients with epilepsy.

METHODS

We enrolled 102 patients for this investigation. The steady-state concentration was determined after patients maintained a consistent PER dosing regimen for at least 21 days. Plasma PER concentrations were measured using liquid chromatography-tandem mass spectrometry. Leftover samples from standard therapeutic drug monitoring were allocated for genotyping analysis. The primary measure of efficacy was the rate of seizure reduction with PER treatment at the final check-up.

RESULTS

The CYP3A4×10 GC phenotype exhibited the highest average plasma concentration of PER at 491.1 ± 328.1 ng/mL, in contrast to the CC phenotype at 334.0 ± 161.1 ng/mL. The incidence of adverse events was most prominent in the CYP3A4×1 G TT and CYP3A4×10 GC groups, with rates of 77.8 % (7 of 9 patients) and 50.0 % (46 of 92 patients), respectively. Moreover, the percentage of patients for whom PER was deemed ineffective was least in the CYP3A4×1 G TT and CYP3A4×10 CC groups, recorded at 11.1 % (1 of 9 patients) and 10.0 % (1 of 10 patients), respectively. There was a significant correlation between PER plasma concentration and either exposure or toxicity (both with p < 0.05). We suggest a plasma concentration range of 625-900 ng/mL as a suitable reference for PER in Chinese patients with epilepsy.

CONCLUSION

The CYP3A4×10 gene's genetic polymorphisms influence plasma concentrations of PER in Chinese pediatric patients with epilepsy. Given that both efficacy and potential toxicity are closely tied to plasma PER levels, the CYP3A4 genetic phenotype should be factored in when prescribing PER to patients with epilepsy.

Population pharmacokinetics and dosing optimization of perampanel in children with epilepsy: A real-world study

OBJECTIVE

The purposes of this study were to explore the pharmacokinetics of perampanel (PER) in children with epilepsy, identify factors that contribute to pharmacokinetic variations among subjects, evaluate the connection between PER exposure and clinical outcome, and establish an evidence-based approach for tailoring individualized antiepileptic treatment in this specific population.

METHODS

In this prospective study, PER plasma concentrations and genetic information on metabolic enzymes were obtained from 194 patients younger than 18 years. The disposition kinetics of PER in pediatric patients following oral dosing were characterized using nonlinear mixed effect models. The effective range for the plasma concentration of PER was determined by assessing the efficacy and safety of PER treatment and analyzing the relationship between drug exposure and clinical response. Monte Carlo simulations were then performed to evaluate and optimize the current dosing regimens.

RESULTS

The pharmacokinetic profile of PER was adequately described by a one-compartment model with first-order absorption and elimination. Body weight, total bilirubin level, and concomitant oxcarbazepine were found to have significant influences on PER pharmacokinetics. Model estimates of apparent clearance and volume of distribution were .016 ± .009 L/h/kg and 1.47 ± .78 L/kg, respectively. The effective range predicted from plasma concentration data in responders was 215-862 μg/L. Dosing scenarios stratified according to essential covariates were proposed through simulation analysis.

SIGNIFICANCE

In this study, we captured the pharmacokinetic/pharmacodynamic characteristics of PER in pediatric epilepsy patients through analysis of real-world data and adopted a pharmacometric approach to support an individualized dosing strategy for PER in this specific population.

Effect of Age, Comedications, and CYP3A4/5 Polymorphisms on Perampanel Exposure in Chinese Pediatric Patients With Epilepsy

Perampanel (PER) is a new type of antiseizure medication used for partial or generalized seizures. However, the plasma concentration shows obvious individual variability in children. The present study aims to ascertain the effect of age, comedications, and cytochrome P450 (CYP) 3A4/5 polymorphisms on PER exposure in Chinese pediatric patients with epilepsy. Clinical data were retrospectively collected in a tertiary children's hospital medical records system from January 2021 to December 2022. The influence factors on the daily dose, plasma concentration, and concentration-to-dose ratio (CDR) of PER were investigated. A total of 135 pediatric patients with 178 blood samples were involved. With a median daily dose of 4.0 mg (interquartile range, 3.0-5.0 mg), the median plasma concentration was 409.4 ng/mL (interquartile range, 251.7-639.4 ng/mL). The CDR in patients aged less than 4 years was significantly decreased by 48.0% and 39.1% compared with those aged 4-11 years and 12 years or older, respectively. Enzyme inducers significantly decreased the CDR of PER by 34.5%, while valproic acid showed an increase of 71.7%. In addition, genotype CYP3A5*3/*3 carriers presented a significant increase of 21.5% compared to the CYP3A5*1/*3 expresser. No correlations were observed between the CDR and CYP3A4∗1G polymorphism. PER showed high variations in individual plasma concentrations. Age younger than 4 years, comedication with enzyme inducers or valproic acid, and possession of the CYP3A5*3 genotype potentially predicted PER exposure in pediatric patients with epilepsy.

Phase IV PROVE study: Perampanel in real-world clinical care of pediatric patients with epilepsy

INTRODUCTION

The non-interventional Phase IV PROVE study (NCT03208660) assessed retention, efficacy, safety and tolerability, and perampanel dosing in patients with epilepsy during routine clinical care. This analysis evaluated final data from patients aged <4 years and 4-<12 years.

METHODS

Data were obtained retrospectively from medical/pharmacy records of patients in the United States initiating perampanel after January 1, 2014, according to treating clinician recommendations. Retention rate was the primary endpoint. Secondary assessments included median percent changes in seizure frequency, seizure-freedom rates, investigator impression of seizure effect, and safety and tolerability.

RESULTS

The Safety Analysis Set (SAS) included 41 patients (<4 years; mean maximum dose, 3.5 mg/day) and 203 patients (4-<12 years; mean maximum dose, 5.3 mg/day); 24-month retention rates were 35.7% (n = 5/14) and 42.0% (n = 47/112), respectively. In the Full Analysis Set, during Months 1-3, median percent reductions in seizure frequency were 33.3% (n = 8 [<4 years]) and 26.0% (n = 32 [4-<12 years]), and seizure-freedom rates were 12.5% in both groups (n = 1/8 and n = 4/32); patient numbers were low at later time points. Most patients showed improvements in seizure control (45.9% [<4 years] versus 52.4% [4-<12 years]) or no change (45.9% versus 34.5%) (SAS). Treatment-emergent adverse events (TEAEs) were reported in 12 (<4 years: 29.3%; most common, irritability [7.3%]) and 64 patients (4-<12 years: 31.5%; most common, aggression [6.9%]).

CONCLUSIONS

Perampanel was generally well tolerated with <21% of TEAEs leading to withdrawal at 24 months, had favorable retention rates (≥50% and >35% at 12 and 24 months, respectively), and sustained efficacy in pediatric patients during routine clinical care.

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.

Therapeutic Drug Monitoring of Perampanel in Children With Refractory Epilepsy: Focus on Influencing Factors on the Free-Perampanel Concentration

BACKGROUND

This study aimed to assess the effect of perampanel dose, age, sex, and antiseizure medication cotherapy on steady-state free-perampanel concentration in children with refractory epilepsy, as well as the relationship between inflammation and the pharmacokinetics of perampanel.

METHODS

This prospective study in China included 87 children with refractory epilepsy treated with adjunctive perampanel therapy. Free and total perampanel concentrations in plasma were determined using liquid chromatography-tandem mass spectrometry. Free-perampanel concentration was compared among patients with various potential influencing factors.

RESULTS

A total of 87 pediatric patients (44 female children) aged 2-14 years were enrolled. The mean free-perampanel concentration and free concentration-to-dose (CD) ratio in plasma were 5.7 ± 2.7 ng/mL (16.3 ± 7.7 nmol/L) and 45.3 ± 21.0 (ng/mL)/(mg/kg) [129.6 ± 60.1 (nmol/L)/(mg/kg)], respectively. The protein binding of perampanel in plasma was 97.98%. A linear relationship was observed between perampanel dose and free concentration in plasma, and a positive relationship was found between the total and free-perampanel concentrations. Concomitant use of oxcarbazepine reduced the free CD ratio by 37%. Concomitant use of valproic acid increased the free CD ratio by 52%. Five patients had a plasma high-sensitivity C-reactive protein (Hs-CRP) level of >5.0 mg/L (Hs-CRP positive). The total and free CD ratios of perampanel were increased in patients with inflammation. Two patients with inflammation developed adverse events, which disappeared as the Hs-CRP level returned to normal, and neither required perampanel dose reduction. Age and sex did not influence the free-perampanel concentration.

CONCLUSIONS

This study found complex drug interactions between perampanel and other concomitant antiseizure medications, providing valuable information to enable clinicians to apply perampanel in the future reasonably. In addition, it may be important to quantify both the total and free concentrations of perampanel to assess complex pharmacokinetic interactions.

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.

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.

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 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.

Effectiveness and tolerability of adjunctive perampanel in pediatric patients (aged 4-12 years) with refractory epilepsy: An observational study

Information on the effects of perampanel in Chinese children ≤12 years of age with refractory epilepsy is limited; thus, we conducted an observational study to assess the effectiveness, safety, and tolerability of adjunctive perampanel in this pediatric population. In this study, we reviewed the medical records of pediatric patients aged 4 to 12 years with refractory epilepsy who were admitted to Children's Hospital of Soochow University and prescribed perampanel between January 2020 and January 2021. Effectiveness of perampanel was measured by 50% responder rates, seizure-freedom rates, and retention rates for up to 48 weeks. Adverse events were monitored and recorded throughout the study. A total of 34 patients (male, n = 15) who exhibited refractory epilepsy were included in this study, and 64.71% of patients had focal-onset seizures combined with generalized epilepsy. The mean (± standard deviation) age of patients was 7.21 (± 2.12) years, with a mean (± standard deviation) age at seizure onset of 4.57 (± 2.59) years. After the addition of perampanel, the 50% responder rates at 4, 8, 12, 24, 36, and 48 weeks were 37.50% (12/32), 43.75% (14/32), 53.13% (17/32), 59.38% (19/32), 59.38% (19/32), and 62.07% (18/29). Two patients withdrew from perampanel treatment due to adverse events in the first 2 weeks. Adverse events were reported by 44.12% (15/34) of patients, and the retention rates at 36 and 48 weeks were 94.12% (32/34) and 85.29% (29/34), respectively. Overall, perampanel exhibited good effectiveness, safety, and tolerability in the treatment of pediatric patients (aged 4-12 years) with refractory epilepsy. These findings suggest that personalized treatment and better baseline seizure control may increase the responder rate and retention rate of perampanel.

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.

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.

Perampanel as adjunctive therapy in drug resistant epilepsy in adolescents and children waiting for epilepsy surgery: A multicenter observational study in Thailand

PURPOSE

To evaluate the effectiveness and tolerability of perampanel (PER) in real-world settings in patients between 1 month and 18 years of age with drug resistant epilepsy (DRE) waiting for epilepsy surgery.

METHODS

In this multicenter study, patients between 1 month and 18 years of age with DRE treated with PER between January 2020 and June 2021 were selected. The study outcome was effectiveness of PER treatment reported as reduction in seizure frequency and seizure freedom rate. Effectiveness was assessed at 30, 60, 90, 120, 150 and 180 days after initiation of PER. Tolerability profiles were reported as adverse events according to the observations of the patients' family members and physician.

RESULTS

Eighty-five patients treated with PER were included in the study. The mean initial dose and mean maximum dose of adjunctive PER was 2 mg/day and 5.8 mg/day, respectively. The mean seizure frequency (rate/week) was 41.3, 25.4, 18.9, 14.3, 11.2, 11.1 and 8.9 seizures at baseline, 30, 60, 90, 120, 150 and 180 days, respectively; the reduction in the mean seizure frequency at all timepoints was significant compared at the baseline (p<0.001). At 180 days, ≥75% seizure reduction was seen in 64.9% (37/57) of the patients and seizure freedom was achieved in 36.8% (21/57). Drowsiness, ataxia, and behavioral changes were the common adverse events observed, and these improved after the dose of PER was reduced. No discontinuation of PER was required due to side effects or intolerance.

CONCLUSION

In real-world settings, PER is well tolerated and effective in seizure control in pediatric and adolescent patients with DRE.

PROVE-Phase IV Study of Perampanel in Real-World Clinical Care of Patients with Epilepsy: Interim Analysis in Pediatric Patients

PROVE is a retrospective, phase IV study assessing retention, dosing, efficacy, and safety of perampanel when administered to patients during routine clinical care. We report an interim analysis of preadolescent (1 to <12 years) and adolescent (12 to <18 years) patients. Data were obtained from medical records of patients with epilepsy initiating perampanel after January 1, 2014; cut-off date for this analysis was October 10, 2018. Overall, 151 preadolescent and 183 adolescent patients were included. Retention rates following 24 months on perampanel were 42.5% (preadolescent subgroup; n = 31/73) and 55.7% (adolescent subgroup; n = 54/97). Treatment-emergent adverse events occurred in 53 (35.1%) preadolescent (most common: aggression, irritability, and somnolence) and 78 (42.6%) adolescent patients (most common: somnolence, aggression, and dizziness). These data indicate that daily oral doses of perampanel are generally well tolerated during routine clinical care, with favorable retention rates for ≤2 years, in patients aged 1 to <18 years.

Adjunctive perampanel therapy for patients with epileptic spasms

BACKGROUND

Perampanel is an antiepileptic drug. Some studies have documented the efficacy of perampanel in epileptic spasms. We aimed to evaluate the efficacy and safety of adjunctive perampanel therapy (PT) in patients with epileptic spasms.

METHODS

We retrospectively surveyed the efficacy and safety of adjunctive PT in 14 patients with epileptic spasms at the Saitama Children's Medical Center between June 2016 and September 2021. Seizure outcomes and safety were evaluated 12 months after commencing PT. Response to perampanel was defined as complete remission of epileptic spasms for more than 3 months.

RESULTS

The median age at onset of epileptic spasms was 0.4 years (range, 0.1-1.3 years). The etiology was structural in 11 patients, genetic in two, and unknown in one. The median age at the commencement of PT was 3.2 years (1.5-10.3 years). The initial and maintenance doses of perampanel were administered at 0.04 (range, 0.02-0.05) mg/kg/day and 0.12 (range, 0.03-0.24) mg/kg/day, respectively. Five of the 14 patients (35.7%) showed remission of epileptic spasms for more than 3 months at 12 months after PT; these patients had a structural etiology. The median duration between commencement of perampanel and spasm remission was 2 months (range, 1-6 months). No serious adverse effects occurred.

CONCLUSIONS

This is the first case series evaluating adjunctive PT for epileptic spasms. PT is worth investigating to treat epileptic spasms in patients with structural etiologies. As our study population primarily comprised children aged 2 years and older, PT may be useful for epileptic spasms beyond infancy.

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.

[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.

Perampanel in real-world clinical care of patients with epilepsy: Interim analysis of a phase IV study

Objective

To assess the retention rate, efficacy, safety, and dosing of perampanel administered to patients with epilepsy during routine clinical care in the retrospective phase IV, PROVE Study (NCT03208660).

Methods

Exposure, efficacy, and safety data were obtained from the medical records of patients initiating perampanel after January 1, 2014, across 29 US study sites. The cutoff date for this interim analysis was October 10, 2018. The primary efficacy endpoint was retention rate. Secondary efficacy endpoints included median percent changes in seizure frequency, seizure-freedom rate, and overall investigator impression of seizure effect.

Results

All enrolled patients (N = 1121) received perampanel. Mean (standard deviation [SD]) cumulative duration of exposure to perampanel was 16.6 (14.7) months; overall mean (SD) daily perampanel dose was 5.7 (2.7) mg. Perampanel uptitration occurred weekly (21.1%), biweekly (23.8%), every 3 weeks (1.5%), other (43.3%), and unknown (10.3%). Across the Safety Analysis Set (N = 1121), retention rate on perampanel at 24 months was 49.5% (n = 319/645).At 12 months, the median reduction in seizure frequency per 28 days from baseline in the small number of patients for whom data were available was 75.0% (n = 85), and 30/85 (35.3%) patients were seizure free. Based on investigator impression at the end of treatment, improvement, no change (ie, stable), or worsening of seizures was reported in 54.3%, 33.7%, and 12.0% of patients, respectively.Treatment-emergent adverse events occurred in 500 (44.6%) patients; the most common were dizziness (9.2%), aggression (5.4%), and irritability (4.5%). Serious treatment-emergent adverse events occurred in 32 (2.9%) patients.

Significance

Favorable retention and sustained efficacy were demonstrated for ≥12 months following initiation of perampanel during routine clinical care in patients with epilepsy.

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.

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.