Adjunctive perampanel in partial-onset seizures: Asia-Pacific, randomized phase III study

Efficacy and safety of add-on antiseizure medications for focal epilepsy: A network meta-analysis

OBJECTIVE

Several antiseizure medications (ASMs) have been approved for the treatment of focal epilepsy. However, there is a paucity of evidence on direct comparison of ASMs. We evaluated the comparative efficacy and safety of all approved add-on ASMs for the treatment of focal epilepsy using network meta-analysis.

METHODS

Data through extensive literature search was retrieved from PubMed, Embase, Cochrane, and ClinicalTrial.gov databases using predefined search terms from inception through March 2023. PRISMA reporting guidelines (CRD42023403450) were followed in this study. Efficacy outcomes assessed were ≥50%, ≥75%, and 100% responder rates. Patient retention rate and safety outcomes such as overall treatment-emergent adverse events (TEAEs) and individual TEAEs were assessed. "Gemtc" 4.0.4 package was used to perform Bayesian analysis. Outcomes are reported as relative risks (RRs) and 95% confidence interval (CI).

RESULTS

Literature search retrieved 5807 studies of which, 75 studies were included in the analysis. All ASMs showed significantly higher ≥50% responder rate compared with placebo. Except the ≥75% seizure frequency reduction for zonisamide (2.23; 95% CI: 1.00-5.70) and 100% for rufinamide (2.03; 95% CI: 0.54-11.00), all other interventions showed significantly higher ≥75% and 100% responder rates compared with placebo. Among treatments, significantly higher 100% responder rate was observed with cenobamate compared to eslicarbazepine (10.71; 95% CI: 1.56-323.9) and zonisamide (10.63; 95% CI: 1.37-261.2). All ASMs showed a lower patient retention rate compared to placebo, with the least significant value observed for oxcarbazepine (0.77; 95% CI: 0.7-0.84). Levetiracetam showed a lower risk of incidence (1.0; 95%CI: 0.94-1.1; SUCRA: 0.885067) for overall TEAE compared with other medications.

SIGNIFICANCE

All approved ASMs were effective as add-on treatment for focal epilepsy. Of the ASMs included, cenobamate had the greatest likelihood of allowing patients to attain seizure freedom.

PLAIN LANGUAGE SUMMARY

This article compares the efficacy and safety of antiseizure medications (ASMs) currently available to neurologists in the treatment of epileptic patients. Several newer generation ASMs that have been developed may be as effective or better than the older medications. We included 75 studies in the analysis. In comparison, all drugs improved ≥50%, ≥75% and 100% responder rates compared to control, except for Zonisamide and Rufinamide in the ≥75% and 100% responder rate categories. Retention of patients undergoing treatment was lower in drugs than placebo. All drugs were tolerated, the levetiracetam showed the best tolerability. Cenobamate more likely help completely to reduce seizures.

Efficacy and Safety of adjunctive Perampanel in a prospective, real-world, Phase IV study in Indian patients aged ≥12 years for Treatment of focal-onset Epilepsy: Study 508

OBJECTIVE

ESPRITE (Study 508; NCT03836924) evaluated the real-world safety, tolerability, and efficacy of adjunctive perampanel in patients aged ≥12 years with focal-onset seizures (FOS), with or without focal to bilateral tonic-clonic seizures (FBTCS), in India.

METHODS

ESPRITE was a prospective, multicenter, single-arm, observational, Phase IV study with a 6-month Treatment Period. Patients were aged ≥12 years and had been prescribed perampanel for adjunctive treatment of FOS, with or without FBTCS. Assessments included incidence of treatment-emergent adverse events (TEAEs; primary endpoint), median percent reduction in seizure frequency per 28 days from baseline, 50% responder rates, and seizure-freedom rates.

RESULTS

Overall, 200 patients were enrolled (199 patients in the Safety Analysis Set and 174 patients who completed all visits in the main efficacy analyses). TEAEs (all mild or moderate in severity) were reported in 18.1% (n = 36/199) of patients (the most common were dizziness [3.0%] and irritability [2.0%]). TEAEs leading to discontinuation of perampanel were reported in 2.0% of patients; no deaths or serious TEAEs occurred. At 6 months, median percent reduction in seizure frequency was 100.0%, 50% responder rate was 83.3%, and seizure-freedom rate was 49.4%.

SIGNIFICANCE

Adjunctive perampanel (at a mean daily dose of 4 mg/day) was shown to be well tolerated and effective in patients aged ≥12 years with FOS, with or without FBTCS, from India.

PLAIN LANGUAGE SUMMARY

Many patients do not receive adequate treatment for epilepsy and need effective seizure control medications. In this 6-month clinical study, 199 patients from India, aged 12 years or older, added perampanel to the anti-seizure medications they were already taking. At 6 months, 49% of patients experienced no seizures since starting perampanel and seizure frequency was reduced by half in 83% of patients. Side effects occurred in 18% of patients (most commonly dizziness and irritability) and caused 2% to stop perampanel; no deaths were reported. Perampanel was an effective and generally safe added medication for patients with epilepsy from India.

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.

A comparison of cenobamate with other newer antiseizure medications for adjunctive treatment of focal-onset seizures: A systematic review and network meta-analysis

PURPOSE

To compare the efficacy, safety, and tolerability of cenobamate with other newer anti-seizure medications (ASMs) including brivaracetam, eslicarbazepine, lacosamide, perampanel, and zonisamide, approved for adjunctive treatment of drug-resistant focal-onset seizures (FOS) in adults with epilepsy.

METHODS

A systematic literature review (SLR) was conducted to obtain relevant efficacy, safety, and tolerability data for ASMs for the treatment of drug-resistant FOS. All studies were thoroughly assessed for potential sources of heterogeneity and analysed via Bayesian network meta-analyses (NMAs). Efficacy outcomes were ≥50 % responder rate and seizure freedom during the maintenance period, which were modelled simultaneously using a multinomial Bayesian NMA. Safety and tolerability outcomes were the proportion of patients who experienced at least one treatment-emergent adverse event (TEAE) and the proportion who experienced at least one TEAE leading to discontinuation.

RESULTS

The SLR identified 76 studies, of which 23 were included in the Bayesian NMAs. Cenobamate was associated with statistically significant higher rates for the ≥50 % responder rate and seizure freedom outcomes compared with all ASMs analysed. The point estimates indicated that cenobamate was associated with higher rates of experiencing at least one TEAE and at least one TEAE leading to discontinuation compared with brivaracetam, lacosamide, and zonisamide; however, no results were statistically significant.

CONCLUSION

Cenobamate was associated with increased efficacy compared with all ASMs analysed. There were no statistically significant differences in the safety and tolerability outcomes. The results presented corroborate the conclusions drawn from previous published NMAs, which also highlight the notable efficacy of cenobamate in comparison with other ASMs.

Clinical observation and analysis of rash caused by lacosamide in children with epilepsy

PURPOSE

To draw clinical attention to rashes caused by lacosamide.

METHODS

This retrospective analysis included patients admitted to the Department of Pediatrics, Second Affiliated Hospital of Xi'an Jiaotong University between January 2021 and September 2023. We focused on patients who developed rashes after lacosamide treatment and analyzed all patients who exhibited rashes after lacosamide treatment to analyze the risk factors.

RESULTS

In total, 190 patients received lacosamide, of whom four developed allergies (2.1 %). Three patients had severe rashes, and two patients had high fever. All of these adverse events improved after the withdrawal of lacosamide. Of the 13 patients reported to date, including the four patients in this study, eight used various antiseizure medicines, including seven patients who used four or more antiseizure medicines. Four patients underwent testing for HLA-B*1502, and two patients were positive. Patients developed rashes within 1-10 days after treatment initiation, and the duration of the rash ranged 2-37 days.

CONCLUSIONS

Lacosamide-induced rash was detected in 2.1 % of patients in our cohort. Rashes are potentially serious, and prompt evaluation is required. Rashes are more likely to occur when multiple antiseizure medicines are used simultaneously, typically within 10 days of treatment initiation.

Long-term efficacy and safety of adjunctive perampanel in patients from the Asia-Pacific region with refractory focal-onset seizures in Study 335 open-label extension

OBJECTIVE

To evaluate the long-term efficacy, safety, and tolerability of adjunctive perampanel for the treatment of patients with refractory focal-onset seizures (FOS), with or without focal to bilateral tonic-clonic seizures (FBTCS), from the Asia-Pacific region.

METHODS

Study 335 (NCT01618695) was a randomized, double-blind, placebo-controlled, Phase III study. Patients aged ≥12 years with refractory FOS who completed the Core Study could enter an open-label extension (OLEx) Phase (6-week Conversion and ≥46-week Maintenance Period). Endpoints included median percent reduction in seizure frequency per 28 days, 50% responder and seizure-freedom rates, and treatment-emergent adverse events (TEAEs).

RESULTS

The Intent-to-Treat Analysis Set included 704 patients (529 received perampanel and 175 received placebo during the Core Study; all patients received perampanel during OLEx). The median percent reduction in seizure frequency and 50% responder rates in patients who received perampanel during the Core Study were maintained throughout the OLEx Phase (Week 64-75: 55.9% and 54.3%, respectively). Seizure freedom for ≥12 consecutive months at any time during perampanel treatment was achieved by 4.1% of patients with FOS and 14.2% of patients with FBTCS. Among patients treated with perampanel 4 mg/day (n = 83), median reduction in seizure frequency was lower in those who received concomitant enzyme-inducing anti-seizure medications (EIASMs) than those who received non-EIASMs. The most common TEAE was dizziness (n = 318; 46.8%); 141 (20.8%) patients had TEAEs that led to study/drug withdrawal.

SIGNIFICANCE

Overall, long-term seizure control was achieved with adjunctive perampanel in patients with refractory FOS, with or without FBTCS, in an Asia-Pacific population.

Efficacy, tolerability and safety of add-on third-generation antiseizure medications in treating focal seizures worldwide: a network meta-analysis of randomised, placebo-controlled trials

Background

Adjunctive newer antiseizure medications (ASMs) are being used in patients with treatment-resistant focal-onset seizures (FOS). An updated network meta-analysis (NMA) was necessary to compile evidence in this critical area.

Methods

We systematically searched PubMed, Embase, Cochrane Library, Web of Science, and Scopus from their inception until 17 January 2024, evaluating the efficacy, tolerability, and safety of rufinamide (RUF), brivaracetam (BRV), cenobamate (CNB), eslicarbazepine (ESL), lacosamide (LCM), retigabine (RTG), and perampanel (PER) as adjunctive treatments for FOS. Efficacy outcomes included seizure response and seizure freedom. Tolerability was assessed by discontinuation due to adverse events (AEs). Safety outcomes were evaluated based on the number of patients experiencing at least one AE and serious adverse events (SAEs). This review is registered with PROSPERO (CRD42023485130).

Findings

A total of 29 studies involving 11,750 participants were included. For seizure response, all ASMs were significantly superior to placebo, with RTG ranking highest, followed by CNB. Considering dosage, CNB 400 mg/d was top-ranked, followed by RTG 1200 mg/d. For seizure freedom, BRV was highest-ranked, followed by CNB, with BRV 100 mg/d leading, followed by CNB 400 mg/d. Regarding tolerability, LCM 600 mg/d had the lowest ranking, followed by CNB 400 mg/d. For the safety outcome of AEs, ESL 1200 mg/d was ranked lowest, followed by CNB 400 mg/d. Regarding SAEs, LCM 400 mg/d was ranked lowest, followed by RTG 1200 mg/d.

Interpretation

ASMs at different dosages have varying efficacy and tolerability profiles. We have provided hierarchical rankings of ASMs for efficacy and safety outcomes. Our findings offer the most comprehensive evidence available to inform patients, families, physicians, guideline developers, and policymakers about the choice of ASMs in patients with treatment-resistant FOS.

Funding

None.

WRAPPER study: Real-world effectiveness and tolerability of adjunctive perampanel for people with drug-resistant epilepsy in Hong Kong

OBJECTIVE

The Prince of Wales Hospital (PWH) Real-world Analysis of People with Drug-Resistant Epilepsy (DRE) on PERampanel (WRAPPER) study assessed effectiveness and tolerability of adjunctive perampanel in people with DRE attending PWH.

METHODS

This was a prospective single-center real-world observational study involving 70 people with DRE between July 2016 and June 2021. A post hoc analysis after the initial study period of 16 weeks assessed outcomes for an extended period up to 52 weeks.

RESULTS

After 16 weeks, median dose of perampanel was 2 mg (IQR 24 mg). 50% responder rates were 40.0%, 41.5%, and 48.7% at 16, 26, and 52 weeks. Seizure freedom was 12.9%, 20.7%, and 25.6% at 16, 26, and 52 weeks. Monthly seizure frequency reduced from 3.0 (IQR 3.0-6.6) at baseline to 2.0 (IQR 2.0-6.0, p = 0.005) at 16 weeks; 2.0 (IQR 2.0-5.0, p = 0.01) at 26 weeks; and 2.0 (IQR 0.0-4.0, p = 0.018) at 52 weeks. Older age predicted 50% responders (OR 1.08, 95% CI 1.01-1.14, p = 0.048). At 16 weeks, 51.4% (36/70) had treatment-emergent adverse effects (TEAEs). Most common was seizure exacerbation at 35.7% (25/70) followed by fatigue at 15.7% (11/70). NPI-12 and ZBI scores indicated no increase in neuropsychiatric symptoms on perampanel.

SIGNIFICANCE

Low-dose 2-4 mg adjunctive perampanel for people with DRE conferred appreciable improvements in seizure reduction without significant neuropsychiatric adverse effects in the real-world setting at a tertiary center in Hong Kong and had better antiseizure effect with advancing age.

PLAIN LANGUAGE SUMMARY

This real-world study from Hong Kong found low-dose perampanel was effective and tolerable for people with drug-resistant epilepsy. Furthermore, perampanel was also potentially more effective with advancing age.

Efficacy and tolerability of perampanel: a Chinese real-world observational study in epilepsy

Purpose

To investigate whether there exists a statistically significant distinction between the effectiveness and tolerance of perampanel (PER) and the number of antiseizure medications (ASMs) that were tried prior to administering PER.

Method

A prospective, observational study was performed at West China Hospital of Sichuan University. The study included patients diagnosed with epilepsy who were prescribed PER and were monitored for a minimum of 6 months. The efficacy of PER was evaluated at 1, 3, 6, and 12-month intervals by examining the retention rate and the 50% response rate. All statistical analyses were conducted using IBM SPSS Statistics version 25 (IBM Corporation, Armonk, New York).

Results

A total of 1,025 patients were identified, of which 836 were included in the analysis. Seven hundred and eighty-nine patients (94.4%) were followed up for a year. The median age of the patients was 29.32 ± 14.06 years, with 45.81% of the patients being male and 17.0% being adolescents. The average duration of epilepsy was 11.22 ± 8.93 years. Overall, PER was discontinued in 49.5% of patients, with the most common reasons being inadequate therapeutic effect and treatment-emergent adverse events (TEAEs). At the 6-month follow-up, the retention rate was 54.2% (454/836), and 39.6% of patients had a 50% response. At the 12-month follow-up, the retention rate was 49.4% (340/789), and 44.5% of patients had a 50% response. Patients who received PER as monotherapy had the highest retention rates (P = 0.034) and 50% response rates (P < 0.001) at any follow-up point. TEAEs were reported in 32.0% of patients, and these led to discontinuation in 15.4% of patients. The most common TEAEs were dizziness and somnolence. There was no significant difference between subgroups (P = 0.57), but there was a significant difference between the dosage of PER and TEAEs (P < 0.001).

Main findings

The study concludes that PER is effective in treating both focal and generalized tonic-clonic seizures. Patients who had fewer previous exposures to ASMs exhibited higher response rates to PER. TEAEs related to PER dosage were more prevalent during the first 3 months of treatment and tended to improve with continued use, ultimately demonstrating favorable long-term tolerability.

Intravenous perampanel as an alternative to the oral formulations in Japanese patients with epilepsy

OBJECTIVE

Perampanel is an oral anti-seizure medication, which is approved in Japan for focal-onset seizures, with/without focal to bilateral tonic-clonic seizures, as monotherapy/adjunctive therapy in patients aged 4 years and older. Treatment for generalized tonic-clonic seizures as adjunctive therapy in patients aged 12 years and older is approved as well. We evaluated the feasibility of intravenous (IV) administration of perampanel as an alternative to oral administration.

METHODS

Study 240 (NCT03754582) was an uncontrolled, open-label study of IV perampanel, conducted in 21 Japanese patients with epilepsy who received a stable dose of 8-12 mg/day of oral perampanel. Patients received 30-minute IV infusions at equivalent daily doses of oral perampanel for 4 days, then were switched back to oral perampanel. Safety, tolerability, plasma concentration, and maintenance of efficacy throughout the transition between IV and oral dosing of perampanel were assessed. As supportive data, a subgroup analysis was also conducted using data from healthy Japanese subjects (n = 18) who were enrolled in Study 050 (NCT03376997) investigating the pharmacokinetics and safety of IV perampanel in healthy subjects who received an IV infusion (30-, 60-, or 90-minute) of perampanel 12 mg and a single oral administration of perampanel 12-mg tablet.

RESULTS

In Study 240, the transition between 30-minute IV and oral perampanel dosing was associated with a ≤1.4-fold increase in the mean change in maximum observed concentration of perampanel. Seizure outcomes demonstrated no considerable changes in efficacy before, during, or after 30-minute IV dosing of perampanel. The safety profiles were similar between IV and oral formulations. In Study 050, the pharmacokinetics of 30- or 60-minute IV infusion of perampanel further support the interchangeability between oral and IV formulations in the Japanese subjects.

SIGNIFICANCE

These results support that 30-minute IV perampanel may be a potential short-term alternative to oral formulations for patients with epilepsy.

Efficacy and Safety of Five Broad-Spectrum Antiseizure Medications for Adjunctive Treatment of Refractory Epilepsy: A Systematic Review and Network Meta-analysis

BACKGROUND

Overall, up to one-third of epilepsy patients have drug-resistant epilepsy. However, there was previously no meta-analysis to support the guidelines for broad-spectrum antiseizure medication selection for the adjunctive treatment of refractory epilepsy. In the present meta-analysis, we assessed the efficacy and safety of three second-generation broad-spectrum antiseizure medications, lamotrigine (LTG), levetiracetam (LEV), and topiramate (TPM), and two third-generation broad-spectrum antiseizure medications, perampanel (PER) and lacosamide (LCM), for the adjunctive treatment of refractory epilepsy.

METHODS

We systematically searched PubMed, Embase, and CENTRAL from inception to July 15, 2022. The studies included in the meta-analysis were required to meet the following criteria: (1) be randomized, double-blind clinical trials; (2) include patients aged >2 years with a clinical diagnosis of drug-resistant epilepsy; (3) have at least 8 weeks for the treatment period excluding the titration phase; and (4) report the outcomes of seizure response, seizure freedom and the withdrawal rate due to treatment-emergent adverse effects. Data were extracted, and the risk of bias for each study was assessed by two authors independently using RoB2 tools. We performed the network meta-analysis for each outcome through a group of programs in the mvmeta and network packages in Stata. Relative odds ratios with 95% confidence intervals were calculated as the result of the analyses. The surface under the cumulative ranking curve (SUCRA) and mean ranks were used to rank these treatments.

RESULTS

Forty-two randomized controlled trials (RCTs) (LTG-placebo: n = 6, LEV-placebo: n = 13, TPM-placebo: n = 9, PER-placebo: n = 6, LCM-placebo: n = 7, LEV-TPM: n = 1) with 10257 participants (LTG = 569, LEV = 1626, TPM = 701, PER = 1734, LCM = 1908, placebo = 3719) were included. Levetiracetam had subequal efficacy in 50 % seizure frequency reduction to TPM [odds ratio (OR) 1.00, 95% confidence interval (CI) 0.73-1.38], and LEV had a higher rate of ≥ 50% seizure frequency reduction than LCM (OR 1.49, 95% CI 1.11-2.01) and PER (OR 1.68, 95% CI 1.24-2.29). Levetiracetam was also related to a higher proportion of seizure freedom participants than TPM (OR 1.87, 95% CI 1.20-2.89), PER (OR 2.23, 95% CI 1.12-4.43), and LCM (OR 2.97, 95% CI 1.46-6.05). In addition, LEV was associated with a lower risk of experiencing at least one treatment-emergent adverse event (TEAE) than PER (OR 0.63, 95% CI 0.46-0.85) and TPM (OR 0.51, 95 % CI 0.36-0.72) and a lower proportion of patients experiencing TEAEs leading to discontinuation than PER (OR 0.51, 95% CI 0.27-0.97) and TPM (OR 0.50, 95 % CI 0.27-0.93).

CONCLUSIONS

Third-generation drugs (PER and LCM) had no advantages in terms of efficacy and safety for adjunctive treatment of refractory epilepsy compared with several second-generation drugs (LEV and LTG). Levetiracetam was the priority choice for adjunctive treatment of refractory epilepsy. Perampanel and LCM had no advantages in terms of efficacy and safety among the five drugs.

REGISTRATION

PROSPERO registration number, CRD42022344153; last edited on December 23, 2022.

Perampanel and lacosamide monotherapy in pediatric patients with newly diagnosed focal epilepsy: A prospective study evaluating efficacy, tolerability, and behavior

PURPOSE

Perampanel (PER) and lacosamide (LCM) are the new third-generation anti-seizure medications (ASMs) that were approved for the monotherapy of focal epilepsy in children over four years of age in China, in 2021. Very few studies have analyzed the application of PER monotherapy among pediatric patients aged ≥four years, and no study compared the efficacy and tolerability of PER monotherapy with LCM monotherapy in pediatric patients with focal epilepsy. The present study aimed to investigate the efficacy, tolerability, and effect on behavior and emotion of PER and LCM as monotherapy in pediatric patients with newly diagnosed focal epilepsy, which is beneficial for clinicians to have more choices to treat pediatric patients with focal epilepsy.

METHODS

This was a prospective, single-center, observational study that involved pediatric patients (disease onset age ≥four years) with newly diagnosed focal epilepsy treated with PER or LCM as primary monotherapy. Outcomes included retention, being responders, and seizure-free rates after 3, 6, and 12 months. Adverse events (AEs) were noticed throughout the follow-up period. Behavioral outcomes were evaluated with Achenbach Child Behavior Checklist (CBCL/4-16) at baseline and after three and six months.

RESULTS

Using randomization, 60 patients receiving PER (31 females, 29 males, median age: 7.79 [5.34, 10.16] years, median dose: 3.0 [2.0, 4.0] mg/day) and 60 patients receiving LCM (25 females, 35 males, median age: 7.72 [5.91, 10.72] years, median dose: 150.0 [100.0, 200.0] mg/day) were enrolled in the study. At the 12-month follow-up, the retention rates in the PER and LCM groups, both were 90.4%, and the responder rates were 65.4% and 71.2%, while seizure-free rates were 57.7% and 67.3%, respectively. There were no significant differences in the retention, responder and seizure-free rates between the two groups (P > 0.05). There were no significant differences in the responder rates between patients with BECTS, abnormal brain magnetic resonance imaging (MRI), or types of seizure in the two groups (P > 0.05). In the PER group, 28.8% (15/52) of patients experienced AEs, of which the most frequently reported were irritability (n = 7; 13.5%), dizziness (n = 5; 9.6%), somnolence (n = 3; 5.8%), ataxia (n = 1; 1.9%), headache (n = 1; 1.9%), and rash (n = 1; 1.9%). In the LCM group, 15.4% (8/52) of the patients had AEs, including headache (n = 4; 7.5%), dizziness (n = 4; 7.5%), nausea (n = 2; 3.8%), somnolence (n = 2; 3.8%), irritability (n = 1; 1.9%), stomach ache (n = 1; 1.9%), and vomiting (n = 1; 1.9%). The incidence of irritability was significantly higher in the PER group than in the LCM group (13.5% vs. 1.9%, P = 0.031), which occurred mainly within eight weeks after drug administration. Patients with irritability were not dangerous to surrounding people by the assessment of parental observation in the life. And the symptoms were relieved spontaneously within a few months. The outcomes of total scores, internalizing scores, and externalizing scores of the CBCL did not show statistically significant differences in the PER and LCM groups between baseline and three and six months. Characteristics of behavior and emotion did not have substantial changes in patients treated with PER and LCM monotherapy.

CONCLUSIONS

The present study documented similar good effectiveness and good tolerance of PER and LCM as monotherapy in pediatric patients with newly diagnosed focal epilepsy and showed no behavioral or emotional impact, as assessed by the CBCL. Though the incidence of irritability with PER monotherapy may be higher than that with LCM monotherapy soon after medication initiation, this side effect appears to resolve spontaneously within a few months. At present, this study was the first research about PER and LCM monotherapy in pediatric patients with newly diagnosed focal epilepsy evaluating efficacy, tolerability, and behavior in China.

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.

Safety and effectiveness of perampanel monotherapy after adjunctive therapy through retention rate in subjects with focal-onset seizures with or without focal to bilateral tonic-clonic seizures: A multicenter retrospective study in Korea

OBJECTIVE

To assess the effectiveness and tolerability of perampanel monotherapy following conversion from adjunctive therapy.

METHODS

This was a multicenter, retrospective, non-interventional study of Korean patients aged ≥12 years with focal-onset seizures (FOS) with or without focal to bilateral tonic-clonic seizures. Data were extracted from electronic medical records of perampanel-treated patients from 1 February 2016 to 31 October 2020. Kaplan-Meier estimated retention rates, effectiveness, and safety were recorded.

RESULTS

Subjects (n = 66, mean age 46.2 years) were mostly male (68.2%) with focal to bilateral tonic-clonic seizure (71.2%). Mean duration of illness was 86.3 months. Retention rates after conversion to perampanel monotherapy at 3, 6, and 12 months (primary outcome) were 96.0%, 96.0%, and 75.6%, respectively. Overall retention rates in patients receiving perampanel as adjunctive or monotherapy at 3, 6, 12, 18, and 24 months after perampanel add-on were 100%, 98.3%, 95.9%, 92.6%, and 92.6%, respectively. Mean retention duration was 41.2 months (overall perampanel administration) and 21.4 months (monotherapy). Mean seizure frequency/28 days in the Full Analysis Set (n = 61) was comparable for adjunctive and monotherapy (0.2 ± 0.79 vs 0.2 ± 0.64; change between adjunctive and monotherapy periods: 0.0 ± 0.59; p = 0.498). Perampanel was well tolerated and no new safety signals were identified. Dizziness (4.6%), only reported during adjunctive therapy, was the most common treatment-emergent adverse event.

CONCLUSIONS

Conversion to perampanel monotherapy from adjunctive therapy showed promising results in subjects with FOS with/without focal to bilateral tonic-clonic seizures; further studies in a larger population are needed to confirm these encouraging data.

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).

Perampanel add-on for drug-resistant focal epilepsy

BACKGROUND

Epilepsy is one of the most common neurological disorders. Approximately 30% of people with epilepsy are considered to be drug-resistant, and usually need treatment with a combination of other antiepileptic drugs. Perampanel is a newer antiepileptic drug that has been investigated as add-on therapy for drug-resistant focal epilepsy.

OBJECTIVES

To evaluate the benefits and harms of perampanel as add-on therapy for people with drug-resistant focal epilepsy.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 20 October 2022.

SELECTION CRITERIA

We included randomised controlled trials comparing add-on perampanel with placebo.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcome was 1. 50% or greater reduction in seizure frequency. Our secondary outcomes were 2. seizure freedom, 3. treatment withdrawal due to any reason, 4. treatment withdrawal due to adverse effects, and 5.

ADVERSE EFFECTS

We used an intention-to-treat population for all primary analyses. We presented the results as risk ratios (RR) with 95% confidence intervals (CIs), except for individual adverse effects, which we reported with 99% CIs to compensate for multiple testing. We used GRADE to assess certainty of evidence for each outcome.

MAIN RESULTS

We included seven trials involving 2524 participants, all aged over 12 years. The trials were double-blind, randomised, placebo-controlled trials with treatment duration of 12 to 19 weeks. We assessed four trials at overall low risk of bias, and three trials at overall unclear risk of bias, due to risk of detection, reporting, and other biases. Compared with placebo, participants receiving perampanel were more likely to achieve a 50% or greater reduction in seizure frequency (RR 1.67, 95% CI 1.43 to 1.95; 7 trials, 2524 participants; high-certainty evidence). Compared to placebo, perampanel increased seizure freedom (RR 2.50, 95% CI 1.38 to 4.54; 5 trials, 2323 participants; low-certainty evidence) and treatment withdrawal (RR 1.30, 95% CI 1.03 to 1.63; 7 trials, 2524 participants; low-certainty evidence). Participants treated with perampanel were more likely to withdraw from treatment due to adverse effects compared to those receiving placebo (RR 2.36, 95% CI 1.59 to 3.51; 7 trials, 2524 participants; low-certainty evidence). A higher proportion of participants receiving perampanel reported one or more adverse effects when compared to participants who received placebo (RR 1.17, 95% CI 1.10 to 1.24; 7 trials, 2524 participants; high-certainty evidence). Compared with placebo, participants receiving perampanel were more likely to experience ataxia (RR 14.32, 99% CI 1.09 to 188.31; 2 trials, 1098 participants; low-certainty evidence), dizziness (RR 2.87, 99% CI 1.45 to 5.70; 7 trials, 2524 participants; low-certainty evidence), and somnolence (RR 1.76, 99% CI 1.02 to 3.04; 7 trials, 2524 participants). Subgroup analysis indicated that a larger proportion of participants who received perampanel at a dose of 4 mg/day (RR 1.38, 95% CI 1.05 to 1.83; 2 trials, 710 participants), 8 mg/day (RR 1.83, 95% CI 1.51 to 2.22; 4 trials, 1227 participants), or 12 mg/day (RR 2.38, 95% CI 1.86 to 3.04; 3 trials, 869 participants) achieved a 50% or greater reduction in seizure frequency compared to placebo; however, treatment with perampanel 12 mg/day also increased treatment withdrawal (RR 1.77, 95% CI 1.31 to 2.40; 3 trials, 869 participants).

AUTHORS' CONCLUSIONS

Add-on perampanel is effective at reducing seizure frequency and may be effective at maintaining seizure freedom for people with drug-resistant focal epilepsy. Although perampanel was well-tolerated, there was a higher proportion of treatment withdrawals with perampanel compared with placebo. Subgroup analysis suggested that 8 mg/day and 12 mg/day are the most efficacious perampanel doses; however, the use of 12 mg/day would likely increase the number of treatment withdrawals. Future research should focus on investigating the efficacy and tolerability of perampanel with longer-term follow-up, as well as exploring an optimal dose.

The Role of Glutamate Receptors in Epilepsy

Glutamate is an essential excitatory neurotransmitter in the central nervous system, playing an indispensable role in neuronal development and memory formation. The dysregulation of glutamate receptors and the glutamatergic system is involved in numerous neurological and psychiatric disorders, especially epilepsy. There are two main classes of glutamate receptor, namely ionotropic and metabotropic (mGluRs) receptors. The former stimulate fast excitatory neurotransmission, are N-methyl-d-aspartate (NMDA), α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA), and kainate; while the latter are G-protein-coupled receptors that mediate glutamatergic activity via intracellular messenger systems. Glutamate, glutamate receptors, and regulation of astrocytes are significantly involved in the pathogenesis of acute seizure and chronic epilepsy. Some glutamate receptor antagonists have been shown to be effective for the treatment of epilepsy, and research and clinical trials are ongoing.

A Single- and Multiple-Dose Pharmacokinetic Study of Oral Perampanel in Healthy Chinese Subjects

BACKGROUND AND OBJECTIVE

Perampanel is a once-daily oral anti-seizure medication indicated for focal-onset seizures and generalized tonic-clonic seizures. This study investigated the single- and multiple-dose pharmacokinetics of perampanel in healthy Chinese adults.

METHODS

Study 052 (NCT03424564) was a phase I, single-center, open-label, parallel-group study. In the single-dose part of the study, subjects received a single oral dose of perampanel 2, 4, or 8 mg. In the multiple-dose part, subjects received once-daily oral perampanel 2 mg on Days 1-7 and 4 mg on Days 8-21. Pharmacokinetic parameters were determined from perampanel plasma concentrations using non-compartmental analysis. Dose proportionality after single doses of perampanel was assessed. Safety and tolerability were evaluated.

RESULTS

In the single-dose part (N = 30), median time to reach maximum concentration (t_max) was 0.75-1.0 h, mean terminal elimination phase half-life (t_½) was 85.6-122 h, mean maximum observed concentration (C_max) was 77.9-276 ng/mL, and mean area under the concentration-time curve from time zero to time of the last quantifiable concentration (AUC_(0-t)) was 4070-15100 ng·h/mL. Single-dose pharmacokinetics were linear for perampanel 2-8 mg. In the multiple-dose part (N = 12), Day 21 steady-state (4 mg/day) parameters were median time at which the highest drug concentration occurs at steady state (t_ss,max), 1.25 h; mean t_½, 109 h; mean maximum observed concentration at steady state (C_ss,max), 453 ng/mL; and mean area under the concentration-time curve over the dosing interval on multiple dosing (AUC_{(0- τ)}), 7540 ng·h/mL. For single- and multiple-dose perampanel, the most common treatment-emergent adverse events were dizziness and somnolence.

CONCLUSIONS

Single- and multiple-dose pharmacokinetics of perampanel in healthy Chinese adults revealed rapid perampanel absorption, slow elimination, and a linear relationship with single perampanel doses of 2-8 mg. Findings were consistent with previous studies of perampanel pharmacokinetics in other ethnic/racial populations of healthy subjects. Single and multiple doses of perampanel were generally safe and well tolerated.

CLINICAL TRIAL REGISTRATION

NCT03424564; registered February 2018.

The safety of perampanel in different disorders and doses: A meta-analysis

PURPOSE

To investigate the safety of perampanel in different disorders and doses.

METHODS

Embase, the Cochrane Library, Medline, and ClinicalTrials.gov were searched from inception to July 2022 for randomized controlled trials (RCTs). The meta-analysis was performed by using Review Manager 5.3 and R 4.2.1 software.

RESULTS

A total of 17 RCTs with 5711 subjects were included in the final analysis. The double-blind treatment phase was from 12 weeks to 48 weeks. Our results showed that 11 adverse events (aggression, ataxia, balance disorder, dizziness, fall, fatigue, irritability, rash, somnolence, vertigo, and weight increase) were statistically significantly associated with perampanel, and 4 of them (ataxia, dizziness, fatigue, and somnolence) showed a clear dose-response relationship. Psychiatric adverse events occurred most frequently among serious treatment-emergent adverse events (TEAEs). At 8 mg/day, seven adverse events (aggression, balance disorder, dizziness, fatigue, irritability, vertigo, and weight increase) occurred more frequently in patients with epilepsy than in patients with other disorders, whereas dose discontinuation rates due to adverse events were lower in patients with epilepsy than in patients with other disorders.

CONCLUSION

The safety profile of perampanel is dependent on diseases and dose. The risk of adverse events was statistically significantly higher, with doses exceeding 4 mg/day. Despite a higher risk of adverse events, patients with epilepsy had a lower perampanel discontinuation rate than patients with other disorders.

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.

Assessment of the long-term efficacy and safety of adjunctive perampanel in adolescent patients with epilepsy: Post hoc analysis of open-label extension studies

OBJECTIVE

This post hoc analysis of four open-label extension (OLEx) studies evaluated the long-term efficacy and safety of adjunctive perampanel in adolescent patients (aged 12 to ≤17 years) with focal-onset seizures (FOS), with/without focal to bilateral tonic-clonic seizures (FBTCS), or generalized tonic-clonic seizures (GTCS).

METHODS

Patients who completed one of six double-blind, placebo-controlled studies could enter one of four OLEx studies comprising a blinded Conversion Period (6-16 weeks) followed by a Maintenance Phase (27 to ≤256 weeks; perampanel dose: ≤12 mg/day). Exposure, retention, seizure outcomes, and treatment-emergent adverse events (TEAEs) were analyzed. Efficacy outcomes were analyzed using observed case and last observation carried forward (LOCF) approaches; the latter was used to account for early dropouts.

RESULTS

The Full Analysis Set comprised 309 adolescents with FOS (FBTCS, n = 109) and 19 with GTCS, and the Safety Analysis Set comprised 311 with FOS (FBTCS, n = 110) and 19 with GTCS. Mean (standard deviation) cumulative duration of perampanel exposure (weeks) was: FOS, 77.7 (58.7); FBTCS, 88.7 (63.8); and GTCS, 97.0 (35.5). Retention rates were maintained for ≤2 years (FOS, 50.0 %; FBTCS, 57.1 %; GTCS, 41.7 %). Seizure control (median percent reduction in seizure frequency/28 days) was sustained for up to 2 years; FOS (59.4 %, n = 113), FBTCS (64.6 %, n = 53), and GTCS (86.5 %, n = 17). At Year 2, 50 % responder rates were: FOS, 58.4 % (n = 66); FBTCS, 54.7 % (n = 29); and GTCS, 82.4 % (n = 14); seizure-freedom rates were: FOS, 5.3 % (n = 6); FBTCS, 24.5 % (n = 13); and GTCS, 35.3 % (n = 6). Long-term seizure control was observed even in LOCF analyses. The incidence of TEAEs was highest during Year 1 (FOS, n = 269 [86.5 %]; FBTCS, n = 95 [86.4 %]; GTCS, n = 15 [78.9 %]), compared with Years 2-4; the most common (≥10 % of patients) were dizziness, somnolence, and nasopharyngitis. No new safety signals emerged with long-term treatment.

CONCLUSIONS

This post hoc analysis suggests that long-term (≤2 years) adjunctive perampanel (≤12 mg/day) is efficacious and generally well tolerated in adolescent patients with FOS, with or without FBTCS, or GTCS.

Effectiveness of Perampanel as the Only Add-on: Retrospective, Multicenter, Observational Real Life Study on epilepsy patients

OBJECTIVE

Perampanel (PER) is indicated as adjunctive antiseizure medication (ASM) in adolescents and adults with epilepsy. Data from clinical trials show good efficacy and tolerability, while limited information is available on the routine clinical use of PER, especially when used as only add-on treatment.

METHODS

we performed an observational, retrospective, multicenter study on people with focal or generalized epilepsy aged >12 years, consecutively recruited from 52 Italian epilepsy centers. All patients received PER as the only add-on treatment to a background ASM according to standard clinical practice. Retention rate, seizure frequency and adverse events were recorded at 3, 6 and 12 months after PER introduction. Sub-analyses by early or late use of PER and by concomitant ASM were also conducted.

RESULTS

503 patients were included (age 36.5±19.9 years). Eighty-one per cent had focal epilepsy. Overall, the retention rate was very high in the whole group (89% at 12 months) according with efficacy measures. No major differences were observed in the sub-analyses, although patients who used PER as early add-on, as compared with late add-on, more often reached early seizure freedom at 3 months follow-up (66% vs. 53%, p=0.05). Treatment-emergent adverse events occurred in 25%, far less commonly than in PER randomized trials.

SIGNIFICANCE

this study confirms the good efficacy and safety of PER for focal or generalized epilepsy in real-life conditions. We provide robust data about its effectiveness as only add-on treatment even in patients with a long-standing history of epilepsy and previously treated with many ASMs.

New evidence in adjunctive treatment of focal-onset seizures in adults: a critical appraisal

Anti-seizure medications (ASMs) represent the pillar of the treatment of epilepsy. The rate of drug-resistant epilepsy remained substantially unchanged over time and there is still the need for new and more effective treatment options. Brivaracetam, cenobamate, eslicarbazepine acetate, lacosamide and perampanel are 'third-generation' ASMs. The aim of this article is to summarize the currently available evidence about the relative efficacy and tolerability of the 'third-generation' ASMs as adjunctive treatment of focal-onset seizures in adults. So far, no randomized controlled study directly compared these ASMs, and their comparative efficacy and tolerability have been indirectly evaluated by one network meta-analysis. Sixteen trials were included in the network meta-analysis. The efficacy endpoints were the rates of seizure response and seizure freedom, defined as ≥ 50% and 100% reduction in baseline monthly seizure frequency. The tolerability endpoints were the rate of patients who developed any treatment emergent adverse events (TEAEs) and any TEAE leading to drug discontinuation. Cenobamate had the greatest likelihood of being the best option for the ≥ 50% and 100% seizure frequency reduction. Brivaracetam and lacosamide had the greatest likelihood to rank as the best-tolerated treatments for the occurrence of any TEAE and TEAE leading to discontinuation. Although network meta-analyses are not substitutes of direct comparisons, they can provide valuable evidence about the hierarchy of interventions. Additional real-world data can be useful complement to characterize the clinical profile and therapeutic potentialities of third-generation ASMs.

Intravenous Perampanel as an Interchangeable Alternative to Oral Perampanel: A Randomized, Crossover, Phase I Pharmacokinetic and Safety Study

Intravenous (IV) drug administration enables treatment of epilepsy when oral administration is temporarily not feasible. Perampanel is a once‐daily antiseizure medication currently available as oral formulations. Study 050 (NCT03376997) was an open‐label, randomized, single‐dose, crossover study to evaluate the interchangeability of oral and IV perampanel in healthy subjects (N = 48). Bioequivalence of single 12‐mg doses of IV (30‐, 60‐, or 90‐minute infusion) and oral perampanel, ≥6 weeks apart, was assessed. Analyses indicated bioequivalence of area under the plasma concentration–time curve extrapolated to infinity for 30‐ and 60‐minute IV infusions and oral perampanel doses (geometric mean ratio [90% confidence interval], 0.93 [0.84–1.02] and 1.03 [0.97–1.09], respectively); however, IV maximum observed drug concentration (C_max) values were 1.35‐ to 1.61‐fold higher than C_max. Simulated plasma concentration–time profiles using pooled pharmacokinetic data further supported oral and IV perampanel interchangeability in two scenarios: 12‐mg per day IV dosing during a temporary 7‐day switch from oral steady‐state maintenance therapy, and treatment initiation with 2‐mg perampanel. Thirty‐four (70.8%) subjects experienced treatment‐related adverse events. The IV perampanel safety profile was similar to that of oral perampanel without new safety concerns. Perampanel IV infusions may be a suitable temporary alternative to oral perampanel for treatment maintenance and/or initiation.

Perampanel markedly improved clinical seizures in a patient with a Rett‐like phenotype and 960‐kb deletion on chromosome 9q34.11 including the STXBP1

Intractable epilepsy was successfully controlled using perampanel, an α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazole propionic acid‐type glutamate receptor antagonist, in a 27‐year‐old woman who presented with a Rett syndrome‐like phenotype and novel 960‐kb deletion involving syntaxin‐binding protein 1 on chromosome 9q34.11. Perampanel may be an effective antiepileptic drug for intractable epilepsy associated with STXBP1 mutations.

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.

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.

Third-Generation Antiseizure Medications for Adjunctive Treatment of Focal-Onset Seizures in Adults: A Systematic Review and Network Meta-analysis

Background

Brivaracetam (BRV), cenobamate (CNB), eslicarbazepine acetate (ESL), lacosamide (LCM) and perampanel (PER) are antiseizure medications (ASMs) approved for adjunctive treatment of focal-onset seizures. So far, no randomised controlled trial directly compared the efficacy and safety of these drugs.

Objective

We estimated the comparative efficacy and safety of these ASMs for the treatment of focal-onset seizures in adults with epilepsy using a network meta-analysis (NMA).

Methods

We systematically searched (June week 4, 2021) MEDLINE (accessed by PubMed), the Cochrane Central Register of Controlled Trials (CENTRAL), and the US National Institutes of Health Clinical Trials Registry (http://www.clinicaltrials.gov). There were no date limitations or language restrictions. Randomised, double-blinded, controlled, parallel-group, add-on studies that compared oral BRV, CNB, ESL, LCM, and PER versus any comparator over maintenance periods of at least 12 weeks and included adult patients with focal seizures uncontrolled by concomitant ASMs were identified. The efficacy outcomes were the proportions of patients with ≥ 50% and 100% reduction in baseline seizure frequency during the maintenance period. The tolerability outcomes were the proportions of participants who experienced at least one treatment-emergent adverse event (TEAE) and experienced at least one TEAE leading to discontinuation. Effect sizes were estimated by network meta-analyses within a frequentist framework. The hierarchy of competing interventions was established using the surface under the cumulative ranking curve (SUCRA).

Results

Sixteen trials (BRV: n = 3, CNB: n = 1, ESL: n = 4, LCM: n = 4, PER: n = 4) were included, overall enrolling 4507 patients randomised to add-on active treatments (BRV = 803, CNB = 221, ESL =9 90, LCM = 1104, and PER = 1389) and 2246 to add-on placebo. Cenobamate was associated with a higher rate of ≥ 50% seizure frequency reduction than BRV [odds ratio (OR) 2.02, 95% confidence interval (CI) 1.11–3.66], ESL (OR 1.93, 95% CI 1.07–3.48), LCM (OR 1.86, 95% CI 1.04–3.32), and PER (OR 2.07, 95% CI 1.16–3.70). There was a not statistically significant trend favouring CNB over ESL, LCM and PER for the seizure freedom outcome. Brivaracetam (OR 0.61, 95% CI 0.44–0.86) and LCM (OR 0.60, 95% CI 0.40–0.88) were associated with a lower proportion of participants experiencing TEAEs compared to ESL, and patients treated with PER were associated with a higher risk to experience at least one TEAE (OR 1.42, 95% CI 1.02–1.96) than BRV. According to SUCRA, CNB had the greatest likelihood of being the best option for the ≥ 50% and 100% seizure frequency reduction, and BRV and LCM had the highest probabilities of being the best-tolerated treatments.

Conclusions

Cenobamate ranked best for efficacy, and BRV and LCM were best tolerated over the other comparators. Although NMAs cannot replace direct comparisons, they may support physicians in clinical decision making.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40265-021-01661-4.

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.

The efficacy and safety of adjunctive Perampanel for the treatment of refractory focal-onset seizures in patients with epilepsy:A meta-analysis

Objective

The last decade has seen an increase in the use of anti‐seizure medications (ASMs); however, the burden of treating drug‐resistant epilepsy has not fallen. We performed this meta‐analysis to evaluate the optimal dose of Perampanel (PER) as a new adjunctive treatment for drug‐resistant seizures.

Methods

We searched for studies published from inception to February 1, 2021 from PubMed, Central Register of Controlled Trials (CENTRAL), and ScienceDirect. Research characteristics, patients' characteristics, and treatment regimen, concomitant ASMs, clinical outcomes were extracted. The practical outcome included a reduction in seizures frequency ≥50%, ≥75%, and ≥100% from baseline convulsive seizure frequency, and the safety outcome included the proportion of drug withdrawal and adverse reactions. Odds ratios (OR) for 95% confidence intervals (95% CI) were estimated by the inverse variance method.

Results

Four trials which enrolled 2187 participants (1569 in the PER group and 618 in the placebo group) were included. Results showed that 8 or 12 mg per day had the best effect on all three outcomes, with no significant difference between 8 and 12 mg per day (≥50% reduction, 35.5% vs 36.1%, P = .84; ≥75% reduction, 17.8% vs 19.1%, P = .64; seizure‐free, 3.5% vs 3.7%, P = .85). In addition, 12‐mg PER compared to 8 mg had a higher proportion of trial withdrawal (8.7% vs 17.0%; P < .00001) and treatment‐emergent adverse event (TEAE) resulting in dose reduction/discontinuation (18.5% vs 32.0%; P < .00001). The adverse events (AEs) significantly associated with adjunctive PER were dizziness, somnolence, fatigue, and irritability.

Significance

Adjunctive treatment of PER was associated with a more significant reduction in the frequency of seizures in patients with refractory epilepsy than placebo, but with a higher frequency of AEs. PER at a daily dose of 8 mg appears to have the best ratio between efficacy and tolerance in most study participants.

Efficacy and Tolerability of Perampanel as Adjunctive Therapy in Chinese Patients With Focal-Onset Seizures: An Observational, Prospective Study

Purpose: To evaluate the efficacy and tolerability of adjunctive perampanel (PER) in Chinese patients with focal-onset seizures, with or without secondarily generalized tonic-clonic seizures. Methods: Fifty-six patients aged 14-72 years were recruited consecutively in this single-center prospective observational study. All patients received PER as add-on treatment on the basis of clinical judgment. Seizure frequency, adverse events (AEs), and retention rates were obtained at 3 and 6 months after PER introduction. Results: The overall response rates were 60 and 71.1% after 3 and 6 months, respectively, and the freedom of seizures at the same points were reached in 8 and 15.8%. The retention rates were 89.3% at the 3-month follow-up and 67.9% at the 6-month follow-up. The overall incidence of adverse events was 55.4%. The leading reported AEs were dizziness (39.3%) and somnolence (25%). Conclusions: Our study confirmed the efficacy and tolerability of adjunctive PER in Chinese patients in real-life conditions. Based on our treatment experience, a lower maintenance dose of PER would be needed in Chinese patients.

Value of Perampanel as Adjunctive Treatment for Partial-Onset Seizures in Epilepsy: Cost-Effectiveness and Budget Impact Analysis

Introduction: China has ~6 million patients with active epilepsy every year, around 60% of whom suffer from partial-onset seizures. Perampanel (PER) is a novel anti-epileptic drug for partial-onset seizures. PER has been included in the latest Chinese National Reimbursement Drug List (NRDL) in 2020. However, there is still a lack of evaluation evidence on the value of PER in China. Methods: This study selected a health system perspective. A Markov model was established to simulate the lifelong transition of different response levels and calculate the number of seizures in Chinese patients. Based on the utility value and mortality risk, the life years and quality-adjusted life years (QALYs) of patients using PER vs. lacosamide (LCM) were estimated. Efficacy data were derived from clinical trials and the literature. Cost data (in US dollars) included drug costs and medical service costs. A lifetime horizon was adopted. Health outcomes and costs were discounted at an annual discount rate of 5%. Deterministic sensitivity analysis, probability sensitivity analysis, and scenario analysis were performed. The impact of the inclusion of PER in the NRDL on the medical insurance budget over 3 years (2021-2023) was also estimated. Results: Cost-effectiveness analysis indicates that 8 mg/day of PER increases QALYs by 0.054 and saves costs by $2,390 compared with 400 mg/day of LCM. 4 mg/day of PER increases QALYs by 0.010 and saves costs by $860 compared with 200 mg/day of LCM. Deterministic sensitivity analysis reveals that utility value and the extreme discount rate are the factors with the greatest impact on the incremental cost-effectiveness ratio. Probabilistic sensitivity analysis and scenario analysis show that the results are robust. Budget impact analysis indicates that after inclusion of PER in the NRDL, the incremental budget would be $1.28, $2.83, and $4.56 million from 2021 to 2023, respectively, but covering more eligible epileptic patients in the same time (1,918, 4,287, and 8,983, respectively). Conclusion: PER (8 or 4 mg/day) is of relatively high value as an add-on therapeutic regimen for partial-onset seizures in China because of its dominate advantage of cost-effectiveness over LCM and acceptable budget impact.

Anti-seizure medications and efficacy against focal to bilateral tonic-clonic seizures: A systematic review with relevance for SUDEP prevention

We conducted a systematic review of anti-seizure medications (ASMs) and their efficacy for the control of focal to bilateral tonic-clonic seizures (FBTCS). FBTCS, especially when nocturnal, are recognized as one of the major risk factors for Sudden Unexpected Death in Epilepsy (SUDEP). We searched different online databases for all the randomized, double-blinded, and placebo-controlled clinical trials of ASMs that were FDA-approved after 1990 and that reported specifically on the reduction in FBTCS; when possible, this was compared to reduction in focal impaired awareness (FIA) seizures. The ASMs that yielded the most data (3 or more studies) were topiramate (TPM), followed by tiagabine (TGB), brivaracetam (BRV), and lamotrigine (LTG). TPM trials showed a reduction in FBTCS of 44.8% to 100% (4.5-99% over placebo); TGB 21.8% to 46.7% (21.8-61% over placebo); BRV 33.9% to 82.1% (11.6-57.4% over placebo); and LTG 55.2% (20.3-52% over placebo). Promising results, but with data from only one or two studies, were seen with cenobamate (18-59% efficacy above placebo), lacosamide (45.1-78.7%), levetiracetam (40.1-60.3%), oxcarbazepine (58.5-81.5%), and gabapentin (50-53.8%). Higher responses were often seen at higher doses, including at doses above those currently approved by the FDA. Results specific to nocturnal FBTCS were never reported for any ASM. Moreover, complete freedom from FBTCS specifically was very rarely reported, despite its relevance for SUDEP prevention. In conclusion, there are few data specifically comparing the efficacy of ASMs for prevention of FBTCS despite the known strong association of BTCS with SUDEP. This review was our attempt at filling a gap in the literature and calling for universal reporting of data specific to BTC seizure reduction in all future studies, preferably including specific reporting on nocturnal BTCS. This will help enable rational ASM selection to minimize BTC seizures and thereby decrease the risk of SUDEP.

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.

Efficacy and safety of adjunctive perampanel in patients with focal seizures or generalized tonic-clonic seizures: Post hoc analysis of Phase II and Phase III double-blind and open-label extension studies in India

Objective

This post hoc analysis assessed the efficacy and safety of adjunctive perampanel in patients (aged ≥ 12 years) with focal seizures (FS), with/without focal to bilateral tonic‐clonic seizures (FBTCS), or generalized tonic‐clonic seizures (GTCS) in India.

Methods

Centers in India were identified from six double‐blind, randomized, Phase II and Phase III studies of adjunctive perampanel (2–12 mg/day) and their open‐label extensions (OLEx). Efficacy assessments included median percent change in seizure frequency per 28 days, 50% and 75% responder and seizure‐freedom rates. Treatment‐emergent adverse events (TEAEs) were monitored.

Results

Overall, 128 patients (placebo, n = 39; perampanel, n = 89) were included in the double‐blind Safety Analysis Set and 126 (FS, n = 113 [placebo, n = 32; perampanel, n = 81]; FBTCS, n = 35 [placebo, n = 14; perampanel, n = 21]; GTCS, n = 13 [placebo, n = 6; perampanel, n = 7]) comprised the Full Analysis Set. Median percent reductions in seizure frequency per 28 days for placebo vs perampanel for Indian patients were as follows: 34.8% vs 49.8% (FS; not significant [NS]) and 43.1% vs 60.5% (FBTCS; NS) at 4–12 mg/day, respectively, and −22.4% vs 8.2% (GTCS; NS) at 8 mg/day, respectively. Fifty‐percent responder rates were 37.5% vs 55.1% (FS; NS), 42.9% vs 60.0% (FBTCS; NS), and 16.7% vs 42.9% (GTCS; NS), respectively; seizure‐freedom rates were 0.0% vs 5.8%, 7.1% vs 10.0%, and 0.0% vs 14.3%, respectively (all NS). Overall, 110 patients entered OLEx studies (FS, n = 99; GTCS, n = 11). Perampanel was efficacious for up to four years for FS and FBTCS and two years for GTCS. Across double‐blind and OLEx studies, TEAEs occurred in 58.4% and 83.6% of Indian perampanel‐treated patients, respectively; dizziness was most common. Efficacy and safety outcomes were generally similar overall between Indian and non‐Indian patients.

Significance

These data suggest adjunctive perampanel (up to 12 mg/day) may be a suitable anti‐seizure medication for patients (aged ≥ 12 years) with FS, with/without FBTCS, or GTCS in India.

A meta-analysis: efficacy and safety of anti-epileptic drugs prescribed in Korea as monotherapy and adjunctive treatment for patients with focal epilepsy

Focal epilepsy is the most common type of epilepsy in Korea, and anti-epileptic drugs (AEDs) are the main treatment option for patients. This study aimed to compare the efficacy and safety of AEDs for focal epilepsy through a meta-analysis. The AEDs prescribed in Korea as monotherapy and adjunctive treatment for patients with focal epilepsy were included for analysis. Relevant articles were searched for randomized clinical trials of AEDs and treatment outcomes were analyzed on the basis of the 50% responder rate, seizure-free rate, treatment withdrawal rate, and emergence rates of adverse events (AEs). The odds ratios (ORs) and their 95% confidence intervals (CI) of study outcome were calculated using combined data from multiple studies. A total of 47 studies were included in the meta-analysis. The seizure-free rate, treatment withdrawal rate, and AE rate were not significantly different among the AEDs recommended for monotherapy. Among the AEDs recommended for adjunctive treatment, topiramate and oxcarbazepine yielded the highest OR in comparison with placebo for each efficacy parameter: the 50% responder rate for topiramate = 6.42 (3.76–11.6) and the seizure-free rate for oxcarbazepine = 32.7 (6.05–899). The third-generation AEDs (brivaracetam and perampanel) yielded relatively better safety outcomes than other AEDs. In general, the 50% responder rate and treatment withdrawal rate tended to increase as the dose of the AEDs increased. The results from the current meta-analysis of the efficacy and safety data of various AEDs may provide insight into optimal pharmacotherapy for the treatment of focal epilepsy.

Bioequivalence of perampanel fine granules and tablets in healthy Japanese subjects

Objective: Perampanel is an approved anti-seizure drug. A new formulation of perampanel fine granules (FG; 1% perampanel) has been developed for patients who are unable to take tablets. Bioequivalence between the 4-mg FG and tablet perampanel formulations, as well as their safety and tolerability, were assessed. Materials and methods: In this phase I, single-center, open-label, 2-period, 2-sequence, crossover, bioequivalence study (NCT03399734), healthy Japanese subjects were randomized to receive single doses of the 4-mg FG perampanel and 4-mg perampanel tablet (separated by a ≥ 6-week washout period). Plasma samples for perampanel concentration analysis were collected pre-dose and at intervals up to 168 hours post-dose. The maximum observed concentration (C_max) and area under the concentration–time curve from time zero to 168 hours (AUC_(0–168h)) were used to assess the bioequivalence of the two formulations. Results: The 90% confidence intervals (CIs) for the geometric mean ratio of test/reference for C_max and AUC_(0–168h) were within the bioequivalence criteria of 80 – 125% (C_max 90% CI 90.8%, 110%; AUC_(0–168h) 90% CI 98.2%, 112%; N = 21). 10/24 (41.7%) subjects with FG experienced ≥ 1 treatment-emergent adverse event (TEAE). The events were mild in severity and resolved within 4 hours of onset. There were no deaths, severe TEAEs, serious AEs, or TEAEs leading to study-drug withdrawal. Conclusion: Bioequivalence of 4-mg FG and 4-mg tablet of perampanel was demonstrated. Both perampanel formulations were generally safe and well tolerated. These data suggest that perampanel FG may be a suitable alternative formulation for patients with epilepsy who have difficulties taking perampanel tablets.

Efficacy, safety, and tolerability of adjunctive perampanel in patients from China with focal seizures or generalized tonic-clonic seizures: Post hoc analysis of phase III double-blind and open-label extension studies

Aims

This post hoc analysis assessed the efficacy and safety/tolerability of adjunctive perampanel in patients from China (aged ≥12 years) with focal seizures (FS), with/without focal to bilateral tonic‐clonic seizures (FBTCS), or generalized tonic‐clonic seizures (GTCS).

Methods

Study centers in China were identified using data from five double‐blind, randomized, phase III studies of adjunctive perampanel (2‐12 mg/day) and their open‐label extensions (OLEx). Efficacy assessments included median percent reduction in seizure frequency per 28 days, and 50% and 75% responder and seizure‐freedom rates. Safety/tolerability assessments included monitoring of treatment‐emergent adverse events (TEAEs).

Results

Overall, 277 patients (placebo, n = 79; perampanel, n = 198) were included in the double‐blind safety analysis set. The full analysis set comprised 274 patients (FS, n = 238 [placebo, n = 60; perampanel, n = 178]; FBTCS, n = 120 [placebo, n = 31; perampanel, n = 89]; GTCS, n = 36 [placebo, n = 18; perampanel, n = 18]). Median percent reductions in seizure frequency for placebo vs perampanel were as follows: 16.6% vs 32.4% (FS; P < 0.05) and 39.1% vs 48.2% (FBTCS; not significant [NS]) at 4‐12 mg/day, and 37.9% vs 82.6% (GTCS; NS) at 8 mg/day; 50% responder rates were 31.7% vs 37.4% (FS; NS), 48.4% vs 51.9% (FBTCS; NS), and 33.3% vs 61.1% (GTCS; NS), respectively. Seizure‐freedom rates were 1.7% vs 9.2%, 16.1% vs 25.3%, and 16.7% vs 44.4%, respectively (all NS). Overall, 262 patients entered the OLEx (FS, n = 228; GTCS, n = 34). Perampanel was efficacious for up to four years for FS and FBTCS and up to two years for GTCS. Across the double‐blind and OLEx studies, TEAEs were reported in 65.7% and 81.3% of perampanel‐treated patients, respectively; the most common was dizziness. Efficacy and safety/tolerability outcomes were generally similar between Chinese and non‐Chinese patients.

Conclusion

Adjunctive perampanel (up to 12 mg/day) may be a suitable treatment for Chinese patients with FS, with/without FBTCS, or GTCS, with similar efficacy and safety/tolerability compared to non‐Chinese patients.

Assessment of the long-term efficacy and safety of adjunctive perampanel in tonic-clonic seizures: Analysis of four open-label extension studies

OBJECTIVE

This post hoc analysis evaluated long-term efficacy and safety in patients with focal to bilateral tonic-clonic seizures (FBTCS) or generalized tonic-clonic seizures (GTCS) who entered open-label extension (OLEx) studies to receive long-term adjunctive perampanel.

METHODS

Patients aged 12 years and older who completed phase II or III randomized, double-blind, placebo-controlled studies could enter an OLEx study, each comprising a blinded conversion period followed by an open-label maintenance period (32-424 weeks; maximum perampanel dose = 12 mg/d). Exposure, seizure outcomes, and treatment-emergent adverse events (TEAEs) were analyzed.

RESULTS

Baseline characteristics were generally balanced between patients with FBTCS (n = 720) and GTCS (n = 138). Mean (standard deviation) cumulative duration of perampanel exposure was 102.3 (70.3) weeks (FBTCS) and 83.9 (38.4) weeks (GTCS). Retention rates were 50.0% for up to 4 years (FBTCS) and 49.2% for up to 2 years (GTCS). Across OLEx treatment durations, median reductions in seizure frequency per 28 days were 66.7% (FBTCS) and 80.6% (GTCS). Fifty percent and 75% responder and seizure-freedom rates were 59.5%, 45.3%, and 18.4%, respectively (FBTCS), and 72.5%, 51.5%, and 16.7%, respectively (GTCS). Efficacy was sustained for up to 4 years (FBTCS) and up to 3 years (GTCS), even when accounting for early dropouts. TEAE incidence was highest during Year 1 (FBTCS, 85.3%; GTCS, 86.2%); most common were dizziness and somnolence. During Year 1, serious TEAEs were reported in 81 (11.3%; FBTCS) and 10 (7.2%; GTCS) patients. TEAEs were consistent with the known safety profile of perampanel; no new safety signals were identified with long-term treatment.

SIGNIFICANCE

This post hoc analysis suggests long-term (up to 4 years) adjunctive perampanel (up to 12 mg/d) is efficacious and well tolerated in patients (aged 12 years and older) with FBTCS or GTCS.

Efficacy and safety of perampanel monotherapy in patients with focal-onset seizures with newly diagnosed epilepsy or recurrence of epilepsy after a period of remission: The open-label Study 342 (FREEDOM Study)

Objective

Our study assessed perampanel monotherapy in patients (aged ≥12 years) with focal‐onset seizures (FOS) with or without focal to bilateral tonic‐clonic seizures (FBTCS) in Japan and South Korea.

Methods

Study 342 (NCT03201900; FREEDOM) is a single‐arm, open‐label, Phase III study. Patients initially received perampanel in a 32‐week 4‐mg/d Treatment Phase (6‐week Titration; 26‐week Maintenance Periods). If they experienced a seizure during the 4‐mg/d Maintenance Period, they could be up‐titrated to 8 mg/d across an additional 30‐week Treatment Phase (4‐week Titration; 26‐week Maintenance Periods). Primary endpoint was the seizure‐freedom rate during the Maintenance Period (4 mg/d and last evaluated dose [4 or 8 mg/d]). Secondary endpoints included time to first seizure onset and to withdrawal during Maintenance. Treatment‐emergent adverse events (TEAEs) were monitored.

Results

At data cutoff (February 28, 2019), 89 patients with FOS (84 [94.4%] with newly diagnosed epilepsy and 5 [5.6%] with recurrence of epilepsy after a period of remission) had received ≥1 perampanel dose; 16 patients discontinued during the 4‐mg/d Titration Period, meaning 73 patients entered the 4‐mg/d Maintenance Period and were included in the primary analysis set for efficacy. Seizure‐freedom rate in the 26‐week Maintenance Period was 46/73 (63.0%; 95% confidence interval [CI]: 50.9‐74.0) at 4 mg/d and 54/73 (74.0%; 95% CI: 62.4‐83.5) at 4 or 8 mg/d. Cumulative probability of seizure‐onset and withdrawal rates during Maintenance was 30.8% (95% CI: 21.5‐43.0) and 23.7% (95% CI: 15.4‐35.3) at 4 mg/d, and 18.2% (95% CI: 11.0‐29.3) and 23.3% (95% CI: 15.2‐34.8) at 4 or 8 mg/d. Perampanel was generally well tolerated, and the most common TEAE was dizziness.

Significance

Perampanel monotherapy (4 to 8 mg/d) was efficacious and consistent with the known safety profile up to 26 weeks in patients (≥12 years) with primarily newly diagnosed FOS with or without FBTCS.

Efficacy, safety, and tolerability of perampanel in Asian and non-Asian patients with epilepsy

People of different ethnic or racial backgrounds may experience variations in pharmacokinetic and pharmacodynamic responses to drug therapies. Our post hoc analysis evaluated the efficacy, safety, and tolerability of perampanel in Asian and non-Asian populations with refractory focal seizures with or without focal to bilateral tonic-clonic (FBTC) seizures. This analysis pooled data from 4 randomized, placebo-controlled, phase-3 studies involving patients aged ≥12 years who have focal seizures with or without FBTC seizures. Patients were receiving 2, 4, 8, or 12 mg perampanel (or placebo) by the end of a 6-week titration period and for a further 13 weeks during the maintenance phase. Efficacy endpoints included median percent change in seizure frequency per 28 days, and 50% and seizure-freedom responder rates relative to baseline. The median percent change in seizure frequency per 28 days from baseline was significantly greater than placebo for perampanel 8 and 12 mg (-31.1% and -38.1% change, respectively; each P < 0.0001) in the Asian population, and for perampanel 4, 8, and 12 mg (-21.1% [P = 0.0001], -26.3% [P < 0.0001], and -27.7% [P = 0.0001] change, respectively) in the non-Asian population. The 50% responder rate relative to baseline was significantly greater than placebo for perampanel 8 and 12 mg (40.1% and 43.8%, respectively; each P < 0.0001) in the Asian population, and for perampanel 4, 8, and 12 mg (29.4% [P = 0.0002], 32.8% [P < 0.0001] and 34.5% [P = 0.0001]), respectively, in the non-Asian population. Seizure-freedom rate among all patients was 4.9%-11.7% for perampanel 2, 4, 8, and 12 mg. The most frequently reported treatment-emergent adverse events (TEAEs) across both populations were dizziness, somnolence, irritability, headache, and fatigue. The most common psychiatric TEAEs were aggression and irritability. Perampanel demonstrated a favorable and similar risk-benefit profile in both Asian and non-Asian populations with refractory focal seizures.

Efficacy and safety of perampanel in generalized and focal to bilateral tonic-clonic seizures: A comparative study of Asian and non-Asian populations

Perampanel is an approved adjunctive treatment for focal seizures with or without focal to bilateral tonic-clonic (FBTC) seizures and generalized tonic-clonic (GTC) seizures. We compared efficacy and safety of perampanel vs placebo in Asian and non-Asian populations in a post hoc analysis of pooled data from 5 randomized phase 3 studies. Patients (≥12 years old) with focal + FBTC seizures received perampanel 2, 4, 8, or 12 mg or placebo; patients with GTC seizures received perampanel 8 mg or placebo (titration: 4-6 weeks; maintenance: 13 weeks). Efficacy endpoints included median percentage change in FBTC or GTC seizure frequency per 28 days and 50% responder rate relative to baseline. Median percentage change in FBTC seizure frequency was significantly greater for perampanel 8 and 12 mg than placebo in the Asian population (median difference from placebo: -30.32%, P = 0.0017; -30.06%, P = 0.0008, respectively) and perampanel 4, 8, and 12 mg in the non-Asian population (-35.07%, P = 0.0001; -37.78%, P < 0.0001; -34.53%, P < 0.0001, respectively). In both populations, median percentage change in GTC seizure frequency was significantly greater for perampanel 8 mg than placebo (median difference from placebo: Asian, -37.37%, P = 0.0139; non-Asian, -27.04%, P = 0.0006). The 50% responder rates were significantly greater than placebo for perampanel 8 and 12 mg for FBTC seizures (Asian: 58.0%, P = 0.0017 and 58.6%, P = 0.0013, respectively; non-Asian: 59.3%, P < 0.0001 and 54.3%, P = 0.0050, respectively) and perampanel 8 mg for GTC seizures (Asian: 57.6%, P = 0.0209; non-Asian: 68.8%, P = 0.0329). Pooled FBTC/GTC seizure data showed generally similar patterns of response to perampanel in both populations. The most frequent treatment-related adverse events were fatigue, irritability, dizziness, somnolence, and headache. Perampanel was effective, well tolerated, and can be considered a therapeutic option for FBTC/GTC seizures in Asian populations.

Ionotropic Glutamate Receptors in Epilepsy: A Review Focusing on AMPA and NMDA Receptors

It is widely accepted that glutamate-mediated neuronal hyperexcitation plays a causative role in eliciting seizures. Among glutamate receptors, the roles of N-methyl-D-aspartate (NMDA) and α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors in physiological and pathological conditions represent major clinical research targets. It is well known that agonists of NMDA or AMPA receptors can elicit seizures in animal or human subjects, while antagonists have been shown to inhibit seizures in animal models, suggesting a potential role for NMDA and AMPA receptor antagonists in anti-seizure drug development. Several such drugs have been evaluated in clinical studies; however, the majority, mainly NMDA-receptor antagonists, failed to demonstrate adequate efficacy and safety for therapeutic use, and only an AMPA-receptor antagonist, perampanel, has been approved for the treatment of some forms of epilepsy. These results suggest that a misunderstanding of the role of each glutamate receptor in the ictogenic process may underlie the failure of these drugs to demonstrate clinical efficacy and safety. Accumulating knowledge of both NMDA and AMPA receptors, including pathological gene mutations, roles in autoimmune epilepsy, and evidence from drug-discovery research and pharmacological studies, may provide valuable information enabling the roles of both receptors in ictogenesis to be reconsidered. This review aimed to integrate information from several studies in order to further elucidate the specific roles of NMDA and AMPA receptors in epilepsy.

Efficacy and safety of adjunctive perampanel in adolescent patients with epilepsy: Post hoc analysis of six randomized studies

OBJECTIVE

This post hoc analysis of six randomized, double-blind, Phase II and III studies evaluated efficacy and safety of adjunctive perampanel (2-12 mg/day) in adolescent patients (aged ≥12 to ≤17 years) with uncontrolled partial-onset seizures, with or without secondarily generalized (SG) seizures, or primary generalized tonic-clonic (PGTC) seizures.

METHODS

Adolescent patients from Studies 304 (NCT00699972), 305 (NCT00699582), 306 (NCT00700310), 335 (NCT01618695), 235 (NCT01161524), and 332 (NCT01393743) were included. Efficacy assessments (split by seizure type) included median percent change in seizure frequency per 28 days from baseline and seizure-freedom rates. Safety assessments (all seizure types combined) included monitoring of treatment-emergent adverse events (TEAEs).

RESULTS

The Safety Analysis Set included 372 adolescent patients (placebo, n = 114; perampanel, n = 258); the Full Analysis Set included 346 patients with partial-onset seizures (placebo, n = 103; perampanel, n = 243), of whom 125 experienced SG seizures during baseline (placebo, n = 37; perampanel, n = 88), and 22 with PGTC seizures (placebo, n = 9; perampanel, n = 13). Compared with placebo, perampanel 8 and 12 mg/day conferred greater median percent reductions in seizure frequency per 28 days for partial-onset seizures (18.0% vs 35.9% and 53.8% [both P < 0.01]) and SG seizures (24.4% vs 72.8% [P < 0.001] and 57.8% [P < 0.01]), and greater seizure-freedom rates (partial-onset: 7.8% vs 13.2% and 11.8% [not statistically significant]; SG: 8.1% vs 40.7% [P < 0.001] and 41.7% [P < 0.01]). For PGTC seizures, and compared with placebo, perampanel 8 mg/day was also associated with greater median percent reductions in seizure frequency per 28 days (29.8% vs 88.0%) and greater seizure-freedom rates (11.1% vs 23.1%). Treatment-emergent adverse events were reported in 76 (66.7%) placebo- and 192 (74.4%) perampanel-treated patients (most common: dizziness, somnolence, headache, and nasopharyngitis). Serious TEAEs occurred in 5 (4.4%) placebo- and 11 (4.3%) perampanel-treated patients.

CONCLUSIONS

Adjunctive perampanel was efficacious and generally well tolerated in adolescent patients with partial-onset, SG, or PGTC seizures and represents a potentially beneficial treatment option for adolescents with uncontrolled epilepsy.

Efficacy and safety of adjunctive perampanel 4 mg/d for the treatment of focal seizures: A pooled post hoc analysis of four randomized, double-blind, phase III studies

OBJECTIVE

This post hoc analysis evaluated the efficacy and safety of adjunctive perampanel 4 mg/d received as modal dose, which may have differed from randomized dose, for treatment of focal seizures.

METHODS

Data were pooled from four randomized, double-blind, placebo-controlled, phase III studies of adjunctive perampanel in patients (aged ≥12 years) with focal seizures, with/without focal to bilateral tonic-clonic (FBTC) seizures: studies 304 (NCT00699972), 305 (NCT00699582), 306 (NCT00700310), and 335 (NCT01618695). Efficacy assessments included median percentage reductions in seizure frequency per 28 days and seizure-freedom rates for patients receiving placebo and perampanel 4 mg/d (modal dose). Treatment-emergent adverse events (TEAEs) were assessed in patients receiving perampanel 4 mg/d at their TEAE onset. Outcomes were also assessed with/without enzyme-inducing antiseizure medications (EIASMs).

RESULTS

The full analysis set included 979 patients with focal seizures (placebo: n = 616 [235 with FBTC seizures]; perampanel 4 mg/d: n = 363 [134 with FBTC seizures]). Compared with placebo, perampanel 4 mg/d conferred significantly greater median percentage reductions in seizure frequency per 28 days for focal (12.6% vs 21.1%; P = .0004) and FBTC seizures (17.4% vs 49.8%; P < .0001), and seizure-freedom rates for focal (0.8% vs 3.6%; P = .0018) and FBTC seizures (11.1% vs 18.7%; P = .0424). Seizure improvements with perampanel 4 mg/d were greater without EIASMs than with EIASMs. For assessment of TEAEs, overall 1376 patients with focal seizures received perampanel 4 mg/d at any time (FBTC seizures, n = 499). TEAEs with perampanel 4 mg/d occurred in 419 of 1376 (30.5%) and 148 of 499 (29.7%) patients with focal and FBTC seizures, respectively; most common was dizziness. The proportion of TEAEs was similar with or without EIASMs.

SIGNIFICANCE

This post hoc analysis showed adjunctive perampanel 4 mg/d was efficacious and well tolerated in patients with focal seizures, with or without FBTC seizures. This dose may be a valuable treatment option in patients unable to tolerate higher perampanel doses up to 12 mg/d.