Perampanel for tonic-clonic seizures in idiopathic generalized epilepsy A randomized trial

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.

Improving Therapy of Pharmacoresistant Epilepsies: The Role of Fenfluramine

Epilepsy is among the most common neurological chronic disorders, with a prevalence of 0.5-1%. Despite the introduction of new antiepileptic drugs during recent years, about one third of the epileptic population remain drug-resistant. Hence, especially in the pediatric population limited by different pharmacokinetics and pharmacodynamics and by ethical and regulatory issues it is needed to identify new therapeutic resources. New molecules initially used with other therapeutic indications, such as fenfluramine, are being considered for the treatment of pharmacoresistant epilepsies, including Dravet Syndrome (DS) and Lennox-Gastaut Syndrome (LGS). Drug-refractory seizures are a hallmark of both these conditions and their treatment remains a major challenge. Fenfluramine is an amphetamine derivative that was previously approved as a weight loss drug and later withdrawn when major cardiac adverse events were reported. However, a new role of fenfluramine has emerged in recent years. Indeed, fenfluramine has proved to be a promising antiepileptic drug with a favorable risk-benefit profile for the treatment of DS, LGS and possibly other drug-resistant epileptic syndromes. The mechanism by which fenfluramine provide an antiepileptic action is not fully understood but it seems to go beyond its pro-serotoninergic activity. This review aims to provide a comprehensive analysis of the literature, including ongoing trials, regarding the efficacy and safety of fenfluramine as adjunctive treatment of pharmacoresistant epilepsies.

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.

Long-term open-label perampanel: generalized tonic-clonic seizures in idiopathic generalized epilepsy

Objective

Assess the longer‐term efficacy and safety of adjunctive perampanel (up to 12 mg/day) in patients aged ≥12 years with generalized tonic–clonic (GTC) seizures from the Open‐label Extension (OLEx) Phase of Study 332 to determine whether responses obtained during the Core Study are maintained during long‐term treatment.

Methods

Patients with GTC seizures previously enrolled in a randomized placebo‐controlled trial of perampanel could enter an OLEx Phase comprising 6‐week blinded conversion (during which patients previously randomized to placebo‐switched to perampanel) and up to 136‐week maintenance periods (maximum perampanel dose of 12 mg/day). A 4‐week follow‐up period was completed by all patients after the last on‐treatment visit during the OLEx. We assessed seizure frequency outcomes from preperampanel baseline and the Core Study Pre‐randomization Phase, retention rates, doses selected, and treatment‐emergent adverse events (TEAEs).

Results

Overall, 138 patients entered the OLEx. Median percent reductions in GTC seizures per 28 days from preperampanel were 77% (Weeks 1‐13) and 90% (Weeks 40‐52). Retention rates were 88% (6 months) and 75% (12 months). Seizure‐freedom rates were maintained for at least 2 years regardless of prior treatment received during the Core Study. Most common modal daily dose was >4‐8 mg/day (n = 93). Across the Core and OLEx Phases, 120 (87%) patients experienced TEAEs; the most common was dizziness.

Significance

Perampanel was generally well‐tolerated, and the TEAEs reported here are consistent with the known safety profile of perampanel. Perampanel offers a long‐term treatment option for patients (aged ≥12 years) with GTC seizures.

Approach to the Medical Treatment of Epilepsy

PURPOSE OF REVIEW

This article discusses the use of antiseizure medications in the treatment of focal and generalized epilepsies using an evidence-based approach.

RECENT FINDINGS

In recent years, several new antiseizure medications with differing mechanisms of action have been introduced in clinical practice, and their efficacy and safety has been evaluated in randomized controlled clinical trials. Currently, all antiseizure medications can prevent seizure occurrence, but they have no proven disease-modifying or antiepileptogenic effects in humans. The choice of therapy should integrate the best available evidence of efficacy, tolerability, and effectiveness derived from clinical trials with other pharmacologic considerations, the clinical expertise of the treating physicians, and patient values and preferences. After the failure of a first antiseizure medication, inadequate evidence is available to inform policy. An alternative monotherapy (especially if the failure is because of adverse effects) or a dual therapy (especially if failure is because of inadequate seizure control) can be used.

SUMMARY

Currently, several antiseizure medications are available for the treatment of focal or generalized epilepsies. They differ in mechanisms of action, frequency of administration, and pharmacologic properties, with a consequent risk of pharmacokinetic interactions. Major unmet needs remain in epilepsy treatment. A substantial proportion of patients with epilepsy continue to experience seizures despite two or more antiseizure medications, with a negative impact on quality of life. Therefore, more antiseizure medications that could provide higher seizure control with good tolerability and that could positively affect the underlying disease are needed.

Sustained seizure freedom with adjunctive perampanel in patients with convulsive seizures: Post hoc analysis of open-label extension studies 307 and 332

OBJECTIVE

Since increased mortality rates have been associated with convulsive seizures, it is important to achieve seizure control in these patients. Here, we report post hoc analyses to assess long-term seizure-freedom rates with adjunctive perampanel in patients (aged ≥ 12 years) with refractory focal to bilateral tonic-clonic seizures (FBTCS) or generalized tonic-clonic seizures (GTCS) who participated in open-label extension (OLEx) studies.

METHODS

Patients with focal-onset seizures, with/without FBTCS, who completed double-blind, Phase III Studies 304, 305, or 306 could enter OLEx Study 307 (16-week blinded Conversion; 256-week Maintenance). Patients with GTCS who completed the double-blind phase of Study 332 could enter the OLEx Phase (6-week blinded Conversion; 136-week Maintenance). Maximum perampanel dose: 12 mg/day. Seizure-freedom rates for up to 24 months were assessed in perampanel-treated patients who achieved seizure freedom during the double-blind studies to determine if their seizure-free status was maintained during the OLEx. In addition, to ensure any patients who only achieved seizure freedom during the OLEx were captured, seizure-freedom rates were also assessed in all patients who achieved and maintained a seizure-free status for a period of at least six consecutive months at any time during the double-blind and/or OLEx studies; some of these patients may have received placebo during the double-blind study but only their time on perampanel is included in the seizure-free analysis. Univariate and multivariate analyses were used to identify predictive factors for achieving seizure freedom for at least 6 months. Treatment-emergent adverse events (TEAEs) were assessed.

RESULTS

Overall, 53.8% (n = 42/78) of patients who received perampanel and were FBTCS free during the double-blind studies remained seizure free for up to 24 months during Study 307, and 31.6% (n = 6/19) of patients who were GTCS free during the double-blind phase of Study 332 remained seizure free for up to 24 months during the OLEx Phase. Over 40% (FBTCS, 41.5% [n = 197/475]; GTCS, 52.9% [n = 73/138]) of patients were seizure free for a period of at least six consecutive months. Multivariate analysis showed that the best predictors of achieving seizure freedom from FBTCS for at least 6 months were lower baseline seizure frequency (p = 0.0014) and absence of enzyme-inducing anti-seizure medications at baseline (p = 0.0056); multivariate analysis was not conducted for GTCS since only one variable was identified as a significant predictor of seizure freedom in the univariate analysis (lower baseline seizure frequency). Perampanel was generally well tolerated with no new safety signals identified. The most common TEAE was dizziness. For both seizure types, 10% or fewer seizure-free patients discontinued perampanel due to TEAEs.

CONCLUSIONS

These results suggest that adjunctive perampanel may be a suitable long-term treatment option for patients (aged ≥ 12 years) with convulsive seizures to achieve and maintain seizure freedom.

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.

Genetic generalized epilepsies in adults - challenging assumptions and dogmas

Genetic generalized epilepsy (GGE) syndromes start during childhood or adolescence, and four commonly persist into adulthood, making up 15-20% of all cases of epilepsy in adults. These four GGE syndromes are childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy and epilepsy with generalized tonic-clonic seizures alone. However, in ~20% of patients with GGE, characteristics of more than one syndrome are present. Novel insights into the genetic aetiology, comorbidities and prognosis of the GGE syndromes have emerged and challenge traditional concepts about these conditions. Evidence has shown that the mode of inheritance in GGE is mostly polygenic. Neuropsychological and imaging studies indicate similar abnormalities in unaffected relatives of patients with GGE, supporting the concept that underlying alterations in bilateral frontothalamocortical networks are genetically determined. Contrary to popular belief, first-line anti-seizure medication often fails to provide seizure freedom in combination with good tolerability. Nevertheless, long-term follow-up studies have shown that with advancing age, many patients can discontinue their anti-seizure medication without seizure relapses. Several outcome predictors have been identified, but prognosis across the syndromes is more homogeneous than previously assumed. Overall, overlap in pathophysiology, seizure types, treatment responses and outcomes support the idea that GGEs are not separate nosological entities but represent a neurobiological continuum.

Proposal for an updated seizure classification framework in clinical trials

The International League Against Epilepsy (ILAE) seizure classification scheme has been periodically updated to improve its reliability and applicability to clinicians and researchers alike. Here, members of the Epilepsy Study Consortium propose a pragmatic seizure classification, based on the ILAE scheme, designed for use in clinical trials with a focus on outcome measures that have high reliability, broad interpretability across stakeholders, and clinical relevance in the context of the development of novel antiseizure medications. Controversies around the current ILAE classification scheme are discussed in the context of clinical trials, and pragmatic simplifications to the existing scheme are proposed, for intended use by investigators, industry sponsors, and regulatory agencies.

OUP accepted manuscript

Presurgical identification of the epileptogenic zone is a critical determinant of seizure control following surgical resection in epilepsy. Excitatory glutamate α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor is a major component of neurotransmission. Although elevated α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor levels are observed in surgically resected brain areas of patients with epilepsy, it remains unclear whether increased α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor-mediated currents initiate epileptic discharges. We have recently developed the first PET tracer for α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor, [¹¹C]K-2, to visualize and quantify the density of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors in living human brains. Here, we detected elevated [¹¹C]K-2 uptake in the epileptogenic temporal lobe of patients with mesial temporal lobe epilepsy. Brain areas with high [¹¹C]K-2 uptake are closely colocalized with the location of equivalent current dipoles estimated by magnetoencephalography or with seizure onset zones detected by intracranial electroencephalogram. These results suggest that epileptic discharges initiate from brain areas with increased α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors, providing a biological basis for epileptic discharges and an additional non-invasive option to identify the epileptogenic zone in patients with mesial temporal lobe epilepsy.

Eslicarbazepine Acetate as Adjunctive Therapy for Primary Generalized Tonic-Clonic Seizures in Adults: A Prospective Observational Study

BACKGROUND

Eslicarbazepine acetate (ESL), a novel sodium channel blocker, is approved for mono and adjunctive treatment of partial epileptic seizures with or without secondary generalization. Its efficacy in primary generalized seizures has not yet been evaluated.

OBJECTIVE

To evaluate the efficacy and safety of ESL in primary generalized tonic-clonic seizures (PGTCS) in an observational study.

METHODS

The data were collected from a prospective population-based register. Effectiveness was measured as relative reduction in standardized seizure frequency (SSF), responder rate (≥ 50% reduction in SSF), and seizure freedom rate at 6 and 12 months after initiation of ESL. Safety and tolerability were evaluated using patients' diaries.

RESULTS

Fifty-six adult patients with PGTCS were treated with ESL as adjunctive therapy. Of these, 30.4% (n = 17) had myoclonic seizures in addition to PGTCS. The retention rate after 12 months was 80.4% (n = 45). After initiating ESL therapy, reduction in SSF for PGTCS on ESL was 56.0% after 6 months and 56.9% after 12 months (p &lt; 0.01), whereas myoclonic seizures did not show any significant improvement in frequency. The responder rate for PGTCS was 64.3% after 6 months and 66.1% after 12 months, and seizure freedom was achieved in 32.1% and 35.7%, respectively. Forty-three patients (73.2%) reported no side effects. Among the reported side effects of ESL therapy, headache (7.1%), dizziness (8.9%), tiredness (7.1%), nausea (5.4%), and hyponatremia (5.4%) were the most prevalent.

CONCLUSIONS

Our data suggest that ESL may provide additional benefits in the treatment of patients with PGTCS and motivate randomized controlled trials in this indication.

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.

Adjunctive perampanel therapy for patients with epileptic spasms

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Differences in aggression as psychiatric side effect of levetiracetam and perampanel in patients with epilepsy

PURPOSE

Aggression is the most commonly encountered antiepileptic-drug (AED)-induced psychiatric adverse effects. Levetiracetam (LEV) is well known to be associated with increased rates of aggression, while perampanel (PER) is also recognized as a potentially aggression-promoting agent, though opinions vary. However, few studies have addressed questions regarding whether the nature of irritability-aggression differs between those drugs. The present study used a standardized rating scale to examine aggression among patient with epilepsy who received LEV or PER using specific measures to confirm the effects of the drugs.

METHODS

We enrolled 144 consecutive outpatients receiving treatment for epilepsy with LEV (n = 103) or PER (n = 41), and determined their effects regarding aggression using the Buss-Perry Aggression Questionnaire (BAQ). For analysis, total BAQ scores for the LEV and PER subjects were compared to determine whether the aggression-promoting effects of the agents differed, and which BAQ subdomains (physical aggression, verbal aggression, anger, hostility) were related to production of aggression in patients taking either LEV or PER. As a subsidiary analysis, clinical variables inclusive of administered AED type that showed a significant impact on BAQ scores were determined.

RESULTS

The LEV group had a significantly higher hostility score (19.4 ± 5.8) as compared to the PER group (17.2 ± 6.3) in subscale analysis (p < 0.05). In multiple regression analysis, LEV had a significant association with higher hostility score (P = 0.006).

CONCLUSION

Our results indicate that while easily visible outward-directed aggression tends to be dominant in patients given PER, aggression provoked by LEV may be felt more subjectively or in an inward-directed manner, which can lead to more diverse expression and misrecognition.

Current Concepts in the Management of Idiopathic Generalized Epilepsies

Idiopathic generalized epilepsies (IGEs) are a group of epilepsies characterized by an underlying genetic predisposition and a good response to antiseizure medicines (ASMs) in the majority of the patients. Of the various broad-spectrum ASMs, valproate is the most effective medicine for the control of seizures in IGEs. However, with the availability of many newer ASMs and evidence showing the high teratogenic potential of valproate, the choice of ASMs for IGEs has become increasingly difficult, especially in women of the child-bearing age group. In this article, we review the current evidence regarding the efficacy and safety of various ASMs in patients with IGEs and provide practical guidelines for choosing appropriate ASMs in various subgroups of patients with IGEs.

PROVE: retrospective, non-interventional, Phase IV study of perampanel in real-world clinical care of patients with epilepsy

Objective

To assess retention, dosing, efficacy, and safety of perampanel in a large cohort of patients with epilepsy during routine clinical care.

Methods

PROVE was a retrospective, non‐interventional Phase IV study (NCT03208660). Data were obtained retrospectively from the medical records of patients in the United States initiating perampanel after January 1, 2014, according to treating clinicians' recommendation. Retention rate was the primary efficacy endpoint. Secondary efficacy endpoints included median percent changes in seizure frequency per 28 days from baseline, seizure‐freedom rate, and overall investigator impression of seizure effect. Safety endpoints included incidence of treatment‐emergent adverse events (TEAEs). Efficacy and safety were also assessed according to baseline use of enzyme‐inducing antiseizure medications (EIASMs).

Results

Overall, 1703 patients were enrolled and included in the Safety Analysis Set (SAS; ≥1 baseline EIASMs, n = 358 [21.0%]; no baseline EIASMs, n = 1345 [79.0%]). Mean (standard deviation [SD]) cumulative duration of exposure to perampanel was 17.4 (15.7) months; mean (SD) daily perampanel dose was 5.6 (2.7) mg. The most frequent perampanel titration intervals were weekly (23.4%) and every 2 weeks (24.7%). Across the SAS, 24‐month retention rate was 48.1% (n = 501/1042). Based on overall investigator impression at the end of treatment, 51.9%, 35.8%, and 12.3% of patients in the SAS experienced improvement, no change, or worsening of seizures, respectively. TEAEs occurred in 704 (41.3%) patients; 79 (4.6%) had serious TEAEs. The most common TEAE was dizziness (7.3%). There was some variation in efficacy according to EIASM use, while retention rates and safety were generally consistent.

Significance

In this final analysis of >1700 patients with epilepsy receiving perampanel in routine clinical care, favorable retention and sustained efficacy were demonstrated for ≥12 months.

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

Background

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

Methods

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

Results

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

Conclusion

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

Supplementary Information

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

The role of the TNFα-mediated astrocyte signaling pathway in epilepsy

Epilepsy is a common disease  in the central nervous system. There is growing evidence that epilepsy is associated with glial cells, including astrocytes. Tumor necrosis factor α (TNFα) is a “master regulator” of proinflammatory cytokine production and is secreted by microglia and astrocytes. TNFα secreted by microglia can activate astrocytes. Additionally, TNFα can regulate neuron activity and induce epilepsy by increasing the glutamate release, reducing the expression of γ-aminobutyric acid, inducing neuroinflammation and affecting the synaptic function in astrocytes. This review summarizes the signaling pathways and receptors of TNFα acting on astrocytes that are related to epilepsy and provides insights into the potential therapeutic strategies of epilepsy for clinical practice.

Risk factors for psychiatric adverse effects associated with perampanel therapy

PURPOSE

To identify the risk factors for psychiatric adverse effects associated with perampanel therapy.

METHODS

We retrospectively evaluated the adverse effects of perampanel by reviewing clinical records from 895 Japanese patients with epilepsy (aged 1-86 years) who started perampanel therapy at National Epilepsy Center, Shizuoka, Japan, between June 2016 and December 2019. Patients were classified into 3 groups: those without adverse effects (Group I), those with psychiatric adverse effects (Group II), and those with common adverse effects (Group III).

RESULTS

The number of patients assigned to each group was as follows: Group I, n = 641; Group II, n = 93; and Group III, n = 161. The mean follow-up period was 458 ± 265 days (median, 511 days). Kaplan-Meier survival estimates showed that the median time to treatment failure was shorter in Group II than in Group III (294 vs. 392 days, respectively; log-rank test, p < 0.001). According to polytomous logistic regression, younger age (<16 years) was associated with a lower risk of common and psychiatric adverse effects. The risk factors for psychiatric adverse effects (Group II) were intellectual disability (adjusted odds ratio [AOR], 2.6; 95% confidence interval (CI), 1.5-4.5) and psychiatric comorbidity (AOR, 3.8; 95% CI, 2.3-6.3); in patients with intellectual disability, the occurrence of psychiatric adverse effects was concentration dependent. Patients with lamotrigine use had a 0.54-fold lower risk of psychiatric adverse effects. In Group III, concomitant use of inducers was associated with a decreased risk of common adverse effects (AOR, 0.68; 95% CI, 0.46-0.99).

SIGNIFICANCE

We found clear differences in the risk factors for psychiatric adverse effects. In patients with intellectual disability, care must be taken when titrating perampanel, and therapeutic drug monitoring should be performed.

Intraoperative seizure outcome of levetiracetam combined with perampanel therapy in patients with glioma undergoing awake brain surgery

OBJECTIVE

This study aimed to evaluate the efficacy of levetiracetam (LEV) combined with perampanel (PER) therapy for intraoperative seizure treatment to determine whether a combination of LEV and PER can aid in the prevention of intraoperative intractable seizures during awake surgery.

METHODS

The authors performed a retrospective cohort study in 78 consecutive patients with glioma who underwent awake surgery using intraoperative direct electrical stimulation mapping. To prevent intraoperative seizures, 50 patients were treated with the antiepileptic drug LEV only (LEV group) from January 2017 to January 2019, while the remaining 28 patients were treated with LEV plus PER (LEV + PER group) between March 2019 and January 2020. LEV (1000-3000 mg) and/or PER (2-4 mg) were administered before the surgery.

RESULTS

Preoperative seizures with International League Against Epilepsy (ILAE) class II-VI occurred in 44% of the patients in the LEV group and in 35.7% of patients in the LEV + PER group, with no significant difference between groups (p = 0.319). Total intraoperative seizures occurred in 18 patients (36.0%) in the LEV therapy group and in 2 patients (7.1%) in the LEV + PER group (p = 0.009). Of these, there were no patients (0%) with intractable seizures in the LEV + PER group. Regarding factors that influence intraoperative seizures in glioma patients during awake brain surgery, multivariate logistic regression models revealed that the occurrence of intraoperative seizures was significantly related to the involvement of motor-related regions (positive vs negative, HR 6.98, 95% CI 1.71-28.56, p = 0.007), preoperative seizure (ILAE class II-VI vs ILAE class I, HR 4.44, 95% CI 1.22-16.11, p = 0.024), and LEV + PER group (positive vs negative, HR 0.07, 95% CI 0.01-0.44, p = 0.005). Treatment-related adverse effects were rare and mild, including sleepiness, tiredness, and dizziness in both treatment groups.

CONCLUSIONS

This study demonstrates that LEV + PER therapy is significantly associated with a lower risk of intraoperative seizures compared with LEV therapy alone in patients with glioma during awake brain mapping. These findings will help neurosurgeons conduct safe and reliable awake surgeries and reduce the rate of intraoperative intractable seizures during such procedures.

Efficacy and tolerability of antiseizure drugs

Drug-resistant epilepsy occurs in 25-30% of patients. Furthermore, treatment with a first-generation antiseizure drug (ASD) fails in 30-40% of individuals because of their intolerable adverse effects. Over the past three decades, 20 newer- (second- and third-)generation ASDs with unique mechanisms of action and pharmacokinetic profiles have been introduced into clinical practice. This advent has expanded the therapeutic armamentarium of epilepsy and broadens the choices of ASDs to match the individual patient's characteristics. In recent years, research has been focused on defining the ASD of choice for different seizure types. In 2017, the International League Against Epilepsy published a new classification for seizure types and epilepsy syndrome. This classification has been of paramount importance to accurately classify the patient's seizure type(s) and prescribe the ASD that is appropriate. A year later, the American Academy of Neurology published a new guideline for ASD selection in adult and pediatric patients with new-onset and treatment-resistant epilepsy. The guideline primarily relied on studies that compare the first-generation and second-generation ASDs, with limited data for the efficacy of third-generation drugs. While researchers have been called for investigating those drugs in future research, epilepsy specialists may wish to share their personal experiences to support the treatment guidelines. Given the rapid advances in the development of ASDs in recent years and the continuous updates in definitions, classifications, and treatment guidelines for seizure types and epilepsy syndromes, this review aims to present a complete overview of the current state of the literature about the efficacy and tolerability of ASDs and provide guidance to clinicians about selecting appropriate ASDs for initial treatment of epilepsy according to different seizure types and epilepsy syndromes based on the current literature and recent US and UK practical guidelines.

Temporal lobe epilepsy: A never-ending story

INTRODUCTION

Semiology and anatomo-electroclinical correlations remain invaluable for maintaining the level of excellence in temporal lobe epilepsy (TLE) surgery, in parallel to the constantly evolving technical progress. The aim of this study was to address semiological frequent and not so frequent signs, rarities and red flags in a long follow-up surgical series of patients suffering from TLE.

METHODS

Patients operated within the boundaries of the TL at our center, with presurgical video-EEG recorded seizures and seizure free after a postoperative follow-up of at least 24 months were included. Ictal semiology was systematically described and new red flags were explored by comparing with a second group of patients with the same inclusion criteria but whose outcome had been unfavorable (Engel II-IV).

RESULTS

Sixty-two patients were included, 46 seizure free and 16 with outcome Engel II-IV. Most seizure-free patients had a classical semiological presentation including aura (69.6%, abdominal the most frequent), followed by loss of responsiveness (90.2%) oral automatisms (90.7%), ipsilateral gestural automatisms (53.5%), contralateral upper limb dystonia (37.5%) or immobility (39.1%), and early ipsilateral non-versive head orientation (33.3%). More infrequent presentations were also present in the group of seizure-free patients: ictal language disturbance (13%), maintenance of responsiveness during seizures (9.8%), and contralateral rhythmic non manipulative automatism (6.9%). The presence of an isolated viscerosensory and/or psychic aura was significantly more frequent in the seizure-free group (p = 0.017), as well as oroalimentary automatisms (p = 0.005). Two signs were only present in the group with outcome Engel II-IV, constituting possible red flags (0.06 < p < 0.07): inferior limbs stepping-like automatisms and postictal dysarthria.

CONCLUSION

An adequate clinical exam during seizures and a careful analysis of video recordings allow to recognize infrequent but well-characterized ictal signs that are part of the range of semiology in TLE, together with the most frequent and classical ictal presentations. Special attention to the localization hypothesis must be paid in the absence of oroalimentary automatisms or when the signs classified as possible red flags emerge.

Neuropharmacology of Antiseizure Drugs

BACKGROUND

Antiseizure drugs (ASDs) are the primary therapy for epilepsy, with more than 20 drugs introduced into clinical practice to date. These drugs are typically grouped by their mechanisms of action and therapeutic spectrum. This article aims to educate non-neurologists and medical students about the new frontiers in the pharmacology of ASDs and presents the current state of the literature on the efficacy and tolerability of these agents.

METHODS

Randomized controlled trials, observational studies, and evidence-based meta-analyses of ASD efficacy and tolerability as initial monotherapy for epileptic seizures and syndromes were identified in PubMed, EMBASE, the Cochrane Library, and Elsevier Clinical Pharmacology.

RESULTS

The choice of ASD varies primarily according to the seizure type. Practical guidelines for ASD selection in patients with new-onset and drug-resistant epilepsy were recently published. The guidelines have shown that the newer-generation drugs, which have unique mechanistic and pharmacokinetic properties, are better tolerated but have similar efficacy compared with the older drugs. Several ASDs are effective as first-line monotherapy in focal seizures, including lamotrigine, carbamazepine, phenytoin, levetiracetam, and zonisamide. Valproate remains the first-line drug for many patients with generalized and unclassified epilepsies. However, valproate should be avoided, if possible, in women of childbearing potential because of teratogenicity. Toxicity profile precludes several drugs from use as first-line treatment, for example, vigabatrin, felbamate, and rufinamide.

CONCLUSIONS

Antiseizure drugs have different pharmacologic profiles that should be considered when selecting and prescribing these agents for epilepsy. These include pharmacokinetic properties, propensity for drug-drug interactions, and adverse effects.

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

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

Suicidality Risk of Newer Antiseizure Medications: A Meta-analysis

Importance

Most antiseizure medications (ASMs) carry a US Food and Drug Administration-mandated class label warning of increased suicidality risk, based on a meta-analysis comparing suicidality between individuals treated with medications vs placebo in randomized clinical trials done before 2008. ASMs approved since then carry this warning although they were not similarly studied.

Objective

To review all placebo-controlled phase 2 and 3 studies of 10 ASMs approved since 2008 to evaluate the risk of suicidality of these drugs compared with placebo.

Data Sources

Primary publications and secondary safety analyses in PubMed of all phase 2 and 3 randomized placebo-controlled epilepsy trials of ASMs approved since 2008, using keywords epilepsy, antiepileptic drugs, seizures, suicidality, suicidal ideation, and the names of individual drugs.

Study Selection

All phase 2 and 3 randomized clinical trials of adjunctive treatment of drug-resistant epilepsy and their secondary safety analyses.

Data Extraction and Synthesis

Articles were reviewed for frequency of suicidality (ideation, attempts, and completed suicides). Mode of suicidality ascertainment included treatment-emergent adverse event reports, Standardized Medical Dictionary for Regulatory Activities queries for events in prespecified categories including suicidal ideation and behavior, prospective collection of suicidality data as a prespecified safety outcome using the Columbia-Suicide Severity Rating Scale, and retrospective evaluation by blinded review using the Columbia-Classification Algorithm of Suicide Assessment. A meta-analysis compared risk for drugs vs placebo of each outcome for all drugs overall and by individual drugs and trials.

Main Outcomes and Measures

Suicidality (total and by ideation), attempts, and completed suicides.

Results

Excluding studies that did not evaluate suicidality (everolimus and fenfluramine) or did not evaluate it prospectively (lacosamide, ezogabine, and clobazam), 5 drugs were analyzed: eslicarbazepine, perampanel, brivaracetam, cannabidiol, and cenobamate. Suicidality was evaluated in 17 randomized clinical trials of these drugs, involving 5996 patients, of whom 4000 patients were treated with ASMs and 1996 with placebo. There was no evidence of increased risk of suicidal ideation (drugs vs placebo overall risk ratio, 0.75; 95% CI, 0.35-1.60) or attempt (risk ratio, 0.75; 95% CI, 0.30-1.87) overall or for any individual drug. Suicidal ideation occurred in 12 of 4000 patients treated with ASMs (0.30%) vs 7 of 1996 patients treated with placebo (0.35%) (P = .74). Three patients treated with ASMs and no patients treated with placebo attempted suicide (P = .22). There were no completed suicides.

Conclusions and Relevance

There is no current evidence that the 5 ASMs evaluated in this study increase suicidality in epilepsy and merit a suicidality class warning.

Therapeutic approach to difficult-to-treat typical absences and related epilepsy syndromes

Introduction: typical absences (TAs), are brief, generalized epileptic seizures of abrupt onset and termination clinically manifesting with impairment of awareness and associated with 3 Hz spike-wave discharges on EEG. TAs may occur in different idiopathic generalized epilepsies (IGE). Despite treatment with adequate anti-seizure medications (ASMs), TAs may persist in ~25% of subjects. This narrative review focuses on the therapeutic approach to difficult-to-treat TAs occurring in the setting of IGE.Areas covered: a literature search was conducted on the topic of treatment of TAs.Expert opinion: ethosuximide (ESX), valproic acid (VPA) and lamotrigine (LTG), alone or in combination, are considered the first-choice drugs. In women of childbearing potential, VPA should be avoided. Alternative therapies (benzodiazepines, levetiracetam, topiramate, or zonisamide) should be considered in subjects unresponsive to monotherapy after the exclusion of pseudo-drug resistance. Newer ASMs such as brivaracetam and perampanel seem to be promising options. Well-conducted clinical trials aimed to evaluate the efficacy of alternative monotherapy (beyond ESX, VPA or LTG) or combination of ASMs on difficult-to-treat TAs, are warranted.

Perampanel and Visuospatial Skills in Children With Epilepsy

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

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

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

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

The effect of Perampanel on EEG spectral power and connectivity in patients with focal epilepsy

OBJECTIVE

Quantitative Encephalography (qEEG) depicts synthetically the features of EEG signal and represents a promising tool in the assessment of neurophysiological changes brought about by Anti-Seizure Medications (ASMs). In this study we characterized qEEG alterations related to add-on therapy with Perampanel (PER). PER is the only ASM presenting a direct glutamatergic antagonism, hence the characterization of PER induced EEG changes could help to better understand its large spectrum of efficacy.

METHODS

We analysed standard-19 channel-EEG from 25 People with Epilepsy (PwE) both before (T0) and after (T1) the introduction of PER as add-on treatment. Normal values were obtained in 30 healthy controls (HC) matched for sex and age. EEGs were analysed using Matlab™ and the EEGlab and Brainstorm toolkits. We extracted spectral power and connectivity (Phase locking Value) of EEG signal and then compared these features between T0 and T1 and across groups (PwE, HC), we also evaluated the correlations with clinical features.

RESULTS

PwE showed increased theta power (p = 0.036) after the introduction of PER but no significant change of EEG connectivity. We also found that PwE have reduced beta power (p = 0.012) and increased connectivity in delta (p = 0.013) and theta (p = 0.007) range as compared to HC, but no significant change was observed between T0 and T1 in PwE. Finally, we found that PwE classified as drug responders to PER have greater alpha power both at T0 and at T1 (p = 0.024) suggesting that this parameter may predict response to treatment.

CONCLUSIONS

PER causes slight increase of theta activity and does not alter connectivity as assessed by standard EEG. Moreover, greater alpha power could be a good marker of response to PER therapy, and potentially ASM therapy in general.

SIGNIFICANCE

Our results corroborate the hypothesis that pharmaco-EEG is a viable tool to study neurophysiological changes induced by ASM. Additionally, our work highlights the role of alpha power as a marker of ASM therapeutic response.

The Pharmacoresistant Epilepsy: An Overview on Existent and New Emerging Therapies

Epilepsy is one of the most common neurological chronic disorders, with an estimated prevalence of 0. 5 - 1%. Currently, treatment options for epilepsy are predominantly based on the administration of symptomatic therapy. Most patients are able to achieve seizure freedom by the first two appropriate drug trials. Thus, patients who cannot reach a satisfactory response after that are defined as pharmacoresistant. However, despite the availability of more than 20 antiseizure medications (ASMs), about one-third of epilepsies remain drug-resistant. The heterogeneity of seizures and epilepsies, the coexistence of comorbidities, and the broad spectrum of efficacy, safety, and tolerability related to the ASMs, make the management of these patients actually challenging. In this review, we analyze the most relevant clinical and pathogenetic issues related to drug-resistant epilepsy, and then we discuss the current evidence about the use of available ASMs and the alternative non-pharmacological approaches.

Efficacy and tolerability of adjuvant perampanel: an Australian multicenter real-world observational study in refractory focal and generalized epilepsy syndromes

PURPOSE

To explore the efficacy and tolerability of adjuvant perampanel (PER) and their associated risk factors in late add-on drug-resistant epilepsy.

METHOD

Retrospective multicenter 'real-world' observational study. Consecutively identified patients commenced on PER, with mixed epilepsy syndromes, from nine Australian epilepsy centers. Primary efficacy endpoints were at least 50% reduction in seizure frequency (responders), seizure freedom, and retention at 6 and 12 months, following a 3-month titration period. Tolerability endpoints were cessation of PER for any reason, cessation of PER due to treatment-emergent adverse events (TEAE), or cessation due to inefficacy. Outcomes were assessed for a-priori risk factors associated with efficacy and tolerability.

RESULTS

Three-hundred and eighty seven adults were identified and followed up for a median of 12.1 months (IQR 7.0-25.2). Focal epilepsy accounted for 79.6% (FE), idiopathic generalized epilepsy (IGE), 10.3% and developmental epileptic encephalopathy (DEE) 10.1%, of the cohort. All patients had drug-resistant epilepsy, 71.6% had never experienced six months of seizure freedom, and the mean number of antiepileptic medications (AEDs) prior to starting PER was six. At 12 months, with missing cases classified as treatment failure, retention was 40.0%, responder 21.7%, and seizure freedom 9.0%, whereas, using last outcome carried forward (LOCF), responder and seizure freedom rates were 41.3% and 14.7%, respectively. Older age of epilepsy onset was associated with a marginal increase in the likelihood of seizure freedom at 12-month maintenance (OR 1.04, 95% CI 1.02, 1.06). Male sex (adjusted OR [aOR] 2.06 95% CI 1.33, 3.19), lower number of prior AEDs (aOR 0.84, 95% CI 0.74, 0.96) and no previous seizure-free period of at least 6-month duration (aOR 2.04 95% CI 1.21, 3.47) were associated with retention. Perampanel combined with a GABA receptor AED was associated with a lower responder rate at 12 months but reduced cessation of PER. The most common TEAEs were neuropsychiatric (18.86%), followed by dizziness (13.70%), and sleepiness (5.68%).

CONCLUSIONS

Adjuvant PER treatment, even in late-add on drug-resistant epilepsy is an effective and well-tolerated treatment for drug-resistant epilepsy.

Effect and tolerability of perampanel in patients with drug-resistant epilepsy

OBJECTIVE

Perampanel is one of the most recently approved antiseizure medications. The aim of the present study was to assess clinical efficacy and tolerability, in combination with pharmacokinetic variability, of perampanel treatment in patients at a tertiary referral center for epilepsy.

METHODS

We performed a retrospective observational study of patients given perampanel as adjunctive treatment in the period January 2013 - February 2019 at the National Center for Epilepsy at Oslo University Hospital, Norway.

RESULTS

Clinical data were available for 175 mainly adult patients with drug-resistant epilepsy with mean treatment duration of 16.1 months. We found that 23% (40 patients) were responders (i.e., achieving more than 50% reduction in seizure frequency), four of whom became seizure free, 29% (51 patients) experienced a modest effect, whereas for 29% (50 patients) perampanel had no seizure-reducing effect. A paradoxical effect, with seizure aggravation, was reported in 9% (15 patients). The responder rate was significantly higher in those with slow vs. fast dosage titration. Logistic regression analysis showed better efficacy among those with generalized vs. those with focal epilepsy. Adverse effects were reported by 135 patients (77%), ranging from mild (34%), to moderate (41%) and severe (2%). In 55 patients (41%), these adverse effects resulted in discontinuation of treatment with perampanel. The most frequent adverse effects were psychiatric symptoms (34%), dizziness (31%), and sleepiness (26%). Of the 31 patients for whom serum concentration measurements were available, the mean daily perampanel dose was 6.3 mg (SD 3.0), with a mean serum concentration at steady state of 1.03 μmol/L (range: 0.15-3.59 μmol/L). There were pronounced differences between patients, as demonstrated by a 12-fold variability in the range of concentration/dose (C/D)-ratios (0.06 to 0.69 μmol/L/mg), where enzyme inducers contributed.

CONCLUSION

Our results demonstrate that perampanel had a modest seizure-reducing effect in this very treatment-resistant patient group. Predictors of treatment success were generalized epilepsy and slow dosage titration. In patients without a history of psychiatric problems, clinicians could consider increasing dose of perampanel beyond 6 mg daily, taking co-medication and serum concentrations into account.

Diagnostic and therapeutic approach to drug-resistant juvenile myoclonic epilepsy

INTRODUCTION

Juvenile myoclonic epilepsy (JME), also known as Janz syndrome, is a common form of generalized epilepsy of presumed genetic origin representing up to 10% of all epilepsy cases. Despite adequate anti-seizure medication (ASM) treatment, seizures persist in one-third of JME patients.

AREAS COVERED

A literature search was conducted using Pubmed search on the topics of drug-resistant JME.

EXPERT OPINION

About 30% of JME patients are drug-resistant. Valproate (VPA) is considered the first-choice drug. In women of childbearing potential, levetiracetam (LEV) should represent the first-choice treatment. Alternative monotherapy or add-on therapy should be considered in subjects with resistant seizures after the exclusion of pseudo-drug resistance. The choice of the add-on ASM depends on the predominant seizure type. In subjects with persistent bilateral tonic-clonic seizures, LEV or lamotrigine should be firstly considered. In patients with difficult-to-treat myoclonic seizures, clonazepam or LEV are recommended. In case of persistent absences, ethosuximide should be considered. With appropriate selection and safeguards in place, VPA should remain available as an option in women of childbearing potential whose seizures are resistant to other treatments.

Glutamatergic Mechanisms in Glioblastoma and Tumor-Associated Epilepsy

The progression of glioblastomas is associated with a variety of neurological impairments, such as tumor-related epileptic seizures. Seizures are not only a common comorbidity of glioblastoma but often an initial clinical symptom of this cancer entity. Both, glioblastoma and tumor-associated epilepsy are closely linked to one another through several pathophysiological mechanisms, with the neurotransmitter glutamate playing a key role. Glutamate interacts with its ionotropic and metabotropic receptors to promote both tumor progression and excitotoxicity. In this review, based on its physiological functions, our current understanding of glutamate receptors and glutamatergic signaling will be discussed in detail. Furthermore, preclinical models to study glutamatergic interactions between glioma cells and the tumor-surrounding microenvironment will be presented. Finally, current studies addressing glutamate receptors in glioma and tumor-related epilepsy will be highlighted and future approaches to interfere with the glutamatergic network are discussed.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

SIGNIFICANCE

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

Study protocol for a phase II randomised, double-blind, placebo-controlled trial of perampanel as an antiepileptogenic treatment following acute stroke

INTRODUCTION

Stroke is a common cause of epilepsy that may be mediated via glutamate dysregulation. There is currently no evidence to support the use of antiseizure medications as primary prevention against poststroke epilepsy. Perampanel has a unique antiglutamatergic mechanism of action and may have antiepileptogenic properties. This study aims to evaluate the efficacy and safety of perampanel as an antiepileptogenic treatment in patients at high risk of poststroke epilepsy.

METHODS AND ANALYSIS

Up to 328 patients with cortical ischaemic stroke or lobar haemorrhage will be enrolled, and receive their first treatment within 7 days of stroke onset. Patients will be randomised (1:1) to receive perampanel (titrated to 6 mg daily over 4 weeks) or matching placebo, stratified by stroke subtype (ischaemic or haemorrhagic). Treatment will be continued for 12 weeks after titration. 7T MRI will be performed at baseline for quantification of cerebral glutamate by magnetic resonance spectroscopy and glutamate chemical exchange saturation transfer imaging. Blood will be collected for measurement of plasma glutamate levels. Participants will be followed up for 52 weeks after randomisation.The primary study outcome will be the proportion of participants in each group free of late (more than 7 days after stroke onset) poststroke seizures by the end of the 12-month study period, analysed by Fisher's exact test. Secondary outcomes will include time to first seizure, time to treatment withdrawal and 3-month modified Rankin Scale score. Quality of life, cognitive function, mood and adverse events will be assessed by standardised questionnaires. Exploratory outcomes will include correlation between cerebral and plasma glutamate concentration and stroke and seizure outcomes.

ETHICS AND DISSEMINATION

This study was approved by the Alfred Health Human Research Ethics Committee (HREC No 44366, Reference 287/18).

TRIAL REGISTRATION NUMBER

ACTRN12618001984280; Pre-results.

Behavioral adverse events with brivaracetam, levetiracetam, perampanel, and topiramate: A systematic review

PURPOSE

To understand the currently available post-marketing real-world evidence of the incidences of and discontinuations due to the BAEs of irritability, anger, and aggression in people with epilepsy (PWE) treated with the anti-seizure medications (ASMs) brivaracetam (BRV), levetiracetam (LEV), perampanel (PER), and topiramate (TPM), as well as behavioral adverse events (BAEs) in PWE switching from LEV to BRV.

METHODS

A systematic review of published literature using the Cochrane Library, PubMed/MEDLINE, and Embase was performed to identify retrospective and prospective observational studies reporting the incidence of irritability, anger, or aggression with BRV, LEV, PER, or TPM in PWE. The incidences of these BAEs and the rates of discontinuation due to each were categorized by ASM, and where possible, weighted means were calculated but not statistically assessed. Behavioral and psychiatric adverse events in PWE switching from LEV to BRV were summarized descriptively.

RESULTS

A total of 1500 records were identified in the searches. Of these, 44 published articles reporting 42 studies met the study criteria and were included in the data synthesis, 7 studies were identified in the clinical trial database, and 5 studies included PWE switching from LEV to BRV. Studies included a variety of methods, study populations, and definitions of BAEs. While a wide range of results was reported across studies, weighted mean incidences were 5.6% for BRV, 9.9% for LEV, 12.3% for PER, and 3.1% for TPM for irritability; 3.3%* for BRV, 2.5% for LEV, 2.0% for PER, and 0.2%* for TPM for anger; and 2.5% for BRV, 2.6% for LEV, 4.4% for PER, and 0.5%* for TPM for aggression. Weighted mean discontinuation rates were 0.8%* for BRV, 3.4% for LEV, 3.0% for PER, and 2.2% for TPM for irritability and 0.8%* for BRV, 2.4% for LEV, 9.2% for PER, and 1.2%* for TPM for aggression. There were no discontinuations for anger. Switching from LEV to BRV led to improvement in BAEs in 33.3% to 83.0% of patients (weighted mean, 66.6%). *Denotes only 1 study.

CONCLUSIONS

This systematic review characterizes the incidences of irritability, anger, and aggression with BRV, LEV, PER, and TPM, and it provides robust real-world evidence demonstrating that switching from LEV to BRV may improve BAEs. While additional data remain valuable due to differences in methodology (which make comparisons difficult), these results improve understanding of the real-world incidences of discontinuations due to these BAEs in clinical practice and can aid in discussions and treatment decision-making with PWE.

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

RATIONALE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Real-world impact of antiepileptic drug combinations with versus without perampanel on healthcare resource utilization in patients with epilepsy in the United States

OBJECTIVES

Combination regimens of antiepileptic drugs (AEDs) with various mechanisms of action (MOA) are commonly used in patients with refractory epilepsy. However, outcomes related to combination AEDs with novel MOA, such as perampanel (PER), are not well described. This study compared healthcare resource utilization (HRU) among recipients of PER-based combinations versus recipients of other non-PER-based combinations.

METHODS

This retrospective study used claims data from the Symphony Health's IDV® (Integrated Dataverse) database (August 2012 to July 2018). Patients were aged ≥12 years with epilepsy or non-febrile convulsions, were treated with AED combinations, and had ≥12 and ≥6 months pre- and post-index date, respectively (date of initiation of the second AED in the combination). AEDs were categorized based on MOA: selective non-competitive antagonist of AMPA receptors (i.e., PER), sodium channel blocker (SC), synaptic vesicle protein 2A binding (SV2), and gamma-aminobutyric acid analog (G). Patients were then classified into MOA-based cohorts: PER + SC, PER + SV2, PER + G, SC + SC, SC + SV2, SC + G, SV2 + G, and G + G. HRU outcomes were evaluated during follow-up and compared between PER-based cohorts and non-PER-based cohorts.

RESULTS

On average, patients in the PER + SC (N = 3,592), PER + SV2 (N = 2,200), and PER + G (N = 1,313) cohorts were younger and had a lower Quan-Charlson comorbidity index than those in non-PER-based cohorts. PER + SC and PER + SV2 users had significantly fewer all-cause hospitalizations than non-PER-based users (adjusted RR range: 0.66-0.89, all P < 0.05), while PER + G recipients had fewer all-cause hospitalizations than recipients of SV2 + G and G + G (adjusted RR range: 0.92-0.94). Similar trends were observed for epilepsy-related hospitalizations. Across all comparisons, PER-based combinations were associated with significantly lower rates of all-cause clinic/office/outpatient visits relative to non-PER-based combinations (adjusted RR range: 0.69-0.86, all P < 0.05).

SIGNIFICANCE

Results showed that patients treated with PER-based combinations had fewer all-cause and epilepsy-related hospitalizations, and fewer all-cause clinic/office/outpatient visits compared with patients treated with most other non-PER-based combinations.

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

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

Treatment of pharmacoresistant sleep-related hypermotor epilepsy (SHE) with the selective AMPA receptor antagonist perampanel

This study aimed to evaluate the efficacy and tolerability of perampanel (PER) as adjunctive therapy in patients with pharmacoresistant sleep-related hypermotor epilepsy (SHE). Patients diagnosed with SHE who received PER treatment between 2016 and 2019 were included, and their data were reviewed retrospectively. Diagnosis was based on reports of patients or family members witnessing the events and clinical characteristics of seizures captured by video or during video-electroencephalography monitoring. Among 36 SHE patients, 20 with pharmacoresistant SHE (six female; mean age: 34.1 ± 9.0 years) who received PER as adjunctive therapy were included in this study. Fourteen out of the 20 patients received PER with mean length of PER exposure of 24.6 ± 15.7 months: 10 of them were responders and four non-responders. The remaining six patients discontinued PER for adverse events (n = 5) and patient choice (n = 1). Among the 10 responders, six (60%) reported seizure-free periods lasting ≥6 months. The most common PER-associated adverse event was dizziness (25%) followed by malaise (10%). Clinical experience with these patients demonstrated that PER might be considered as an add-on anti-seizure medication for patients with highly pharmacoresistant SHE.

Positive and negative effects of perampanel treatment on psychiatric and behavioral symptoms in adult patients with epilepsy

PURPOSES

The purpose of the study was to investigate the positive and negative effects of perampanel (PER) treatment on the psychiatric and behavioral symptoms in patients with epilepsy and to evaluate factors associated with the psychiatric and behavioral changes caused by PER.

METHODS

We retrospectively examined medical records of patients with epilepsy treated with PER in the Department of Psychiatry, Epilepsy Center, Nishiniigata Chuo National Hospital. Multiple regression analyses were performed with the psychiatric and behavioral prognoses as dependent variables and clinical characteristics of the patients as independent variables.

RESULTS

Thirty-two of 135 patients (23.7%) had psychiatric and behavioral deterioration after the initiation of PER, whereas 22 patients (16.3%) showed improvement in psychiatric and behavioral symptoms after PER administration. Etiology of structural abnormalities, concomitant use of nitrazepam, and comorbidities of irritability and depression were significantly associated with increasing incidence of psychiatric and behavioral deterioration. Concomitant use of carbamazepine was significantly associated with decreasing incidence of psychiatric and behavioral deterioration. Suppression of awareness-impaired seizures by PER, concomitant use of carbamazepine, and comorbidities of insomnia, anxiety, and amnesia were significantly associated with an increasing incidence of psychiatric and behavioral improvement. Improvements in psychiatric symptoms by PER were associated with a reduction in the use of psychotropic drugs. In particular, about 1/4 of benzodiazepines had been discontinued.

CONCLUSIONS

Perampanel therapy may aggravate or even ameliorate psychiatric and behavioral symptoms in patients with epilepsy. The psychiatric and behavioral prognoses after administration of PER vary depending on the type of psychiatric and behavioral comorbidities in patients with epilepsy. Psychiatric and behavioral symptoms may improve in patients with successful suppression of seizures by PER. Additionally, combination therapy consisting of PER and carbamazepine may be associated with good outcomes of psychiatric and behavioral symptoms in patients with epilepsy.

Perampanel Improves Cortical Myoclonus and Disability in Progressive Myoclonic Epilepsies: A Case Series and a Systematic Review of the Literature

Introduction: Progressive myoclonic epilepsies (PMEs) are a heterogenous group of genetic diseases presenting with epilepsy, cognitive impairment, and severe action myoclonus, which can severely affect daily life activities and independent walking ability. Perampanel is a recent commercially available antiseizure medication with high efficacy against generalized seizures. Some reports supported the role of perampanel in ameliorating action myoclonus in PMEs. Here, we aimed to describe a case series and provide a systematic literature review on perampanel effects on PMEs.

Methods: We report the perampanel effectiveness on myoclonus, daily life activities, and seizures on an original Italian multicenter case series of 11 individuals with PMEs. Then, using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, we performed a systematic review on perampanel effect on myoclonus and disability in PMEs. We searched PubMed, Scopus, and Google Scholar articles on perampanel and PMEs up to June 2020. No prospective trials were found. We reviewed 11 case series manuscripts reporting 104 cases of different PMEs.

Results: Here, we are reporting the effectiveness of perampanel in five individuals affected by Unverricht–Lundborg disease, three by Lafora disease, two by sialidosis, and one by an undetermined PME. Nine out of 11 individuals improved their disability related to the action myoclonus (two with Lafora disease did not). Among the 104 persons with PMEs collected by the systematic review, we found that more than half of the patients receiving perampanel exhibited an amelioration of action myoclonus and, consequently, of their independence in daily life activities. The Unverricht–Lundborg disease seemed to show the best clinical response to perampanel, in comparison with the other more severe PMEs. A significant seizure reduction was achieved by almost all persons with active epilepsy. Only 11% of PME patients dropped out due to inefficacy.

Conclusions: Perampanel demonstrated a beneficial effect with regard to action myoclonus, disability, and seizures and was well-tolerated in people with PMEs, independently from their genetic diagnosis. Given the limited scientific evidence, broader prospective trials should be encouraged.

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.

Clinical experience on the use of perampanel in epilepsy among child neurologists in the Philippines

BACKGROUND

Perampanel is the latest anti-seizure medication introduced in the Philippines in 2015. This was initially approved as an adjunctive treatment for focal seizures and those with secondary generalization among individuals 12 years old and above. By March 2020, it has been approved also for generalized seizures and in children 4 years and above. The general objective of this research is to describe the clinical experience of Filipino child neurologists on the use of perampanel in children.

METHODS

This is a cross-sectional descriptive study that surveyed child neurologists with review of medical records of children who have received perampanel as either an adjunctive therapy or monotherapy for epilepsy.

RESULTS

There were 65 patients included in the study aged 1 to 18 years with a mean age of 10.0 ± 5.2 years and a median of 10 years. Follow-up duration were between 2 weeks to more than a year. Perampanel was started in 98.5% as an add-on treatment between 5 months and 18 years of age. The responder rate is 69.2% (45/65), seizure-free rate is 29.2% (19/65), seizure-aggravation rate is 9.2% (6/65), and perampanel retention rate is 83.1% (54/65). Treatment emergent adverse events were noted in 53.8% of the children with somnolence (20.0%), gait problems (12.3%), weight gain (10.8%) and dizziness (9.2%) as the most common events experienced. Dizziness was experienced significantly more among children 12 to 18 years of age.

CONCLUSION

Perampanel is seen to be effective and relatively safe to use among Filipino children.

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.

Effects of the noncompetitive AMPA receptor antagonist perampanel on thalamo-cortical excitability: A study of high-frequency oscillations in somatosensory evoked potentials

OBJECTIVE

Wedesignedalongitudinalcohortstudyon People with Epilepsy (PwE) with the aimofassessingthe effect of Perampanel (PER) oncortico-subcortical networks, as measured by high-frequency oscillations of somatosensory evoked potentials (SEP-HFOs). SEP-HFOs measure the excitability of both thalamo-corticalprojections(early HFOs) and intracortical GABAergic synapses (late HFOs), thus they could be used to study the anti-glutamatergic action of PER, a selective antagonist of the AMPA receptor.

METHODS

15 PwE eligible for PER add-on therapy, were enrolled prospectively. Subjects underwent SEPs recording from the dominant hand at two times: PwE_T0 (baseline, before PER titration) and PwE_T1 (therapeutic dose of 4 mg). HFOs were obtained by filtering N20 scalp response in the 400-800 Hz range. Patients were compared with a normative population of 15 healthy controls (HC) matched for age and sex.

RESULTS

We found a significant reduction ofTotal HFOs and mostly early HFOs area between PwE_T0 and PwE_T1 (p = 0.05 and p = 0.045 respectively) and between HC and PwE_T1 (p = 0.01). Furthermore, we found a significant reduction of P24/N24 Amplitude between PwE_T0 and HC and between PwE_T0 and PwE_T1 (p = 0.006 and p = 0.032, respectively).

CONCLUSIONS

Introduction of PER as add-on therapy reduced the area of total HFOs, acting mainly on the early burst, related to thalamo-cortical pathways. Furthermore P24/N24 amplitude, which seems to reflect a form of cortico-subcortical integration, resulted increased in PwE at T0 and normalized at T1.

SIGNIFICANCE

Our findings suggest that PER acts on cortico-subcortical excitability. This could explain the broad spectrum of PER and its success in forms of epilepsy characterized by thalamo-cortical hyperexcitability.