A two-year retrospective evaluation of perampanel in patients with highly drug-resistant epilepsy and cognitive impairment

An analysis of suicidal and self-injurious behavior reports with antiseizure medications in the FDA adverse event database

BACKGROUND

Pharmacovigilance systems such as the FDA Adverse Event Reporting System (FAERS), are established models for adverse event surveillance that may have been missed during clinical trials. We aimed to analyze twenty-five anti-seizure medications (ASMs) in FAERS to assess for increased reporting of suicidal and self-injurious behavior.

METHODS

Twenty-five ASMs were analyzed: brivaracetam, cannabidiol, carbamazepine, clobazam, clonazepam, diazepam, eslicarbazepine, felbamate, gabapentin, lacosamide, lamotrigine, levetiracetam, oxcarbazepine, perampanel, phenobarbital, phenytoin, pregabalin, primidone, rufinamide, stiripentol, tiagabine, topiramate, valproate, vigabatrin, zonisamide. Reports of "suicidal and self-injurious behavior" were collected from January 1, 2004, to December 31, 2020, using OpenVigil 2.1 tool with indication as "Epilepsy". Relative reporting ratio, proportional reporting ratio, and reporting odds ratio were calculated utilizing all other drug reports for epilepsy patients as a control.

RESULTS

Significant relative operating ratio, ROR (greater than 1, p<0.05) were observed for diazepam (2.909), pregabalin (2.739), brivaracetam (2.462), gabapentin (2.185), clonazepam (1.649), zonisamide (1.462), lacosamide (1.333), and levetiracetam (1.286).

CONCLUSIONS

Of the 25 ASMs that were analyzed in this study, 4 (16%) were identified to have been linked with a likely true adverse event. These drugs included diazepam, brivaracetam, gabapenetin, and pregabalin. Although several limitations are present with the FAERS database, it is imperative to closely monitor patient comorbidities for increased risk of suicidality with the use of several ASMs.

Unveiling the potential of perampanel and pregabalin in addressing pentylenetetrazole-induced electrographic alterations and neurobehavioral anomalies

Chemical kindling is broadly used experimental model to investigate novel treatments on the process of epileptogenesis and coexisting behavioral comorbidities. The current study aimed to investigate the low dose perampanel (PER) (0.125 and 0.5 mg/kg) and pregabalin (PG) (15 mg/kg) as standalone treatments and in combination on kindling-induced seizure progression with concurrent electroencephalographic alterations. Mice were subjected to pentylenetetrazole (PTZ)-induced kindling followed by neurobehavioral assessment for anxiety-like activity and cognitive deficit through behavioral experiments. The monotherapy with PER at 0.5 mg/kg and PG at 15 mg/kg delayed the kindling process but PRP+PG yielded pronounced benefits and hindered the development of seizures of higher severity. PER+PG combination relieved the animals from anxiety-like behavior in various employed anxiogenic tests. Furthermore, the kindling-associated cognitive deficit was protected by PER+PG combination as increased alteration behavior, discrimination index and latencies to enter the dark zone were noted in y-maze, object recognition and passive avoidance tests, respectively while shorter escape latencies were noted in water maze. The brain samples of kindled mice had elevated malondialdehyde and reduced catalase, superoxide dismutase and glutathione peroxidase enzymes while treatment with PER and PG combination shielded the mice from heightened kindling-associated oxidative stress. Overall, the findings of the present study illustrate that concurrent administration of PER and PG effectively hindered the process of epileptogenesis by protecting neuronal excitability and brain oxidative stress. The results predict the dominance of PER and PG combination over monotherapy which might serve as an effective novel combination to combat drug resistance and behavioral disorders in epileptic patients.

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

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

Efficacy and tolerability of perampanel in patients with seizures in real-world clinical practice: A systematic review and meta-analysis

Objectives: The aim of this study was to systematically review the efficacy and tolerability of perampanel (PER) when used as add-on treatment or monotherapy in patients with epilepsy aged 12 years and older in routine clinical practice.

Methods: Electronic and clinical trials databases were searched for observational studies of PER published up to 1 March 2022. The outcomes of interest were responder rates, adverse effects (AEs), and withdrawal rates. Subgroup analyses were performed to explore the potential factors that might affect the efficacy and safety of PER usage.

Results: A total of 56 studies, which included 10,688 patients, were enrolled. The results showed that after 3, 6, and 12 months of PER treatment, the pooled 50% responder rates in patients with epilepsy were 50.0% (95% CI: 0.41–0.60), 44.0% (95% CI: 0.38–0.50), and 39.0% (95% CI: 0.31–0.48), respectively, and the pooled seizure-free rates were 24.0% (95% CI: 0.17–0.32), 21.0% (95% CI: 0.17–0.25), and 20.0% (95% CI: 0.16–0.24), respectively. Subgroup analyses revealed that the efficacy of PER could be affected by the way in which PER is administrated. Patients in the groups where PER was used as the first add-on, primary monotherapy, or combined with non–enzyme-inducing AEDs (non-EIAEDs) displayed a high 50% responder rate and seizure-free rate when compared with those in the late add-on, conversion therapy, or combined with the EIAEDs groups, respectively. Furthermore, the incidences of AEs at 3, 6, and 12 months of PER treatment were 46% (95% CI: 0.38–0.55), 52.0% (95% CI: 0.43–0.60), and 46.0% (95% CI: 0.40–0.52), respectively. The withdrawal rates due to AEs were 8.0% (95% CI: 0.06–0.11), 16.0% (95% CI: 0.13–0.20), and 16% (95% CI: 0.11–0.21) at 3, 6, and 12 months of PER treatment, respectively. Subgroup analyses showed a higher withdrawal rate in the rapid (30%, 95% CI: 0.22–0.38) than in the slow (12%, 95% CI: 0.06–0.18) titration group.

Conclusion: Altogether, PER was effective and could be fairly tolerated in both short-term and long-term usage in patients with epilepsy in routine clinical practice. Furthermore, PER appeared to be more effective when PER was used as the first add-on, monotherapy, or concomitant with non-EIAEDs.

Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022384532.

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

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

Perampanel as adjuvant treatment in epileptic encephalopathies: A multicenter study in routine clinical practice

OBJECTIVE

Developmental and epileptic encephalopathies (DEEs) are a heterogeneous group of syndromes, including Lennox-Gastaut syndrome (LGS), which are refractory to multiple therapies. Perampanel efficacy has been reported in LGS but further real-world evidence is needed in DEEs.

METHODS

A multicenter, retrospective, 1-year observational study in patients with DEEs on adjuvant perampanel treatment was conducted to assess perampanel safety and effectiveness in this type of patients in a real-world setting. Seizure types [focal onset seizures (FOS), generalized tonic-clonic seizures (GTCS), tonic seizures (TS), atonic seizures (AtS), atypical absences (AA), and myoclonic seizures (MS)] and seizure clusters were divided in different frequency groups: daily, weekly, and monthly seizures, and absent or seizure freedom. Patients could have more than one seizure type. For each frequency group, group change and seizure freedom were analyzed.

RESULTS

Eighty-seven patients diagnosed with DEEs (45 males) of median age 22 [1-70] years were included. The most frequent DEEs were LGS (35.6%) and Lennox-like syndrome (37.9%). At baseline 20 patients had three to five types of seizures, 36 patients had two types of seizures and 31 patients had one predominant type of seizure. The mean number of seizure types per patient at baseline was 2.12 ± 0.97 which was reduced to 1.62 ± 0.91 at 12 months (p < 0.001). Overall, 51.7% of patients had a significant improvement in at least one seizure type. At baseline, 45 patients had GTCS, 42 FOS, 41 TS, 18 AA, 16 AtS, 11 MS, and 30 seizures clusters. Seizure freedom for each specific type at 12 months was significantly achieved by 35% of patients with GTCS (p < 0.001), 17% (p = 0.016) with TS and 37% with seizure clusters (p < 0.001). Patients achieved seizure freedom from other seizure types but with no statistical significance: 7% FOS-free, 28% AA-free, 6% Ats-free, and 18% MS-free. Regarding changes of group at 12 months, 22% of TS and 19% of FOS improved significantly to a group with lower seizure frequency (p = 0.004 and p = 0.02, respectively). In remaining groups (4% of GTCS, 11% of AA, 18% of Ats, 18% of MS, and 13% of seizure clusters), the improvement was not statistically significant. Twenty-nine patients discontinued perampanel: 18 (21%) due to AEs, 8 (9%) due to lack of efficacy, and 3 (3%) due to seizure worsening. Adverse events, mostly mild or moderate, were reported in 53% of patients, and irritability/mood changes (22%) and somnolence (17%) were the most frequent.

CONCLUSION

This is the first large-scale real-world study with perampanel across different seizure types in patients with DEEs. Perampanel was effective, especially in GTCS, TS, and FOS, as well as in seizure clusters. Perampanel was generally well-tolerated without unexpected AEs.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Does a psychiatric history play a role in the development of psychiatric adverse events to perampanel… and to placebo?

OBJECTIVE

The purpose of this study was to establish whether a past psychiatric history could play a role in the development of psychiatric treatment-emergent adverse events (PTEAEs) in patients randomized to perampanel (PER) or placebo.

METHODS

The development of PTEAEs was compared between patients with/without a psychiatric history in a post hoc analysis from four randomized placebo-controlled trials (RPCTs) of PER (304/305/306/335) in patients with treatment-resistant focal epilepsy.

RESULTS

Among the 2,187 patients enrolled in the RPCTs, 352 (16.1%) had a psychiatric history (PER n = 244; placebo n = 108), while 1835 patients (83.9%) did not (PER n = 1325; placebo n = 510). Compared to patients without a psychiatric history, those with a positive history reported more PTEAEs for both patients randomized to PER (11.8% vs. 29.9%, p < 0.01) or to placebo (9.2% vs. 19.4%, p < 0.01). The prevalence of PTEAEs was not higher among patients randomized to 2 mg and 4 mg/day doses than placebo in both those with and without psychiatric history. Rather, the higher prevalence rates were among subjects randomized to 8 mg (29.8%) and 12 mg (36.4%) PER doses in patients with a past psychiatric history.

SIGNIFICANCE

A psychiatric history appears to increase the risk of PTEAEs in patients randomized to placebo and to PER at doses of 8 and 12 mg/day. It should be identified in all patients considered for treatment with PER, particularly when prescribed at doses above 4 mg/day.

A Severe Dementia Case in End of Life Care with Psychiatric Symptoms Treated by Perampanel

Epilepsy is known to comorbid with Alzheimer’s disease. It can promote cognitive decline, and eventually worsen their prognosis and mortality. It is sometimes difficult to find a suitable drug because of the adverse effects. Perampanel has a unique mechanism of action that antagonizes α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid type glutamate receptor. Here, we report a case of severe dementia due to Alzheimer’s disease with intractable epilepsy, which perampanel effected for controlling seizures with less adverse effects. The subject is an 89-year-old Japanese woman with severe dementia due to Alzheimer’s disease and intractable myoclonic epilepsy. She also had psychiatric symptoms, such as circadian rhythm disorder and irritability. Valproic acid, lacosamide, or carbamazepine were prescribed, but none of them was effective. Shortly after perampanel started, however, myoclonus and these psychiatric symptoms improved. Moreover, it did not cause any obvious adverse effects, which made it possible to continue perampanel until the end of her life. Perampanel may be useful for controlling intractable epilepsy accompanied by Alzheimer’s disease. It may also improve psychiatric symptoms with less adverse effect. Accumulation of studies is necessary to evaluate the effectiveness of perampanel on the epilepsy of Alzheimer’s disease patients and further understand that mechanism.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

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.

An evaluation of the effectiveness of perampanel in people with epilepsy who have previously undergone resective surgery and/or implantation of a vagal nerve stimulator

About 30% of people with epilepsy (PWE) are drug-resistant. Those with focal seizures may be suitable for epilepsy surgery. Those not amenable to resective surgery can be considered for vagus nerve stimulation (VNS). However, after operative procedures, around 50% of patients continue to experience seizures. A multi-center retrospective study assessing perampanel effectiveness and tolerability for PWE who have undergone surgical resection and/or VNS implantation was performed. The primary outcome was ≥50% reduction in seizure frequency while secondary outcomes included side effects (SEs), dose-related effectiveness, and toxicity. The median perampanel dose was 6 mg. Only one PWE became seizure free. A ≥50% decrease in seizure frequency was observed in 52.8% of the post-resection group and 16.9% of the VNS group (p < 0.001), while SEs were seen in 44.8% and 41.1%, respectively. Perampanel doses greater than 8 mg led to better response in both groups, especially in the post-VNS cohort. SEs were not dose-related and the safety profile was similar to previous observational studies. Perampanel can be beneficial in these two super-refractory epilepsy groups, particularly in PWE with seizures after surgical resection. Doses of more than 8 mg appear to be well tolerated and may be more effective than lower doses in PWE after surgical interventions.

Differences in levetiracetam and perampanel treatment-related irritability in patients with epilepsy

PURPOSE

The present study evaluated whether patients with epilepsy who received both levetiracetam (LEV) and perampanel (PER) therapy showed side effects of irritability. The study also examined the relationship between patient characteristics and irritability when it occurred as a side effect.

METHODS

We retrospectively examined medical records of 98 patients with epilepsy who were treated with both LEV and PER at the Department of Psychiatry in the Epilepsy Center of Nishiniigata Chuo National Hospital in Japan. We performed multiple regression analyses with the presence/absence of irritability due to LEV or PER as the dependent variables and clinical characteristics of the patients as independent variables.

RESULTS

LEV and PER caused irritability in 7 and 17 of 98 patients, respectively. LEV- and PER-related irritability did not occur in the same patients. A logistic multiple regression analysis revealed that EEG findings of temporal focal epileptic discharge were significantly associated with increased incidence of irritability due to LEV. LEV-related irritability decreased significantly with higher dosages of LEV. Another logistic multiple regression analysis revealed that a psychiatric comorbidity of irritability and EEG findings of nontemporal focal epileptic discharge were significantly associated with increased incidence of irritability due to PER.

CONCLUSIONS

LEV and PER cause irritability in different patient groups. Additionally, irritability as a side effect was present only at low dosages of LEV, but PER tended to cause irritability even at high dosages.

Expanding the Treatment Landscape for Lennox-Gastaut Syndrome: Current and Future Strategies

Lennox-Gastaut syndrome (LGS), a childhood-onset severe developmental and epileptic encephalopathy (DEE), is an entity that encompasses a heterogenous group of aetiologies, with no single genetic cause. It is characterised by multiple seizure types, an abnormal EEG with generalised slow spike and wave discharges and cognitive impairment, associated with high morbidity and profound effects on the quality of life of patients and their families. Drug-refractory seizures are a hallmark and treatment is further complicated by its multiple morbidities, which evolve over the patient's lifetime. This review provides a comprehensive overview of the current and future options for the treatment of seizures associated with LGS. Six treatments are specifically indicated as adjunct therapies for the treatment of seizures associated with LGS in the US: lamotrigine, clobazam, rufinamide, topiramate, felbamate and most recently cannabidiol. These therapies have demonstrated reductions in drop seizures in 15%-68% of patients across trials, with responder rates (≥ 50% reduction in drop seizures) of 37%-78%. Valproate is still the preferred first-line treatment, generally in combination with lamotrigine or clobazam. Other treatments frequently used off-label include the broad spectrum anti-epileptic drugs (AED) levetiracetam, zonisamide and perampanel, while recent evidence from observational studies has indicated that a newer AED, the levetiracetam analogue brivaracetam, may be effective and well tolerated in LGS patients. Other treatments in clinical development include fenfluramine in late phase III, perampanel, soticlestat-OV953/TAK-953, carisbamate and ganaxolone. Non-pharmacologic interventions include the ketogenic diet, vagus nerve stimulation and surgical interventions; these are also expanding, with the potential for less invasive techniques for corpus callosotomy that have promise for reducing complications. However, despite these advancements, patients continue to experience a significant burden. Because LGS is not a single entity, tailoring of treatment is needed as opposed to a 'one size fits all' approach. Further research is needed into the underlying aetiologies and pathophysiology of LGS, together with advancements in treatments that encompass the spectrum of seizures associated with this complex syndrome.

Effectiveness and safety of perampanel monotherapy for focal and generalized tonic-clonic seizures: Experience from a national multicenter registry

OBJECTIVE

To assess the effectiveness and tolerability of perampanel (PER) monotherapy in routine clinical practice for the treatment of focal onset and generalized tonic-clonic seizures (GTCS).

METHODS

This multicenter, retrospective, observational study was conducted in patients aged ≥12 years treated with PER as primary monotherapy or converted to PER monotherapy by progressive reduction of background antiepileptic drugs. Outcomes included retention, responder, and seizure-free rate after 3, 6, and 12 months and tolerability throughout the follow-up.

RESULTS

A total of 98 patients (mean age = 49.6 ± 21.7 years, 51% female) with focal seizures and/or GTCS were treated with PER monotherapy for a median exposure of 14 months (range = 1-57) with a median dose of 4 mg (range = 2-10). The retention rates at 3, 6, and 12 months and last follow-up were 93.8%, 89.3%, 80.9%, and 71.4%, respectively. The retention rates according to the type of monotherapy (primary vs conversion) did not differ (log-rank P value = .57). Among the 98 patients, 61.2% patients had seizures throughout the baseline period, with a median seizure frequency of 0.6 seizures per month (range = 0.3-26). Responder rates at 3, 6, and 12 months were 79.6%, 70.1%, and 52.8%, respectively, and seizure freedom rates at the same points were 62.7%, 56.1%, and 41.5%. Regarding the 33 patients who had GTCS in the baseline period, 87.8% were seizure-free at 3 months, 78.1% at 6 months, and 55.1% at 12 months. Over the entire follow-up, PER monotherapy was generally well tolerated, and only 16% of patients discontinued PER due to adverse events (AEs). Female patients were found to be at a higher risk of psychiatric AEs (female vs male odds ratio = 2.85, 95% confidence interval = 1-8.33, P = .046).

SIGNIFICANCE

PER demonstrated good effectiveness and a good safety profile when used as primary therapy or conversion to monotherapy at relatively low doses, in a clinical setting with patients with focal seizures and GTCS.

Clinical experience combined with therapeutic drug monitoring of lacosamide

OBJECTIVE

Lacosamide (LCM) is an antiepileptic drug (AED) with insufficient clinical experience in patients with intellectual disability (ID). They often have more severe epilepsy with comorbidities. The objective was to evaluate the efficacy and tolerability of lacosamide (LCM) in patients with refractory epilepsy with and without ID in a real-life setting, taking drug monitoring (TDM) data into account therapeutic.

METHODS

Retrospectively, we identified 344 patients using LCM from the TDM service covering the majority of the country, at the National Center for Epilepsy in Norway (2013-2018). Clinical and TDM data were available for 132 patients.

RESULTS

Forty-four of the 132 patients (33%) had ID. The retention rate was significantly higher in the ID vs the non-ID group after 1 year (84% vs 68%, P < .05). By combining clinical and TDM data, we demonstrated that 37/38 responding patients had serum concentrations above the lower limit of the reference range (>10 µmol/L), and 16/17 with lower concentrations were non-responders. Mean serum concentration/dose ratios were similar in both groups, 0.06 and 0.07 µmol/L/mg. There were no significant differences regarding efficacy and tolerability. The risk of LCM withdrawal was significantly higher when LCM was added to sodium channel blockers, even if the latter was discontinued.

SIGNIFICANCE

Lacosamide was generally well tolerated in patients with drug-resistant epilepsy, where one third had ID, and in these patients the retention rate was higher. The combination of clinical and TDM data could possibly facilitate LCM therapy in these vulnerable patients.

Improved irritability, mood, and quality of life following introduction of perampanel as late adjunctive treatment for epilepsy

OBJECTIVE

The objective of this study was to evaluate the efficacy and tolerability of perampanel (PER) in late adjunctive treatment of focal epilepsy. We assessed outcomes 1) according to patients' clinical profiles and the broad mechanism of action (MoA) of concomitant antiepileptic drugs (AEDs) and 2) the effects of PER on adverse events, irritability, mood, and quality of life (QOL).

METHODS

Consecutive patients commenced on PER at two epilepsy centers in Melbourne, Australia were identified. A nested cohort underwent detailed prospective assessment, while the remainder were retrospectively analyzed. Six- and 12-month efficacy endpoints were at least a 50% reduction in seizure frequency (responders) and complete seizure freedom. The prospective cohort underwent standardized validated questionnaires at 0, 1, 3, 6, and 12 months using the modified semi-structured seizure interview (SSI), Liverpool Adverse Events Profile (LAEP), Quality of Life in Epilepsy-Patient-Weighted (QOLIE-10-P), Neurological Disorders Depression Inventory Epilepsy (NDDI-E), and an Irritability Questionnaire.

RESULTS

One hundred sixty patients were followed for a median of 6 months: the mean number of prior AEDs was 6, 99% had drug-resistant epilepsy, and 72% had never experienced a prior seizure-free period of at least 6 months (=continuously refractory epilepsy). Perampanel was associated with responder and seizure freedom rates of 30.6% and 9.4% at 6 months and 19.4% and 4.4% (5.6% adjusted for the titration period) at 12 months. Having "continuously refractory epilepsy" was associated with a reduced likelihood of seizure freedom at 6 months (5% vs. 30%; p = 0.001) and 12 months (3% vs. 13%; p = 0.058). Quality of Life in Epilepsy-Patient-Weighted, irritability, and NDDI-E showed mean improvement at 6 months from baseline.

SIGNIFICANCE

Even when used as late add-on adjunctive therapy in patients with highly refractory focal epilepsy, PER can result in 12-month seizure freedom of 5.6%. The likelihood of seizure freedom was associated with prior "continuous medication refractoriness". Six months after introduction of PER patients reported improved mood, QOL, and decreased irritability.

Therapeutic approach to Lennox-Gastaut syndrome: a systematic review

Lennox-Gastaut syndrome (LGS) is a rare, age-related syndrome, characterized by multiple seizure types, mental regression, and specific EEG abnormalities. It is one of the most challenging epilepsy: treatment is rarely effective and the final prognosis remains poor, despite the availability of several antiepileptic drugs, validated through well-designed, randomized, controlled trials. However, it is reasonable to consider non-medical treatments, such as surgery, after failure of two-to-three drugs. This review has as goal to describe systematically the different therapeutic options for LGS, including, not only recognized antiepileptic drugs, but also new oral drugs, immune therapy, diet, surgery, and neurostimulation techniques.

Efficacy and tolerability of perampanel in patients with genetic generalized epilepsy (GGE): A retrospective, single-center study from the United Arab Emirates (UAE)

•52.4% achieved seizure freedom at six months from baseline in our cohort of PWE from the UAE.•38.1% achieved ≥50% reduction in seizure frequency at six months from baseline.•90.5% remained on perampanel treatment beyond the six-month period.•33.3% maintained perampanel monotherapy beyond six months.•9.5% discontinued perampanel treatment due to treatment-induced adverse events.

Mechanisms Underlying Aggressive Behavior Induced by Antiepileptic Drugs: Focus on Topiramate, Levetiracetam, and Perampanel

Antiepileptic drugs (AEDs) are effective against seizures, but their use is often limited by adverse effects, among them psychiatric and behavioral ones including aggressive behavior (AB). Knowledge of the incidence, risk factors, and the underlying mechanisms of AB induced by AEDs may help to facilitate management and reduce the risk of such side effects. The exact incidence of AB as an adverse effect of AEDs is difficult to estimate, but frequencies up to 16% have been reported. Primarily, levetiracetam (LEV), perampanel (PER), and topiramate (TPM), which have diverse mechanisms of action, have been associated with AB. Currently, there is no evidence for a specific pharmacological mechanism solely explaining the increased incidence of AB with LEV, PER, and TPM. Serotonin (5-HT) and GABA, and particularly glutamate (via the AMPA receptor), seem to play key roles. Other mechanisms involve hormones, epigenetics, and “alternative psychosis” and related phenomena. Increased individual susceptibility due to an underlying neurological and/or a mental health disorder may further explain why people with epilepsy are at an increased risk of AB when using AEDs. Remarkably, AB may occur with a delay of weeks or months after start of treatment. Information to patients, relatives, and caregivers, as well as sufficient clinical follow-up, is crucial, and there is a need for further research to understand the complex relationship between AED mechanisms of action and the induction/worsening of AB.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Perampanel as adjunctive therapy in highly refractory epilepsies: Real-world data from an Italian tertiary care epilepsy centre

Perampanel (PER) is a selective non-competitive α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor antagonist, licensed as adjunctive therapy in focal epilepsy and primary generalized tonic-clonic seizures (pGTCSs). We performed a retrospective study on highly refractory adult patients taking PER, with 1-year follow-up. Retention rate represented the primary outcome of our work; seizure frequency reduction (≥50%), "switch rate" and proportion of adverse events (AEs) were evaluated as secondary endpoints. Eighty-nine subjects (47 females, age range: 19-78 years) were included. Seventy-three had focal epilepsy (FE), 9 generalized epilepsy and 7 epileptic encephalopathy. All patients were highly drug-resistant (medication failures: 5-17). Retention rate was 87.6%, 63% and 51.7% at 3, 6 and 12 months. Responders were 27/89 (30.3%), with 8/27 seizure-free. The number of previous treatment failures and the concomitant use of enzyme inducers negatively influenced clinical response, whereas no correlation was documented between PER dose and outcome. Responder proportion was more satisfying in structural FE than in FE of unknown etiology (33% versus 20%), and in secondarily GTCSs than focal seizures (54% vs 28%), whereas pGTCSs showed a lower reponse rate (25%). Mild-to-moderate AEs (mainly dizziness, gait disturbances and psychiatric effects) were reported by 40% of patients; serious psychiatric AEs usually occurred in subjects with psychiatric comorbidities. Our study confirms the tolerability and effectiveness of PER in highly drug-resistant patients with different epilepsy syndromes and aetiologies.

Psychiatric and behavioral side effects of antiepileptic drugs in adults with epilepsy

PURPOSE

Psychiatric and behavioral side effects (PBSEs) are common, undesirable effects associated with antiepileptic drug (AED) use. The objective of the study was to compare the PBSE profiles of older and newer AEDs in a large specialty practice-based sample of patients diagnosed with epilepsy.

METHODS

As part of the Columbia and Yale AED Database Project, we reviewed patient records including demographics, medical history, AED use, and side effects for 4085 adult patients (age: 18 years) newly started on an AED regimen. Psychiatric and behavioral side effects were determined by patient or physician report in the medical record, which included depressive mood, psychosis, anxiety, suicidal thoughts, irritability, aggression, and tantrum. Significant non-AED predictors of PBSE rate were first determined from 83 variables using logistic regression. Predictors were then controlled for in the comparison analysis of the rate of PBSEs and intolerable PBSEs (PBSEs that led to dosage reduction or discontinuation) between 18 AEDs.

RESULTS

Psychiatric and behavioral side effects occurred in 17.2% of patients and led to intolerability in 13.8% of patients. History of psychiatric condition(s), secondary generalized seizures, absence seizures, and intractable epilepsy were associated with increased incidence of PBSE. Levetiracetam (LEV) had the greatest PBSE rate (22.1%). This was statistically significant when compared with the aggregate of the other AEDs (P<0.001, OR=6.87). Levetiracetam was also significantly (P<0.001) associated with higher intolerability rate (17.7%), dose decreased rate (9.4%), and complete cessation rate (8.3%), when compared with the aggregate of the other AEDs. Zonisamide (ZNS) was also significantly associated with a higher rate of PBSE (9.7%) and IPBSE (7.9%, all P<0.001). On the other hand, carbamazepine (CBZ), clobazam (CLB), gabapentin (GBP), lamotrigine (LTG), oxcarbazepine (OXC), phenytoin (PHT), and valproate (VPA) were significantly associated with a decreased PBSE rates (P<0.001). Carbamazepine, GBP, LTG, PHT, and VPA were also associated with lower IPBSE rates when compared individually with the aggregate of other AEDs. All other AEDs were found to have intermediate rates that were not either increased or decreased compared with other AEDs. When each AED was compared to LTG, only CBZ had a significantly lower PBSE rate. The main limitations of this study were that the study design was retrospective and not blinded, and the AEDs were not randomly assigned to patients.

CONCLUSIONS

Psychiatric and behavioral side effects occur more frequently in patients taking LEV and ZNS than any other AED and led to higher rates of intolerability. Lower PBSE rates were seen in patients taking CBZ, CLB, GBP, LTG, OXC, PHT, and VPA. Our findings may help facilitate the AED selection process.

AMPA receptors and perampanel behind selected epilepsies: current evidence and future perspectives

INTRODUCTION

The alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors are the major mediators of glutamate-mediated excitatory neurotransmission, and are critical for synchronization and spread of epileptic activity. Areas covered: AMPA receptor antagonists have been also developed as antiepileptic drugs and perampanel (PER) is the first highly selective, non-competitive AMPA-type glutamate receptor antagonist that is available on the market. It is approved as adjunctive therapy for the treatment of partial-onset seizures with or without secondary generalization, and for primary generalized tonic-clonic seizures in idiopathic generalized epilepsy, in patients aged ≥ 12 years. This article reviews the role of AMPA receptors in the neuronal hyperexcitability underlying epilepsy, the mechanism of action and clinical experience on the anti-seizure activity of PER. Moreover, the rationale for targeting AMPA receptor in specific epileptic disorders, including brain tumor-related epilepsy, mesial temporal lobe epilepsy with/without hippocampal sclerosis, and status epilepticus is evaluated. Finally, the pharmacological rationale for the development of AMPA receptor antagonists in other neurological disorders beyond epilepsy is considered. Expert opinion: Further research aimed at better understanding the pharmacology and blocking mechanism of PER and other AMPA receptor antagonists will drive future development of therapeutic agents that target epilepsy and other neurological diseases.

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

Purpose

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

Summary

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

Conclusion

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

Current role of perampanel in pediatric epilepsy

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