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

Therapeutic drug monitoring of perampanel: Clinical utility and impact of co-medication on pharmacokinetic variability

Background

Perampanel (PER) is a newly developed antiseizure medication (ASM). This study aimed to determine the utilization of therapeutic drug monitoring (TDM) for PER in a real-world clinical setting and investigate the influence of concomitant use of ASMs on the plasma concentration profile of PER.

Method

We analyzed data from the Chang Gung Research Database, which is the largest multi-institutional electronic medical records database in Taiwan. The main outcomes were the comparisons of PER plasma concentration and the ratio of concentration to the weight-adjusted dose (C/D; [ng/mL]/[mg/kg/d]) among patients received TDM of different clinical indication and among different ASM co-medication subgroups.

Results

Overall, 88 plasma samples were collected from 66 epilepsy patients treated with PER. The majority of patients (77.3 %) underwent PER TDM owing to poorly controlled seizures. There was a trend toward a higher plasma concentration and C/D ratio in those suspected of having PER toxicity owing to adverse events than of other indications. The PER concentration exhibited dose linearity. The mean PER plasma concentrations in patients co-medicated with enzyme-inducing ASMs were significantly lower than those in the patients who were not prescribed enzyme-inducing or enzyme-inhibiting ASMs, and co-medication with carbamazepine (CBZ) resulted in a significant reduction in the PER concentration.

Conclusion

PER concentration exhibited a linear regression relationship with PER dose, and the plasma concentration of the drug was highly susceptible to the drug's interactions with enzyme-inducing ASMs. TDM with clear indication could help determine the influence of ASMs used concomitantly on PER concentrations and guide clinical adjustments.

Five-Year Retention of Perampanel and Polytherapy Patterns: 328 Patients From a Single Center in South Korea

BACKGROUND AND PURPOSE

Perampanel (PER) is an α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid antagonist used to treat focal and generalized epilepsy. Comprehensive data from real-world settings with long-term follow-ups are still scarce. This study aimed to determine the factors related to PER retention and the polytherapy pattern with PER.

METHODS

We reviewed all patients with epilepsy with a history of PER prescription during 2008-2017 and over a follow-up of >3 years. PER usage patterns and associated factors were analyzed.

RESULTS

Among the 2,655 patients in the cohort, 328 (150 females, 178 males) were enrolled. The ages at onset and diagnosis were 21.1±14.7 years and 25.6±16.1 years (mean±standard deviation), respectively. The age at the first visit to our center was 31.8±13.8 years. Seizure types were focal, generalized, and unknown onset in 83.8%, 15.9%, and 0.3% of patients, respectively. The most common etiology was structural (n=109, 33.2%). The maintenance duration of PER was 22.6±19.2 months (range=1-66 months). The initial number of concomitant antiseizure medications was 2.4±1.4 (range=0-9). The most common regimen was PER plus levetiracetam (n=41, 12.5%). The median number of 1-year seizures before PER usage was 8 (range=0-1,400). A seizure reduction of >50% was recorded in 34.7% of patients (52.0% and 29.2% in generalized and focal seizures, respectively). The 1-, 2-, 3-, 4-, and 5-year retention rates for PER were 65.3%, 50.4%, 40.4%, 35.3%, and 21.5%, respectively. A multivariate analysis indicated that lower age at onset was associated with longer retention (p=0.01).

CONCLUSIONS

PER was safely used in patients with diverse characteristics and was maintained for a long time in a real-world setting, especially in patients with a lower age at onset.

Sleep-wake cycle and daytime sleepiness in patients with epilepsy after initiating perampanel as adjunctive therapy

BACKGROUND

Antiseizure medications (ASMs) may affect nocturnal sleep and daytime vigilance. Perampanel (PER), a third-generation ASM, showed to improve nocturnal sleep in patients with epilepsy (PWE). Although ASMs can have beneficial effects on nocturnal sleep and daytime sleepiness, no study investigated the effect of PER on both sleep-wake cycle and daytime sleepiness. Therefore, this study aimed to objectively evaluate the sleep-wake cycle and daytime sleepiness in PWE treated with PER as adjunctive therapy.

METHODS

This prospective study included adult PWE who received PER as add-on treatment. Sleep-wake cycle was assessed through actigraphic monitoring and daytime sleepiness by the multiple sleep latency test (MSLT) performed at the end of the actigraphic recording. All patients performed both tests at baseline and at 6-month follow-up.

RESULTS

Ten patients (mean age: 44.50 ± 22.71 years, 50.0% female) were included. The mean monthly seizure frequency was 3.20 ± 5.94. Six of ten patients started PER as a first add-on treatment. The final PER dose was 5.11 ± 2.02 mg/day, and nine of ten patients achieved seizure freedom at follow-up. There was a significant decrease in mean monthly seizure frequency from baseline to follow-up (p = 0.004). No significant changes were found in the sleep-wake cycle parameters. An increase in sleep latency mean was observed at MSLT at 6-month follow-up (p = 0.005).

CONCLUSIONS

This study confirms that adjunctive PER is effective on seizures without pathologically change of the sleep-wake cycle in PWE and can even improve daytime sleepiness. This effect can be mediated by the achievement of seizure control. Therefore, PER may be promising in PWE with sleep disturbances and daytime sleepiness.

The real-world effectiveness and safety of perampanel in Europe: A scoping review

In order to characterize the real-world effectiveness and safety of perampanel during clinical use in Europe, we conducted a structured literature search and scoping review of real-world studies conducted in Europe in adolescents (aged ≥ 12 years) or adults who were prescribed perampanel for focal epilepsy or primary generalized tonic-clonic seizures in the context of idiopathic generalized epilepsy, published between January 2016 and July 2021. We identified 29 relevant studies (20 retrospective and 9 prospective) in 3608 patients; median study duration was 12 months. Most patients (76.1%) were receiving two or more antiseizure drugs (ASDs) when perampanel was initiated. The maintenance perampanel dose ranged from 2 to 16 mg/day (most commonly 6 mg/day). Retention rate at 12 months ranged from 46% to 90.5% (median 71.1%). The proportion of patients who were free of seizures during perampanel ranged from 1.8% to 84.6%, but were consistently below 20% in studies where patients had received an average of ≥5 prior ASDs and above 20% where patients had received an average of <5 prior ASDs. The proportion of patients who achieved ≥50% reduction in seizures during perampanel ranged from 20.0% to 85.7%. Across all studies, the incidence of adverse events (AEs) ranged from 18.2% to 67.4% (median 37.1%) and discontinuation due to AEs from 6.2% to 56% (median 12.5%). Discontinuation rates tended to be higher in UK studies than in studies from Italy or Spain. The most commonly reported individual AEs were dizziness/vertigo (median incidence 13.7%), somnolence (median 11.9%), aggression (median 9.8%), irritability (median 9.1%), and cognitive deficits (median 7.0%). There was no relationship between the overall rate of AEs and perampanel dose, perampanel plasma levels, or number of concomitant medications. Our global overview of European observational studies with perampanel provides evidence that this agent is effective and safe in clinical practice in a range of countries, patients, and settings.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Movement disorders associated with antiseizure medications: A systematic review

New-onset movement disorders have been frequently reported in association with the use of antiseizure medications (ASMs). The frequency of specific motor manifestations and the spectrum of their semiology for various ASMs have not been well characterized. We carried out a systematic review of literature and conducted a search on CINAHL, Cochrane Library, EMBASE, MEDLINE, PsycINFO, and Scopus from inception to April 2021. We compiled the data for all currently available ASMs using the conventional terminology of movement disorders. Among 5123 manuscripts identified by the search, 437 met the inclusion criteria. The largest number of reports of abnormal movements were in association with phenobarbital, valproic acid, lacosamide, and perampanel, and predominantly included tremor and ataxia. The majority of attempted interventions for all agents were discontinuation of the offending drug or dose reduction which led to the resolution of symptoms in most patients. Familiarity with the movement disorder phenomenology previously encountered in relation with specific ASMs facilitates early recognition of adverse effects and timely institution of targeted interventions.

Perampanel add-on therapy for drug-refractory epilepsy: A single-center retrospective study based on 6-month treatment outcomes in Central China

OBJECTIVE

To systematically evaluate the efficacy, tolerability and retention of perampanel (PER) for treating drug-refractory epilepsy (DRE), and to investigate the independent factors affecting efficacy and retention. We hope this will provide clinicians with guidelines for the use of PER to treat patients with DRE.

METHODS

We conducted a single-center retrospective observational study of patients with DRE who received PER as add-on therapy at the Epilepsy Center of the People's Hospital of Henan Province, China, between 2020 Mar. and 2021 Sep. We collected clinical data from these patients. The observation period was 6 months. The observation endpoint is the drug response and retention rate at 6 months of PER use. Regression analyses were used to compare the differences in efficacy and retention rates, respectively.

RESULTS

Clinical data were obtained for 72 patients with DRE (mean duration of treatment: 10.6 months). At 6 months, 25% of patients (n = 18) were seizure free; 18.1% of patients (n = 13) remained seizure free for 6 months after the addition of PER. 22.2% of patients (n = 16) had a response (One of the patients was withdrawn 5 months after adding PER due to financial difficulties). The retention rate of PER at 6 months was 77.8%. Adverse effects tended to be dominated by neuropsychiatric symptoms. Multifactorial logistic regression analysis showed significant differences in whether the baseline seizure frequency exceeded 4 seizures/month (OR = 0.232, 95%CI: 0.077-0.702, p = 0.01) and whether the number of previously failed ASMs exceeded 3 (OR = 0.316; 95%CI:0.109-0.920, p = 0.035). This indicates that the risk of experiencing a nonresponse is higher with a higher baseline seizure frequency as well as with a higher number of previous ASM failures. Therefore, a baseline frequency exceeding four seizures/month and more than three previous ASM failures were independent influencing factors for PER addition treatment for patients with DRE. Multifactorial COX regression showed that patients with DRE due to infection had a lower retention rate (OR = 15.957, 95% CI: 3.692-68.972, P < 0.001) than patients with DRE due to other noninfectious etiologies. Patients with DRE who only had a single seizure type (OR = 0.053, 95% CI:0.006-0.476, P = 0.009), and patients who did not have cognitive impairment (OR = 134.253, 95% CI:5.623-3205.104, P = 0.002) showed longer durations of PER use. Infection-related epilepsy etiology, experiencing multiple types of seizures, and with cognitive impairment were independent influencing factors on PER use retention in patients with DRE.

CONCLUSION

Our study demonstrated the efficacy of PER for reducing seizure frequency in patients with DRE and found significant differences in efficacy and retention rate, respectively. This provides a basis for assessing the expected efficacy and duration of use of PER for patients with DRE.

Psychiatric and Behavioural Side Effects Associated With Perampanel in Patients With Temporal Lobe Epilepsy. A Real-World Experience

Psychiatric and behavioural side effects are common, undesirable effects associated with antiseizure medication use. Temporal lobe epilepsy is the most common focal epilepsy in adults and it is frequently associated with drug resistance. Patients with intractable epilepsy are more likely to have psychiatric and behavioural side effects when taking antiseizure medications and seem to be at higher risk for psychiatric comorbidities. Perampanel is a novel anti-seizure medication approved for focal and generalised epilepsies as add-on therapy. This is a 12-week short-term observational prospective study on people with focal epilepsy consecutively recruited from an Italian tertiary epilepsy centre, aimed to compare incidence and severity of psychiatric and behavioural side effects associated with perampanel use in patients with temporal lobe epilepsy as compared to other focal epilepsies. All patients received add-on perampanel according to indication and clinical judgement. Incidence and severity of psychiatric and behavioural side effects were rated by Neuropsychiatric Inventory Questionnaire. All patients enrolled answered the questionnaire before starting perampanel and after 12 weeks of treatment. We found no significant difference in terms of incidence and severity of psychiatric and behavioural side effects associated with perampanel in patients with temporal lobe epilepsy as compared to other focal epilepsies. In line with the literature, the most common adverse effects were “irritability” for both groups and “aggression” for patients with other focal epilepsies.

Perampanel may represent an effective treatment for the prevention of migraine comorbid with epilepsy

INTRODUCTION

Migraine is a common comorbidity in patients with epilepsy. Considering the proven associations and the common pathophysiological features linking epilepsy and migraine, some anti-seizure medications (ASMs) have been considered as a treatment for both disorders. This study aimed at assessing both the effectiveness of perampanel (PER) on epileptic seizures and migraine attacks in patients with epilepsy and comorbid migraine, as well as the reduction in the monthly mean rate usage of rescue migraine medications.

METHODS

This observational, multi-centre study included adult patients with epilepsy and comorbid migraine who started PER to better control epileptic seizures and who were followed up for 12 months.

RESULTS

Thirty-one patients were included (mean age 40.13 ± 13.13 years; 67.0% female). At the 12-month follow-up visit, 27 patients were continuing PER concomitantly with 1 (45.2%) or 2 ASMs (54.8%). A significant reduction in epileptic seizures, migraine attacks, and the monthly use of rescue migraine medications between baseline and both 6- and 12-month follow-up visits was documented.

CONCLUSION

PER demonstrated good effectiveness in reducing both epileptic seizures and migraine attacks in patients with comorbid epilepsy and migraine. Future studies with possibly larger samples are needed to evaluate the efficacy of PER in migraine other than epilepsy.

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

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

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.

Perampanel effectiveness and tolerability in patients with epilepsy at long-term follow-up

INTRODUCTION

The main of the present study was to assess the effectiveness and tolerability of perampanel (PER) in association with 1 or 2 concomitant antiseizure medications (ASMs) in patients with epilepsy throughout a follow-up period of 24 months or longer in a real-world setting.

METHODS

This retrospective, observational, multi-center study collected data from both underage (<18 years old) and adult patients who had started PER in association with 1 or 2 ASMs. Only patients who had started PER and were followed up for at least 24 months were included. Response to treatment was analyzed at the 24-, 36-, and 48-month visits by considering the last visit undergone by patients. Subgroup analyses were performed according to age, gender, and epilepsy type and patients were categorized following PER treatment in concomitance with 1 or 2 ASMs to evaluate the factors affecting the achievement of seizure freedom (SF) at the 24-month FU.

RESULTS

Ninety-four patients were included (mean age 36.89 years; 51.1% female). At the 24-month follow-up visit, 90 (95.74%) patients were still receiving PER concomitantly with 1 or 2 ASMs. The mean PER dose was 6.02 mg/day and SF was achieved by 33 (35.1%) patients. A significantly higher SF rate was found in patients who had started PER with only 1 ASM when compared to those who had started PER with 2 concomitant ASMs. Effectiveness was maintained also in the subgroups of patients with a 36- or 48-month follow-up visit. Adult patients had a higher final daily dosage of PER than underage patients. Logistic regression found that the lowest number of previously failed ASMs was associated with a higher SF rate (p = 0.036).

CONCLUSION

Perampanel demonstrated a good effectiveness in association with 1 or 2 ASMs in both pediatric and adult patients, without having to use a high dose of the drug. The possibility to present SF was higher when PER was added early. Finally, the maintenance of effectiveness was observed also in the subgroups of patients with a follow-up of 36 and 48 months.

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.

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.

Exploring the Evidence for Broad-Spectrum Effectiveness of Perampanel: A Systematic Review of Clinical Data in Generalised Seizures

BACKGROUND

The effectiveness of adjunctive perampanel has not been systematically assessed in seizure types other than its approved indications of focal seizures and primary generalised tonic-clonic seizures (PGTCS) in idiopathic generalised epilepsies (IGEs).

OBJECTIVE

We aimed to identify and review available evidence on outcomes with perampanel in generalised seizures and epilepsies to examine its potential as a broad-spectrum anti-seizure medication.

METHODS

Bibliographic databases of publications, clinical trials, and conference abstracts were searched up to August 2020 to identify studies reporting seizure or safety outcomes in patients of any age, with any type of epilepsy-associated generalised seizures treated with perampanel. Data extracted from selected records were tabulated by seizure type and syndrome, and analysed qualitatively (PROSPERO protocol CRD42020201564).

RESULTS

Ninety-one reports met inclusion criteria and were selected: 15 reports of 1 randomised controlled trial (RCT), 8 reports of 4 non-randomised interventional studies, 37 reports of observational studies, 21 case reports and 10 systematic reviews and meta-analyses. Extracted data included 359 patients with PGTCS of any aetiology, 251 with myoclonic seizures, 112 with absence seizures, 50 with tonic seizures and 32 children with epileptic spasms. The most commonly reported epilepsy type was IGE (N = 378) and the most common syndromes were juvenile myoclonic epilepsy (N = 92), progressive myoclonic epilepsies (N = 59) and absence epilepsies (N = 43). The RCT provided Class I evidence of the efficacy and tolerability of adjunctive perampanel for PGTCS in patients aged ≥ 12 years with IGE. Data from other studies provides weaker (observational) evidence of its effectiveness in multiple generalised seizure types, including myoclonic, absence and tonic seizures. There were no patterns suggesting seizure worsening or aggravation in any seizure or epilepsy type.

CONCLUSIONS

The identified studies suggest the potential of perampanel as a broad-spectrum antiseizure medication. Much of the available data, however, come from non-randomised, non-controlled studies and are open to high risk of bias. Further studies are warranted to provide more robust evidence.

Relationship between plasma concentrations and clinical effects of perampanel: A prospective observational study

PURPOSE

The purpose of the study was to investigate the potential correlation between plasma concentration of the newer antiseizure medication (ASM) perampanel (PMP) and both tolerability and seizure control in patients with epilepsy.

METHODS

The study design was multicenter, open, and prospective. Plasma samples were collected in the morning 12 h apart from once-a-day bedtime PMP dose. Perampanel tolerability was assessed on the day of drug monitoring by clinical examination and patients' interview. Response to PMP was defined as ≥50% reduction from baseline seizure frequency (pretreatment). The main outcomes were the comparisons of PMP plasma concentration-to-weight-adjusted dose ratio (C/D) [(μg/mL)/(mg/kg/day)] between patients with and without PMP-related adverse effects (AEs) and between responders and nonresponders.

RESULTS

Ninety-seven patients (54% men), mean ± SD age 36 ± 14 years were enrolled in the study. The mean PMP dose was 6.7 ± 2.3 mg, drug treatment averaged 46 ± 34 weeks. The mean plasma concentration was 360 ± 268 ng/mL (range: 37-1213 ng/mL). Forty patients (41%) reported at least one AE, mainly dizziness and behavioral changes. No significant difference was found in median PMP C/Ds between patients with (2.94) and without (2.76) AEs, otherwise comparable for clinical variables. Forty-four patients (45%) were responders, at a median PMP C/D of 3.10, similar to the value of 2.76 found in nonresponders. These two groups also overlapped for clinical characteristics.

CONCLUSION

This is the first prospective real-life study to evaluate the relationship between PMP plasma concentrations, seizure control, and AEs. In line with the few real-world available data, we did not find any significant correlation between PMP plasma concentrations and both tolerability and seizure control.

Perampanel as add-on therapy in epilepsies with known etiology: A single center experience with long-term follow-up

•

PER showed good efficacy for the treatment of epilepsies with known etiology.

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PER showed greater efficacy in patients with epilepsy due to a focal brain lesion .

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PER was globally well tolerated with a good profile of safety.

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EEG pattern , expression of a structural epilepsy, correlates with a better response.

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EEG pattern might help in the choice of correct antiseizure medication.

We report a retrospective monocentric study performed on 63 patients affected by epilepsy with known etiology, receiving perampanel as add-on therapy with at least 12-month follow-up. The purpose of our study was to evaluate efficacy and tolerability of perampanel in this group of epilepsies. Patients were classified into 2 groups based on the presence/absence of a single focal brain lesion on MRI, as epilepsy etiology: 48 subjects were affected by focal lesional epilepsy and 15 by non-focal lesional epilepsy. The retention rate was 76.2% and 53.9% at 12 and 24 months respectively. At 12 months, at least 40% of patients resulted responders, with a significant reduction in seizure frequency (p = 0.01), confirmed at 24 months. Considering epilepsy etiology, we found a better PER response in patients with focal lesional epilepsy. A significant correlation was observed between responder rates and EEG pattern. Only 30% of patients reported mild-moderate adverse events. Efficacy and tolerability of PER, in our study, are in line with the results reported in other real-world studies. Our data suggest the possibility of better PER response in patients with focal brain lesions, which indicates that this drug could be a therapeutic option in this population.

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.

Preliminary evidence about irritability in patients with epilepsy treated by perampanel as first add-on therapy compared to levetiracetam and valproic acid

Aims

Irritability has been described as a frequent adverse event in patients affected by epilepsy and treated with perampanel (PER), levetiracetam (LEV), and less frequently with valproic acid (VPA). Since the questionnaire for irritability (I‐EPI) is a validated instrument to measure this psychiatric manifestation in patients affected by epilepsy, in this study we aimed at investigating the effect of PER as first add‐on therapy on I‐EPI. Moreover, we compared the effectiveness and I‐EPI scores obtained at 12‐month follow‐up visits in patients treated by PER, LEV, or VPA in order to measure irritability as a consequence of these treatments.

Methods

We collected data from 17 patients treated by PER, 16 patients treated by LEV, and 16 patients under VPA treatment followed for 12 months.

Results

We did not document significant changes of I‐EPI questionnaire between baseline and follow‐up in the PER group. As concerning the comparison of I‐EPI among PER, LEV, and VPA groups, we documented lower global scores in PER than both LEV (P < 0.05) and VPA (P < 0.05) groups. Moreover, patients under PER treatment showed lower scores than LEV and VPA (P < 0.05) in I‐EPI items measuring the gentle personality, anxiety of having epileptic seizures in front of others, and irritability in thinking that they can have an epileptic seizure.

Conclusions

This retrospective study described a stable and possibly lower degree of irritability in patients starting PER than LEV and VPA treatments, although we documented the comparable effectiveness of PER, LEV, and VPA as first add‐on treatments in patients affected by uncontrolled epileptic seizures. However, the small sample of patients included in this study and the absence of I‐EPI scores obtained at baseline visits in LEV and VPA groups require further investigations to confirm this preliminary evidence.