Cenobamate as add-on therapy for drug resistant epilepsies: effectiveness, drug to drug interactions and neuropsychological impact. What have we learned from real word evidence?

Background: Cenobamate (CNB) is an anti-seizure medication (ASM) approved in 2021 in Europe for adjunctive treatment of focal-onset seizures in adults who were not adequately controlled with at least two previous ASMs. Methods: seizure outcome, treatment-emergent adverse events, neuropsychological profile, and blood levels of CNB and concomitant ASM were analyzed in a real world setting in two different Italian epilepsy centers in the context of CNB early access program. All patients performed a general cognitive evaluation, while 32 patients underwent the administration of a battery of neuropsychological tests at baseline and 6 months after CNB treatment. We performed CNB quantification in plasma in 31 patients at different doses in the range of 100-400 mg/day (65 measures). Results: we enrolled 54 patients with a median age of 27.9 years. The mean follow-up was 10.7 months. Most (91%) completed the efficacy analysis. At last follow-up visit, a 69.5% median seizure reduction was registered. Thirty-two patients (59.2%) had a ≥50% reduction of seizures that was ≥75% in 20 (42.0%) cases, whilst 10 (20.2%) patients were seizure-free. The most common adverse events were somnolence (53.1%), dizziness (28.1%) and diplopia (12.5%). The correlation between CNB dose and plasma concentration, revealed a significant linear correlation (r = 0.86, p < 0.0001), and there was a significant difference in mean plasma concentration/dose administered ratio (C/D ratio) between patients taking or not at least one inducer (0.10 ± 0.04 [(μg/mL)/(mg/day)]; n = 47 vs. 0.13 ± 0.05 [(μg/mL)/(mg/day)]; n = 18, p = 0.04). CNB dose was inversely correlated (r = -0.31, p = 0.02) to the C/D ratio of Carbamazepine blood levels. and positively correlated (r = 0.74, p < 0.0001) with an increased plasma concentration of the active Clobazam metabolite N-desmethylclobazam. General Anxiety Disorder-7 showed a significant improvement of score from baseline evaluation of 6.82 to follow-up 6 months evaluation of 4.53 (p = 0.03). Conclusion: In this real-world study, we registered a clinically meaningful reduction in seizure frequency after CNB administration in most patients along with a good tolerability profile. CNB treatment is correlate to a reduction in symptom severity of anxiety score. Plasma levels measurements confirm that CNB acts both as "victim" and as "perpetrator" of drug-drug interactions.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

SIGNIFICANCE

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

PLAIN LANGUAGE SUMMARY

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

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

OBJECTIVE

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

METHODS

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

RESULTS

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

SIGNIFICANCE

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

Efficacy and safety of perampanel monotherapy in Chinese patients with focal-onset seizures: A single-center, prospective, real-world observational study

OBJECTIVE

Efficacy and safety of perampanel monotherapy for treating focal-onset seizures (FOS) has been barely studied in China. This observational study aimed to evaluate the efficacy and safety of perampanel monotherapy in treating Chinese patients with FOS.

METHODS

This single-center, prospective, real-world observational study enrolled patients aged ≥4 years with FOS who visited the Epilepsy Out-Patient Clinic of Nanjing Brain Hospital affiliated to Nanjing Medical University from January 2020 to December 2021. All patients were treated with perampanel monotherapy. Seizure-freedom rates after 6 and 12 months of treatment were calculated. Adverse events (AEs) were recorded.

RESULTS

Seventy patients with FOS were enrolled. The mean maintenance perampanel dose was 4.64 ± 1.55 mg/day. The 6- and 12-month retention rates of perampanel monotherapy were 78.6% (55/70) and 70.0% (49/70), respectively. The 6- and 12-month seizure-freedom rates were 69.84% (44/63) and 65.08% (41/63), respectively. Patients with focal to bilateral tonic-clonic seizures had significantly higher 6-month and numerically higher 12-month seizure freedom rates than patients with focal impaired awareness seizures (P = 0.046 and P = 0.204, respectively). Twenty-six (37.1%) patients experienced treatment-emergent AEs, and the most common AE was dizziness. Four (5.7%) patients withdrew from the study due to AEs. No new safety concern was observed.

SIGNIFICANCE

This is the first prospective study on the efficacy and safety of perampanel monotherapy in treating Chinese patients with FOS, and perampanel monotherapy was effective and safe in treating Chinese patients aged ≥4 years with FOS up to 12 months. More multicenter, real-world studies with large sample sizes and longer follow-ups are needed to further evaluate the long-term efficacy and safety of perampanel monotherapy.

High-Grade Temporal Ganglioglioma in an Older Adult Woman

Ganglioglioma (GG) is a WHO-grade 1 glioneuronal neoplasm. It is well differentiated with a slow-growing pattern and is composed of a combination of neoplastic ganglion and glial cells. Anaplastic ganglioglioma (AGG) is an extremely rare malignant variant of ganglioglioma, which is not included in the new WHO classification; however, the term is used to talk about gangliogliomas with data of malignancy. AGGs usually occur in children and young adults and are associated with high recurrence and mortality. The authors describe the case of a 62-year-old woman with AGG. She presented with cacosmia, vertigo, nausea, and focal-onset seizures with secondary generalization. Magnetic resonance imaging (MRI) revealed an intra-axial lesion in the left temporal lobe. She underwent microsurgical resection guided by electrocorticography (ECoG), and a diagnosis of AGG based on microscopic morphology and immunohistochemical analysis was obtained. She was discharged a few days after surgery with subtotal resection of the lesion, no additional neurological deficit, and adequate seizure control. AGG is a very rare and poorly studied entity. It is currently a controversial term used to refer to gangliogliomas with signs of malignancy. It occurs mainly in children and young adults with temporal lobe epilepsy. Total resection is the best prognostic factor, given the unknown efficacy of radiotherapy and chemotherapy. In our case, the patient was an adult woman with a subtotal resection followed by concomitant radiotherapy and chemotherapy, obtaining a mean survival similar to that reported in the literature, so it can be thought that there is a benefit obtained with chemotherapy and radiotherapy despite having performed a subtotal resection of the lesion. Further studies are needed to establish clear diagnostic criteria for AGG, and a multicenter database of AGGs is necessary for a better understanding of the pathology and to offer the best treatment and prognosis.

Efficacy and safety of perampanel as early add-on therapy in Chinese patients with focal-onset seizures: a multicenter, open-label, single-arm study

Background

No interventional study has been conducted in China to assess efficacy and safety of perampanel in treating Chinese patients with epilepsy, nor has there been any study on perampanel early add-on therapy in China. This interventional study aimed to assess efficacy and safety of perampanel as an early add-on treatment of focal-onset seizures (FOS) with or without focal-to-bilateral tonic-clonic seizures (FBTCS) in Chinese patients.

Methods

In this multicenter, open-label, single-arm, phase 4 interventional study, Chinese patients ≥ 12 years old with FOS with or without FBTCS who failed anti-seizure medication (ASM) monotherapy from 15 hospitals in China were enrolled and treated with perampanel add-on therapy (8-week titration followed by 24-week maintenance). The primary endpoint was 50% responder rate. Secondary endpoints included seizure-freedom rate and changes in seizure frequency from baseline. Treatment-emergent adverse events (TEAEs) and drug-related TEAEs were recorded.

Results

The full analysis set included 150 patients. The mean maintenance perampanel dose was 5.9 ± 1.5 mg/day and the 8-month retention rate was 72%. The 50% responder rate and seizure-freedom rate for all patients during maintenance were 67.9 and 30.5%, respectively. Patients with FBTCS had higher 50% responder rate (96.0%) and seizure-freedom rate (76.0%) during maintenance. Patients on concomitant sodium valproate had a significantly higher seizure-freedom rate than those on concomitant oxcarbazepine. Eight-six (55.1%) patients experienced treatment-related TEAEs, and the most common TEAEs were dizziness (36.5%), hypersomnia (11.5%), headache (3.9%), somnolence (3.2%), and irritability (3.2%). Withdrawal due to TEAEs occurred to 14.7% of the patients.

Conclusion

Perampanel early add-on was effective and safe in treating Chinese patients≥12 years old with FOS with or without FBTCS.Clinical trial registrationwww.chictr.org.cn, Identifier ChiCTR2000039510.

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

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

Electroclinical markers to differentiate between focal and generalized epilepsies

Generalized-onset seizures originate at a point within the brain and rapidly engage bilaterally distributed networks, whilst focal-onset seizures originate within networks limited to one hemisphere which may be discretely localized or more widely distributed. Challenges in data capturing have resulted in a lack of consistency across incidence and prevalence studies for estimates of generalized versus focal epilepsies in population groups, with a preponderance of unclassified cases. Infants and young children can further challenge delineation due to variable expression at different stages of brain maturation and impaired ability to express sensory seizure semiology. Focal seizures are divided into those in which the affected person is aware and those with impaired awareness; these events can be motor or non-motor. Generalized seizures are also categorized as motor and non-motor, but loss of awareness occurs with most events. Delineation between generalized and focal epilepsies is important for ongoing management. EEG, neuroimaging and other investigations (genetics, immune markers, etc.) can support the outcome but distinction between focal and generalized epilepsy in isolation is rarely achieved using such techniques. Certain clinical settings such as age, underlying aetiologies, and co-morbidities may be more predisposed to specific types of epilepsy. The differentiation between generalized and focal seizures remains a clinical process based on meticulous clinical history and examination, and is of relevance for the selection of antiseizure medications and identification of patients who may be viable for epilepsy surgery.

Brivaracetam for the treatment of focal-onset seizures: pharmacokinetic and pharmacodynamic evaluations

INTRODUCTION

The goal of pharmacologic therapy with antiseizure medications (ASMs) is to achieve a seizure-free state with minimal side effects. About one third of patients treated with available ASMs continue to experience uncontrolled seizures. There is still need for new ASMs with enhanced effectiveness and tolerability.

AREAS COVERED

The present manuscript is based on an extensive Internet and PubMed search from 1999 to 2020. It is focused on the clinical and pharmacological properties of brivaracetam (BRV) in the treatment of epilepsy.

EXPERT OPINION

BRV is approved as add-on or monotherapy (in US) for the treatment of focal-onset seizures with or without secondary generalization. BRV is a high affinity synaptic vesicle glycoprotein 2A ligand, with 15-30-fold higher affinity than levetiracetam. The selectivity of BRV may be associated with fewer clinical adverse effects. BRV shares many of the pharmacokinetic characteristics of an ideal ASMs. Additionally, BRV has a low potential for clinically relevant drug-drug interactions. Its pharmacokinetic profile makes BRV a promising agent for the treatment of status epilepticus (SE). Although BRV is not approved for the treatment of SE, it has demonstrated promising preliminary results. Further studies are needed to explore the efficacy and tolerability of BRV in SE.

Pooled efficacy and safety of eslicarbazepine acetate as add-on treatment in patients with focal-onset seizures: Data from four double-blind placebo-controlled pivotal phase III clinical studies

Purpose

Pooled evaluation of the key efficacy and safety profile of eslicarbazepine acetate (ESL) added‐on to stable antiepileptic therapy in adults with focal‐onset seizures.

Methods

Data from 1703 patients enrolled in four phase III double‐blind, randomized, placebo‐controlled studies were pooled and analyzed. Following a 2 week titration period, ESL was administered at 400 mg, 800 mg, and 1200 mg once‐daily doses for 12 weeks (maintenance period). Pooled efficacy variable was standardized (/4 weeks) seizure frequency (SSF) analyzed over the maintenance period as reduction in absolute and relative SSF and proportion of responders (≥50% reduction in SSF). Pooled safety was analyzed by means of adverse events and clinical laboratory assessments.

Results

SSF was significantly reduced with ESL 800 mg (P < 0.0001) and 1200 mg (P < 0.0001) compared to placebo. Median relative reduction in SSF was 33.4% for ESL 800 mg and 37.8% for 1200 mg (placebo: 17.6%), and responder rate was 33.8% and 43.1% (placebo: 22.2%). ESL was more efficacious than placebo regardless of gender, geographical region, epilepsy duration, age at time of diagnosis, seizure type, and type of concomitant antiepileptic drugs (AED). Incidence of adverse events (AEs) and AEs leading to discontinuation was dose dependent. Most common AEs (>10% patients) were dizziness, somnolence, and nausea. The incidence of treatment‐emergent AEs (dizziness, somnolence, ataxia, vomiting, and nausea) was lower in patients who began taking ESL 400 mg (followed by 400 mg increments to 800 or 1200 mg) than in those who began taking ESL 600 mg or 800 mg.

Conclusions

Once‐daily ESL 800 mg and 1200 mg showed consistent results across all efficacy and safety endpoints, independent of study population characteristics and type of concomitant AEDs. Treatment initiated with ESL 400 mg followed by 400 mg increments to 800 or 1200 mg provides optimal balance of efficacy and tolerability.