Long-term efficacy and safety of perampanel as a first add-on therapy in patients with focal epilepsy: Three-year extension study

Perampanel reduces seizure frequency in patients with developmental and epileptic encephalopathy for a long term

Seizures in patients with developmental and epileptic encephalopathies (DEEs) are often highly resistant to various antiseizure medications. Perampanel (PER) is a novel antiseizure medication that non-competitively inhibits the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor and is expected to reduce seizure frequency not only for focal seizures and generalized tonic-clonic seizures (GTCS) but also for other seizure types. This study aimed to clarify the long-term therapeutic efficacy and tolerability of PER in patients with DEEs. We analyzed data regarding patients' background characteristics, medication retention, trends in seizure frequency, and adverse events obtained from 24 patients with DEEs who had been on PER treatment for 60 months. The retention rates were 62.5% and 46.9% at 12 and 60 months, respectively. At 60 months after PER initiation, the rate of patients with > 50% seizure reduction was 33.3%, 33.3%, 38.5%, 54.5%, 54.5%, and 36.4% among patients with atypical absence seizures, tonic seizures, focal seizures, GTCS, myoclonic seizures, and atonic seizures, respectively. The frequency of adverse events was 70.8%. PER showed long-term efficacy in various seizure types. PER is a promising treatment option for patients with DEEs.

Long-term treatment with Perampanel of Chinese patients with focal-onset seizures, especially in sleep-related epilepsy: a prospective real-world observational study

Background

There is currently a lack of studies examining the long-term therapeutic effectiveness of the third-generation anti-sezure medication, perampanel (PER), for focal-onset seizures (FOS), particularly in Chinese patients with sleep-related epilepsy (SRE). Additionally, the appropriate dosage, plasma concentration, and the relationship between dose and plasma concentration of PER in Chinese patients are still uncertain.

Methods

A prospective, single-center, 24-month observational study was conducted in patients diagnosed with FOS, with a focus on patients with SRE. Changes in seizure frequency from baseline, adverse events, and retention rates were analyzed at 12 and 24 months following the start of the treatment. Tolerability was evaluated based on adverse events and discontinuation profiles. PER plasma concentrations were used to assess dose-concentration-response relationships.

Results

A total of 175 patients were included (median age: 25 years; range: 4-72 years; 53. 1% males and 46.9% females), with the SRE population accounting for 49. 1% (n = 86). The patients diagnosed with SRE showed considerably higher response rates than those who did not have this diagnosis (p = 0.025, odds ratio = 3.8). Additionally, the SRE group adhered better to PER treatment (r = 0.0009). Patients with a shorter duration of epilepsy (median: 3 years; range:2-7 years) demonstrated a more favorable therapeutic response to PER (p = 0.032). Throughout the administration of maintenance doses, among the entire FOS population, the concentration of PER (C0) ranged between 101.5 and 917.4 ng/mL (median, 232.0 ng/mL), and the mean plasma concentration of PER in the responders was 292.8 ng/mL. We revealed a linear relationship between PER dose and plasma concentration, regardless of whether PER was used as monotherapy or add-on therapy. The retention rates were 77.7% and 65. 1% at 12 and 24 months, respectively. Drug-related adverse events occurred in 45.0% of the patients and were mostly manageable.

Conclusion

PER effectively reduced seizure frequency in Chinese patients with FOS, particularly in those with SRE, over a 24-month period. The treatment was well-tolerated and had a clear linear dose-plasma concentration relationship.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Mining and analysis of adverse drug reactions associated with perampanel based on FAERS database

INTRODUCTION

Perampanel (PER) is a non-competitive AMPA glutamate receptor antagonist used as an anti-seizure medication. Large post-marketing databases are still lacking for safety analysis of the new generation of anti-seizure medications. Based on the FDA's adverse event reporting system (FAERS) database, this study aimed to investigate, assess, and offer evidence for the safety of PER to support clinical decision-making.

METHODS

Perampanel-related adverse reaction signals were mined using the reporting odds ratio (ROR), medicines and healthcare products regulatory agency (MHRA), and Bayesian confidence propagation neural network (BCPNN). The rate and occurrence of reported adverse responses were examined.

RESULTS

With the three methodologies used in combination, 83 signals mostly related to psychosis and different nervous system disorders were detected. Among them, suicide behavior, respiratory depression, hepatotoxicity, cognitive impairment, and other possible novel signals warranted consideration. Further examination of the age and gender differences in the detected signals revealed that elderly patients should be closely monitored for any change in consciousness and the occurrence of movement disorders; male patients should be observed for negative mental reactions like a personal attack and homicidal ideation; and female patients should be watched for the occurrence of negative reactions in memory, weight, vision, liver function, and other specific areas.

CONCLUSIONS

This study found that PER had the risk of causing suicide behavior, respiratory depression, hepatotoxicity, and cognitive impairment among other adverse effects. When used clinically, PER should be closely monitored for the occurrence of adverse effects on mental health and behavior. However, these results should be interpreted with caution.

Perampanel outcomes at different stages of treatment in people with focal and generalized epilepsy treated in clinical practice: Evidence from the PERMIT study

Introduction

The PERMIT study is the largest pooled analysis of perampanel (PER) clinical practice data conducted to date.

Methods

This post-hoc analysis of PERMIT investigated the effectiveness, safety and tolerability of PER when used as early add-on therapy (after failure of one or two previous antiseizure medications) in comparison with late add-on therapy (after failure of three or more previous antiseizure medications). Retention and effectiveness were assessed after 3, 6, and 12 months, and at the last visit (last observation carried forward). Effectiveness was assessed by seizure type (total seizures, focal seizures, generalized tonic-clonic seizures [GTCS]) and assessments included seizure freedom rate and responder rate. Safety and tolerability were assessed by evaluating adverse events (AEs) and discontinuation due to AEs.

Results

The Full Analysis Set included 1184 and 2861 PWE treated with PER as early and late add-on therapy, respectively. Compared to the late add-on subgroup, the early add-on subgroup was characterized by later mean age at epilepsy onset, shorter mean duration of epilepsy, lower rates of intellectual disability and psychiatric comorbidity, and lower frequency of seizures per month, suggesting a less severe form of epilepsy in this subgroup. After 12 months, retention was significantly higher in the early versus late add-on subgroup (67.7% vs. 62.4%; p = 0.004). At the last visit, responder rates in the early versus late add-on subgroup were significantly higher for total seizures (68.2% vs. 39.3%; p < 0.001), focal seizures (65.0% vs. 36.8%; p < 0.001) and GTCS (83.7% vs. 67.2%; p < 0.001), as were seizure freedom rates (total seizures, 35.9% vs. 11.9% [p < 0.001]; focal seizures, 29.4% vs. 8.7% [p < 0.001]; GTCS, 69.0% vs. 48.1% [p < 0.001]). Incidence of AEs was significantly lower in the early versus late add-on subgroup (42.1% vs. 54.7%; p < 0.001), as was the rate of discontinuation due to AEs over 12 months (15.0% vs. 18.1%; p = 0.031).

Discussion

This study demonstrated that PER was effective and generally well tolerated when initiated as early or late add-on therapy, but it was significantly more effective and better tolerated when initiated early. These findings support PER's use as a broad-spectrum, early add-on therapy for use in PWE with focal and generalized seizures.

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.

Effectiveness and safety of perampanel as adjunctive therapy among Chinese patients with focal-onset epilepsy: A real-world prospective observational study

OBJECTIVE

Perampanel (PER) has previously been shown to be effective and tolerable when used as an adjunctive therapy for patients with focal-onset seizures (FOS). This study aimed to evaluate the effect of PER as adjunctive therapy for patients with FOS in the Chinese population under real-world conditions for 1 year.

METHODS

A prospective, single-center, 1-year observational study was conducted at Huashan Hospital, enrolling both under age (≥4 years old) and adult patients with FOS. Response to PER was assessed at 3-, 6-, and 12-month checkpoints by analyzing the 50 % responder rate, the seizure-free rate, and reduction in seizure frequency.

RESULTS

One hundred and eight patients (mean age: 26.6 years, 56.5 % males) with FOS were included, with seventy-six patients finishing the 1-year follow-up (retention rate: 70.4 %, mean PER dose: 4.3 mg/day). The seizure frequency was reduced significantly at 3, 6, and 12 months relative to baseline (p < 0.001 for each seizure type). At 12 months, the responder rate was 65.8 %, and the seizure-free rate was 39.5 %. A significantly higher responder rate was found in patients with focal to bilateral tonic-clonic seizures (p = 0.024), among which the percentage of patients with sleep-related epilepsy was significantly high (p = 0.045). Responders had a lower number of concomitant anti-seizure medications (ASMs) than the non-responders (p = 0.009). Drug-related adverse events (AEs) were reported in 37 % of patients, mostly mild or moderate, and the patients who experienced AEs had a higher daily dose of PER than those who did not (p = 0.026).

CONCLUSION

Perampanel, an add-on therapy for focal-onset seizures, was found to be effective and tolerable in Chinese patients at 12 months.

Safety evaluation of perampanel as monotherapy or first adjunctive therapy in patients with epilepsy

INTRODUCTION

There is a need for anti-seizure medications (ASMs) that are well tolerated and effective as monotherapy or first adjunctive therapy to reduce the need for adjunctive ASMs to treat newly diagnosed epilepsy, and to reduce the number of concomitant ASMs in patients with refractory epilepsy. Although the pivotal trials of perampanel evaluated its adjunctive use in patients with refractory seizures, open-label/real-world studies support its use in first/second-line settings.

AREAS COVERED

This paper reviews the pharmacology, efficacy, and safety/tolerability of perampanel, focusing on its use as monotherapy or first adjunctive therapy. The safety of perampanel in special populations and its safety/tolerability compared with that of other ASMs is also discussed.

EXPERT OPINION

Perampanel is a favorable candidate for initial or first adjunctive therapy due to its favorable efficacy and safety/tolerability as monotherapy and adjunctive therapy, its long half-life and ease of use, and its limited drug-drug interactions. The proposed mitigation strategies for managing the risk of serious psychiatric adverse events are appropriate patient selection, use of low doses, and slow titration. The growing body of evidence might shift current treatment strategies towards the early use of perampanel and its use at a low dose (4 mg/day).