Efficacy and safety of perampanel monotherapy in patients with focal-onset seizures with newly diagnosed epilepsy or recurrence of epilepsy after a period of remission: The open-label Study 342 (FREEDOM Study)

Effects of CYP3A5*3 genetic polymorphisms on the pharmacokinetics of perampanel in Chinese pediatric patients with epilepsy

PURPOSE

This study was the first to evaluate the effect of CYP3A5*3 gene polymorphisms on plasma concentration of perampanel (PER) in Chinese pediatric patients with epilepsy.

METHODS

We enrolled 98 patients for this investigation. Plasma PER concentrations were measured using liquid chromatography-tandem mass spectrometry. Leftover samples from standard therapeutic drug monitoring were allocated for genotyping analysis. The primary measure of efficacy was the rate of seizure reduction with PER treatment at the final checkup.

RESULTS

The plasma concentration showed a linear correlation with the daily dose taken ( r  = 0.17; P  < 0.05). The ineffective group showed a significantly lower plasma concentration of PER (490.5 ± 297.1 vs. 633.8 ± 305.5 μg/ml; P  = 0.019). For the mean concentration-to-dose (C/D) ratio, the ineffective group showed a significantly lower C/D ratio of PER (3.2 ± 1.7 vs. 3.8 ± 2.0; P  = 0.040). The CYP3A5*3 CC genotype exhibited the highest average plasma concentration of PER at 562.8 ± 293.9 ng/ml, in contrast to the CT and TT genotypes at 421.1 ± 165.6 ng/ml and 260.0 ± 36.1 ng/ml. The mean plasma PER concentration was significantly higher in the adverse events group (540.8 ± 285.6 vs. 433.0 ± 227.2 ng/ml; P  = 0.042).

CONCLUSION

The CYP3A5*3 gene's genetic polymorphisms influence plasma concentrations of PER in Chinese pediatric patients with epilepsy. Given that both efficacy and potential toxicity are closely tied to plasma PER levels, the CYP3A5*3 genetic genotype should be factored in when prescribing PER to patients with epilepsy.

Effects of CYP3A4 genetic polymorphisms on the pharmacokinetics and efficacy of perampanel in Chinese pediatric patients with epilepsy

OBJECTIVE

This study was the first to evaluate the effect of CYP3A4 gene polymorphisms on the plasma concentration and effectiveness of perampanel (PER) in Chinese pediatric patients with epilepsy.

METHODS

We enrolled 102 patients for this investigation. The steady-state concentration was determined after patients maintained a consistent PER dosing regimen for at least 21 days. Plasma PER concentrations were measured using liquid chromatography-tandem mass spectrometry. Leftover samples from standard therapeutic drug monitoring were allocated for genotyping analysis. The primary measure of efficacy was the rate of seizure reduction with PER treatment at the final check-up.

RESULTS

The CYP3A4×10 GC phenotype exhibited the highest average plasma concentration of PER at 491.1 ± 328.1 ng/mL, in contrast to the CC phenotype at 334.0 ± 161.1 ng/mL. The incidence of adverse events was most prominent in the CYP3A4×1 G TT and CYP3A4×10 GC groups, with rates of 77.8 % (7 of 9 patients) and 50.0 % (46 of 92 patients), respectively. Moreover, the percentage of patients for whom PER was deemed ineffective was least in the CYP3A4×1 G TT and CYP3A4×10 CC groups, recorded at 11.1 % (1 of 9 patients) and 10.0 % (1 of 10 patients), respectively. There was a significant correlation between PER plasma concentration and either exposure or toxicity (both with p < 0.05). We suggest a plasma concentration range of 625-900 ng/mL as a suitable reference for PER in Chinese patients with epilepsy.

CONCLUSION

The CYP3A4×10 gene's genetic polymorphisms influence plasma concentrations of PER in Chinese pediatric patients with epilepsy. Given that both efficacy and potential toxicity are closely tied to plasma PER levels, the CYP3A4 genetic phenotype should be factored in when prescribing PER to patients with epilepsy.

Perampanel as monotherapy or first adjunctive therapy in pediatric and adult patients with epilepsy: the first United States-based phase IV open-label ELEVATE study

ELEVATE (Study 410; NCT03288129) is the first prospective, multicenter, open-label, Phase IV study of perampanel as monotherapy or first adjunctive therapy in patients aged ≥ 4 years with focal-onset seizures or generalized tonic-clonic seizures in the United States. The study included Screening, Titration (≤ 13 weeks), Maintenance (39 weeks), and Follow-up (4 weeks) Periods. During Titration, perampanel was initiated at 2 mg/day and up-titrated to 4 mg/day at Week 3. Depending on response and tolerability, optional up-titrations to a maximum of 12 mg/day occurred. The primary endpoint was retention rate; additional endpoints included seizure-freedom rate, 50% responder rate, and incidence of treatment-emergent adverse events (TEAEs). At baseline, 10 (18.5%) patients were assigned to the monotherapy group and 44 (81.5%) patients to the first adjunctive therapy group. However, due to the addition of an anti-seizure medication along with perampanel on the first day of treatment, one patient was excluded from the monotherapy subgroup analyses. The mean perampanel exposure duration was 39.8 weeks and 32 (59.3%) patients completed the study. Retention rate at 12 months (or study completion) was 63.0% (monotherapy, 77.8%; first adjunctive therapy, 59.1%). Seizure-freedom rate during the Maintenance Period was 32.7% (monotherapy, 44.4%; first adjunctive therapy, 29.5%) and the 50% responder rate was 78.7% (monotherapy, 85.7%; first adjunctive therapy, 76.9%). TEAEs and serious TEAEs were reported by 88.9% (n = 48/54) and 7.4% (n = 4/54) of patients, respectively. Overall, the efficacy and safety of perampanel as monotherapy or first adjunctive therapy support the use of perampanel as early-line treatment for epilepsy.

Serum perampanel levels in patients with seizures are not affected by hemodialysis

Perampanel belongs to a novel class of antiseizure medications (ASMs). Studies examining the effect of hemodialysis on perampanel serum levels in clinical settings are lacking. We aimed to evaluate the changes in serum perampanel levels during hemodialysis. We studied patients with seizures who received oral perampanel between April 2020 and March 2023 and whose serum concentration of perampanel was measured before and after hemodialysis. We analyzed the serum concentrations of levetiracetam and lacosamide for comparison. Fourteen patients, with a mean age of 76.1 ± 7.88 years, were included. The dose of perampanel was 2.14 ± 1.27 mg. The hemodialysis clearance rate of perampanel, levetiracetam, and lacosamide was 0 ± 13%, 69 ± 11%, and 59.6 ± 8.2%, respectively. The post-dialysis CD ratio decreased significantly with levetiracetam but not with perampanel. Adverse but acceptable effects of perampanel were observed in two patients. The serum concentrations of several ASMs have been shown to be reduced during hemodialysis. Our study revealed that the serum perampanel concentration does not decrease during hemodialysis. Owing to the low rate of adverse effects and the stability of perampanel serum concentration during hemodialysis, perampanel could be a favorable choice as an ASM for patients with seizures undergoing hemodialysis. PLAIN LANGUAGE SUMMARY: Our study looked at how hemodialysis affects the serum levels of perampanel, a new type of medication for seizures. In 14 patients who started treatment between April 2020 and March 2023, perampanel serum levels did not decrease during hemodialysis, unlike other seizure medications. This shows that perampanel can be a good option for patients with seizures who need hemodialysis, with fewer side effects compared to other medications.

Population pharmacokinetics and dosing optimization of perampanel in children with epilepsy: A real-world study

OBJECTIVE

The purposes of this study were to explore the pharmacokinetics of perampanel (PER) in children with epilepsy, identify factors that contribute to pharmacokinetic variations among subjects, evaluate the connection between PER exposure and clinical outcome, and establish an evidence-based approach for tailoring individualized antiepileptic treatment in this specific population.

METHODS

In this prospective study, PER plasma concentrations and genetic information on metabolic enzymes were obtained from 194 patients younger than 18 years. The disposition kinetics of PER in pediatric patients following oral dosing were characterized using nonlinear mixed effect models. The effective range for the plasma concentration of PER was determined by assessing the efficacy and safety of PER treatment and analyzing the relationship between drug exposure and clinical response. Monte Carlo simulations were then performed to evaluate and optimize the current dosing regimens.

RESULTS

The pharmacokinetic profile of PER was adequately described by a one-compartment model with first-order absorption and elimination. Body weight, total bilirubin level, and concomitant oxcarbazepine were found to have significant influences on PER pharmacokinetics. Model estimates of apparent clearance and volume of distribution were .016 ± .009 L/h/kg and 1.47 ± .78 L/kg, respectively. The effective range predicted from plasma concentration data in responders was 215-862 μg/L. Dosing scenarios stratified according to essential covariates were proposed through simulation analysis.

SIGNIFICANCE

In this study, we captured the pharmacokinetic/pharmacodynamic characteristics of PER in pediatric epilepsy patients through analysis of real-world data and adopted a pharmacometric approach to support an individualized dosing strategy for PER in this specific population.

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.

Investigating the Effects of Perampanel on Autophagy-mediated Regulation of GluA2 and PSD95 in Epilepsy

Epilepsy is a chronic neurological disorder characterized by recurrent seizures. Despite various treatment approaches, a significant number of patients continue to experience uncontrolled seizures, leading to refractory epilepsy. The emergence of novel anti-epileptic drugs, such as perampanel (PER), has provided promising options for effective epilepsy treatment. However, the specific mechanisms underlying the therapeutic effects of PER remain unclear. This study aimed to investigate the intrinsic molecular regulatory mechanisms involved in the downregulation of GluA2, a key subunit of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors, following epileptic seizures. Primary mouse hippocampal neurons were cultured and subjected to an epilepsy cell model. The expression levels of GluA2 and autophagy-related proteins were assessed using Western blotting and real-time fluorescent quantitative PCR. Immunofluorescence and immunohistochemistry techniques were employed to investigate the nuclear translocation of CREB-regulated transcriptional coactivator 1 (CRTC1). Additionally, status epilepticus animal models were established to further validate the findings. The epilepsy cell model exhibited a significant decrease in GluA2 expression, accompanied by elevated levels of autophagy-related proteins. Immunofluorescence analysis revealed the nuclear translocation of CRTC1, which correlated with the expression of autophagy-related genes. Treatment with an autophagy inhibitor reversed the decreased expression of GluA2 in the epilepsy cell model. Furthermore, the calcium/calmodulin-dependent protein phosphatase inhibitor FK506 and CaN overexpression affected the dephosphorylation and nuclear translocation of CRTC1, consequently influencing GluA2 expression. Animal model results further supported the involvement of these molecular mechanisms in epilepsy. Our findings suggest that the downregulation of GluA2 following epileptic seizures involves the activation of autophagy and the regulation of CRTC1 nuclear translocation. These intrinsic molecular regulatory mechanisms provide potential targets for developing novel therapeutic strategies to alleviate refractory epilepsy and preserve cognitive functions in patients.

Effectiveness and safety of mono- and add-on perampanel in pediatric patients with epilepsy: Experience from a single-center retrospective study

OBJECTIVE

To evaluate the effectiveness and safety of perampanel (PER) monotherapy (MT) or add-on therapy (AT) in Chinese children with epilepsy, as well as to evaluate the data from routine therapeutic drug monitoring (TDM) of PER for these pediatric patients.

METHODS

This retrospective and observational study was carried out on children with epilepsy (n = 340) from 2020 to 2022 at the Children's Hospital of Nanjing Medical University. Outcome measures were the responder rate (50% or greater seizure reduction), long-term efficacy, and tolerability (number and types of adverse events) in MT and AT groups. Concentrations of plasma PER obtained from these patients, if available, were analyzed too.

RESULTS

A total of 279 patients achieved at least 3 months of therapy, and 58.1% responded to PER therapy. 53 of the responders were seizure-free (32.7%). The retention rate dropped from 88.0% at 3 months to 40.6% at 12 months after treatment. Patients with MT achieved better seizure control than those with AT (P < 0.001). Intriguingly, PER exerted a very weak effect on patients who took more than 2 ASMs or were diagnosed with drug-resistant epilepsy. There were no significant differences in tolerability between the two groups. In addition, 179 patients were routinely monitored for PER, and the trough concentrations (C0 ) for these patients ranged from 30.0 to 992.0 ng/mL. However, no significant difference in C0 was observed between responders and nonresponders (333 ng/mL vs 325.5 ng/mL, P = 0.264).

SIGNIFICANCE

This study provides effectiveness and safety data on Chinese children with epilepsy treated with PER either as MT or as AT. The efficacy of patients receiving MT was much better than cases administered with more than 2 ASMs or diagnosed with drug-resistant epilepsy. In addition, no association was found between the plasma PER concentration and efficacy or safety.

PLAIN LANGUAGE SUMMARY

The study reports the effects of perampanel on seizures and adverse effects in Chinese patients with epilepsy younger than 18 years. Seizures decreased in 58.1% of patients (responders); in a third of these responders, seizures stopped. After treatment was started, 88% of patients were still on perampanel at 3 months and 40.6% at 12 months. People who were treated with perampanel only were more likely to respond than those who received perampanel and other antiseizure treatments, although perampanel was tolerated equally well in these groups. Plasma perampanel concentration did not predict seizure response or adverse effects.

Plasma Concentration, Efficacy, and Tolerability of Perampanel in Chinese Pediatric Patients with Epilepsy: Real-World Clinical Experience

BACKGROUND

Information on the efficacy and plasma concentration of perampanel (PER) in Chinese pediatric patients with epilepsy is limited. Therefore, this real-world retrospective study aimed to assess the efficacy, tolerability, and plasma concentration of the maximum dose of PER for epilepsy treatment in Chinese pediatric patients.

METHODS

A total of 107 pediatric patients from 2 hospitals in China were enrolled in this study. The plasma concentration of PER was determined using ultrahigh-performance liquid chromatography. The primary efficacy endpoint was the seizure reduction rate after PER treatment at the last follow-up.

RESULTS

The response rate to PER therapy was 59.8% (64/107). The authors observed that patients younger than 6 years of age (n = 49) showed a significantly lower concentration-to-dose ratio than patients with ages between 6 and 14 years (n = 58) (2.2 ± 1.7 vs. 3.0 ± 1.8 mcg·mL -1 ·kg·mg -1 , respectively; P < 0.05). Patients who received enzyme-inducing antiseizure medication had significantly lower concentration-to-dose ratios than those who did not receive enzyme-inducing antiseizure medication (EIASM) (2.1 ± 1.8 vs. 3.1 ± 2.0 mcg·mL -1 ·kg·mg -1 , P < 0.05). A total of 37 patients (34.6%) reported treatment adverse events. Patients with somnolence and irritability had a significantly higher PER plasma concentration than the "no treatment-emergent adverse effect" groups ( P < 0.05).

CONCLUSIONS

PER is an effective and well-tolerated treatment option for patients with epilepsy. To ensure the clinical efficacy and safety of PER in pediatric patients, it is necessary to monitor its plasma concentrations.

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.

Perampanel and lacosamide monotherapy in pediatric patients with newly diagnosed focal epilepsy: A prospective study evaluating efficacy, tolerability, and behavior

PURPOSE

Perampanel (PER) and lacosamide (LCM) are the new third-generation anti-seizure medications (ASMs) that were approved for the monotherapy of focal epilepsy in children over four years of age in China, in 2021. Very few studies have analyzed the application of PER monotherapy among pediatric patients aged ≥four years, and no study compared the efficacy and tolerability of PER monotherapy with LCM monotherapy in pediatric patients with focal epilepsy. The present study aimed to investigate the efficacy, tolerability, and effect on behavior and emotion of PER and LCM as monotherapy in pediatric patients with newly diagnosed focal epilepsy, which is beneficial for clinicians to have more choices to treat pediatric patients with focal epilepsy.

METHODS

This was a prospective, single-center, observational study that involved pediatric patients (disease onset age ≥four years) with newly diagnosed focal epilepsy treated with PER or LCM as primary monotherapy. Outcomes included retention, being responders, and seizure-free rates after 3, 6, and 12 months. Adverse events (AEs) were noticed throughout the follow-up period. Behavioral outcomes were evaluated with Achenbach Child Behavior Checklist (CBCL/4-16) at baseline and after three and six months.

RESULTS

Using randomization, 60 patients receiving PER (31 females, 29 males, median age: 7.79 [5.34, 10.16] years, median dose: 3.0 [2.0, 4.0] mg/day) and 60 patients receiving LCM (25 females, 35 males, median age: 7.72 [5.91, 10.72] years, median dose: 150.0 [100.0, 200.0] mg/day) were enrolled in the study. At the 12-month follow-up, the retention rates in the PER and LCM groups, both were 90.4%, and the responder rates were 65.4% and 71.2%, while seizure-free rates were 57.7% and 67.3%, respectively. There were no significant differences in the retention, responder and seizure-free rates between the two groups (P > 0.05). There were no significant differences in the responder rates between patients with BECTS, abnormal brain magnetic resonance imaging (MRI), or types of seizure in the two groups (P > 0.05). In the PER group, 28.8% (15/52) of patients experienced AEs, of which the most frequently reported were irritability (n = 7; 13.5%), dizziness (n = 5; 9.6%), somnolence (n = 3; 5.8%), ataxia (n = 1; 1.9%), headache (n = 1; 1.9%), and rash (n = 1; 1.9%). In the LCM group, 15.4% (8/52) of the patients had AEs, including headache (n = 4; 7.5%), dizziness (n = 4; 7.5%), nausea (n = 2; 3.8%), somnolence (n = 2; 3.8%), irritability (n = 1; 1.9%), stomach ache (n = 1; 1.9%), and vomiting (n = 1; 1.9%). The incidence of irritability was significantly higher in the PER group than in the LCM group (13.5% vs. 1.9%, P = 0.031), which occurred mainly within eight weeks after drug administration. Patients with irritability were not dangerous to surrounding people by the assessment of parental observation in the life. And the symptoms were relieved spontaneously within a few months. The outcomes of total scores, internalizing scores, and externalizing scores of the CBCL did not show statistically significant differences in the PER and LCM groups between baseline and three and six months. Characteristics of behavior and emotion did not have substantial changes in patients treated with PER and LCM monotherapy.

CONCLUSIONS

The present study documented similar good effectiveness and good tolerance of PER and LCM as monotherapy in pediatric patients with newly diagnosed focal epilepsy and showed no behavioral or emotional impact, as assessed by the CBCL. Though the incidence of irritability with PER monotherapy may be higher than that with LCM monotherapy soon after medication initiation, this side effect appears to resolve spontaneously within a few months. At present, this study was the first research about PER and LCM monotherapy in pediatric patients with newly diagnosed focal epilepsy evaluating efficacy, tolerability, and behavior in China.

Comparison of the effectiveness and safety of perampanel and oxcarbazepine as monotherapy in children and adolescents with newly diagnosed focal epilepsy

Objective: This study aims to compare the effectiveness and safety of perampanel and oxcarbazepine as monotherapy in children with focal epilepsy (FE). Methods: This is an ambispective, single-center, non-inferiority study comparing the effectiveness and safety of perampanel (PER) monotherapy and oxcarbazepine (OXC) monotherapy in children with newly diagnosed FE. The primary endpoint was a six-month seizure freedom rate. The secondary endpoints included retention, responder, and seizure freedom rates at 3, 6, and 12 months, respectively. Adverse events (AEs) were also recorded for both groups. Results: One hundred and thirty children and adolescents aged from 4 to 18years newly diagnosed with FE between May 2020 and November 2022 in Wuhan Children's Hospital were included. There were 71 patients in the PER group and 59 patients in the OXC group. In the per protocol set (PPS), 50 (78.1%) in the PER group and 43 (78.2%) in the OXC group completed six months of treatment without seizures. The lower 95% CI (66.0%-87.5%) limit of PER was higher than the non-inferiority margin of 62.4% (80% of the 6-month seizure freedom rate in the OXC group); PER was non-inferior to OXC. The 3-month and 12-month seizure freedom rates were 77.1% and 82.9% for the PER group, respectively, while they were 80.4% and 75.8% for the OXC group. There were no serious adverse events in both groups. Conclusion: PER showed comparable effectiveness and safety compared with OXC in children with newly diagnosed focal epilepsy, which might be an effective and safe treatment for children and adolescents with newly diagnosed FE. Clinical Trial Registration: Identifier ChiCTR2300074696.

Efficacy and safety of perampanel monotherapy in patients with focal-onset seizures:A real-world experience in eastern China

OBJECTIVE

To assess the effectiveness and tolerability of perampanel (PER) monotherapy in real-world practice for the treatment of focal-onset seizures (FOS) in eastern China.

METHOD

This is a single-center, retrospective study of patients with FOS, aged ≥ 4 years, who had been prescribed PER as monotherapy. Outcomes included retention, seizure-free, and responder rates at 3, 6 and 12 months and adverse events (AEs) throughout the follow-up period. The efficacy and AEs of PER monotherapy in patients with aged < 14 years old and ≥ 14 years old were also compared.

RESULTS

Sixty-seven patients with FOS who received PER monotherapy and completed a one-year follow-up were included in the analysis. The median maintenance dose was 4 mg. Modified intent-to-treat analysis demonstrated that the retention rates of PER monotherapy at follow-up of 3, 6 and 12months were 75%, 70% and 63%, respectively. At the same points, seizure-free rates of PER monotherapy were 69%, 63% and 52%, and responder rates were 69%, 66% and 61%, respectively. Patients with sleep-related seizures had higher seizure-free rates at 12 months of follow-up. No significant difference in seizure-free and responder rates was found between the aged < 14 years old and the aged ≥ 14 years old. Twenty-one patients (31.3%) had AEs and five patients discontinued using PER because of intolerant AEs. Common AEs were dizziness, irritability and somnolence. The AEs rate in patients < 14 years was 17.9%, significantly lower than patients ≥ 14 years.

CONCLUSIONS

Our findings revealed the real-world data of patients in eastern China with FOS using PER as monotherapy. Patients had good retention, seizure-free and responder rates, and relatively low AEs rate at a low dose of PER treatment.

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.

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.

Effectiveness and tolerability of perampanel monotherapy in children with newly diagnosed focal epilepsy

Objective

To examine the clinical effectiveness and tolerability of perampanel (PER) as initial monotherapy in pediatric patients with newly diagnosed focal epilepsy.

Methods

A retrospective analysis was conducted on 62 children with newly diagnosed focal epilepsy who were treated with PER at the Epilepsy Center of Jinan Children's Hospital from July 2021 to July 2022. The treatment status, prognosis, and adverse reactions were followed up for a minimum of 6 months after the initiation of PER monotherapy. The effectiveness of the patients was estimated by the PER effective rate at 3-, 6-, and 12-month follow-up evaluations and adverse reactions were also recorded. The effective rates of PER in different etiologies and epilepsy syndromes were also statistically analyzed.

Results

The effective rates of PER treatment at the different time points of evaluation were 88.7% (3 months), 79.1% (6 months), and 80.4% (12 months). With PER treatment, seizure freedom varied over time, with 61.3%, 71.0%, and 71.7% of patients at the 3-, 6-, and 12-month follow-ups, respectively. Among the etiologies of epilepsy, the effective rates of genetic etiology, structural etiology, and unknown etiology were generally above 50% at the 3-, 6-, and 12-month follow-ups. Among the epilepsy syndromes, the categories with higher treatment efficacy were self-limiting epilepsy with centrotemporal spikes (SeLECTs), self-limited epilepsy with autonomic seizures (SeLEAS), and childhood occipital visual epilepsy (COVE), with an effective rate of above 80%. Adverse events were documented in 22 patients (35.5%), but they were mild and tolerable. The most common adverse events comprised irritability, drowsiness, dizziness, and increased appetite.

Conclusion

PER has favorable effectiveness and tolerability as initial monotherapy for children with newly diagnosed focal epilepsy, which could be a potential option for long-term medication in the treatment of focal epilepsy in children. The current study provided potential evidence for PER as initial monotherapy in children with focal epilepsy in clinical practice.

Efficacy, Tolerability, and Safety of Treatment With Perampanel in Pediatric Patients With Epilepsy Aged ≥4 Years: A Real-Life Observational Study

Purpose: The safety and effectiveness of perampanel in clinical settings involving Chinese pediatric patients are limited, as perampanel has only recently been approved for use in China, in September 2019. We aimed to evaluate the efficacy and tolerability of perampanel as an adjunctive therapy for pediatric patients with epilepsy aged ≥ 4 years in Xinjiang, Northwest China. Methods: Efficacy was assessed by measuring changes in seizure frequency at 3-, 6-, and 12-month follow-up compared with baseline. The baseline was 3 months before the addition of perampanel, and the seizure frequency was based on the patients' seizure diary. The safety and tolerability depended on the type and frequency of any adverse event during epilepsy treatment across all pediatric patients. Results: Overall, 67 pediatric patients from 2 different hospitals were enrolled in the study. Among the pediatric patients with seizures during the baseline period, the effective rates for all seizure types at 3, 6, and 12 months were 59.1%, 58.7%, and 57.4%, respectively. During perampanel treatment, 34 patients (50.7%) experienced at least 1 adverse reaction. Conclusion: Overall, this real-world retrospective study of pediatric patients validated that perampanel is an effective treatment option as an adjunctive therapy among pediatric patients with epilepsy aged ≥4 years.

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.

Adherence to and persistence with lacosamide, perampanel, lamotrigine, and levetiracetam in adult patients with focal epilepsy in Japan: A descriptive cohort study using a claims database

Objective

We evaluated adherence to and 1-year persistence of two third-generation anti-seizure medications (ASMs), lacosamide and perampanel, in adult patients with focal epilepsy, compared with lamotrigine and levetiracetam.

Methods

A cohort study was conducted using a Japanese health insurance claims database (JMDC Inc.). We identified patients with adult-onset focal epilepsy who initiated any of the four ASMs between August 31, 2016, and October 31, 2019. Patients were further classified into ASM-naïve patients initiating any of the four ASMs as first-line treatment, and ASM-experienced patients initiating any of the four ASMs as second- or later-line treatment. Outcomes included adherence (proportion of days covered [PDC], defined as the total number of days covered by ASMs divided by the total number of days in the follow-up period) and 1-year persistence for the four ASMs.

Results

We identified 141 lacosamide, 75 perampanel, 80 lamotrigine, and 530 levetiracetam initiators. Among these, the proportion of ASM-naïve patients was highest in the levetiracetam group (60.8%), followed by the lamotrigine (25.0%), lacosamide (20.6%), and perampanel groups (1.3%). Mean PDC (standard deviation) was similar across the four groups, at 0.95 (0.08) for lacosamide, 0.93 (0.12) for perampanel, 0.92 (0.10) for lamotrigine and 0.94 (0.11) for levetiracetam. The proportion of patients persisting with treatment for 1 year was highest in the lacosamide group (73.0%), followed by the levetiracetam (58.3%), lamotrigine (57.5%), and perampanel groups (54.7%). In ASM-naïve patients, adherence and 1-year persistence were almost identical in the lacosamide, lamotrigine, and levetiracetam groups. Results for ASM-experienced patients did not significantly differ from those of all patients.

Significance

With regard to adherence and 1-year persistence, lacosamide may be equal to or better than lamotrigine and levetiracetam, especially in patients with experienced ASM, while perampanel may be comparable to lamotrigine and levetiracetam in patients with experienced ASM.

Perampanel Monotherapy for Focal and Generalized Epilepsy in Clinical Practice

Objectives. To investigate the effectiveness, safety, and tolerability of perampanel (PER) when used as monotherapy to treat focal or generalized epilepsy in everyday clinical practice, using data from the PERMIT study. Methods. PERMIT was a pooled analysis of 44 real-world studies from 17 countries, in which people with focal and generalized epilepsy were treated with PER. This post hoc analysis included people with epilepsy (PWE) from PERMIT who were treated with PER monotherapy at baseline. Retention and effectiveness were assessed after 3, 6, and 12 months. Effectiveness assessments included ≥50% responder rate and seizure freedom rate (no seizures since at least the prior visit). Safety and tolerability were assessed by evaluating adverse events (AEs) and discontinuation due to AEs. Results. Overall, 268 PWE were treated with PER monotherapy at baseline. Retention was assessed for 168 PWE, effectiveness for 183 PWE, and safety and tolerability for 197 PWE. Retention rates were 91.1%, 87.3%, and 73.3% at 3, 6, and 12 months, respectively. At 12 months, responder rates were 84.2% overall, 82.9% in PWE with only focal-onset seizures at baseline, and 88.0% in those with only generalized-onset seizures at baseline; corresponding freedom rates were 62.9%, 57.7%, and 80.0%, respectively. AEs were reported for 45.2% of PWE. The most frequently reported AEs (≥5% of PWE) were dizziness/vertigo (16.8%), irritability (11.2%), somnolence (9.1%), and depression (6.6%). Over 12 months, 13.7% discontinued due to AEs. Conclusions. PER was effective when used as monotherapy in clinical practice, particularly in those with generalized-onset seizures, and was generally well tolerated.

Perampanel monotherapy for the treatment of epilepsy: Clinical trial and real-world evidence

Perampanel, a selective, non-competitive α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor antagonist, is a once-daily oral anti-seizure medication (ASM) for focal-onset seizures (FOS) and generalized tonic-clonic seizures (GTCS). In the US, perampanel is approved for the treatment of FOS (adjunctive and monotherapy), with or without focal to bilateral tonic-clonic seizures (FBTCS), in patients aged ≥4 years, and as adjunctive treatment of GTCS in patients aged ≥12 years. The monotherapy approvals in the US were based on the Food and Drug Administration's (FDA's) policy allowing extrapolation of adjunctive data to the monotherapy setting in the absence of randomized controlled monotherapy trials; since then, perampanel monotherapy has received approvals in approximately 48 countries. As there are key differences in clinical evidence of perampanel as adjunctive therapy vs monotherapy, we review the clinical outcomes of perampanel when administered as primary or secondary monotherapy. Eight publications reporting the efficacy and safety outcomes of perampanel monotherapy in clinical trial and real-world settings were selected during our literature search and are included; these comprise three Eisai-sponsored studies in patients with epilepsy: one prospective, open-label, Phase III clinical trial of patients with newly diagnosed epilepsy (Study 342 [FREEDOM]) and two retrospective, real-world Phase IV studies of patients with epilepsy who received perampanel during routine clinical care (Studies 504 and 506 [PROVE]); and five retrospective, real-world studies in patients with epilepsy who were prescribed perampanel during routine clinical care. Results from these studies demonstrated that seizure freedom may be achieved following treatment with perampanel monotherapy (either primary or secondary), with favorable retention rates and safety profiles. Overall, the clinical evidence supports the use of perampanel monotherapy both in newly diagnosed patients and in those who have been unable to control their seizures with other ASMs.

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).

Efficacy and adverse reactions of perampanel in the treatment of epilepsy in children

Objective

To observe the clinical effect and adverse reactions of perampanel in the treatment of epilepsy in children.

Methods

A retrospective analysis was performed on 83 children with epilepsy who were treated with perampanel in the Department of Pediatric Neurology, Second Affiliated Hospital of Xi'an Jiaotong University from April to August 2021. The treatment status, prognosis and adverse reactions were followed up. The effective rates of different age groups, different seizure types and epilepsy syndromes, and different treatment methods were statistically analyzed. The effective rate and adverse reactions of all patients were statistically analyzed.

Results

The overall effective rate of perampanel in the treatment of epilepsy was 62.03%, and there was no significant difference in the effective rate of perampanel in the treatment of epilepsy in patients of different ages (P > 0.05). The effective rates of perampanel in the treatment of focal seizures and generalized seizures were 60.38% and 65.38%, and the effective rates of benign childhood epilepsy with centrotemporal spikes (BECT), BECT combined with electrical status epilepticus during sleep (ESES) and frontal lobe epilepsy (FLE) were 88.89, 72.73, and 66.67%. The effective rates of monotherapy and combination therapy were 88.88 and 58.57%, respectively. The above statistical differences were not statistically significant (P > 0.05). In addition, the adverse reaction rate of perampanel treatment was 16.45%, including irritability, drowsiness, dizziness, nausea, vomiting and abnormal liver function.

Conclusion

Perampanel has a high efficiency and controllable adverse reactions in the treatment of childhood epilepsy. This drug can be used as a reliable choice for long-term use in the treatment of epilepsy in children.

A retrospective, real-world experience of perampanel monotherapy in patient with first new onset focal seizure: A Thailand experience

Objective

Real‐world data on efficacy and tolerability of perampanel (PER) monotherapy in treatment‐naïve patients with focal onset seizures (FOS) and/or focal‐to‐bilateral tonic‐clonic seizures (FBTCS) to assess efficacy effectiveness and tolerability.

Methods

This is a retrospective review of study patients with new FOS with or without FBTCS, aged ≥15 years, who had been prescribed PER as monotherapy. Treatment outcome included retention rate, responder, and seizure‐free rate at observational point 3, 6, and 12 months (OP3, OP6, and OP12). Treatment‐emergent adverse events (TEAEs) and adverse drug reactions were recorded.

Results

A total of 41 patients enrolled in the study (male:female; 17:22, mean age =46.1 ± 21.8 years), with new FOS and/or FBTCS. The proportions of individuals remaining on PER monotherapy at 3, 6, and 12 months were evaluated. The median PER dosage was 4 mg (range 2‐8 mg). The retention rates at OP3, OP6, and OP12 were 88%, 73%, and 61%, respectively. The seizure freedom rates at OP3, OP6, and OP12 were 78%, 80%, and 76%, respectively. About 14% had discontinued the PER monotherapy because of lack of efficacy. Sixteen individuals (41%) had TEAEs; common AEs were dizziness, somnolence, and ataxia; and only one case had depression. The AEs with somnolence and ataxia were found higher in elderly (15% and 30%) than adult patients (7% and 3%), respectively. Only 14% had intolerant adverse events, and it was found higher in elderly (23%).

Significance

Real‐world data of PER monotherapy in treatment‐naïve patients with focal onset seizures demonstrated good effectiveness and a good safety profile at relatively low doses. By starting with low dosage and slow titration of PER help to minimize the impact of adverse effects, maximize adherence, and increase patient retention. PER has a once‐daily dosing schedule that supports patient adherence contributes to achieving seizure freedom.

Experience of perampanel monotherapy beyond initial titration to achieve seizure freedom in patients with focal-onset seizures with newly diagnosed or currently untreated recurrent epilepsy: A post hoc analysis of the open-label Study 342 (FREEDOM)

Objective

This post hoc analysis evaluated whether continued treatment with perampanel monotherapy beyond initial titration may be appropriate for patients with focal‐onset seizures (FOS) with currently untreated epilepsy to achieve seizure freedom with an effective dose.

Methods

Study 342 (NCT03201900; FREEDOM) is a single‐arm, open‐label, Phase III study of perampanel monotherapy. Patients aged ≥12 years with untreated FOS received perampanel 4 mg/d in a 32‐week Treatment Phase (6‐week Titration and 26‐week Maintenance Periods); in case of seizure(s) during Maintenance Period, patients could enter a 30‐week Treatment Phase (4‐week Titration and 26‐week Maintenance Periods) to be up‐titrated to perampanel 8 mg/d. The primary endpoint was seizure‐freedom rate during Maintenance Period in the modified Intent‐to‐Treat (mITT) Analysis Set (patients who had ≥1 post‐dose efficacy measurement during Maintenance Period); safety was monitored. This analysis of 4‐mg/d efficacy data assessed the proportion of patients achieving seizure freedom during the Maintenance Period (responders) relative to patients with an early/later response (depending on seizure status during the Titration Period).

Results

In the mITT population (n = 73), 46 patients were 4‐mg/d responders; of whom, 37 (80.4%) were early responders and nine (19.6%) were later responders. The mean (standard deviation) percent reductions in FOS frequency from baseline at the end of the 4‐mg/d Titration Period were 100.0% (0.0%; early responders) and 46.3% (97.3%; later responders). Among the 27 4‐mg/d nonresponders, nine (33.3%) patients who had an early response experienced seizure(s) during the subsequent 4‐mg/d Maintenance Period. Safety outcomes were similar, regardless of responder status, without new safety concerns.

Significance

Some patients with untreated FOS may benefit from continued treatment beyond initial titration of perampanel monotherapy to achieve seizure freedom, suggesting that it may not be appropriate to make treatment decisions to discontinue or switch from perampanel monotherapy solely based on seizure response before an effective dose has been reached.

Optimal Use of Perampanel in Asian Patients with Epilepsy: Expert Opinion

Perampanel is a once-daily, first-in-class AMPA receptor antagonist approved for the treatment of epilepsy and exhibits broad-spectrum efficacy in a range of seizure types when used as both monotherapy and adjunctive therapy. Clinical studies and real-world evidence have demonstrated the advantages of initiating perampanel at low doses and utilizing a slow titration strategy. Initiating perampanel at an early stage has also been shown to be associated with better patient outcomes. However, the optimal use and place of perampanel in clinical practice has not yet been clearly defined for the Asian patient population. Use of perampanel in clinical practice varies markedly across the Asia region because of variation in knowledge, attitudes, and practice. There is currently no specific guidance on best practices for prescribing perampanel in Asian patients or how to optimize treatment strategies to maximize adherence. A group of epilepsy experts attended a virtual meeting in September 2020 to discuss their experience with using perampanel in the Asian practice setting, including their views regarding appropriate patient populations, optimal starting and maintenance doses, optimal titration regimens, key barriers to adherence, and prevention and management of adverse events. This article summarizes key clinical and real-world evidence for perampanel and consolidates the experts’ opinions on optimization of perampanel prescribing and adherence in real-world practice, providing practical strategies for clinicians to implement to improve outcomes for people with epilepsy in Asia.

Perampanel dosage in plasma samples: development and validation of a novel HPLC method with combined UV-Fluorescence detection

Therapeutic drug monitoring (TDM) is a recognized method to improve the quality of use of antiepileptic drugs, such as perampanel (PRP). It is the first compound in the class of selective non-competitive antagonists of AMPA receptors approved in 2012 in Europe and United States for adjunctive therapy of partial seizures. Although several studies have recently underlined that a general reference range for PRP plasmatic concentration might be difficult to propose, TDM of this drug is important in specific clinical situations, as hepatic or renal impairment or co-administration with enzyme-inducing antiepileptics. Several methods have been described in literature for the determination of PRP in different biological matrices, which include the use of liquid chromatography methods coupled with ultraviolet, fluorescence, mass or tandem-mass spectrometry detection. Here we describe the development and validation of a novel method for the measurement of PRP in plasma samples, based on a HPLC-UV/FL double detection approach and using ketoprofen as internal standard. PRP concentration in a small subset of plasma samples of treated patients was evaluated using both our approach and a commercially available CE-IVD LC-MS/MS method. The results obtained were compared, and confirmed the possibility to use our method as an alternative to LC-MS/MS in clinical routine.

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

INTRODUCTION

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

METHODS AND ANALYSIS

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

ETHICS AND DISSEMINATION

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

TRIAL REGISTRATION NUMBER

ACTRN12618001984280; Pre-results.