A post hoc analysis of the long‐term safety and efficacy of perampanel in Asian patients with epilepsy

This post hoc analysis assessed the long‐term safety, tolerability, and efficacy of perampanel in Asian patients with refractory focal seizures; an additional analysis assessed the effect of perampanel on focal impaired awareness seizures (FIAS) with focal to bilateral tonic‐clonic (FBTC) seizures. In this subanalysis, data from Asian patients ≥12 years of age who had focal seizures with FBTC seizures despite taking one to 3 concomitant antiepileptic drugs at baseline, and who had entered either the long‐term extension phase of 3 phase‐3 perampanel trials (study 307) or the 10‐week extension phase of study 335, were analyzed for the effect of perampanel on duration of exposure, safety, and seizure outcomes. Of 874 Asian patients included in the analysis, 205 had previously received placebo during the double‐blind phase‐3 trials and 669 had previously received perampanel 2‐12 mg/day; 313 had FIAS with FBTC seizures at core study baseline. The median duration of exposure to perampanel was 385.0 days, and the retention rate at one year was 62.6%. Overall, during the first 52 weeks of perampanel treatment, 777 patients (88.9%) had treatment‐emergent adverse events (TEAEs), most of which were mild to moderate in severity. The most frequent TEAEs were dizziness (47.1%), somnolence (22.3%), and nasopharyngitis (17.4%). During the first 52 weeks of perampanel treatment, median percent change in seizure frequency per 28 days from pre‐perampanel baseline for all focal seizures was ?28.1%, and ?51.7% for FIAS with FBTC seizures. The 50% responder rate relative to pre‐perampanel baseline for all focal seizures was 33.8%, and 51.1% for FIAS with FBTC seizures. Long‐term treatment with perampanel in Asian patients had safety, tolerability, and efficacy similar to that of the global population in the phase‐3 trials and extension study 307. The safety profile and response rate suggest benefit for an Asian population of patients with refractory epilepsy.     

吡仑帕奈治疗难治性癫痫部分发作的Meta分析

目的 系统评价吡仑帕奈治疗难治性癫痫部分发作的有效性与安全性。方法 计算机检索PubMed、EBSCO、EMbase、Cochrane Library、中国生物医学文献数据库（CBM）、中国期刊全文数据库（CNKI）、中文科技期刊全文数据库（VIP）和万方数据库,收集吡仑帕奈治疗难治性癫痫部分发作的随机对照试验,检索时限从建库至2017年2月,采用RevMan 5.0软件对各效应指标进行Meta分析。结果 共纳入5项研究,计1 500例患者。Meta分析结果显示：吡仑帕奈组癫痫完全不发作率[OR=3.75,95%CI （1.77,7.93）,P=0.000 6]、发作频率减少≥ 50%的患者百分率[OR=2.08,95%CI （1.69,2.56）,P<0.001]均高于安慰剂组,差异有统计学意义;吡仑帕奈主要不良反应有眩晕、困倦、头痛、共济失调、鼻咽炎等;吡仑帕奈8 mg和12 mg组总不良反应发生率高于安慰剂组,差异有统计学意义（P<0.05）。结论 吡仑帕奈治疗难治性癫痫部分发作能有效减少癫痫发作频率,且不良反应较轻,患者基本耐受。     

The AMPA receptor antagonist perampanel is a new hope in the treatment for epilepsy

Perampanel is a novel drug recently approved as adjunctive therapy in epileptic patients aged 12 years and older who have drug‐resistant partial epilepsy with and without secondary generalization. Pharmacological researches revealed that perampanel reduces neuronal excitability by a non‐competitive antagonistic activity against the ionotropic alpha‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazole propionic acid (AMPA) receptors causing modulation of glutamatergic neurotransmission. The pharmacological profile of the drug showed complete absorption following oral administration, and extensive metabolism in the liver by oxidation followed by glucuronidation with an elimination half‐life of approximately 53–165 h (average: 105 h), allowing once‐daily administration. Randomized placebo‐controlled trials demonstrated an effective dose range of the drug, between 4 and 12 mg/day, to significantly reduce seizure frequency in patients with partial‐onset seizure that are pharmacoresistant with a favorable tolerability profile. The most frequent adverse events of the drug reported in phase III clinical trials were dizziness, somnolence, fatigue, and headache. However, the data raised from the studies can give a hope that perampanel offers a valuable option as an adjuvant therapy for pharmacoresistant partial‐onset and secondarily generalized seizures.     

Comparison of the effectiveness and tolerability of perampanel and brivaracetam: a real‐world,observational, retrospective study

Aim. Perampanel (PER) and brivaracetam (BRV) are third‐generation antiseizure medications. The aim of the present retrospective, double‐centre study was to compare the effectiveness and tolerability between PER and BRV in adult patients with epilepsy. Methods. We reviewed the clinical charts of patients affected by epilepsy, admitted to the Epilepsy Centre at the University Hospital of Rome “Tor Vergata” and the Cardarelli Hospital in Naples, who started BRV or PER as add‐on treatment for controlling seizures with a follow‐up of 12 months. Seizure freedom, >50% seizure reduction, retention rate, and adverse events reported during follow‐up were compared between the two drugs. Moreover, we considered the effects of both drugs in specific subsets of patients: age ≥60 years, male or female, in patients with genetic generalized epilepsy, and considering previous treatment with levetiracetam (LEV). Results. Forty‐three patients treated with BRV and 64 patients treated with PER were included in this study and followed at both sites for 12 months. Similar effectiveness was observed between BRV and PER, with similar rates of seizure freedom (30% vs 31%) and >50% seizure reduction (32% vs 34%) during follow‐up. Moreover, PER and BRV discontinuation rates, due to ineffectiveness or adverse events, were similar. Groups of patients who started BRV or PER as first add‐on treatments were also compared but no differences in effectiveness or tolerability were identified. Lastly, BRV was shown to be more effective in patients who were not previously treated with LEV. Conclusions. This retrospective study reveals comparable effectiveness and tolerability between PER and BRV also when used as first add‐on treatments, in patients with epilepsy.     

European perspective of perampanel response in people with Intellectual Disability

Background

Epilepsy prevalence is over 20% for those with ID. It is difficult to diagnose and treat and more likely to be treatment resistant. The evidence informing prescribing is sparse, particularly for new drugs such as perampanel (PMP).

Aims of the Study

This study seeks to strengthen the research evidence regarding PMP for people with ID by pooling information from two isolated and separately conducted studies: the UK-based Epilepsy Database Register (Ep-ID) and the data from the Kempenhaeghe clinic in the Netherlands.

Methods

A single data set of comparable data was created and analysed under agreement and supervision of a UK statistician.

Results

Seizure reduction within twelve months was evident in 62% of Dutch and 47% of UK patients. Retention rates were higher for those in the UK (P = .01) and for patients with moderate to profound ID, whilst side effects were more prominent in the Dutch cohort.

Conclusions

Comparable rates of seizure reduction are in line with estimates for non-ID patients, adding to the evidence suggesting that PMP has a similar impact on those with ID. Taking a European perspective and sharing data across centres can help strengthen the evidence for prescribing antiepileptic drugs in the ID population.

     

Perampanel in patients with refractory and super‐refractory status epilepticus in a neurological intensive care unit: A single‐center audit of 30 patients

In refractory status epilepticus (SE), γ‐aminobutyric acidergic drugs become less effective and glutamate plays a major role in seizure perpetuation. Data on the efficacy of perampanel (PER) in treatment of refractory SE in humans are limited. Here, we present a single‐center case series of patients with refractory SE who received PER orally in an intensive care unit. We retrospectively analyzed treatment response, outcome, and adverse effects of all patients with refractory SE in our Neurological Intensive Care Unit who received add‐on PER between September 2012 and February 2018. Thirty patients with refractory SE (median = 72 years, range = 18‐91, 77% women) were included. In 14 patients (47%), a high‐dose approach was used, with a median initial dose of 24 mg (range = 16‐32). In five patients (17%), SE could be terminated after PER administration (median dose = 6 mg, range = 6‐20 mg, 2/5 patients in high‐dose group). Clinical response was observed after a median of 24 hours (range = 8‐48 hours), whereas electroencephalogram resolved after a median of 60 hours (range = 12‐72 hours). Time to treatment response tended to be shorter in patients receiving high‐dose PER (median clinical response = 16 hours vs 18 hours; electroencephalographic response = 24 hours vs 72 hours), but groups were too small for statistical analysis. Continuous cardiorespiratory monitoring showed no changes in cardiorespiratory function after “standard” and “high‐dose” treatment. Elevated liver enzymes without clinical symptoms were observed after a median of 6 days in seven of 30 patients (23%; 57% high dose vs 43% standard dose), of whom six also received treatment with phenytoin (PHT). Outcome was unfavorable (death, persistent vegetative state) in 13 patients (43%; 39% high dose vs 61% standard dose), and good recovery (no significant disability, moderate disability) was achieved in nine patients (56% high dose vs 44% standard dose). Oral PER in loading doses up to 32 mg were well tolerated but could terminate SE only in a few patients (5/30; 17%). Long duration of SE, route of administration, and severe underlying brain dysfunction might be responsible for the modest result. An intravenous formulation is highly desired to explore the full clinical utility in the treatment of refractory SE.     

Evaluation and improvement of CuI-mediated 11C-cyanation

CuI-mediated ¹¹C-cyanation was evaluated by synthesizing [¹¹C]perampanel ([¹¹C] 5 ) as a model compound and compared with previous reports. To a DMF solution with 5′-(2-bromophenyl)-1′-phenyl-[2,3′-bipyridin]-6′(1′H)-one ( 4 ) and CuI, [¹¹C]NH₄CN in a stream of ammonia/nitrogen (5:95, v/v) gas was bubbled. Subsequently, the reaction mixture was heated at 180°C for 5 min. After HPLC purification, [¹¹C] 5 was obtained in 7.2 ± 1.0% (n = 4) non-decay corrected radiochemical yield with >99% radiochemical purity and a molar activity of 98 ± 28 GBq/μmol. In vivo evaluations of [¹¹C] 5 were performed using small animals. PET scans to check the kinetics of [¹¹C] 5 in the whole body of mice suggested that [¹¹C] 5 spreads rapidly into the brain, heart, and lungs and then accumulates in the small intestine. To evaluate the performance of CuI-mediated ¹¹C-cyanation reaction, bromobenzene ( 6a ) was selected as the model compound; however, it failed. Therefore, optimization of the reaction conditions has been performed, and consequently, the addition of K₂CO₃ and prolonging the reaction time improved the radiochemical yield about double. With this improved method, CuI-mediated ¹¹C-cyanation of various (hetero)aromatic bromides was performed to exhibit the tolerance of most functional groups and to provide ¹¹C-cyanated products in good to moderate radiochemical yields.