Potential role of brivaracetam in pediatric epilepsy

Brivaracetam (BRV) is a new antiseizure medication (ASM) that is currently approved for adjunctive treatment in patients with focal onset seizures. Similarly to levetiracetam (LEV), BRV works by binding SV2A vesicles with a high affinity and a linear pharmacokinetic profile. Retrospective studies and randomized clinical trials have already proven the efficacy of BRV, even in patients who failed treatment with LEV. Most studies about the efficacy and tolerability conducted so far were performed in adult cohorts, whereas few studies have been performed in children; however, BRV was proven to be a useful ASM for pediatric focal epilepsies, with fewer studies and conflicting results among patients with generalized epilepsies and epileptic syndromes. Retention rates were high in the cohorts analyzed, and no serious treatment‐emergent adverse events were reported in the majority of patients, with somnolence, drowsiness, irritability, aggression, and decreased appetite being the most frequently reported side effects. Although there are few original papers published on the subject so far, the analysis of the literature data demonstrated the efficacy and safety of BRV in pediatric patients, with more evidence for children aged 4‐16 years with an onset of focal seizures. However, a positive response was also achieved in patients affected by encephalopathic epilepsies (eg, Jeavons' epilepsy, Dravet syndrome, Lennox‐Gastaut syndrome, and juvenile myoclonic epilepsy), and ongoing studies are now testing BRV in order to widen its application to other forms of epilepsy and to test its effectiveness when used in monotherapy. This review aims to provide a comprehensive analysis of the literature surrounding the efficacy and tolerability of BRV for pediatric patients.     

Brivaracetam: a new drug in development for epilepsy and neuropathic pain

Background: Epilepsy is a neurological disorder with a worldwide prevalence estimated to be 0.5 – 1.0% of the population. Many potent antiepileptic drugs (AED) have been used for treatment but still about 30% of patients are resistant to current AEDs. Some AEDs are also used for the treatment of neuropathic pain. Objective: The aim of this report is to present preclinical and clinical studies of brivaracetam (UCB-34714), a new drug developed by UCB Pharma. Methods: Published results of preclinical studies in several animal models of epilepsy, neuropathic pain, essential tremor and results of Phase I and II evaluations of brivaracetam have been analysed. Results/conclusion: Brivaracetam represents a new mechanism of action being a ligand of synaptic vesicle protein 2A. It is undergoing Phase III evaluation after a successful Phase II programme in which was effective as an adjunctive treatment in partial-onset epilepsy (50 mg/day). It is well tolerated, without serious adverse side effects.     

Third-generation antiepileptic drugs: mechanisms of action,pharmacokinetics and interactions

This review briefly summarizes the information on the molecular mechanisms of action, pharmacokinetic profiles and drug interactions of novel (third-generation) antiepileptic drugs, including brivaracetam, carabersat, carisbamate, DP-valproic acid, eslicarbazepine, fluorofelbamate, fosphenytoin, ganaxolone, lacosamide, losigamone, pregabalin, remacemide, retigabine, rufinamide, safinamide, seletracetam, soretolide, stiripentol, talampanel, and valrocemide. These novel antiepileptic drugs undergo intensive clinical investigations to assess their efficacy and usefulness in the treatment of patients with refractory epilepsy.     

Evaluation of brivaracetam: a new drug to treat epilepsy

Introduction: High prevalence of therapy-resistant epilepsy demands development of anticonvulsants with new mechanisms of action. Brivaracetam is an analogue of levetiracetam which binds to the synaptic vesicle protein 2A (SV2A) and decreases release of excitatory neurotransmitters.

Areas covered: Relevant published studies were searched for by predefined strategy in MEDLINE, EBSCO and SCINDEKS electronic databases. Brivaracetam is effective as adjunctive therapy for uncontrolled partial-onset seizures with or without secondary generalization in patients 16 years and older with epilepsy. It reduces baseline-adjusted focal seizure frequency per week from 7.3 to 12.8% over placebo. Adverse events rate in patients with brivaracetam is not higher than in patients with placebo.

Expert opinion: Brivaracetam is an important step forward in the treatment of therapy-resistant partial-onset seizures with or without secondary generalization. Its development was systematic and targeted. Due to its efficacy and excellent safety profile, it is likely that brivaracetam will be often prescribed. In future, efficacy and safety of brivaracetam should be tested in monotherapy settings and also in the first-line therapy of partial-onset seizures.     

布瓦西坦片在健康受试者中的生物等效性研究

目的 研究布瓦西坦片在空腹和餐后给药状态下的生物等效性。方法 采用单中心、单剂量、随机、开放、两周期、交叉试验设计,空腹和餐后组28例受试者最终入组,分别单次给予布瓦西坦片受试制剂或参比制剂50 mg即1片,用240m L温水送服。采用HPLC-MS/MS法测定人血浆样本中布瓦西坦,使用PhoenixWinNonlin8.1软件计算药动学参数,SAS9.4软件进行统计分析。结果 布瓦西坦片两种制剂的主要药动学参数(AUC_0-∞、AUC_0-t和C_max)几何均值均在生物等效性80.00%～125.00%。结论 布瓦西坦受试制剂与参比制剂在健康受试者空腹和餐后给药状态下具有生物等效性。     

Emerging drugs for epilepsy

Epilepsy affects ≤ 1% of the world's population. Antiepileptic drugs (AEDs) are the mainstay of treatment, although more than a third of patients are not rendered seizure free with existing medications. Uncontrolled epilepsy is associated with increased mortality and physical injuries, and a range of psychosocial morbidities, posing a substantial economic burden on individuals and society. Limitations of the present AEDs include suboptimal efficacy and their association with a host of adverse reactions. Continued efforts are being made in drug development to overcome these shortcomings employing a range of strategies, including modification of the structure of existing drugs, targeting novel molecular substrates and non-mechanism-based drug screening of compounds in traditional and newer animal models. This article reviews the need for new treatments and discusses some of the emerging compounds that have entered clinical development. The ultimate goal is to develop novel agents that can prevent the occurrence of seizures and the progression of epilepsy in at risk individuals.     

Brivaracetam as add‐on treatment in focal epilepsy: A real‐world time‐based analysis

The study assessed the clinical response to add‐on brivaracetam (BRV) in real‐world practice by means of time‐to‐baseline seizure count methodology. Patients with focal epilepsy who were prescribed add‐on BRV were identified. Primary endpoint was the time‐to‐baseline seizure count defined as the number of days until each patient experienced the number of focal seizures that occurred in the 90 days before BRV initiation. Subgroup analysis was performed according to levetiracetam (LEV) status (naive vs prior use). Three‐hundred eighty‐seven patients were included. The overall median time‐to‐baseline seizure count was 150 (95% confidence interval [CI] = 130‐175) days. The median time‐to‐baseline seizure count was 198 (lower limit of 95% CI = 168) days for LEV‐naive patients, 126 (95% CI = 105‐150) days for patients with prior LEV use and withdrawal due to insufficient efficacy, and 170 (95% CI = 128‐291) days for patients who discontinued LEV due to adverse events (P = .002). The number of prior antiseizure medications (adjusted hazard ratio [_adjHR] = 1.07, 95% CI = 1.02‐1.13, P = .009) and baseline monthly seizure frequency (_adjHR = 1.004, 95% CI = 1.001‐1.008, P = .028) were independently associated with the primary endpoint. Add‐on BRV improved seizure control in LEV‐naive and LEV‐prior patients. The time‐to‐baseline seizure count represents an informative endpoint alongside traditional study outcomes and designs.     

The pharmacokinetics, CNS pharmacodynamics and adverse event profile of brivaracetam after multiple increasing oral doses in healthy men

AIMS

Brivaracetam is a novel synaptic vesicle protein 2A ligand that has shown potent activity in animal models of epilepsy. This study examined the pharmacokinetics, central nervous system pharmacodynamics and adverse event profile of multiple oral doses of brivaracetam in healthy male subjects.

METHODS

Three successive panels of 12 healthy male subjects received double-blind brivaracetam 200, 400 or 800 mg day⁻¹ (all doses well above the expected therapeutic range) or placebo (9 : 3), in two divided doses, for 14 days.

RESULTS

Brivaracetam was rapidly absorbed (t_max∼2 h) and eliminated (t_1/2 7–8 h). Volume of distribution was slightly lower than total body water. A small fraction of the dose (5–8%) was excreted unchanged in urine together with significant levels of metabolites, suggesting predominantly metabolic clearance. Based on 6-β-hydroxycortisol/cortisol ratios in urine, there was no evidence of induction of CYP3A4 activity. Saliva and plasma brivaracetam levels were highly correlated. Adverse events were mostly mild to moderate, central nervous system-related and resolved within the first day of treatment. No clinically relevant changes were observed in laboratory tests, vital signs, physical examinations or ECGs. Pharmacodynamic tests showed dose-related sedation and decreased alertness that only persisted at 800 mg daily.

CONCLUSIONS

Brivaracetam was well tolerated by healthy male volunteers at doses of 200–800 mg daily for 2 weeks, well above the expected clinically effective dose range. Brivaracetam had a favourable pharmacokinetic profile in this population, characterized by rapid absorption, volume of distribution limited to total body water, apparent single-compartment elimination and dose proportionality.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• The pharmacokinetic profile, metabolism and proof of concept of a single oral dose of brivaracetam have been reported.
• Previous studies have shown that it was well absorbed, had linear kinetics and was well tolerated, and suggested effective doses of 10–80 mg in photoparoxysmal epilepsy.

WHAT THIS STUDY ADDS

• We now report the pharmacokinetics, pharmacodynamics and tolerability in healthy volunteers after multiple doses.