Bioavailability and bioequivalence comparison of brivaracetam 10, 50, 75, and 100 mg tablets and 100 mg intravenous bolus

Investigating clinical pharmacokinetics of brivaracetam by using a pharmacokinetic modeling approach

The development of technology and the processing speed of computing machines have facilitated the evaluation of advanced pharmacokinetic (PK) models, making modeling processes simple and faster. The present model aims to analyze the PK of brivaracetam (BRV) in healthy and diseased populations. A comprehensive literature review was conducted to incorporate the BRV plasma concentration data and its input parameters into PK-Sim software, leading to the creation of intravenous (IV) and oral models for both populations. The developed physiologically based pharmacokinetic (PBPK) model of BRV was then assessed using the visual predictive checks, mean observed/predicted ratios (Robs/pre), and average fold error for PK parameters including the maximum systemic concentration (Cmax), the area under the curve at time 0 to t (AUC0-∞), and drug clearance (CL). The PBPK model of BRV demonstrated that mean Robs/pre ratios of the PK parameters remained within the acceptable limits when assessed against a twofold error margin. Furthermore, model predictions were carried out to assess how AUC0-∞ is affected following the administration of BRV in individuals with varying degrees of liver cirrhosis, ranging from different child-pugh (CP) scores like A, B, and C. Moreover, dose adjustments were recommended by considering the variations in Cmax and CL in various kidney disease stages (mild to severe).

Pharmacokinetics, Safety, and Tolerability of Brivaracetam in Healthy Elderly Participants

The pharmacokinetics, metabolism, safety, and tolerability of the antiseizure medication brivaracetam (BRV) were characterized in 16 healthy elderly participants (8 men/8 women) aged 65-78 years who received a single 200-mg oral dose of BRV on day 1, followed by 200 mg twice daily from day 3 until day 12. BRV and three metabolites were determined in plasma and urine. Adverse events, vital signs, electrocardiograms, laboratory tests, general and neurological examinations, and psychometric rating scales were recorded at regular intervals. No clinically relevant changes or abnormalities were detected. The adverse events were similar to those observed in pivotal trials. Rating scales indicated transiently increased sedation and decreased alertness. BRV pharmacokinetics and metabolism were unchanged relative to younger populations. Based on our observations in this healthy elderly population receiving oral BRV 200 mg twice daily (twice the maximum recommended dose), dose reductions are not warranted relative to other, younger populations. Further investigations may be necessary in frail elderly populations aged >80 years.

Real-life evidence about the use of intravenous brivaracetam in urgent seizures: The BRIV-IV study

PURPOSE

Urgent seizures are a medical emergency for which new therapies are still needed. This study evaluated the use of intravenous brivaracetam (IV-BRV) in an emergency setting in clinical practice.

METHODS

BRIV-IV was a retrospective, multicenter, observational study. It included patients ≥18 years old who were diagnosed with urgent seizures (including status epilepticus (SE), acute repetitive seizures, and high-risk seizures) and who were treated with IV-BRV according to clinical practice in 14 hospital centers. Information was extracted from clinical charts and included in an electronic database. Primary effectiveness endpoints included the rate of IV-BRV responder patients, the rate of patients with a sustained response without seizure relapse in 12 h, and the time between IV-BRV administration and clinical response. Primary safety endpoints were comprised the percentage of patients with adverse events and those with adverse events leading to discontinuation.

RESULTS

A total of 156 patients were included in this study. The mean age was 57.7 ± 21.5 years old with a prior diagnosis of epilepsy for 57.1% of patients. The most frequent etiologies were brain tumor-related (18.1%) and vascular (11.2%) epilepsy. SE was diagnosed in 55.3% of patients. The median time from urgent seizure onset to IV treatment administration was 60.0 min (range: 15.0-360.0), and the median time from IV treatment to IV-BRV was 90.0 min (range: 30.0-2400.0). Regarding dosage, the mean bolus infusion was 163.0 ± 73.0 mg and the mean daily dosage was 195.0 ± 87.0 mg. A total of 77.6% of patients responded to IV-BRV (66.3% with SE vs. 91% other urgent seizures) with a median response time of 30.0 min (range: 10.0-60.0). A sustained response was achieved in 62.8% of patients. However, adverse events were reported in 14.7%, which were predominantly somnolence and fatigue, with 4.5% leading to discontinuation. Eighty-six percent of patients were discharged with oral brivaracetam.

CONCLUSION

IV-BRV in emergency settings was effective, and tolerability was good for most patients. However, a larger series is needed to confirm the outcomes.

Physiologically based pharmacokinetic modeling of brivaracetam and its interactions with rifampin based on CYP2C19 phenotypes

Brivaracetam (BRV), a third-generation antiepileptic drug (AED), is primarily metabolized through amidase hydrolysis and CYP2C19-mediated hydroxylation in vivo. This study utilized physiologically based pharmacokinetic (PBPK) modeling to explore the pharmacokinetics of BRV and drug interactions between BRV and rifampin (RIF), a CYP2C19 inducer, based on CYP2C19 genetic polymorphisms. A PBPK model of BRV was developed in the general population and in individuals with different CYP2C19 phenotypes by adjusting catalytic rate constants (k_cat), and the model was validated with observed clinical data. The model was then extrapolated to predict BRV steady-state plasma concentration in individuals with different CYP2C19 phenotypes, with or without coadministration of RIF. The developed model adequately described BRV exposure in the abovementioned populations. The predicted steady-state area under the curve (AUC_τ-ss) increases by 20% in heterozygous extensive metabolizers (hEMs) and 55% in poor metabolizers (PMs), compared to homozygous extensive metabolizer (EMs). When coadministered with RIF, the model predicted the most significant magnitude of drug-drug interaction (DDI) in EMs, while the exposure change of BRV was minimal in PMs. Referencing the recommended concentration for therapeutic drug monitoring (TDM), we concluded that the current clinical maintenance dose of BRV is acceptable regardless of CYP2C19 polymorphisms and coadministration with RIF.

Method Development and Validation of a Novel UHPLC Coupled with MS/MS System for the Estimation of Brivaracetam in Human (K2EDTA) Plasma Samples and its Application to Pharmacokinetic Study

Background:

Brivaracetam is a novel antiepileptic drug clinically approved for the treatment of partial onset seizures in adults and adolescents. It has some abuse potential and assigns to Schedule V category under the Controlled Substance Act by the Drug Enforcement Administration. It is essential to develop a faster, simple, and highly sensitive method for the quantification of Brivaracetam in human plasma by employing simple liquid-liquid extraction.

Objective:

The objective of this study is to develop and validate a novel UHPLC-MS/MS method for the estimation of brivaracetam in human plasma samples and application to pharmacokinetic study.

Methods:

An ultra-high-pressure liquid chromatography-tandem mass spectrometry method was developed and validated according to current regulatory guidelines for bioanalytical methods. Sample processing (50 μL) involved only a simple liquid-liquid extraction by ethyl acetate as extraction solvent. Brivaracetam-d7 was used as an internal standard. The chromatographic analysis was performed by a Unisol C18 (4.6 X 100 mm, 5μm) column using 0.1% formic acid in water/acetonitrile (20/80 V/V) as an isocratic mobile phase, at a flow rate of 1.0 mL/min with a run time of 2.2 min. Brivaracetam and its internal standard Brivaracetam D7 were detected and quantified in positive ion mode using multiple reaction monitoring transitions at m/z 213.100→168.100 and m/z 220.000→175.100, respectively. The developed method was applied to assess pharmacokinetic parameters like Cmax, Tmax, t1/2 and AUC for Brivaracetam in healthy, male, and adult humans.

Results:

The method was validated over a concentration range of 20.000 ng/mL to 4000. 000 ng/mL. Both intra- and inter-assay precision and accuracy were <15% for all quality control samples. No matrix effect was observed. Pharmacokinetic results showed that test formulation is bioequivalent with reference formulation.

Conclusion:

The present assay is faster, highly sensitive and simpler than previously published analytical reports for brivaracetam in human plasma samples and is suitable for pharmacokinetic evaluation of any marketed formulation.

Intravenous Brivaracetam in the Management of Acute Seizures in the Hospital Setting: A Scoping Review

Background

Clinical considerations for drug treatment of acute seizures involve variables such as safety, tolerability, drug-drug interactions, dosage, route of administration, and alterations in pharmacokinetics because of critical illness. Therapy options that are easily and quickly administered without dilution, well tolerated, and effective are needed for the treatment of acute seizures. The objective of this review is to focus on the clinical considerations relating to the use of intravenous brivaracetam (IV BRV) for the treatment of acute seizures in the hospital, focusing on critically ill patients.

Methods

This was a scoping literature review of PubMed from inception to April 13, 2021, and search of the American Academy of Neurology (AAN) 2021 Annual Meeting website for English language publications/conference abstracts reporting the results of IV BRV use in hospitalized patients, particularly in the critical care setting. Outcomes of interest relating to the clinical pharmacology, safety, tolerability, efficacy, and effectiveness of IV BRV were reviewed and are discussed.

Results

Twelve studies were included for analysis. One study showed that plasma concentrations of IV BRV 15 min after the first dose were similar between patients receiving IV BRV as bolus or infusion. IV BRV was generally well tolerated in patients with acute seizures in the hospital setting, with a low incidence of individual TEAEs classified as behavioral disorders. IV BRV demonstrated efficacy and effectiveness and had a rapid onset, with clinical and electrophysiological improvement in seizures observed within minutes. Although outside of the approved label, findings from several studies suggest that IV BRV reduces seizures and is generally well tolerated in patients with status epilepticus.

Conclusions

IV BRV shows effectiveness, and is generally well tolerated in the management of acute seizures in hospitalized patients where rapid administration is needed, representing a clinically relevant antiseizure medication for potential use in the critical care setting.

Bioavailability, safety and tolerability of intravenous brivaracetam in healthy Japanese participants

We characterised the bioavailability, safety, and tolerability of brivaracetam 100 mg intravenous bolus and 15-min infusion versus oral reference tablet in 24 healthy Japanese participants.In this randomised, open-label, three-period crossover study, participants received three 100 mg single doses of brivaracetam, intravenous bolus, infusion, and oral tablets. Maximum plasma concentration (C_max), area under the plasma concentration-time curve from time zero to the time of last quantifiable concentration (AUC_t), and area under the plasma concentration-time curve extrapolated to infinity (AUC_inf), were compared using analysis of variance following logarithmic transformation. Bioavailability comparisons were based on the 90% confidence intervals (CIs) around the geometric least squares means ratios (intravenous:oral). Safety and tolerability were monitored throughout the study.The 90% CIs around AUC_t and AUC_inf ratios were entirely contained within the bioequivalence limits (0.80-1.25), but C_max was outside the limits (90% CI: 1.77-2.08 and 1.44-1.70 for intravenous bolus and infusion, respectively). All participants completed the study. Brivaracetam was well tolerated.Because response to brivaracetam in epilepsy is related to exposure (AUC), no dose adjustment is warranted when switching from oral to intravenous dosing. However, investigations are needed to assess the safety and tolerability of intravenous administration in Japanese patients with epilepsy.

Pharmacokinetics, safety, and tolerability of intravenous brivaracetam in pediatric patients with epilepsy: An open-label trial

Objective

To evaluate the pharmacokinetics, safety, and tolerability of brivaracetam (BRV) as 15‐min intravenous (IV) infusion and bolus (≤2‐min injection).

Methods

EP0065 (ClinicalTrials.gov: NCT03405714) was a Phase 2, multicenter, open‐label trial in patients ≥1 month to <16 years of age with epilepsy. Patients received up to 5 mg/kg/day BRV (not exceeding 200 mg/day). Enrollment was sequential by descending age, depending on safety review. Outcomes included BRV plasma concentrations before and after IV administration, treatment‐emergent adverse events (TEAEs), and discontinuations due to TEAEs.

Results

Fifty patients were enrolled, received BRV, and completed the trial. Twenty‐six patients (52.0%) received 15‐min infusions and 24 (48.0%) received bolus injections. Most patients (80.0%) received one IV dose. In the 15‐min infusion group, geometric mean (GeoMean) BRV concentrations 15 (±2) min (n = 21) and 3 h (±15 min) (n = 21) post dose were 1903.0 ng/mL (geometric coefficient of variation [GeoCV]: 60.7%) and 1130.3 ng/mL (58.8%), respectively. In the bolus group, GeoMean BRV concentrations 15 (±2) min (n = 19) and 3 h (±15 min) (n = 21) post dose were 1704.8 ng/mL (GeoCV: 74.5%) and 1383.9 ng/mL (85.0%), respectively. Overall, 14 patients (28.0%) had TEAEs (15‐min infusion: 8 [30.8%]; bolus: 6 [25.0%]), most commonly (≥5% of patients) somnolence (3 [6.0%]). Ten patients (20.0%) had drug‐related TEAEs (15‐min infusion: 6 [23.1%]; bolus: 4 [16.7%]). No patients discontinued due to TEAEs, and no deaths occurred.

Significance

IV BRV (up to 200 mg/day) was well tolerated in patients ≥1 month to <16 years of age, regardless of whether BRV was administered as 15‐min infusion or bolus. No unexpected safety or pharmacokinetic differences were observed between patients receiving 15‐min infusions or bolus, and plasma concentrations were in the expected range. Safety results were consistent with the known safety profile of oral BRV, with no new safety concerns identified.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Safety and tolerability of adjunctive brivaracetam in epilepsy: In-depth pooled analysis

OBJECTIVE

The objective of this analysis was to provide a comprehensive analysis of safety data for adjunctive brivaracetam (BRV), an antiepileptic drug (AED) of the racetam class, for treatment of focal seizures in patients with epilepsy.

METHODS

Data were pooled from two phase II, placebo-controlled, double-blind, dose-ranging trials (N01114 [ClinicalTrials.gov: NCT00175929], N01193 [NCT00175825]) and three phase III, placebo-controlled, double-blind, 12-week trials (N01252 [NCT00490035], N01253 [NCT00464269], and N01358 [NCT01261325]) in patients aged ≥16 years with focal seizures, as well as a phase III, placebo-controlled, double-blind, 16-week trial in patients aged ≥16 years with focal or generalized epilepsy (N01254 [NCT00504881]). Data are presented for the approved therapeutic dose range of 50-200 mg/day. Data for BRV administered intravenously (25-150 mg doses) were pooled separately from one phase III trial (N01258 NCT01405508]) and two clinical pharmacology trials (N01256 [Part B] [UCB Pharma, data on file]; EP0007 [NCT01796899]). Adverse events (AEs) of interest were summarized in relevant categories.

RESULTS

The safety pool comprised 1957 patients: 1271 receiving adjunctive BRV and 686 receiving placebo. Overall, the incidence of treatment-emergent adverse events (TEAEs) was 66.9% with BRV versus 62.8% with placebo. The most frequently reported TEAEs with BRV (≥5% of patients) versus placebo were somnolence (13.3% vs. 7.9%), headache (10.5% vs. 11.5%), dizziness (10.0% vs. 7.0%), and fatigue (8.2% vs. 4.2%). Incidence of psychiatric disorder-related TEAEs was 11.3% with BRV versus 8.2% with placebo. Behavioral disorder-related TEAE incidence was low (4.0% with BRV vs. 2.5% with placebo). Irritability was reported in 2.7% of BRV-treated patients vs. 1.5% of patients receiving placebo; anger, aggression, and agitation were each reported by ≤1% of patients receiving BRV. Treatment-emergent adverse events potentially associated with psychosis were psychotic disorder (three patients on BRV vs. two patients on placebo), auditory hallucination, illusion, visual hallucination (one patient each on BRV), epileptic psychosis, and hallucination (one patient each on placebo). No additional safety concerns were identified in patients with intravenous (IV) BRV administration (n = 104).

CONCLUSIONS

These safety data for adjunctive BRV support its acceptable safety and tolerability profile.

Brivaracetam in the treatment of epilepsy: a review of clinical trial data

Brivaracetam (BRV), an analog of levetiracetam (LEV), was discovered during a target-based rational drug discovery program that aimed to identify potent synaptic vesicle protein 2A (SV2A) ligands. Among the 12,000 compounds screened in vitro, BRV was found to have 15-30 times greater affinity for SV2A and faster brain permeability than LEV. Although preclinical and post-marketing studies suggest broad spectrum of efficacy, BRV is currently only approved as monotherapy and adjunctive therapy of focal-onset seizures in patients age 4 years and older. This review examines the use of BRV as add-on (5-200 mg/day) therapy for epilepsy with a particular emphasis on the six regulatory randomized clinical trialsinvolving 2399 participants. Participants receiving BRV add-on at doses of 50-200 mg/day were more likely to experience a 50% or greater reduction in seizure frequency (pooled risk ratio [RR]) 1.79 with 95% CI of 1.51-2.12) than those receiving placebo. Participants receiving BRV were also more likely to attain seizure freedom (57 [3.3%] vs 4 [0.5%]; RR 4.74, 95% CI 2.00-11.25) than those receiving placebo. In addition, BRV demonstrated a favorable safety profile similar to placebo across all BRV doses. Treatment emergent adverse events significantly associated with BRV were irritability, fatigue, somnolence, and dizziness. Post-hoc analysis of regulatory trials, post-marketing studies, and indirect comparison meta-analyses demonstrated equivalent efficacy and better tolerability of BRV when compared to other antiseizure drugs. Further, these studies appear to suggest that behavioral adverse events are likely to be less frequent and less severe with BRV than LEV. Therefore, switching to BRV may be considered for patients who have seizure control with LEV, but who cannot tolerate its behavioral adverse effects. In this setting, immediate switch from LEV to BRV at a 10:1-15:1 ratio without titration is feasible. Further research is needed to examine the long-term tolerability and efficacy of BRV as well as its role in the treatment of other types of epilepsies, particularly dementia-related epilepsy and brain tumor-related epilepsy.

Safety and Tolerability of Adjunctive Brivaracetam in Pediatric Patients < 16 Years with Epilepsy: An Open-Label Trial

OBJECTIVE

This trial evaluated the short-term safety and tolerability, steady-state pharmacokinetics, and preliminary efficacy of brivaracetam oral solution in children aged 1 month to < 16 years with epilepsy.

METHODS

This was a phase IIa, open-label, single-arm, fixed three-step dose escalation trial of 3-weeks duration (N01263; NCT00422422). Patients were taking one to three concomitant antiepileptic drugs. Brivaracetam oral solution dosage, in two divided daily doses, was increased each week: approximately 0.8, 1.6, and 3.2 mg/kg/day for patients aged ≥ 8 years, and 1.0, 2.0, and 4.0 mg/kg/day for patients aged < 8 years.

RESULTS

Of the 100 patients enrolled, 90 (90.0%) completed the trial. The safety population comprised 99 patients. Treatment-emergent adverse events (TEAEs) considered drug related by the investigator were reported by 32/99 (32.3%) patients, most commonly (≥ 5%) somnolence (7.1%) and decreased appetite (6.1%). TEAEs were reported by 66/99 (66.7%) patients, most commonly (≥ 5%) convulsion, irritability, pyrexia, somnolence, and decreased appetite. In patients with a history of focal seizures with or without secondary generalization and no primary generalized seizures aged 4 to < 16 years (n = 34), drug-related TEAEs and TEAE incidences were 47.1% and 67.6%, respectively. Steady-state trough brivaracetam and brivaracetam metabolite plasma concentrations increased proportionally with dose. The ≥ 50% responder rates (all seizure types) were 21.3% (all patients, n = 80) and 36.4% (patients with focal seizures, aged 4 to < 16 years, n = 22).

CONCLUSIONS

This open-label trial in pediatric patients with epilepsy provides preliminary information that short-term, adjunctive brivaracetam treatment is well tolerated and effective. Plasma concentrations of brivaracetam and metabolites increased with increasing dose.

Intravenous brivaracetam in status epilepticus: Correlation between loading dose, plasma levels and clinical response

Brivaracetam is available in intravenous formulation, and its favourable pharmacokinetic profile makes it a promising agent in the treatment of status epilepticus (SE). Its availability as an intravenous formulation and its favourable pharmacokinetic profile make it a promising agent in the treatment of status epilepticus. Our aim was to assess the correlation between BRV exposure and clinical response. We retrospectively studied all consecutive SE patients treated with BRV in our centre from September 2016 to March 2018. Correlations between loading doses, plasma concentrations, extrapolated exposures (approach based on a population pharmacokinetics model) and the clinical response (defined as BRV being able to resolve SE without the need of further treatment), were analysed. Among 14 patients, 7 (50%) responded to BRV. Responders received significantly greater median loading dosage per body weight (3.3 mg/kg) compared to non-responders (1.5 mg/kg) (p = 0.02); no responders had loading doses below 1.9 mg/kg. There was a significant correlation of the clinical response with calculated exposure parameters, whereas measured BRV concentrations did not. BRV doses higher than 1.9 mg/kg are associated with greater probabilities of response in SE; consequently, a minimum dose of 2 mg/kg seems advisable in treatment of SE. It is unclear whether increasing further BRV loading doses would provide any additional benefit. BRV concentrations performed outside the frame of a standardised protocol merely ascertain BRV administration. This study is however limited by its small sample size.

Pharmacology of new and developing intravenous therapies for the management of seizures and epilepsy

INTRODUCTION

Antiepileptic drugs (AEDs) are administered orally for chronic use. Parenteral formulations might be necessary when the oral route is not feasible (e.g. an impairment of consciousness, trauma, dysphagia, gastrointestinal illness) or for treatment of seizure emergencies. At present, few intravenous (IV) formulations are available on the market.

AREAS COVERED

The purpose of this review is to summarize the pharmacological characteristics and clinical applications of IV medications that have been recently introduced to the armamentarium of epilepsy therapy or are currently being developed. Apart from AEDs, other compounds belonging to different pharmacological classes (e.g. diuretics, anesthetics), which have shown potential effectiveness in seizure control, are taken into consideration, and the pathophysiological premises supporting their use for epilepsy treatment are illustrated. The authors give particular focus to immunomodulatory and immunosuppressive agents, which have become the therapeutic cornerstones for immune-mediated epilepsies, despite regulatory obstacles.

EXPERT OPINION

In several circumstances, especially in the case of seizure-related emergencies, clinical practice seems not match literature-based evidence, and several IV AEDs are still used off-label. Strong evidence derived from randomized clinical trials (RCTs) is needed to support the effectiveness and tolerability of any therapeutic approach, however common and "accepted' it may be, in order to guarantee patient safety and well-being.

A review of the pharmacology and clinical efficacy of brivaracetam

Brivaracetam (BRV; Briviact) is a new antiepileptic drug (AED) approved for adjunctive treatment of focal (partial-onset) seizures in adults. BRV is a selective, high-affinity ligand for synaptic vesicle 2A (SV2A) with 15- to 30-fold higher affinity than levetiracetam, the first AED acting on SV2A. It has high lipid solubility and rapid brain penetration, with engagement of the target molecule, SV2A, within minutes of administration. BRV has potent broad-spectrum antiepileptic activity in animal models. Phase I studies indicated BRV was well tolerated and showed a favorable pharmacokinetic profile over a wide dose range following single (10–1,000 mg) and multiple (200–800 mg/day) oral dosing. Three pivotal Phase III studies have demonstrated promising efficacy and a good safety and tolerability profile across doses of 50–200 mg/day in the adjunctive treatment of refractory focal seizures. Long-term data indicate that the response to BRV is sustained, with good tolerability and retention rate. BRV is highly effective in patients experiencing secondarily generalized tonic–clonic seizures. Safety data to date suggest a favorable psychiatric adverse effect profile in controlled studies, although limited postmarketing data are available. BRV is easy to use, with no titration and little drug–drug interaction. It can be initiated at target dose with no titration. Efficacy is seen on day 1 of oral use in a significant percentage of patients. Intravenous administration in a 2-minute bolus and 15-minute infusion is well tolerated. Here, we review the pharmacology, pharmacokinetics, and clinical data of BRV.

Brivaracetam: a novel antiepileptic drug for focal-onset seizures

Brivaracetam (BRV), the n-propyl analogue of levetiracetam (LEV), is the latest antiepileptic drug (AED) to be licensed in Europe and the USA for the adjunctive treatment of focal-onset seizures with or without secondary generalization in patients aged 16 years or older. Like LEV, BRV binds to synaptic vesicle protein 2A (SV2A), but BRV has more selective binding and a 15- to 30-fold higher binding affinity than LEV. BRV is more effective than LEV in slowing synaptic vesicle mobilization and the two AEDs may act at different binding sites or interact with different conformational states of the SV2A protein. In animal models, BRV provides protection against focal and secondary generalized seizures and has significant anticonvulsant effects in genetic models of epilepsy. The drug undergoes first-order pharmacokinetics with an elimination half-life of 7-8 h. Although BRV is metabolized extensively, the main circulating compound is unchanged BRV. Around 95% of metabolites undergo renal elimination. No dose reduction is required in renal impairment, but it is recommended that the daily dose is reduced by one-third in hepatic dysfunction that may prolong half-life. BRV has a low potential for drug interactions. The efficacy and tolerability of adjunctive BRV in adults with focal-onset seizures have been explored in six randomized, placebo-controlled studies. These showed significant efficacy outcomes for doses of 50-200 mg/day. The most common adverse events reported were headache, somnolence, dizziness, fatigue and nausea. Patients who develop psychiatric symptoms with LEV appear to be at risk of similar side effects with BRV, although preliminary data suggest that these issues are likely to be less frequent and perhaps less severe. As with all AEDs, a low starting dose and slow titration schedule help to minimize side effects and optimize seizure control and thereby quality of life.

Evaluation of brivaracetam efficacy as monotherapy in adult patients with focal seizures

Brivaracetam is a selective, high-affinity ligand for synaptic vesicle protein 2A, recently approved as adjunctive therapy in the treatment of focal (partial-onset) seizures in patients 16 years of age and older with epilepsy. The goal of the present analysis was to determine if the dose-response of brivaracetam as monotherapy would fall within the range associated with brivaracetam efficacy as adjunctive therapy. An existing brivaracetam population pharmacokinetic model consisting of first-order absorption, single compartment distribution, and first-order elimination components was extended by estimating the clearance changes due to co-administration of 12 widely prescribed AEDs. Data for the population pharmacokinetic analysis originated from three Phase III add-on trials and two terminated Phase III monotherapy trials. An existing population model of daily seizure rate versus brivaracetam daily average concentration was applied to the data from the three add-on trials. Simulations allowed the assessment of the combined impact of covariate effects on both the pharmacokinetics and the pharmacodynamics of brivaracetam, and indicated that in the absence of other AEDs, only marginal changes in the overall dose-response relationship would be expected. This suggests that brivaracetam can be used as monotherapy without dose modifications.

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.

Brivaracetam population pharmacokinetics in children with epilepsy aged 1 month to 16 years

Purpose

The aims of the study were to develop a population pharmacokinetic model of orally administered brivaracetam in paediatric patients and to provide dosing suggestions.

Methods

Analysis included 600 brivaracetam plasma concentrations from a phase 2a study (NCT00422422; N01263) in 96 paediatric patients with epilepsy aged 1 month to 16 years, taking one to three concomitant antiepileptic drugs (AEDs). Pharmacokinetic analysis was performed using non-linear mixed effects modelling, and a stepwise covariate search was used to determine factors influencing brivaracetam clearance. Simulations were performed to investigate dosing regimens.

Results

The final model consisted of first-order absorption, single compartment distribution and first-order elimination components with allometric scaling of clearance and volume using lean body weight and fixed allometric exponents. Co-administration with phenobarbital or carbamazepine was associated with a 29% (95%CI 17%/39%) and 32% (22%/42%) decrease in exposure, respectively. Co-administration with valproate was associated with an 11% (1%/23%) increase in exposure. Simulations demonstrated that the majority of children were predicted to have an exposure similar to that in adults, using an age-independent dosing regimen of 2.0 mg/kg bid with a maximum of 100 mg bid for body weight >50 kg.

Conclusions

A paediatric dose adaptation of 2.0 mg/kg twice daily with a maximum of 100 mg twice daily for body weight >50 kg is predicted to ensure steady-state plasma concentrations in the same range as in adult patients receiving 100 mg twice daily (highest recommended dose). Data suggest no need to change brivaracetam dosing when used concomitantly with carbamazepine, phenobarbital or valproate.

Electronic supplementary material

The online version of this article (doi:10.1007/s00228-017-2230-6) contains supplementary material, which is available to authorized users.

Brivaracetam: A Review in Partial-Onset (Focal) Seizures in Patients with Epilepsy

Brivaracetam (Briviact(®); BRIVLERA™) is a high affinity synaptic vesicle protein 2A (SV2A) ligand available orally (as a tablet or solution) or intravenously (as a bolus or infusion) in various countries worldwide, including the USA, Canada and those of the EU. It is approved as adjunctive therapy for the treatment of partial-onset seizures (POS) in adults (aged ≥18 years) [USA, EU and Canada] and adolescents (aged 16 to <18 years) [USA and EU] with epilepsy. In multinational, phase III studies in adults and adolescents (aged ≥16 years), oral brivaracetam as adjunctive therapy to other antiepileptic drugs (AEDs) was generally associated with significant median percent reductions over placebo in seizure frequency and significant improvements in the proportion of patients achieving a ≥50 % reduction in seizure frequency compared with placebo. These benefits appeared to be sustained during up to 96 months' therapy in follow-up studies. Whether administered orally or intravenously, adjunctive brivaracetam was generally well tolerated in clinical studies, with the majority of treatment-emergent adverse events (TEAEs) being mild or moderate in intensity. In the absence of head-to-head studies, definitive conclusions on the comparative efficacy and tolerability of brivaracetam versus newer AEDs are not yet possible. In the meantime, brivaracetam extends the options currently available for the treatment of POS in patients aged ≥16 years with epilepsy.