Brivaracetam efficacy and safety in focal epilepsy

Ru-Catalyzed Asymmetric Hydrogenation of α,β-Unsaturated γ-Lactams

A highly efficient Ru-catalyzed asymmetric hydrogenation of α,β-unsaturated γ-lactams has been developed by using a C2-symmetric ruthenocenyl phosphine-oxazoline as the chiral ligand. This method achieves the enantioselective synthesis of chiral β-substituted γ-lactams in high yields and with excellent enantioselectivities (up to 99% yield with 99% ee). Mechanistic studies based on detailed control experiments and computational investigation revealed that the cationic Ru-complex acts as the active catalytic species; the protonation process of the oxa-π-allyl-Ru complex, which is formed by the migratory insertion of the C=C double bond to the Ru-H bond (the stereocontrolling step) followed by an isomerization process, is the rate-determining step, and the existence of PPh3 is crucial for the highly efficient catalytic behavior. The protocol provides a straightforward and practical pathway for the synthesis of key intermediates for several chiral drugs and bioactive compounds, particularly for the 150 kg-scale industrial production of Brivaracetam, an antiepileptic drug that shows 13-fold more potent binding to the synaptic vesicle protein 2A compared with the well-known Levetiracetam.

Impact of Third-Generation Antiseizure Medications on People with Epilepsy in a Low-Income Population: The Brivaracetam Experience in a Real-World Study

BACKGROUND

Third-generation antiseizure medications, such as brivaracetam, are recognized for their superior safety, tolerability, and pharmacokinetic profiles. However, their potential benefits are often limited in low-income populations because of challenges related to availability and affordability.

OBJECTIVE

We aimed to evaluate the effectiveness and safety of brivaracetam for treating epilepsy in a low-income population, within a real-world setting.

METHODS

This retrospective cohort study included individuals with epilepsy from a low-income population in Bogotá, Colombia, who were treated with brivaracetam between January 2020 and July 2023. Effectiveness (mean seizure reduction and ≥ 50% seizure reduction) and safety (retention rate and adverse events) were evaluated.

RESULTS

A total of 106 individuals were included, with a median age of 33 years (interquartile range: 24-44). Most had focal epilepsy with a median disease duration of 25.4 years (standard deviation: 13.6). The baseline seizure frequency was 4 seizures per month (interquartile range: 2-15) and individuals had previously received a mean of 4.4 (standard deviation: 1.8) antiseizure medications. The mean percentage seizure reduction at 3, 6, and 12 months was 55.3%, 66.9%, and 63.8%, respectively. Additionally, 60%, 63.8%, and 65.9% of individuals achieved a ≥ 50% seizure reduction at 3, 6, and 12 months, respectively. Retention rate at 3 months was 89% (n = 95) and 18.7% (n = 20) reported adverse effects.

CONCLUSIONS

In a real-world setting, brivaracetam has been shown to be safe and effective for the treatment of epilepsy in individuals from a low-income population. This study suggests that people with epilepsy living in this context can significantly benefit from the use of third-generation antiseizure medications.

New Pharmacological Therapies in the Treatment of Epilepsy in the Pediatric Population

Epilepsy is a disorder characterized by abnormal brain neuron activity, predisposing individuals to seizures. The International League Against Epilepsy (ILAE) categorizes epilepsy into the following groups: focal, generalized, generalized and focal, and unknown. Infants are the most vulnerable pediatric group to the condition, with the cause of epilepsy development being attributed to congenital brain developmental defects, white matter damage, intraventricular hemorrhage, perinatal hypoxic-ischemic injury, perinatal stroke, or genetic factors such as mutations in the Sodium Channel Protein Type 1 Subunit Alpha (SCN1A) gene. Due to the risks associated with this condition, we have investigated how the latest pharmacological treatments for epilepsy in children impact the reduction or complete elimination of seizures. We reviewed literature from 2018 to 2024, focusing on the age group from 1 month to 18 years old, with some studies including this age group as well as older individuals. The significance of this review is to present and compile research findings on the latest antiseizure drugs (ASDs), their effectiveness, dosing, and adverse effects in the pediatric population, which can contribute to selecting the best drug for a particular patient. The medications described in this review have shown significant efficacy and safety in the studied patient group, outweighing the observed adverse effects. The main aim of this review is to provide a comprehensive summary of the current state of knowledge regarding the newest pharmacotherapy for childhood epilepsy.

Identification of degradation products of brivaracetam using liquid chromatography quadrupole time-of-flight tandem mass spectrometry: Degradation pathway elucidation

RATIONALE

Pyrrolidone-based drugs find widespread use in treating conditions such as epilepsy and Alzheimer's disease, and in various other medical applications. Brivaracetam, the latest generation of pyrrolidone drugs, has exhibited significant promise owing to chemical structure modifications. Its affinity to the SV2A receptor is double that of the previous-generation drug, levetiracetam. Consequently, brivaracetam holds substantial potential for diverse applications. As a novel drug not yet included in the pharmacopeias of developed nations, comprehensive analysis and research are necessary to guarantee its safe utilization in clinical settings.

METHODS

A liquid chromatography quadrupole time-of-flight tandem mass spectrometry (LC/QTOFMS) method has been developed to effectively separate, identify and characterize both the degradation products and process-related substances of brivaracetam. Stress testing of the sample was carried out following the guidelines outlined in ICH Q1A(R2). The structures of these impurities were identified through positive electrospray ionization QTOF high-resolution MS and NMR spectroscopy. Additionally, the formation mechanism of each degradation product is thoroughly discussed.

RESULTS

Under the analytical conditions outlined in this paper, brivaracetam and its degradation products were effectively separated. Thirteen degradation products were detected and characterized, shedding light on their origins and degradation pathways. Among these, three degradation products align with previously reported impurities, and two unreported degradation products were synthesized and confirmed through NMR spectroscopy. The stress testing results revealed the instability of brivaracetam under acidic, alkaline, oxidative and thermal stress conditions, while it exhibited relative stability under photolytic stress conditions.

CONCLUSION

The study developed an analytical method for brivaracetam that enabled the effective detection and separation of brivaracetam and its 13 degradation products. This method addresses a gap in both current domestic and foreign drug standards. The structures of all the major degradation products were characterized by high-resolution LC/QTOFMS, which is essential for quality control during the drug production process, stability evaluation and the establishment of proper storage conditions.

Channeling of New Neuropsychiatric Drugs-Impact on Safety and Effectiveness Studies

This study aimed to examine differential prescribing due to channeling and propensity score non-overlap over time in new versus established treatments for common neurological conditions. We conducted cross-sectional analyses on a national sample of US commercially insured adults using 2005-2019 data. We compared new users of recently approved versus established medications for management of diabetic peripheral neuropathy (pregabalin versus gabapentin), Parkinson disease psychosis (pimavanserin versus quetiapine), and epilepsy (brivaracetam versus levetiracetam). Within these drug pairs, we compared demographic, clinical, and healthcare utilization characteristics of recipients of each drug. In addition, we fit yearly propensity score models for each condition and assessed propensity score non-overlap over time. For all three drug pairs, users of the more recently approved medications more frequently had prior treatment (pregabalin = 73.9%, gabapentin = 38.7%; pimavanserin = 41.1%, quetiapine = 14.0%; brivaracetam = 93.4%, levetiracetam = 32.1%). Propensity score non-overlap and its resulting sample loss after trimming were the greatest in the first year that the more recently approved medication was available (diabetic peripheral neuropathy, 12.4% non-overlap; Parkinson disease psychosis, 6.1%; epilepsy, 43.2%) and subsequently improved. Newer neuropsychiatric therapies appear to be channeled to individuals with refractory disease or intolerance to other treatments, leading to potential confounding and biased comparative effectiveness and safety study findings when compared to established treatments. Propensity score non-overlap should be reported in comparative studies that include newer medications. When studies comparing newer and established treatments are critically needed as soon as new treatments enter the market, investigators should recognize the potential for channeling bias and implement methodological approaches like those demonstrated in this study to understand and improve this issue in such studies.

A review of cognitive and behavioral outcomes of Brivaracetam

Anti-seizure medications (ASMs) can cause cognitive or behavioral adverse drug reactions, which is an important consideration when selecting an appropriate ASM. Brivaracetam (BRV) is a newer synaptic vesicle protein 2A ligand, which is expected to result in fewer neuropsychiatric adverse effects due to its mechanism of action. To understand the impact of BRV on cognition and behavior compared with other ASMs, we conducted a review of the literature using the Cochrane Library, PubMed/MEDLINE, and Embase. After the screening process, a total of two animal studies, one randomized controlled trial, one pooled analysis of clinical trials, one controlled study, and nine observational studies were included. The animal studies showed that BRV did not worsen cognitive or behavioral performance in rodents. The human studies showed that BRV was associated with fewer cognitive adverse events compared with other second- or third-generation ASMs. In addition, BRV was less associated with behavioral disturbance than levetiracetam. In summary, this review revealed that BRV has a limited impact on cognition and behavior. For patients who are intolerant to levetiracetam and have levetiracetam-related behavioral side effects, switching to BRV could be beneficial. However, heterogeneity between studies resulted in low-quality of evidence, and further trials are needed to confirm the findings.

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.

An update on brivaracetam for the treatment of pediatric partial epilepsy

Introduction: Brivaracetam (BRV) is an antiseizure medication (ASM), which has been approved as an adjunctive treatment in adults and pediatric patients aged four years and older with focal onset seizures. It is a second-generation levetiracetam (LEV) derivative, sharing the same mechanism of action, binding synaptic vesicles 2A (SV2A). BRV shows higher binding affinity and selectivity and higher brain permeability than LEV.Areas covered: This article reviews randomized controlled trials, retrospective and prospective studies published up to December 2020, searched in electronic databases MEDLINE, EMBASE and the Clinical Trial Database and provide an overview of efficacy, safety and tolerability of BRV in pediatric patients with partial epilepsy. Furthermore, the authors provide their expert opinion on the drug and give their future perspectives.Expert opinion: The analysis of the literature data has demonstrated the safety and efficacy of BRV in pediatric patients, with more evidence in children aged 4 to 16 years with an onset of focal seizures. However, a positive response was also achieved in patients affected by some encephalopathic epilepsies. Comparative efficacy studies between BRV and other ASMs, in addition to well-designed RCTs that include larger pediatric populations are needed to better define the role and potentiality of this ASM.

The Integrated Effects of Brivaracetam, a Selective Analog of Levetiracetam, on Ionic Currents and Neuronal Excitability

Brivaracetam (BRV) is recognized as a novel third-generation antiepileptic drug approved for the treatment of epilepsy. Emerging evidence has demonstrated that it has potentially better efficacy and tolerability than its analog, Levetiracetam (LEV). This, however, cannot be explained by their common synaptic vesicle-binding mechanism. Whether BRV can affect different ionic currents and concert these effects to alter neuronal excitability remains unclear. With the aid of patch clamp technology, we found that BRV concentration dependently inhibited the depolarization-induced M-type K⁺ current (I_K(M)), decreased the delayed-rectifier K⁺ current (I_K(DR)), and decreased the hyperpolarization-activated cation current in GH3 neurons. However, it had a concentration-dependent inhibition on voltage-gated Na⁺ current (I_Na). Under an inside-out patch configuration, a bath application of BRV increased the open probability of large-conductance Ca²⁺-activated K⁺ channels. Furthermore, in mHippoE-14 hippocampal neurons, the whole-cell I_Na was effectively depressed by BRV. In simulated modeling of hippocampal neurons, BRV was observed to reduce the firing of the action potentials (APs) concurrently with decreases in the AP amplitude. In animal models, BRV ameliorated acute seizures in both OD-1 and lithium-pilocarpine epilepsy models. However, LEV had effects in the latter only. Collectively, our study demonstrated BRV’s multiple ionic mechanism in electrically excitable cells and a potential concerted effect on neuronal excitability and hyperexcitability disorders.

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.

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.