Brivaracetam for the treatment of epilepsy

Increase of Brivaracetam serum concentration with introduction of Cenobamate

Introduction

Cenobamate is a new antiseizure medication approved for polytherapy of focal epilepsy with complex hepatic metabolism and effects on liver enzymes. So far, data are limited with regard to possible interactions with other antiseizure medications. We here report effects of Cenobamate on serum levels of Brivaracetam, a SV2-agent modulating presynaptic neurotransmitter release.

Methods

Retrospective analysis of Brivaracetam serum concentrations with new introduction of Cenobamate with Brivaracetam as a constant baseline antiseizure medication in 19 patients with focal epilepsy. Statistical analysis using paired Fisher´s exact t-Test.

Results

New introduction of Cenobamate lead to a statistically significant increase in Brivaracetam serum concentrations with a mean increase by 27%. This was infrequently accompanied by adverse effects.

Discussion

New introduction of Cenobamate to a pre-existing antiseizure regimen containing Brivaracetam leads to considerably increases in Brivaracetam, probably related to inhibition of CYP2C19. This needs to be taken into account when interpreting changes in treatment efficacy, but also when relating potential adverse effects to baseline vs. newly introduced treatment.

Brivaracetam add-on therapy for drug-resistant epilepsy

BACKGROUND

This is an updated version of the Cochrane Review previously published in 2019. Epilepsy is one of the most common neurological disorders. It is estimated that up to 30% of individuals with epilepsy continue to have epileptic seizures despite treatment with an antiepileptic drug. These patients are classified as drug-resistant and require treatment with a combination of multiple antiepileptic drugs. Brivaracetam is a third-generation antiepileptic drug that is a high-affinity ligand for synaptic vesicle protein 2A. In this review we investigated the use of brivaracetam as add-on therapy for epilepsy.

OBJECTIVES

To evaluate the efficacy and tolerability of brivaracetam when used as add-on treatment for people with drug-resistant epilepsy.

SEARCH METHODS

For the latest update we searched the following databases on 7 September 2021: the Cochrane Register of Studies (CRS Web); MEDLINE (Ovid) 1946 to 3 September 2021. CRS Web includes randomised controlled trials (RCTs) and quasi-RCTs from PubMed, Embase, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform, the Cochrane Central Register of Controlled Trials (CENTRAL), and the specialised registers of Cochrane Review Groups including Cochrane Epilepsy.

SELECTION CRITERIA

We searched for parallel-group RCTs that recruited people of any age with drug-resistant epilepsy. We accepted studies with any level of blinding (double-blind, single-blind, or unblinded).

DATA COLLECTION AND ANALYSIS

In accordance with standard Cochrane methodological procedures, two review authors independently assessed trials for inclusion before evaluating trial quality and extracting relevant data. The primary outcome to be assessed was 50% or greater reduction in seizure frequency. Secondary outcomes were: seizure freedom, treatment withdrawal for any reason, treatment withdrawal due to adverse events, the proportion of participants who experienced any adverse events, and drug interactions. We used an intention-to-treat population for all primary analyses, and presented results as risk ratios (RRs) with 95% confidence intervals (CIs).

MAIN RESULTS

We did not identify any new studies for this update, therefore the results and conclusions of the review are unchanged. The previous review included six studies involving a total of 2411 participants. Only one study included participants with both focal and generalised onset seizures; the other five trials included participants with focal onset seizures only. Study participants were aged 16 to 80 years. Treatment periods ranged from 7 to 16 weeks. We judged two studies to have low risk of bias and four to have unclear risk of bias. Details on the method used for allocation concealment and how blinding was maintained were insufficient in one study each. One study did not report all outcomes prespecified in the trial protocol, and there were discrepancies in reporting in a further study. Participants receiving brivaracetam add-on were more likely to experience a 50% or greater reduction in seizure frequency than those receiving placebo (RR 1.81, 95% CI 1.53 to 2.14; 6 studies; moderate-certainty evidence). Participants receiving brivaracetam were more likely to attain seizure freedom; however, the evidence is of low certainty (RR 5.89, 95% CI 2.30 to 15.13; 6 studies). The incidence of treatment withdrawal for any reason was slightly greater for participants receiving brivaracetam compared to those receiving placebo (RR 1.27, 95% CI 0.94 to 1.74; 6 studies; low-certainty evidence). The risk of participants experiencing one or more adverse events did not differ significantly following treatment with brivaracetam compared to placebo (RR 1.08, 95% CI 1.00 to 1.17; 5 studies; moderate-certainty evidence). However, participants receiving brivaracetam did appear to be more likely to withdraw from treatment due to adverse events compared with those receiving placebo (RR 1.54, 95% CI 1.02 to 2.33; 6 studies; low-certainty evidence).

AUTHORS' CONCLUSIONS

When used as add-on therapy for individuals with drug-resistant epilepsy, brivaracetam may be effective in reducing seizure frequency and may aid patients in achieving seizure freedom. However, add-on brivaracetam is probably associated with a greater proportion of treatment withdrawals due to adverse events compared with placebo. It is important to note that only one of the eligible studies included participants with generalised epilepsy. None of the included studies involved participants under the age of 16, and all studies were of short duration. Consequently, the findings of this review are mainly applicable to adult patients with drug-resistant focal epilepsy. Future research should focus on investigating the tolerability and efficacy of brivaracetam during longer-term follow-up, as well as assess the efficacy and tolerability of add-on brivaracetam in managing other types of seizures and in other age groups.

Brivaracetam add-on therapy for drug-resistant epilepsy

BACKGROUND

Epilepsy is one of the most common neurological disorders. It is estimated that up to 30% of patients with epilepsy continue to have epileptic seizures despite treatment with an antiepileptic drug. These patients are classified as drug-resistant and require treatment with a combination of multiple antiepileptic drugs. Brivaracetam is a third-generation antiepileptic drug that is a high-affinity ligand for synaptic vesicle protein 2A. This review investigates the use of brivaracetam as add-on therapy for epilepsy.

OBJECTIVES

To evaluate the efficacy and tolerability of brivaracetam when used as add-on treatment for people with drug-resistant epilepsy.

SEARCH METHODS

We searched the following databases on 9 October 2018: the Cochrane Register of Studies (CRS Web), which includes the Cochrane Epilepsy Group Specialized Register and the Cochrane Central Register of Controlled Trials (CENTRAL); Medline (Ovid) 1946 to 8 October 2018; ClinicalTrials.gov; and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). Originally we also searched SCOPUS as a substitute for Embase, but this is no longer necessary, because randomised and quasi-randomised controlled trials in Embase are now included in CENTRAL.

SELECTION CRITERIA

We sought randomised controlled trials with parallel-group design, recruiting people of any age with drug-resistant epilepsy. We accepted studies with any level of blinding (double-blind, single-blind, or unblind).

DATA COLLECTION AND ANALYSIS

In accordance with standard methodological procedures expected by the Cochrane Collaboration, two review authors independently assessed trials for inclusion before evaluating trial quality and extracting relevant data. The primary outcome to be assessed was 50% or greater reduction in seizure frequency. Secondary outcomes were: seizure freedom, treatment withdrawal for any reason, treatment withdrawal due to adverse events, the proportion of participants who experienced any adverse events, and drug interactions. We used an intention-to-treat (ITT) population for all primary analyses, and we presented results as risk ratios (RRs) with 95% confidence intervals (CIs).

MAIN RESULTS

The review included six trials representing 2411 participants. Only one study included participants with both focal and generalised onset seizures; the other five trials included participants with focal onset seizures only. All six studies included adult participants between 16 and 80 years old, and treatment periods ranged from 7 to 16 weeks. We judged two studies to have low risk of bias and four to have unclear risk of bias. One study failed to provide details on the method used for allocation concealment, and one did not report all outcomes prespecified in the trial protocol. One study did not describe how blinding was maintained, and another noted discrepancies in reporting.Participants receiving brivaracetam add-on were significantly more likely to experience a 50% or greater reduction in seizure frequency than those receiving placebo (RR 1.81, 95% CI 1.53 to 2.14; 6 studies; moderate-quality evidence). Participants receiving brivaracetam were also significantly more likely to attain seizure freedom (RR 5.89, 95% CI 2.30 to 15.13; 6 studies; moderate-quality evidence). The incidence of treatment withdrawal for any reason (RR 1.27, 95% CI 0.94 to 1.74; 6 studies; low-quality evidence), as well as the risk of participants experiencing one or more adverse events (RR 1.08, 95% CI 1.00 to 1.17; 5 studies; moderate-quality evidence), was not significantly different following treatment with brivaracetam compared to placebo. However, participants receiving brivaracetam did appear to be significantly more likely to withdraw from treatment specifically because of adverse events compared with those receiving placebo (RR 1.54, 95% CI 1.02 to 2.33; 6 studies; low-quality evidence).

AUTHORS' CONCLUSIONS

Brivaracetam, when used as add-on therapy for patients with drug-resistant epilepsy, is effective in reducing seizure frequency and can aid patients in achieving seizure freedom. However, add-on brivaracetam is associated with a greater proportion of treatment withdrawals due to adverse events compared with placebo. It is important to note that only one of the eligible studies included participants with generalised epilepsy. None of the studies included participants under the age of 16, and all studies were of short duration. Consequently, these findings are mainly applicable to adult patients with drug-resistant focal epilepsy. Future research should thus focus on investigating the tolerability and efficacy of brivaracetam during longer-term follow-up, and should also assess the efficacy and tolerability of add-on brivaracetam in managing other types of seizures and its use in other age groups.

The Mechanism of Anti-Epileptogenesis by Levetiracetam Treatment is Similar to the Spontaneous Recovery of Idiopathic Generalized Epilepsy during Adolescence

OBJECTIVE

The anti-epileptogenic drug levetiracetam has anticonvulsant and anti-epileptogenesis effects. Synergy between cell death and inflammation can lead to increased levels of apoptosis inhibitory factors and brain-derived neurotrophic factor, aberrant neurogenesis and extended axon sprouting. Once hyperexcitation of the neural network occurs, spontaneous seizures or epileptogenesis develops. This study investigated whether the anti-epileptogenic effect of levetiracetam is due to its alternate apoptotic activity.

METHODS

Adult male Noda epileptic rats were treated with levetiracetam or vehicle control for two weeks. mRNA quantification of Bax, Bcl-2 and GAPDH expression were performed from prefrontal cortex and hippocampus tissue samples.

RESULTS

The levetiracetam-treated group showed a significant increase of Bax/Bcl-2 mRNA expression ratio in the prefrontal cortex than the control group, but no change in the Bax/Bcl-2 mRNA expression ratio in hippocampus.

CONCLUSION

Idiopathic generalized epilepsy including childhood absence epilepsy develop at childhood and recover spontaneously during adolescence. The aberrant neural excitable network is pruned by a neural-maturing action. This study suggests the mechanism of acquired anti-epileptogenesis by levetiracetam treatment may be similar to spontaneous recovery of idiopathic generalized epilepsy during adolescence.

Emerging drugs for partial-onset epilepsy: a review of brivaracetam

There are more than 12 new antiepileptic drugs approved in the last 2 decades. Even with these newer agents, seizure remission is still unachievable in around 30% of patients with partial-onset seizures (POS). Brivaracetam (BRV) is chemically related to levetiracetam (LEV) and possesses a strong binding affinity for the synaptic vesicle protein 2A tenfold above that of LEV, and other possible modes of antiepileptic actions. BRV is now under Phase III development for POS, but data from one Phase III trial also suggested its potential efficacy for primary generalized seizures. The purpose of this review is to provide updated information on the mechanisms of action of the available antiepileptic drugs, with a focus on BRV to assess its pharmacology, pharmacokinetics, clinical efficacy, safety, and tolerability in patients with uncontrolled POS. To date, six Phase IIb and III clinical trials have been performed to investigate the efficacy, safety, and tolerability of BRV as an adjunctive treatment for patients with POS. Generally, BRV was well tolerated and did not show significant difference in safety profile, compared to placebo. The efficacy outcomes of BRV, although not consistent across trials, did indicate that BRV was a promising add-on therapy for patients with POS. In conclusion, the many favorable attributes of BRV, like its high oral efficacy, good tolerability, dosing regimen, and minimal drug interaction, make it a promising antiepileptic therapy for patients with uncontrolled partial-onset epilepsy.

Synaptic vesicle protein2A decreases in amygdaloid-kindling pharmcoresistant epileptic rats

Synaptic vesicle protein 2A (SV2A) involvement has been reported in the animal models of epilepsy and in human intractable epilepsy. The difference between pharmacosensitive epilepsy and pharmacoresistant epilepsy remains poorly understood. The present study aimed to observe the hippocampus SV2A protein expression in amygdale-kindling pharmacoresistant epileptic rats. The pharmacosensitive epileptic rats served as control. Amygdaloid-kindling model of epilepsy was established in 100 healthy adult male Sprague-Dawley rats. The kindled rat model of epilepsy was used to select pharmacoresistance by testing their seizure response to phenytoin and phenobarbital. The selected pharmacoresistant rats were assigned to a pharmacoresistant epileptic group (PRE group). Another 12 pharmacosensitive epileptic rats (PSE group) served as control. Immunohistochemistry, real-time PCR and Western blotting were used to determine SV2A expression in the hippocampus tissue samples from both the PRE and the PSE rats. Immunohistochemistry staining showed that SV2A was mainly accumulated in the cytoplasm of the neurons, as well as along their dendrites throughout all subfields of the hippocampus. Immunoreactive staining level of SV2A-positive cells was 0.483 ± 0.304 in the PRE group and 0.866 ± 0.090 in the PSE group (P < 0.05). Real-time PCR analysis demonstrated that 2(-ΔΔCt) value of SV2A mRNA was 0.30 ± 0.43 in the PRE group and 0.76 ± 0.18 in the PSE group (P < 0.05). Western blotting analysis obtained the similar findings (0.27 ± 0.21 versus 1.12 ± 0.21, P < 0.05). PRE rats displayed a significant decrease of SV2A in the brain. SV2A may be associated with the pathogenesis of intractable epilepsy of the amygdaloid-kindling rats.

The efficacy and safety of brivaracetam at different doses for partial-onset epilepsy: a meta-analysis of placebo-controlled studies

OBJECTIVE

This meta-analysis systematically assessed the efficacy and safety of different doses of brivaracetam (BRV) compared with placebo as adjunctive therapy for adults with partial-onset epilepsy.

METHODS

Electronic and clinical trials databases were searched for randomized controlled trials of BRV published up to May 2015. We assessed the risk of bias of the included studies using the Cochrane Risk of Bias tool. The outcomes of interest included 50% responder rates, seizure freedom, the incidence of withdrawal and treatment-emergent adverse events (TEAEs).

RESULTS

Five trials met the inclusion criteria. Compared with placebo, 20, 50, 100 and 150 mg/day BRV was associated with significantly higher 50% responder rates. In addition, the effect of 50 mg BRV on seizure freedom was significantly different than that of placebo. Both fatigue and nasopharyngitis were significantly associated with 20 mg BRV, whereas fatigue and irritability were associated with 50 mg BRV. Somnolence was associated with 150 mg BRV. No significant differences were observed for the other common TEAEs.

CONCLUSION

The use of BRV at doses > 5 mg/day resulted in statistically significant reduction in seizure frequency in respect to the 50% responder rate. BRV was reasonably tolerated by patients. These findings warrant confirmation in future studies.

Advancing the management of childhood epilepsies

Childhood epilepsies comprise a heterogeneous group of disorders and syndromes that vary in terms of severity, prognosis and treatment requirements. Effective management requires early, accurate recognition and diagnosis, and a holistic approach that addresses each individual's medical and psychosocial needs within the context of their overall health status and quality of life. With increasing understanding of underlying aetiologies, new approaches to management and treatment are emerging. For example, genetic testing is beginning to provide a tool to aid differential diagnosis and a means of predicting predisposition to particular types of epilepsy. Despite the availability of an increasing number of antiepileptic drugs (AEDs)--due not only to the development of new AEDs, but also to changes in regulatory requirements that have facilitated clinical development--seizure control and tolerability continue to be suboptimal in many patients, and there is therefore a continuing need for new treatment strategies. Surgery and other non-pharmacological treatments (e.g. vagus nerve stimulation, ketogenic diet) are already relatively well established in paediatric epilepsy. New pharmacological treatments include generational advances on existing AEDs and AEDs with novel modes of action, and non-AED pharmacological interventions, such as immunomodulation. Emerging technologies include novel approaches allowing the delivery of medicinal agents to specific areas of the brain, and 'closed-loop' experimental devices employing algorithms that allow treatment (e.g., electrical stimulation) to be targeted both spatially and temporally. Although in early stages of development, cell-based approaches (e.g., focal targeting of adenosine augmentation) and gene therapy may also provide new treatment choices in the future.