Long-term safety, efficacy, and quality of life during adjunctive brivaracetam treatment in patients with uncontrolled epilepsy: An open-label follow-up trial

Single intravenous and oral dose pharmacokinetics of the antiseizure medication brivaracetam in healthy cats

The number of available antiseizure medications with demonstrated efficacy in cats is limited. As such, there is a need to evaluate the pharmacokinetics of newer medications so that proper dosing regimens can be made. Brivaracetam (BRV) is a more potent analogue of levetiracetam, and is Food and Drug Administration approved for use in people. The goal of this study was to describe the pharmacokinetics of intravenous and oral doses of BRV in healthy cats. A cross-over study involving eight healthy cats, that were administered 10 mg of BRV intravenously as a bolus and orally in the fasted state. Blood samples were collected over 24 h. Analysis was performed using liquid chromatography-mass spectrometry. Data were subjected to non-compartmental analysis. Median (min-max) of maximal concentration, time to maximal concentration, area under the curve, elimination half-life and oral absolute bioavailability were 902 (682-1036) ng/mL, 0.6 (0.5-2.0) h, 6.4 (5.2-7.2) h, 8145 (6669-9351) ng × h/mL and 100% (85-110) respectively. BRV appeared to be well tolerated by all cats. A single dose of BRV is well tolerated both orally and intravenously. Maximal concentrations are produced rapidly and within the human reference interval considered to be therapeutic.

Narrative Review of Brivaracetam: Preclinical Profile and Clinical Benefits in the Treatment of Patients with Epilepsy

One third of patients with epilepsy will continue to have uncontrolled seizures despite treatment with antiseizure medications (ASMs). There is therefore a need to develop novel ASMs. Brivaracetam (BRV) is an ASM that was developed in a major drug discovery program aimed at identifying selective, high-affinity synaptic vesicle protein 2A (SV2A) ligands, the target molecule of levetiracetam. BRV binds to SV2A with 15- to 30-fold higher affinity and greater selectivity than levetiracetam. BRV has broad-spectrum antiseizure activity in animal models of epilepsy, a favorable pharmacokinetic profile, few clinically relevant drug-drug interactions, and rapid brain penetration. BRV is available in oral and intravenous formulations and can be initiated at target dose without titration. Efficacy and safety of adjunctive BRV (50-200 mg/day) treatment of focal-onset seizures was demonstrated in three pivotal phase III trials (NCT00490035/NCT00464269/NCT01261325), including in patients who had previously failed levetiracetam. Efficacy and safety of adjunctive BRV were also demonstrated in adult Asian patients with focal-onset seizures (NCT03083665). In several open-label trials (NCT00150800/NCT00175916/NCT01339559), long-term safety and tolerability of adjunctive BRV was established, with efficacy maintained for up to 14 years, with high retention rates. Evidence from daily clinical practice highlights BRV effectiveness and tolerability in specific epilepsy patient populations with high unmet needs: the elderly (≥ 65 years of age), children (< 16 years of age), patients with cognitive impairment, patients with psychiatric comorbid conditions, and patients with acquired epilepsy of specific etiologies (post-stroke epilepsy/brain tumor related epilepsy/traumatic brain injury-related epilepsy). Here, we review the preclinical profile and clinical benefits of BRV from pivotal trials and recently published evidence from daily clinical practice.

Efficacy, safety, and tolerability of adjunctive brivaracetam in adult Asian patients with uncontrolled focal-onset seizures: A phase III randomized, double-blind, placebo-controlled trial

OBJECTIVE

Evaluate efficacy, safety, and tolerability of adjunctive brivaracetam (BRV) in adult Asian patients with focal-onset seizures (FOS).

METHODS

Phase III, randomized, double-blind, placebo-controlled study (EP0083; NCT03083665) evaluating BRV 50 mg/day and 200 mg/day in patients (≥16-80 years) with FOS with/without secondary generalization (focal to bilateral tonic-clonic seizures) despite current treatment with 1 or 2 concomitant antiseizure medications. Following an 8-week baseline, patients were randomized 1:1:1 to placebo, BRV 50 mg/day, or BRV 200 mg/day, and entered a 12-week treatment period. Efficacy outcomes: percent reduction over placebo in 28-day FOS frequency (primary); 50% responder rate in FOS frequency; median percent reduction in FOS frequency from baseline; seizure freedom during treatment period (secondary). Primary safety endpoints: incidences of treatment-emergent adverse events (TEAEs); TEAEs leading to discontinuation; serious TEAEs.

RESULTS

In this study, 448/449 randomized patients (mean age, 34.5 years; 53.8% female) received ≥1 dose of study medication (placebo/BRV 50 mg/BRV 200 mg/day: n = 149/151/148). Percent reduction over placebo in 28-day adjusted FOS frequency was 24.5% (p = 0.0005) and 33.4% (p < 0.0001) with BRV 50 mg/day and 200 mg/day, respectively, 50% responder rate was 19.0%, 41.1%, and 49.3% with placebo, BRV 50 mg/day, and BRV 200 mg/day, respectively (p < 0.0001 for both BRV groups vs. placebo). Median percent reduction in FOS frequency from baseline was 21.3%/38.9%/46.7% in patients on placebo/BRV 50 mg/BRV 200 mg/day, respectively. Overall, 0, 7 (4.6%), and 10 (6.8%) patients were classified as seizure-free during the treatment period on placebo, BRV 50 mg/day, and BRV 200 mg/day, respectively (p = 0.0146/p = 0.0017 for BRV 50 mg/200 mg/day vs. placebo, respectively). TEAE incidences were similar between patients on placebo (58.4%) and all patients receiving BRV (58.5%); TEAE incidences for BRV 50 mg/day and BRV 200 mg/day were 57.0% and 60.1%, respectively. Overall, 0.7% of patients on placebo and 2.0% of all patients on BRV reported serious TEAEs (incidences for BRV 50 mg/day and BRV 200 mg/day were 1.3% and 2.7%, respectively), 20.1% of patients on placebo and 33.1% of all patients on BRV reported drug-related TEAEs (incidences for BRV 50 mg/day and BRV 200 mg/day were 26.5% and 39.9%, respectively), and 4.7% of patients on placebo and 3.0% of all patients on BRV discontinued due to TEAEs (discontinuation incidences for BRV 50 mg/day and BRV 200 mg/day were 2.6% and 3.4%, respectively).

SIGNIFICANCE

Adjunctive BRV was efficacious and well tolerated in adult Asian patients with FOS. Efficacy and safety profiles were consistent with BRV studies in predominantly non-Asian populations.

PLAIN LANGUAGE SUMMARY

Brivaracetam is used to treat partial or focal seizures in people with epilepsy. Most studies with brivaracetam tablets have involved people from non-Asian racial backgrounds. In this study, 449 Asian adults with epilepsy took part. One third took 50 mg of brivaracetam, one third took 200 mg of brivaracetam, and one third took a placebo each day for 12 weeks. On average, those who took brivaracetam had fewer seizures than those given the placebo. Most of the side effects were mild and the number and type of side effects seen were as expected for this medication.

An analysis of suicidal and self-injurious behavior reports with antiseizure medications in the FDA adverse event database

BACKGROUND

Pharmacovigilance systems such as the FDA Adverse Event Reporting System (FAERS), are established models for adverse event surveillance that may have been missed during clinical trials. We aimed to analyze twenty-five anti-seizure medications (ASMs) in FAERS to assess for increased reporting of suicidal and self-injurious behavior.

METHODS

Twenty-five ASMs were analyzed: brivaracetam, cannabidiol, carbamazepine, clobazam, clonazepam, diazepam, eslicarbazepine, felbamate, gabapentin, lacosamide, lamotrigine, levetiracetam, oxcarbazepine, perampanel, phenobarbital, phenytoin, pregabalin, primidone, rufinamide, stiripentol, tiagabine, topiramate, valproate, vigabatrin, zonisamide. Reports of "suicidal and self-injurious behavior" were collected from January 1, 2004, to December 31, 2020, using OpenVigil 2.1 tool with indication as "Epilepsy". Relative reporting ratio, proportional reporting ratio, and reporting odds ratio were calculated utilizing all other drug reports for epilepsy patients as a control.

RESULTS

Significant relative operating ratio, ROR (greater than 1, p<0.05) were observed for diazepam (2.909), pregabalin (2.739), brivaracetam (2.462), gabapentin (2.185), clonazepam (1.649), zonisamide (1.462), lacosamide (1.333), and levetiracetam (1.286).

CONCLUSIONS

Of the 25 ASMs that were analyzed in this study, 4 (16%) were identified to have been linked with a likely true adverse event. These drugs included diazepam, brivaracetam, gabapenetin, and pregabalin. Although several limitations are present with the FAERS database, it is imperative to closely monitor patient comorbidities for increased risk of suicidality with the use of several ASMs.

Retention, efficacy, tolerability, and quality of life during long-term adjunctive brivaracetam treatment by number of lifetime antiseizure medications: A post hoc analysis of phase 3 trials in adults with focal seizures

OBJECTIVE

To evaluate long-term retention, reasons for discontinuation, efficacy, tolerability, and health-related quality of life (HRQOL) during adjunctive brivaracetam (BRV) treatment in adults with focal seizures by number of lifetime antiseizure medications (ASMs).

METHODS

Post hoc analyses of a randomized, double-blind, placebo-controlled trial (N01358; NCT01261325) and corresponding open-label extension (OLE) (N01379; NCT01339559) of adjunctive BRV in adults (16-80 years of age) with focal seizures. Outcomes were assessed from the first day of BRV treatment in the double-blind (patients randomized to BRV) or open-label trial (patients randomized to placebo) by number of lifetime ASMs (1-2, 3-4, 5-6, or ≥ 7). Lifetime ASMs were defined as previous (stopped before BRV initiation) and concomitant ASMs at BRV initiation.

RESULTS

Seven hundred and forty patients received adjunctive BRV (safety set [SS]; median modal dose: 200 mg/day [N = 737]; median treatment duration: 2.67 years), of whom 13.8 % had 1-2, 20.8 % had 3-4, 21.1 % had 5-6 and 44.3 % had ≥7 lifetime ASMs. Patients with a higher number of lifetime ASMs had a younger age at epilepsy onset, longer epilepsy duration, and higher baseline seizure frequency. Kaplan-Meier estimated retention on BRV at 12 (83.2-65.9 %) and 36 months (63.0-44.1 %) was highest in patients with 1-2 lifetime ASMs and decreased with the number of lifetime ASMs. The estimated proportions of patients who discontinued BRV due to lack of efficacy or treatment-emergent adverse events (TEAEs) increased with the number of lifetime ASMs. Efficacy analyses included seven hundred and thirty eight patients (intention-to-treat set [ITT]). Median percentage reductions from baseline in focal seizure frequency/28 days (76.3-39.6 %), 50 % responder rates (66.7-39.8 %), 75 % responder rates (51.0-19.6 %), and continuous seizure freedom for ≥12 months at any time during BRV treatment (35.3-6.1 %) were highest in patients with 1-2 lifetime ASMs and decreased by the number of lifetime ASMs. The overall incidence of TEAEs (SS) was generally similar in each lifetime ASM subgroup (84.4-90.5 %). Discontinuations due to TEAEs increased with the number of lifetime ASMs (7.8-20.1 %). The greatest improvements in QOLIE-31-P scores occurred in the Seizure Worry and Daily Activities/Social Function subscales, with no clear pattern by the number of lifetime ASMs at 12 months and with the highest improvement in patients with 1-2 lifetime ASMs at 24 months. At 24 months, the Hospital Anxiety and Depression Scale (HADS) Anxiety subscale scores improved in patients (SS) with 1-2 and 3-4 lifetime ASMs. HADS Depression subscale scores were generally stable independent of the number of lifetime ASMs.

CONCLUSIONS

The balance between efficacy, tolerability, and HRQOL was most favorable in patients with focal seizures who had been exposed to one or two ASMs before BRV initiation. However, patients exposed to ≥7 ASMs before BRV initiation also benefitted from long-term adjunctive BRV treatment.

BRIVEST: A 'real-world' observational, single-centre study investigating the efficacy, safety and tolerability of Brivaracetam

OBJECTIVE

Via measures of efficacy, tolerability, and safety, this open-label, single-center study assessed the overall effectiveness of Brivaracetam (BRV) for the treatment of epilepsy in the context of 'real-world' clinical practice.

METHODS

Unselected consecutive patients were recruited and stratified into 3 cohorts with either fully prospective, fully retrospective or mixed data collection, dependent on whether their BRV prescriptions were historical, current, or pending. Prospective data were obtained at baseline, 3 and 6 months, and at 6-month intervals thereafter, from patient interviews and seizure diaries, and retrospective data from medical records. Efficacy variables were derived from seizure-related changes, and tolerability and safety variables from reported treatment-emergent adverse events (TEAEs), BRV withdrawal, and changes to questionnaire scores. Additionally, we investigated treatment outcomes for those with previous levetiracetam (LEV) use, a history of psychiatric comorbidity, a learning disability, and of older age.

RESULTS

One hundred and nine patients (58.7% female, mean age 42 years, range: 18 to 72) were included, 59 with prospective follow-up for a minimum of 6 (47 patients, excluding those who withdrew) and a maximum of 24 months (2 patients). Of the full cohort, 87.2% had drug-resistant epilepsy. Retention: At the study end, the median treatment duration was 384 days (range: 6 to 1514 days), and BRV retention was 68.8%. Kaplan-Meier survival functions predicted retention rates of 74.0% and 70.0% at 6 and 12 months respectively.

EFFICACY

At the last follow-up, there was a ≥ 50% responder rate of 30.8%, with 12.1% seizure-free. Seizure frequency categories improved in 31.4% of patients, remained the same in 44.2%, and worsened in 24.4%. Monthly tonic-clonic seizure frequency had significantly decreased, and of those reporting these seizures, 58.3% showed reductions and 25.0% showed complete tonic-clonic seizure freedom.

TOLERABILITY

91.7% of patients reported at least 1 TEAE, with fatigue (30.3%), irritability (29.4%), and depression/low mood (28.4%) as the most common. Only 58.4% of all TEAEs were persistent. Brivaracetam discontinuation due to side effects occurred in 27.5% of the cohort. Depression and anxiety scores remained stable over time, and quality-of-life scores improved. Subgroups: Measures of BRV efficacy and tolerability did not differ according to previous LEV exposure. Tolerability profiles of those with learning disabilities, histories of psychiatric comorbidities, and older age did not greatly differ from the rest of the cohort. Of note, specific history of depression predicted the reporting of suicidal ideation.

CONCLUSION

The BRIVEST study provides real-world evidence of the effectiveness of BRV, suggesting that neither drug-resistant epilepsy nor previous LEV failure should preclude its use. Furthermore, BRV appears to be well-tolerated, even among those from vulnerable patient populations.

Genetic Testing to Inform Epilepsy Treatment Management From an International Study of Clinical Practice

Importance

It is currently unknown how often and in which ways a genetic diagnosis given to a patient with epilepsy is associated with clinical management and outcomes.

Objective

To evaluate how genetic diagnoses in patients with epilepsy are associated with clinical management and outcomes.

Design, Setting, and Participants

This was a retrospective cross-sectional study of patients referred for multigene panel testing between March 18, 2016, and August 3, 2020, with outcomes reported between May and November 2020. The study setting included a commercial genetic testing laboratory and multicenter clinical practices. Patients with epilepsy, regardless of sociodemographic features, who received a pathogenic/likely pathogenic (P/LP) variant were included in the study. Case report forms were completed by all health care professionals.

Exposures

Genetic test results.

Main Outcomes and Measures

Clinical management changes after a genetic diagnosis (ie, 1 P/LP variant in autosomal dominant and X-linked diseases; 2 P/LP variants in autosomal recessive diseases) and subsequent patient outcomes as reported by health care professionals on case report forms.

Results

Among 418 patients, median (IQR) age at the time of testing was 4 (1-10) years, with an age range of 0 to 52 years, and 53.8% (n = 225) were female individuals. The mean (SD) time from a genetic test order to case report form completion was 595 (368) days (range, 27-1673 days). A genetic diagnosis was associated with changes in clinical management for 208 patients (49.8%) and usually (81.7% of the time) within 3 months of receiving the result. The most common clinical management changes were the addition of a new medication (78 [21.7%]), the initiation of medication (51 [14.2%]), the referral of a patient to a specialist (48 [13.4%]), vigilance for subclinical or extraneurological disease features (46 [12.8%]), and the cessation of a medication (42 [11.7%]). Among 167 patients with follow-up clinical information available (mean [SD] time, 584 [365] days), 125 (74.9%) reported positive outcomes, 108 (64.7%) reported reduction or elimination of seizures, 37 (22.2%) had decreases in the severity of other clinical signs, and 11 (6.6%) had reduced medication adverse effects. A few patients reported worsening of outcomes, including a decline in their condition (20 [12.0%]), increased seizure frequency (6 [3.6%]), and adverse medication effects (3 [1.8%]). No clinical management changes were reported for 178 patients (42.6%).

Conclusions and Relevance

Results of this cross-sectional study suggest that genetic testing of individuals with epilepsy may be materially associated with clinical decision-making and improved patient outcomes.

Retention of brivaracetam in adults with drug-resistant epilepsy at a single tertiary care center

INTRODUCTION

Brivaracetam (BRV) is licensed as an adjunctive treatment for focal epilepsy. We describe our clinical experience with BRV at a large UK tertiary center.

METHODS

Adults initiated on BRV between July 2015 and July 2020 were followed up until they discontinued BRV or September 2021. Data on epilepsy syndrome, duration, seizure types, concomitant and previous antiseizure medication (ASM) use, BRV dosing, efficacy, and side effects were recorded. Efficacy was categorized as temporary (minimum three months) or ongoing (at last follow-up) seizure freedom, ≥50% seizure reduction, or other benefits (e.g., no convulsions or daytime seizures). Brivaracetam retention was estimated using Kaplan-Meier survival analysis.

RESULTS

Two-hundred people were treated with BRV, of whom 81% had focal epilepsy. The mean (interquartile range [IQR]) follow-up time was 707 (688) days, and the dose range was 50-600 mg daily. The mean (IQR) of the previous number of used ASMs was 6.9 (6.0), and concomitant use was 2.2 (1.0). One-hundred and eighty-eight people (94%) had previously discontinued levetiracetam (LEV), mainly due to side effects. 13/200 (6.5%) were seizure free for a minimum of six months during treatment, and 46/200 (23%) had a ≥50% reduction in seizure frequency for six months or more. Retention rates were 83% at six months, 71% at 12 months, and 57% at 36 months. Brivaracetam was mostly discontinued due to side effects (38/75, 51%) or lack of efficacy (28/75, 37%). Concomitant use of carbamazepine significantly increased the hazard ratio of discontinuing BRV due to side effects (p = 0.006). The most commonly reported side effects were low mood (20.5%), fatigue (18%) and aggressive behavior (8.5%). These side effects were less prevalent than when the same individuals took LEV (low mood, 59%; aggressive behavior, 43%). Intellectual disability was a risk factor for behavioral side effects (p = 0.004), and a pre-existing mood disorder significantly increased the likelihood of further episodes of low mood (p = 0.019).

CONCLUSIONS

Brivaracetam was effective at a broad range of doses in managing drug-resistant epilepsy across various phenotypes, but less effective than LEV in those who switched due to poor tolerability on LEV. There were no new tolerability issues, but 77% of the individuals experiencing side effects on BRV also experienced similar side effects on LEV.

Impact of Antiseizure Medications on Appetite and Weight in Children

There are numerous potential factors that may affect growth in children with epilepsy, and these must be evaluated in any child with appetite and weight concerns. Antiseizure medications (ASMs) have potential adverse effects, and many may affect appetite, thus impacting normal growth and weight gain. The aim of this review is to focus on the impact of both epilepsy and ASMs on appetite and weight in children. We systematically reviewed studies using Medline assessing the impact of ASMs on appetite and weight in children. Eligible studies included randomized controlled trials and open-label studies (open-label extension and interventional) that targeted or included the pediatric population (0-18 years of age). Each study was classified using the American Academy of Neurology (AAN) Classification of Evidence for Therapeutic Studies, and the level of evidence for impact on appetite and weight in children was graded. ASMs associated with decreased appetite and/or weight loss include fenfluramine, topiramate, zonisamide, felbamate, rufinamide, stiripentol, cannabidiol, brivaracetam and ethosuximide; ASMs with minimal impact on weight and appetite in children include oxcarbazepine, eslicarbazepine, lamotrigine, levetiracetam, lacosamide, carbamazepine, vigabatrin and clobazam. The ASM most robustly associated with increased appetite and/or weight gain is valproic acid; however, both pregabalin and perampanel may also lead to modest weight gain or increased appetite in children. Certain ASMs may impact both appetite and weight, which may lead to increased morbidity of the underlying disease and impaired adherence to the treatment regimen.

Long-term efficacy and tolerability of adjunctive brivaracetam in adults with focal to bilateral tonic-clonic (secondary generalized) seizures: Post hoc pooled analysis

This post hoc analysis was conducted to evaluate the efficacy, tolerability, and health-related quality of life during long-term adjunctive brivaracetam (BRV) treatment in adult patients with focal to bilateral tonic-clonic seizures (FBTCS). Patients (≥ 16 years) were included in this post hoc analysis if they were randomized to BRV or placebo in double-blind, placebo-controlled (N01252 [NCT00490035], N01253 [NCT00464269], N01358 [NCT01261325]; core) trials, and received adjunctive BRV in the corresponding long-term follow-up (N01125 [NCT00175916], N01199 [NCT00150800], N01379 [NCT01339559]) trials, and reported FBTCS during the 8-week prospective baseline (core trial). Efficacy (concomitant levetiracetam excluded) and tolerability (concomitant levetiracetam included) were assessed from the first day of BRV in patients who initiated BRV at 50-200 mg/day. Two hundred and eighty-four patients reported FBTCS during baseline (core trials) and were included in the Efficacy Set. Patients (mean age of 37.0 years; 51.8% male; mean epilepsy duration of 22.4 years; median baseline frequency of 2.8 FBTCS per 28 days) received BRV for a median treatment duration of 2.5 years (range< 0.1-11.3) at a median modal dose of 150 mg/day. BRV was discontinued by 175 (61.6%) patients, most commonly (≥ 10% of patients) due to adverse event (18.3%), lack of efficacy (18.3%), and consent withdrawn (11.6%); the median time to discontinuation of BRV due to any reason was 358.5 days. The Kaplan-Meier (KM)-estimated retention on BRV at 1, 3, and 5 years, were 69.3%, 48.2%, and 37.3%, respectively. The KM-estimated proportion of patients not discontinuing BRV due to lack of efficacy or adverse event were 80.0%, 63.9%, and 57.2% at 1, 3, and 5 years, respectively. Overall, the median percentage reduction in FBTCS frequency from baseline was 76.2%, and the 50% and 75% responder rates for FBTCS were 68.7% and 50.7%, respectively, which were sustained over time across completer cohorts. Sustained 50%, 75%, and 100% response in FBTCS from day 1 of adjunctive BRV treatment during the entire first year was estimated for 32.5%, 21.1%, and 15.0% of patients, respectively (KM analysis), and showed maintenance or improvement in the response to BRV over time. For patients with ≥ 1 year of BRV exposure, 51.3% were free from FBTCS for ≥ 1 year during any time of the treatment period, and 22.8% of patients did not report FBTCS during the first year from the first day of treatment. Clinically meaningful improvements in total Patient Weighted Quality of Life in Epilepsy Inventory-Form 31 (QOLIE-31-P) score were reported by 43.6% and 46.4% of patients after 1 and 2 years of treatment, respectively. The largest improvements in the QOLIE-31-P score, with > 50% of patients reporting a clinically meaningful improvement, were observed in the seizure worry and daily activities/social functioning subscales after 1 and 2 years of BRV treatment. Overall, 278/313 (88.8%; Safety Set) patients reported at least one treatment-emergent adverse event (TEAE), 170 (54.3%) had a drug-related TEAE, 88 (28.1%) had a serious TEAE, and 55 (17.6%) discontinued BRV due to a TEAE. Overall, long-term adjunctive BRV was generally well tolerated and reduced the frequency of FBTCS in adults, with 22.8% of patients (who completed ≥ 1 year of treatment) not reporting any FBTCS during the first year from the first day of BRV treatment.

Critical Appraisal of Cenobamate as Adjunctive Treatment of Focal Seizures in Adults

Cenobamate (CNB) is the latest antiseizure medication (ASM) authorized for the treatment of focal-onset seizures in adults. Although the precise mechanism of action of CNB is not yet fully understood, this drug inhibits the persistent, rather than transient, voltage-gated sodium channel currents and is a positive allosteric modulator of synaptic and extrasynaptic GABA_A receptors, differently from benzodiazepines. CNB has a non-linear pharmacokinetic with a terminal half-life range of about 50/60 hours within the therapeutic dose range, which allows once daily administration. Cenobamate inhibits cytochrome P450 (CYP) 2C19 and induces CYP3A4 and 2B6, and hence can potentially interact with ASMs (eg, phenytoin, carbamazepine and clobazam) and no-ASMs drugs. In two randomized, double-blind, placebo-controlled trials in patients with focal epilepsies, CNB has shown a particularly good efficacy with a rate of seizure freedom of about 20% during the maintenance period in participants treated with the dose of 400 mg/day. The most common treatment-emergent adverse effects include central nervous system-related symptoms, like dizziness, diplopia, somnolence, and gait disturbances. Safety issues of particular interest are severe skin reactions (drug reaction with eosinophilia and systemic symptoms) and QT shortening, which contraindicates its use in subjects with familial short QT syndrome or in combination with other QT-shortening drugs. The recommended starting dose is 12.5 mg/day, which can be gradually titrated to the target dose (200 mg/day) and further increased up to 400 mg/day. There are several aspects of CNB that need to be still addressed, including the long-term efficacy and the efficacy in patients with generalized seizures. Ongoing studies will clarify these issues. The clinical relevance of the peculiar pharmacokinetics and the pattern of drug-drug interactions also require further investigation.