Cenobamate add-on therapy for drug-resistant focal epilepsy.

BACKGROUND: Although most people with epilepsy achieve complete seizure cessation, approximately one-third of those with the condition continue experiencing seizures despite the use of antiseizure medications (ASMs) given as monotherapy or polytherapy. In this review, we summarised the evidence from randomised controlled trials (RCTs) about cenobamate as an add-on treatment for focal epilepsy uncontrolled by one or more concomitant ASMs. OBJECTIVES: To assess the efficacy and tolerability of add-on oral cenobamate for the treatment of drug-resistant focal-onset seizures, defined as seizures persisting despite treatment with one or more ASMs. SEARCH METHODS: We searched the Cochrane Register of Studies (CRS Web) and MEDLINE Ovid (September 2022). In addition, we contacted the manufacturer of cenobamate and experts in the field to enquire after any ongoing or unpublished studies. SELECTION CRITERIA: RCTs comparing add-on cenobamate to placebo or another ASM in people with focal epilepsy uncontrolled by one or more concomitant ASMs. DATA COLLECTION AND ANALYSIS: Two review authors independently selected trials for inclusion, extracted data, performed risk of bias assessment, and assessed the certainty of the evidence using the GRADE approach. Our primary outcomes were at least a 50% reduction in total seizure frequency, seizure freedom, and the occurrence of adverse events. We used an intention-to-treat approach for our primary analyses. For each outcome we estimated summary risk ratios (RRs) with their 95% confidence intervals (CIs). We summarised the estimates of effects and certainty of the evidence for each outcome in a summary of findings table. MAIN RESULTS: We included two studies (659 adult participants, 442 allocated to cenobamate and 217 to placebo). The overall RR for at least a 50% reduction in seizure frequency for add-on cenobamate at any dose compared to placebo was 2.17 (52% versus 24%, 95% CI 1.66 to 2.84; 2 studies, 605 participants; moderate-certainty evidence). The RR for seizure freedom for add-on cenobamate at any dose compared to placebo was 4.45 (16% versus 5%, 95% CI 2.25 to 8.78; 2 studies, 605 participants; moderate-certainty evidence). The RR for the occurrence of adverse events for add-on cenobamate at any dose compared to placebo was 1.14 (77% versus 67%, 95% CI 1.02 to 1.27; 2 studies, 659 participants; moderate-certainty evidence). We judged the two included RCTs as at low or unclear risk of bias. Both studies were sponsored by the drug company that produces cenobamate. AUTHORS' CONCLUSIONS: Add-on cenobamate is probably better than placebo in reducing the frequency of seizures by at least 50% and in achieving seizure freedom in adults with focal epilepsy uncontrolled by one or more concomitant ASMs (moderate level of certainty). Its use is probably associated with an increased risk of adverse events (moderate level of certainty). Further prospective, controlled trials are required to evaluate the efficacy and tolerability of add-on cenobamate compared to other ASMs. The efficacy and tolerability of cenobamate as adjunctive treatment for focal epilepsy in children should be further investigated. Finally, the long-term efficacy and tolerability of add-on cenobamate treatment in people with other epilepsy types (e.g. generalised epilepsy) or specific epilepsy syndromes, as well as its use as monotherapy, require additional study.

Cenobamate as an Early Adjunctive Treatment in Drug-Resistant Focal-Onset Seizures: An Observational Cohort Study.

BACKGROUND AND OBJECTIVES: Cenobamate (CNB) is a new antiseizure medication (ASM) to treat drug-resistant, focal-onset seizures. Data on its use in early therapy lines are not yet available, and clinicians frequently consider CNB to be a later ASM drug choice. We investigated the efficacy and safety of CNB as an early adjunctive treatment in drug-resistant, focal-onset seizures. METHODS: The study population were patients with drug-resistant, focal-onset seizures who were initiated with CNB after they did not respond to two or three lifetime ASMs, including all prior and concomitant ASMs. These patients were matched (1:2) by sex, age, and seizure frequency to controls who were initiated with any ASM other than CNB. All participants participated in the Mainz Epilepsy Registry. We evaluated the retention rate after 12 months of CNB and after each new adjunctive ASM in the control group. In addition, seizure freedom and the response rate (reduction of seizure frequency by ≥ 50% from baseline) after 12 months were estimated. RESULTS: We included 231 patients aged 44.4 ± 15.8 years. Of these, 33.3% (n = 77) were on CNB, 19.0% (n = 44) on valproate (VPA), 17.3% (n = 40) on lacosamide (LCS), 16.4% (n = 38) on levetiracetam (LEV), and 13.9% (n = 32) on topiramate (TPM). The highest retention rate after 12 months since the beginning of the early adjunctive therapy was observed on CNB (92.0%), compared with LCS (80.0%), LEV (73.3%), VPA (68.2%), or TPM (62.5%) (p < 0.05). Seizure freedom and response rate were also the best on CNB (19.5% and 71.4%, respectively) compared with other ASMs (8.3% and 52.5%, respectively; p < 0.05). No significant differences in adverse events between CNB and other ASMs were observed. CONCLUSIONS: Our study provides evidence that CNB is an effective ASM with a good safety profile in the early therapy lines of drug-resistant, focal-onset seizures. This data should support medical decision making in the management of patients with refractory epilepsy. CLINICAL TRIAL ID: NCT05267405.

Treatment simplification to optimize cenobamate effectiveness and tolerability: A real-world retrospective study in Spain.

OBJECTIVE: This study aimed to explore the impact of co-antiseizure medication (co-ASM) optimization on the effectiveness and tolerability of adjunctive cenobamate (CNB) in patients with drug-resistant epilepsy in a real-world setting. METHODS: This unicentric, retrospective, observational study included adults with focal-onset seizures who had received ≥2 previous ASMs. The main effectiveness endpoints included responder rates and seizure frequency reduction at 3, 6, and 12-month visits. The number of co-ASMs and defined daily dose (DDD) were analyzed at every visit. Safety endpoints included adverse drug reactions (ADRs). RESULTS: Thirty-four patients with a median epilepsy duration of 22 years and a median of 15.5 seizures/month were analyzed. The median number of prior ASMs was 12, and the mean number of co-ASMs was 2.9 (SD 1). There was a reduction in seizure frequency/month from baseline to the last visit (p < 0.0001). Between baseline and the end of the study, the mean number of co-ASMs in the per-protocol (PP) population was reduced from 2.9 to 1.6 (p < 0.0001), and DDD was reduced from 3.6 to 1.4 (p < 0.0001). Sodium channel blockers (carbamazepine and lacosamide) and GABAergic drugs (clobazam) were the agents with the most significant reductions in DDD after 12 months. The percentage of patients in the PP population with ≥3 co-ASMs was reduced from 61.8% at baseline to 14.3% at 12 months; 1 patient was receiving CNB as monotherapy at the last visit. At the last visit, 85.7% of the PP population were ≥50% responders, and 33.3% were seizure-free. The percentage of patients with ADRs in the PP population was 71.9% at 3 months and 52.3% at 12 months. SIGNIFICANCE: Following rational polytherapy, optimization of co-ASM management during CNB treatment allowed high seizure freedom rates despite meaningful reductions in co-medication, while also achieving both good tolerability and patient satisfaction scores in a highly drug-resistant population. PLAIN LANGUAGE SUMMARY: Many patients with epilepsy still have seizures, even after being treated with several different epilepsy drugs. In this study of 34 patients from a Spanish clinic, we show that the epilepsy drug cenobamate can reduce the number of seizures in these patients, even after many other epilepsy drugs have failed. We also show that patients treated with cenobamate can reduce the dose or even stop taking certain other epilepsy drugs. This allows them to simplify their treatment and reduce adverse effects while still keeping control of their epilepsy.

A comparison of cenobamate with other newer antiseizure medications for adjunctive treatment of focal-onset seizures: A systematic review and network meta-analysis.

PURPOSE: To compare the efficacy, safety, and tolerability of cenobamate with other newer anti-seizure medications (ASMs) including brivaracetam, eslicarbazepine, lacosamide, perampanel, and zonisamide, approved for adjunctive treatment of drug-resistant focal-onset seizures (FOS) in adults with epilepsy. METHODS: A systematic literature review (SLR) was conducted to obtain relevant efficacy, safety, and tolerability data for ASMs for the treatment of drug-resistant FOS. All studies were thoroughly assessed for potential sources of heterogeneity and analysed via Bayesian network meta-analyses (NMAs). Efficacy outcomes were ≥50 % responder rate and seizure freedom during the maintenance period, which were modelled simultaneously using a multinomial Bayesian NMA. Safety and tolerability outcomes were the proportion of patients who experienced at least one treatment-emergent adverse event (TEAE) and the proportion who experienced at least one TEAE leading to discontinuation. RESULTS: The SLR identified 76 studies, of which 23 were included in the Bayesian NMAs. Cenobamate was associated with statistically significant higher rates for the ≥50 % responder rate and seizure freedom outcomes compared with all ASMs analysed. The point estimates indicated that cenobamate was associated with higher rates of experiencing at least one TEAE and at least one TEAE leading to discontinuation compared with brivaracetam, lacosamide, and zonisamide; however, no results were statistically significant. CONCLUSION: Cenobamate was associated with increased efficacy compared with all ASMs analysed. There were no statistically significant differences in the safety and tolerability outcomes. The results presented corroborate the conclusions drawn from previous published NMAs, which also highlight the notable efficacy of cenobamate in comparison with other ASMs.

Efficacy and safety of adjunctive cenobamate based on patient etiology: Post-hoc analysis of YKP3089C017 randomized clinical trial.

INTRODUCTION: Adjunctive cenobamate was effective and safe for the treatment of uncontrolled focal onset seizures in a randomized, double-blind, placebo-controlled, phase 2 study (YKP3089C017; NCT01866111). This post-hoc analysis assessed the efficacy of adjunctive cenobamate in the treatment of patients with different epileptic etiologies during the study. METHODS: Adult patients with uncontrolled focal seizures who previously received 1 to 3 antiseizure medications (ASMs) were randomly assigned in a ratio of 1:1:1:1 to receive placebo or cenobamate 100, 200 or 400 mg/day. Patients were further stratified based on their etiologic causes as genetic/presumed genetic, unknown cause, structural cause, and not reported (NR) groups. The frequency per 28 days for an 18-week double-blind treatment period, responder rates (≥50 %, ≥75 %, ≥90 %, and 100 %) during the maintenance phase (12 weeks), and safety were assessed. RESULTS: A total of 394 patients were categorized into the genetic/presumed genetic (n = 9; 2.28 %), unknown cause (n = 199; 50.51 %), structural cause (n = 177; 44.92 %), and NR (n = 13; 3.30 %) groups, with 4 patients were classified into either of the two etiological causes each. The baseline characteristics were comparable. The percentage of reduction in seizure frequency per 28 days was significantly higher in the cenobamate-treated structural (p = 0.01) and unknown cause (p = 0.0003) groups compared with the placebo group. Responder rates of ≥50 %, ≥75 %, ≥90 %, and 100 % were also higher with cenobamate therapy. Notably, no serious treatment-emergent adverse events (TEAEs) were observed in the genetic/presumed genetic group treated with cenobamate. The most common TEAEs (≥10 %) occurring in patients treated with cenobamate were nervous system disorders by system organ class, and somnolence was the most commonly reported TEAE. CONCLUSION: Cenobamate reduces seizures in adult patients previously treated with ASMs, with high responder rates and acceptable safety, regardless of underlying causes.

Association of bone mineral density with trichlorophenol: a population-based study.

BACKGROUND: Trichlorophenols (TCPs) are metabolites of several organochlorine chemicals, including chlorobenzene, hexachlorocyclohexane, and chlorophenoxy acid, present in air, surface water, soil, and sediment. Many studies have shown that endocrine disruptors (EDs)may contribute to decreased bone mass and the increased risk of osteoporosis. However, the relationship between TCP and bone mineral density (BMD) has not been studied yet. METHODS: We conducted a cross-sectional study by using data from the 2005-2010 National Health and Nutrition Examination Survey (NHANES). TCP levels were measured in urine samples from 3385 participants and bone mineral density was obtained by dual X-ray absorptiometry (DXA) lumbar spine and femur scanning. Multiple regression analysis, stratified analysis, curve fitting analysis, and trend tests were used to assess the relationship between TCP and BMD. RESULT: After adjusting for confounding factors, the results of multiple regression analysis only showed that ln-2,4,5-TCP was negatively associated with BMD of lumbar spine. In stratified analyses, Male, Menstruating Female and Menopausal Female were divided into three groups for analysis. The results showed that ln-2,4,5-TCP and ln-2,4,6-TCP were not statistically associated with BMD in total femur, femoral neck, femoral tuberosity, intertrochanteric femur and lumbar spine, which was also confirmed by curve fitting analyses and trend tests. CONCLUSION: This study demonstrated that 2,4,5-TCP and 2,4,6-TCP in urine samples were not significantly associated with BMD in the US population. Therefore, 2,4,5-TCP and 2,4,6-TCP may not be detrimental to BMD.

Efficacy and safety of adjunctive cenobamate: Post-hoc analysis of study C017 in patients grouped by mechanism of action of concomitant antiseizure medications.

PURPOSE: To assess how efficacy and safety outcomes were affected when cenobamate was co-administered with antiseizure medications (ASMs) that use either sodium channel blocker (SCB) or non-sodium channel blocker (non-SCB) mechanisms of action (MoAs) in patients with uncontrolled focal seizures. METHODS: An exploratory post-hoc analysis of a randomized, double-blind, placebo-controlled clinical study (YKP3089C017) was conducted. Baseline concomitant ASMs were grouped as either those that employed an SCB or non-SCB MoA. Efficacy was examined by cenobamate dose (100 mg, 200 mg, and 400 mg/day) and concomitant ASM group using responder rates (≥50%, ≥75%, ≥90% seizure reduction; 100% seizure reduction/seizure freedom) during the maintenance phase and median percentage seizure reduction during the double-blind period. Treatment-emergent adverse events (TEAEs) were examined in the double-blind period. RESULTS: When co-administered with SCBs or non-SCBs, significantly higher percentages of patients achieved ≥50%, ≥75%, and ≥90% responder rates with cenobamate 200 mg/day and/or 400 mg/day versus placebo. Additionally, significantly higher percentages of patients achieved seizure freedom with cenobamate 400 mg/day versus placebo (SCB group, 17.5% versus 1.2%; non-SCB group, 40.0% versus 0.0%). Patients receiving 200 mg/day and 400 mg/day and concomitant SCBs and all patients taking cenobamate combined with non-SCB concomitant ASMs had significantly greater median percentage reductions in focal seizure frequency versus placebo. TEAEs were similar across groups; however, dizziness was more frequently reported in the SCB group. CONCLUSION: Cenobamate is a highly effective new treatment option for patients with uncontrolled focal seizures when co-administered with SCB or non-SCB ASMs.

Indirect treatment comparison of cenobamate to other ASMs for the treatment of uncontrolled focal seizures.

OBJECTIVE: The efficacy and safety of cenobamate relative to other antiseizure medications (ASMs) has not been evaluated. An indirect treatment comparison (network meta-analysis) was performed to determine if adjunctive cenobamate increases the odds ratio (OR) for ≥50% responder rate or for withdrawals due to treatment-emergent adverse events (TEAEs) leading to ASM discontinuation versus adjunctive therapy with other ASMs. METHODS: A systematic literature review was conducted to identify randomized, double-blind, placebo-controlled trials (maintenance phase ≥ 12 weeks) assessing adjunctive ASMs in adults with uncontrolled focal seizures. Cenobamate was compared to a group of seven other ASMs, and to subgroups of branded (brivaracetam, eslicarbazepine acetate, lacosamide, and perampanel) and older (lamotrigine, levetiracetam, and topiramate) ASMs at FDA-recommended daily maintenance doses (FDA-RDMD), at all doses, and at maximum and minimum daily doses. Statistical significance was set at p < 0.05. RESULTS: Twenty-one studies were eligible for analysis. The placebo-adjusted ≥ 50% responder rate for FDA-RDMD of cenobamate was superior (OR 4.200; 95% CI 2.279, 7.742) to FDA-RDMD of all seven assessed (OR 2.202 95% CI 1.915, 2.532; p = 0.044) and branded ASMs (OR 2.148; 95% CI 1.849, 2.494; p = 0.037). There was no significant difference for ≥50% responder rate between FDA-RDMD of cenobamate and FDA-RDMD of older ASMs (OR 2.617; 95% CI 1.767, 3.878; p = 0.202). No significant differences were identified for ≥50% responder rate when comparing all doses and maximum/minimum doses of cenobamate to all seven, branded, and older ASMs. Cenobamate demonstrated comparable TEAE withdrawal rates to all seven ASMs, branded ASMs, and older ASMs across each of the four dose ranges (all p > 0.05). SIGNIFICANCE: Patients receiving FDA-RDMD of cenobamate were more likely to have ≥50% seizure reduction compared with FDA-RDMD of the seven assessed ASMs and branded ASMs, without an increase in treatment discontinuation due to TEAEs.

Bikini textile contact dermatitis: A Sherlockian approach revealing 2,4-dichlorophenol as a potential textile contact allergen.

BACKGROUND: Different textile constituents may act as allergens and/or irritants and provoke textile contact dermatitis (TCD). OBJECTIVES: To report a case of TCD caused by ethylene glycol monododecyl ether and 2,4-dichlorophenol, present in a bikini. METHODS: A woman presented with an eczematous, pruritic rash in the area of the bikini straps and back. Patch testing was performed with the European baseline, textile, sunscreen, and photo-patch series, the bikini "as is", and ethanol and acetone extracts of the bikini. Thin-layer chromatography (TLC) of the extracts and gas chromatography-mass spectrometry (GC-MS) analysis were used to elucidate the culprit agents. RESULTS: Positive reactions were found to the bikini "as is" and to the ethanol and acetone extracts. Patch testing with TLC strips showed a strong reaction to spots-fractions 3 and 4. GC-MS was performed to identify substances in each fraction and those suspected to be skin sensitisers were patch tested. On day (D) 4 positive reactions to ethylene glycol monododecyl ether (irritant reaction) and 2,4-dichlorophenol (++) were observed. CONCLUSION: A myriad of chemical compounds can be found in clothing. Ethylene glycol monododecyl ether and 2,4-dichlorophenol were identified as the potential culprits of this bikini TCD.

Pharmacology of Cenobamate: Mechanism of Action, Pharmacokinetics, Drug-Drug Interactions and Tolerability.

Cenobamate is one of the latest antiseizure medications (ASMs) developed for the treatment of focal onset seizures in adult patients. The recommended starting dose is 12.5 mg/day, titrated gradually to the target daily dose of 200 mg, which may be increased to a maximum of 400 mg/day based on clinical response. Although the high rate of seizure freedom observed in randomized, placebo-controlled clinical trials has resulted in exciting expectations, further clinical studies are needed to better define its clinical profile. Cenobamate is characterized by a peculiar pharmacology regarding both pharmacodynamics and pharmacokinetics. The mechanism of action has only partly been described, with the drug acting on voltage-gated sodium channels through a pronounced action on persistent rather than transient currents. Cenobamate also acts as a positive allosteric modulator of GABAA receptors independently from the benzodiazepine binding site. The bioavailability of cenobamate is not influenced by other drugs, except phenytoin; it can inhibit cytochrome P450 (CYP) 2C19 and induce CYP3A4 and 2B6, and hence can potentially interact with many drugs (e.g. dose adjustments may be required for lamotrigine, carbamazepine and clobazam). The pharmacokinetics of cenobamate are not linear and dosage increases imply a disproportional increase in plasma levels, particularly at doses higher than 300 mg. The most common and dose-related adverse effects associated with cenobamate include central nervous system-related symptoms, mainly somnolence, dizziness, diplopia, and disturbances in gait and coordination. A somewhat higher incidence of adverse events has been observed in patients concomitantly treated with sodium channel blockers. The most relevant safety issues are currently represented by the risk of severe skin reactions (apparently avoidable by a slow titration) and QT shortening (the drug is contraindicated in patients with familial short QT syndrome or taking QT-shortening drugs). Overall, cenobamate is a promising ASM with an intriguing and not fully understood mechanism of action; pharmacokinetic issues need to be considered in clinical practice.

Efficacy and safety of cenobamate in patients with uncontrolled focal seizures: A meta-analysis.

OBJECTIVE: To investigate the efficacy and safety of adjunctive cenobamate for treatment of uncontrolled focal seizures. METHODS: We performed a systematic search of Web of Science, MEDLINE (Ovid and PubMed), Cochrane Library, EMBASE and Google Scholar to identify eligible studies. We included randomized placebo-controlled trials (RCTs) for uncontrolled focal seizures. We calculated the risk ratio (RR) of ≥50%, ≥75% and 100% reduction in seizure frequency from baseline, as well as dropout and serious adverse events related to treatment. Quality of included trials was assessed using the Cochrane Collaboration's tool. RESULTS: Two RCTs with a total of 658 patients were included. A significantly larger proportion of patients allocated to cenobamate achieved 50% seizure reduction (RR 2.06, 95% CI 1.70-2.51, p < 0.001) as compared to placebo, subgroup analysis demonstrated that the most effective dose was at 400 mg (RR 2.28, 95% CI 1.57-3.32, p < 0.001). Patients achieving seizure-freedom during the treatment period were 14.9% with cenobamate and 4.5% with placebo (RR 5.32, 95% CI 2.94-9.62, p < 0.001). Dropouts (RR 1.40, 95% CI 1.01-1.94, p = 0.05) and incidence of serious adverse events (RR 1.48, 95% CI 0.93-2.33, p = 0.1) were not significantly higher in patients receiving cenobamate. However, subgroup analyses based on doses suggested that patients exposed to 400 mg cenobamate were more likely to dropout than placebo (RR 2.09, 95% CI 1.17- 3.71, p = 0.012). CONCLUSION: Cenobamate demonstrated favourable efficacy for treatment of uncontrolled focal seizures and showed a dose-related fashion. Cenobamate could be well tolerated, the most common adverse events associated with cenobamate were dizziness, somnolence, fatigue, headache and nausea. Nevertheless, majority of them were mild to moderate in severity.

The ups and downs of alkyl-carbamates in epilepsy therapy: How does cenobamate differ?

Since 1955, several alkyl-carbamates have been developed for the treatment of anxiety and epilepsy, including meprobamate, flupirtine, felbamate, retigabine, carisbamate, and cenobamate. They have each enjoyed varying levels of success as antiseizure drugs; however, they have all been plagued by the emergence of serious and sometimes life-threatening adverse events. In this review, we compare and contrast their predominant molecular mechanisms of action, their antiseizure profile, and where possible, their clinical efficacy. The preclinical, clinical, and mechanistic profile of the prototypical γ-aminobutyric acidergic (GABAergic) modulator phenobarbital is included for comparison. Like phenobarbital, all of the clinically approved alkyl-carbamates share an ability to enhance inhibitory neurotransmission through modulation of the GABAA receptor, although the specific mechanism of interaction differs among the different drugs discussed. In addition, several alkyl-carbamates have been shown to interact with voltage-gated ion channels. Flupirtine and retigabine share an ability to activate K+ currents mediated by KCNQ (Kv7) K+ channels, and felbamate, carisbamate, and cenobamate have been shown to block Na+ channels. In contrast to other alkyl-carbamates, cenobamate seems to be unique in its ability to preferentially attenuate the persistent rather than transient Na+ current. Results from recent randomized controlled clinical trials with cenobamate suggest that this newest antiseizure alkyl-carbamate possesses a degree of efficacy not witnessed since felbamate was approved in 1993. Given that ceno-bamate's mechanistic profile is unique among the alkyl-carbamates, it is not clear whether this impressive efficacy reflects an as yet undescribed mechanism of action or whether it possesses a unique synergy between its actions at the GABAA receptor and on persistent Na+ currents. The high efficacy of cenobamate is, however, tempered by the risk of serious rash and low tolerability at higher doses, meaning that further safety studies and clinical experience are needed to determine the true clinical value of cenobamate.

Cenobamate tablets as a treatment for focal-onset seizures in adults.

Introduction: Despite the introduction of numerous new antiseizure medications (ASMs) still about one-third of epilepsies remain drug-resistant. Therefore, new compounds with advanced efficacy are urgently needed. Cenobamate (CNB) is a new ASM that has been recently introduced in the United States for the treatment of adults with focal-onset seizures. The approval in Europe is under way.Areas covered: This review covers the pharmacological profile of CNB, the proof-of-concept trial, the two double-blind, placebo-controlled phase 2 trials investigating adjunct CNB in adults with focal-onset seizures, one open-label safety trial, and a variety of published abstract material that provided additional post hoc data.Expert opinion: In two placebo-controlled randomized multicenter phase 2 trials adjunct CNB showed unusually high efficacy with rates of seizure-free people with epilepsy (PWE) partially beyond 20%. However, during the clinical program cases of drug-related reactions with eosinophilia and systemic symptoms (DRESS syndrome) occurred. Therefore, an open-label safety study was performed in more than 1300 PWE with particularly slower titration schedules which did not add more cases with similar reactions. Taking into consideration the promising efficacy and the safety experience from the open-label trial, CNB applied according to the meanwhile recommended titration strategy, might offer a new prospect.

Adjunctive cenobamate for the treatment of focal onset seizures in adults with epilepsy: a critical review.

INTRODUCTION: Uncontrolled epilepsy has persisted despite development of numerous antiseizure medications (ASMs) over the past 25 years, and more effective treatments are needed. Cenobamate is a new ASM approved in the US for treatment of adults with focal onset seizures. AREAS COVERED: This review outlines cenobamate study results from preclinical animal models through phase 2 and 3 clinical studies. Topics include mechanisms of action, pharmacokinetics, efficacy, and safety of cenobamate. Information on dosing, tolerability, and special populations are included to help healthcare providers understand this new ASM. EXPERT OPINION: Adjunctive cenobamate shows a high level of efficacy in patients with refractory focal epilepsy compared to that reported for other ASMs. Most notable are reductions in monthly seizure frequency (up to 55%) and unprecedented seizure-free rates (up to 28%) with cenobamate in patients with refractory epilepsy despite the concomitant use of 1-3 ASMs. Cenobamate was generally safe and well-tolerated, with a safety profile similar to other ASMs. Due to 3 early cases of DRESS, however, the cenobamate starting dose was lowered and titration rate slowed; no additional cases occurred. If efficacy responses in real-world use reflect what have been observed in clinical studies, cenobamate would be a welcome new treatment option.

Cenobamate for the treatment of focal epilepsies.

INTRODUCTION: Antiseizure drugs (ASDs) play a central and crucial role in the treatment of epilepsy patients because the majority require anticonvulsant treatment for an extended period of time. Due to the fact that 30% of patients are refractory to medical treatment, new therapeutic options are necessary. Cenobamate is the latest approved antiepileptic drug in focal epilepsy, and its mode of action is thought to be mediated by blocking voltage-gated sodium channels and interaction with the GABAergic system. AREAS COVERED: This article reviews animal studies, pharmacokinetics, pharmacodynamics, and the phase 1 to 3 trials and open-label extension data on cenobamate. EXPERT OPINION: Cenobamate has the potential to perform as an important ASD because trial data are indicative of remarkable responder and seizure freedom rates so far not seen with other ASDs. Cenobamate demonstrated significant efficacy at a dosage between 100 and 400 mg per day. The side-effect profile of this drug is comparable to other ASDs and is mainly CNS related; in particular, somnolence, dizziness, headache, diplopia, and nystagmus. However, slow titration is mandatory to decrease the risk of drug rash with eosinophilia and systemic symptoms (DRESS) that was observed in several patients with fast uptitration schemes.

Adjunctive Cenobamate for Focal-Onset Seizures in Adults: A Systematic Review and Meta-Analysis.

BACKGROUND: Cenobamate is a novel tetrazole-derived carbamate compound with a dual mechanism of action. This drug can enhance the inactivated state of voltage-gated sodium channels, preferentially inhibiting the persistent component of the sodium channel current, and acts as a positive allosteric modulator of GABAA receptors, binding at a non-benzodiazepine site. OBJECTIVE: We assessed the efficacy and safety of adjunctive cenobamate for the treatment of focal-onset seizures in adult patients with epilepsy using meta-analytical techniques. METHODS: We systematically searched (May, week 4, 2020) MEDLINE (accessed by PubMed), the Cochrane Central Register of Controlled Trials (CENTRAL), and the US National Institutes of Health Clinical Trials Registry ( http://www.clinicaltrials.gov ). There were no date limitations or language restrictions. Randomized, placebo-controlled, single or double-blinded, add-on trials of cenobamate in adult patients with uncontrolled focal-onset seizures were identified. Main outcomes included the proportion of patients with ≥ 50 and 100% reduction in seizure frequency during the maintenance treatment period compared with baseline and the incidence of treatment withdrawal and adverse events (AEs). Risk ratio (RR) with 95% confidence interval (CI) was estimated for each outcome. RESULTS: Two trials were included, overall enrolling 659 patients (442 for the add-on cenobamate group and 217 for the add-on placebo group). Seizure frequency reduction by at least 50% occurred during the maintenance phase in 50.1% of the patients randomized to cenobamate and 23.5% of the placebo-treated participants (RR 2.18, 95% CI 1.67-2.85; p < 0.001). The pooled estimated RR to achieve seizure freedom for the cenobamate group in comparison with placebo was 3.71 (95% CI 1.93-7.14; p < 0.001). Withdrawal from randomized treatment occurred in 16.7 and 11.1% of participants receiving cenobamate and placebo, respectively (RR 1.34, 95% CI 0.85-2.09; p = 0.205). Treatment was discontinued due to AEs in 12.2 and 4.1% of the patients in the active and control arms (RR 2.27, 95% CI 1.08-4.79; p = 0.031). AEs were reported in 76.9 and 66.8% of the patients during treatment with cenobamate and placebo (RR 1.14, 95% CI 1.02-1.26; p = 0.021). The cenobamate-associated AEs included somnolence, dizziness, fatigue, balance disorder, and diplopia. CONCLUSIONS: Adjunctive cenobamate in adult patients with uncontrolled focal-onset seizures is associated with a greater reduction in seizure frequency and a higher rate of AEs than placebo.

Cenobamate for the treatment of focal epilepsy.

Focal-onset or partial seizures are localized to a specific brain area or areas of the cerebral hemisphere. Cenobamate (CNB, Xcopri, YKP-3089; SK Life Science) is a recent U.S. Food and Drug Administration (FDA)-approved drug for the treatment of focal-onset seizures in the adult population. CNB has demonstrated broad-spectrum efficacy in alternative preclinical models of epilepsy. The molecule exerts an antiseizure effect due to its dual mechanism of action: besides inhibiting the voltage-gated persistent component of the sodium currents, CNB is additionally an allosteric GABA(A) channel modulator in a non-benzodiazepine fashion. The superior clinical effect of this molecule over placebo in reducing seizure frequency may be observed after 2 weeks following a starting oral dose of 50 mg/day. The drug can be titrated up to a maximum daily maintenance dose of 400 mg/day. CNB has mild to moderate side effects. During initial development, a critical drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome was noticed in 3 patients. However, the DRESS effect was not observed in the large C021 safety study involving 1,347 patients, suggesting a maximum potential risk of no more than 0.3%. The present monograph describes the background, preclinical and clinical pharmacology, indication and safety of CNB for the treatment of partial/focal seizures.

Pharmacokinetics of Cenobamate: Results From Single and Multiple Oral Ascending-Dose Studies in Healthy Subjects.

Cenobamate (YKP3089) is an antiepileptic drug recently approved by the Food and Drug Administration for the treatment of focal (partial-onset) seizures in adults. The objectives of a first-in-human single-ascending-dose study and 3 multiple-ascending-dose studies were to characterize the pharmacokinetics, safety, and tolerability of cenobamate after single-dose and multiple-dose administration in healthy subjects. The 4 randomized, placebo-controlled, double-blind studies were conducted in 210 healthy subjects receiving single (5 to 750 mg) or multiple (50 to 600 mg/day) oral doses of cenobamate or placebo using capsule formulation. Safety assessments included treatment-emergent adverse events (TEAEs) and laboratory evaluations. Maximum plasma concentrations of cenobamate were observed between 0.8 and 4.0 hours after oral administration. Cmax increased in a dose-proportional manner for single- and multiple-dose administration across all tested doses. Although the AUC of cenobamate increased in a more than dose-proportional manner after single-dose administration, a dose-proportional increase in cenobamate AUCτ was observed after multiple dosing from 50 to 500 mg/day. Cenobamate exhibited low oral clearance (decreasing from approximately 1.4 to 0.50 L/h with dose increase) and long terminal half-life (range, approximately 30 to 76 hours with increasing dose). Steady-state was attained after approximately 2 weeks, and the accumulation ratio was approximately 5 over the 50 to 300 mg/day range. The pharmacokinetic characteristics of cenobamate are consistent with once-daily dosing. Most TEAEs were mild in severity, 2 serious TEAEs were reported, and no deaths occurred across all studies. Except for multiple daily doses of 600 mg, all doses were generally well tolerated.

Suppression of the photoparoxysmal response in photosensitive epilepsy with cenobamate (YKP3089).

OBJECTIVE: To evaluate the effect of cenobamate in patients with photoparoxysmal-EEG response (PPR) to intermittent photic stimulation (IPS) as proof of principle of efficacy in patients with epilepsy. METHODS: In this multicenter, single-blind study, adults with photosensitive epilepsy, with/without concomitant antiepileptic drug therapy, underwent IPS under 3 eye conditions after a single dose of placebo (day -1, day 2) or cenobamate (day 1; 100, 250, or 400 mg). Complete suppression was a standardized photosensitivity range reduction to 0 over ≥1 time points for all eye conditions. Partial suppression was a ≥3-point reduction over ≥3 testing times vs the same time points on day -1 in ≥1 eye condition. Pharmacokinetics and safety were assessed. RESULTS: Of 6 evaluable patients, 5 reentered to receive higher doses. Cenobamate 100 mg produced partial suppression in 1 of 3 patients; 250 mg produced complete suppression in 1 of 4 and partial suppression in 4 of 4 patients; and 400 mg produced complete suppression in 1 of 4 and partial suppression in 2 of 4 patients. PPR was consistently reduced on days 1 and 2 (>24 hours after cenobamate) vs day -1 (placebo) with the 250- and 400-mg doses. Area under the plasma concentration-time curve (before dose to last measurable concentration) values between 201 and 400 µg/h/mL resulted in partial suppression in 4 of 6 (66%) patients. Most common adverse events were dizziness and somnolence. CONCLUSIONS: This proof-of-principle study demonstrated that cenobamate is a potentially effective product for epilepsy. CLINICALTRIALSGOV IDENTIFIER: NCT00616148. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that, for patients with photosensitive epilepsy, cenobamate suppresses IPS-induced PPR.