Safety, Tolerability and Efficacy of Eslicarbazepine Acetate as Adjunctive Therapy in Patients Aged ≥ 65 Years with Focal Seizures

Overnight switch from carbamazepine to eslicarbazepine in a real-life clinical scenario: a retrospective study

BACKGROUND

Carbamazepine (CBZ) is a first-choice anti-seizure medication (ASM) whose efficacy is often invalidated by adverse effects (AEs). Eslicarbazepine (ESL) is a structural derivative of CBZ with better pharmacokinetic/tolerability profiles. We describe our experience of the overnight CBZ to ESL switch in people with epilepsy (PwE) to improve seizure control, AEs, and ASMs adherence.

METHODS

We retrospectively included 19 PwE (12 females, 53 ± 21 years old) who underwent CBZ to ESL overnight switch due to single/multiple issues: poor efficacy (pEff, N = 8, 42%), tolerability (pToll, N = 11, 58%), adherence (pAdh, N = 2, 10%). 9/19 (47%) had psychiatric comorbidities. Clinical variables, seizure frequency, and AEs were recorded at switch time (T0) after 3.5 ± 3 (T1) and 6.5 ± 1.5 months (T2).

RESULTS

At T1, in pEff group, 1/8 (13%) was seizure free, 2/8 (25%) were responders (> 50% seizure reduction), 2/8 (25%) had no seizure changes, 3/8 (37%) had seizure worsening; the latter were those with the most severe epilepsy and encephalopathy. In pToll group, all PwE experienced AEs disappearance/amelioration. In pAdh group, all PwE reported adherence amelioration. Four dropouts. At T2, no changes were recorded within groups, while in the whole sample, 6/15 (40%) were responders, and 4/15 (27%) were seizure-free. No one complained of Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation psychiatric worsening, while 6/19 (32%) experienced mood/behavior benefits.

CONCLUSIONS

CBZ to ESL overnight switch offers an opportunity to improve efficacy, tolerability, adherence, and psychiatric symptoms.

Antiepileptogenesis after stroke-trials and tribulations: Methodological challenges and recruitment results of a Phase II study with eslicarbazepine acetate

There is currently no evidence to support the use of antiseizure medications to prevent unprovoked seizures following stroke. Experimental animal models suggested a potential antiepileptogenic effect for eslicarbazepine acetate (ESL), and a Phase II, multicenter, randomized, double-blind, placebo-controlled study was designed to test this hypothesis and assess whether ESL treatment for 1 month can prevent unprovoked seizures following stroke. We outline the design and status of this antiepileptogenesis study, and discuss the challenges encountered in its execution to date. Patients at high risk of developing unprovoked seizures after acute intracerebral hemorrhage or acute ischemic stroke were randomized to receive ESL 800 mg/d or placebo, initiated within 120 hours after primary stroke occurrence. Treatment continued until Day 30, then tapered off. Patients could receive all necessary therapies for stroke treatment according to clinical practice guidelines and standard of care, and are being followed up for 18 months. The primary efficacy endpoint is the occurrence of a first unprovoked seizure within 6 months after randomization ("failure rate"). Secondary efficacy assessments include the occurrence of a first unprovoked seizure during 12 months after randomization and during the entire study; functional outcomes (Barthel Index original 10-item version; National Institutes of Health Stroke Scale); post-stroke depression (Patient Health Questionnaire-9; PHQ-9); and overall survival. Safety assessments include the evaluation of treatment-emergent adverse events; laboratory parameters; vital signs; electrocardiogram; suicidal ideation and behavior (PHQ-9 question 9). The protocol aimed to randomize approximately 200 patients (1:1), recruited from 21 sites in seven European countries and Israel. Despite the challenges encountered, particularly during the COVID-19 pandemic, the study progressed and included a remarkable number of patients, with 129 screened and 125 randomized. Recruitment was stopped after 30 months, the first patient entered in May 2019, and the study is ongoing and following up on patients according to the Clinical Trial Protocol.

Adjunctive Treatment With Eslicarbazepine Acetate for Adults and Children With Focal-Onset Epilepsy: A Meta-Analysis

Background

The efficacy and tolerability of eslicarbazepine acetate (ESL) in adults and children with focal-onset epilepsy (FOE) according to the dose remain to be validated. A meta-analysis based on randomized controlled trials (RCTs) was therefore conducted as a summary.

Methods

Relevant RCTs were collected by systematic searching the electronic databases of PubMed, Cochrane's Library, Embase, Wanfang and CNKI from inception to May 16, 2022. The random-effect model was adopted to pool the results by incorporating the possible heterogeneity. Efficacy outcomes including responsive rate and effective rate, defined as cases with 50 and ≥75% reduction in seizure frequency compared to baseline, were determined, respectively. Incidence of severe adverse events (AE) leading to drug discontinuation was also evaluated.

Results

Ten studies including 2,565 people with epilepsy contributed to the meta-analysis. For adults, ESL 400 mg/d did not improve the response rate or the effective rate; ESL 800 mg/d was associated with improved response rate (odds ratio [OR] 2.16, 95% confidence interval [CI]: 1.65–2.83, p < 0.001) and effective rate (OR 2.16, 95% CI: 1.41–3.30, p < 0.001) without significantly increased severe AE (OR 1.58, 95% CI: 0.90–2.78, p = 0.11); ESL 1,200 mg/d improved response rate (OR 2.49, p < 0.001) and effective rate (OR 3.09, p = 0.04), but significantly increased severe AE (OR 3.72, p < 0.001). For children, ESL also did not significantly improve the response rate (OR 1.76, p = 0.22) or the effective rate (OR 2.17, p = 0.13).

Conclusion

ESL 800 mg/d is effective and well-tolerated as adjuvants for adults with FOE. Efficacy of ESL in children with FOE should be further evaluated.

Safety of Eslicarbazepine Acetate in Elderly Versus Non-Elderly Patients with Focal Seizures: From Pooled Data of Clinical Studies to 8 Years of Post-Marketing Experience

Introduction

The prevalence of epilepsy increases in elderly patients aged > 65 years, and treatment is challenging because clinical data are limited.

Objective

Our objective was to evaluate the safety of eslicarbazepine acetate (ESL) in patients aged ≥ 65 years versus non-elderly patients with focal seizures.

Methods

The safety data of seven phase II and III, double-blind, open-label, randomized clinical studies of ESL in adults were pooled. At least possibly related treatmentemergent adverse events (TEAEs) and ESL post-marketing adverse drug reactions (ADRs) were analyzed separately by age categories.

Results

The most frequently reported at least possibly related TEAEs in elderly (N = 120) versus non-elderly patients (N = 1863) were dizziness (10.8 vs. 20.3%), somnolence (9.2 vs. 12.6%), and hyponatremia (6.7 vs. 1.5%). Elderly patients presented a higher incidence of serious TEAEs (22.5 vs. 7.6%) and at least possibly related serious TEAEs (6.7 vs. 2.5%), probably because treatment was complicated by comorbidities and comedications. After an estimated cumulative exposure of over 2 million patient-months worldwide and 8 years of post-marketing surveillance, hyponatremia was the most frequently reported ADR (n = 232), accounting for 14.6% and 6.8% of the ADRs reported in elderly (n = 473) and non-elderly patients (n = 2406), respectively. This was followed by ADR/safety information such as drug–dose titration not performed (7.0 vs. 5.4%), product use in unapproved indication (4.9 vs. 1.9%), off-label use (3.4 vs. 2.2%), dizziness (3.4 vs. 3.5%), and seizure (2.1 vs. 5.8%).

Conclusion

No specific safety issue was identified from the pooled studies for elderly compared with non-elderly patients. After 8 years of post-marketing surveillance, the qualitative safety of ESL remains similar to that observed in the clinical studies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40264-021-01097-5.

Comparative analysis of the safety and tolerability of eslicarbazepine acetate in older (≥60 years) and younger (18-59 years) adults

OBJECTIVE

To investigate the safety and tolerability of eslicarbazepine acetate (ESL), a once-daily oral anti-seizure drug (ASD), in older and younger adult patient populations.

METHODS

Two post-hoc pooled data analyses were performed: one from three Phase III studies in patients with focal (partial-onset) seizures who were taking 1-3 concomitant ASDs; the other from five Phase II studies in patients from non-epilepsy populations not taking other ASDs chronically and/or at a clinically-effective anti-seizure dose. The frequencies of treatment-emergent adverse events (TEAEs) were calculated for the older (≥60 years) and younger (18-59 years) adults separately.

RESULTS

In the focal seizures study pool, 4.1 % of patients (58/1431) were aged ≥60 years. The overall frequency of TEAEs was 77.5 % in older ESL-treated patients and 72.6 % in younger ESL-treated patients (p = 0.495). For patients who received placebo, the overall frequency of TEAEs was 50.0 % in the older adults and 57.5 % in the younger adults (p = 0.531). The overall placebo-adjusted frequency of TEAEs was 27.5 % in older adults and 15.1 % in younger adults. The placebo-adjusted frequencies of the TEAEs dizziness, somnolence, headache, nausea, diplopia, blurred vision, and ataxia were ≥5 % higher, and frequencies of vomiting and vertigo were ≥2 % higher in older than younger adults. The overall frequency of TEAEs leading to discontinuation was 15.0 % in older ESL-treated patients and 17.6 % in younger ESL-treated patients (p = 0.647); the frequency increased with increasing ESL dose. For patients who received placebo, the overall frequency of TEAEs leading to discontinuation was 5.6 % in older adults and 6.6 % in younger adults (p = 0.847). In the non-epilepsy study pool, 30.2 % of patients (515/1705) were aged ≥60 years. The overall frequency of TEAEs was 56.9 % in older ESL-treated patients and 58.8 % in younger ESL-treated patients. The placebo-adjusted frequencies were 14.9 % in older and 15.1 % in younger ESL-treated patients. The placebo-adjusted frequencies of the TEAEs nausea, vomiting, fatigue, and vertigo were ≥2 % higher in older adults, whereas somnolence was ≥2 % higher in younger adults. The overall frequency of TEAEs leading to discontinuation was 18.3 % in older ESL-treated patients and 12.1 % in younger ESL-treated patients (p = 0.003); frequencies were not related to ESL dose. For patients who received placebo, the overall frequency of TEAEs leading to discontinuation was 8.0 % in older adults and 5.6 % in younger adults (p = 0.407).

CONCLUSION

Analyses of adverse event data support the safety and tolerability of ESL in adults aged ≥60 years. In the limited number of older patients with focal seizures taking ESL plus concomitant ASDs (n = 40), the frequency of TEAEs was generally higher than in younger adults. However, in the non-epilepsy patient group (in which the number of older patients was ten times larger; 427 patients taking ESL without concomitant ASDs), no marked age-related TEAE differences were observed, suggesting that increased ASD load associated with adjunctive therapy may complicate treatment selection in older patients, due to risk of increased adverse events. As is common practice for all ASDs, balancing clinical response and tolerability is needed in this vulnerable group of patients.

Eslicarbazepine Acetate: A Review in Focal-Onset Seizures

Eslicarbazepine acetate (Zebinix^®), a voltage-gated sodium channel blocker, is a once-daily, orally administered anti-seizure medication available in the EU for use as monotherapy in adults with newly diagnosed focal-onset seizures and as adjunctive therapy in adults, adolescents and children aged > 6 years with focal-onset seizures. In adult patients, adjunctive eslicarbazepine acetate was generally associated with a significant decrease in seizure frequency and an increase in responder rate compared with placebo. The drug was also an effective monotherapy agent in adult patients, demonstrating noninferiority to controlled-release carbamazepine, in terms of seizure freedom rates. In paediatric patients, eslicarbazepine acetate provided seizure control when administered as adjunctive therapy, with the benefits appearing to be dependent on age and dose. The antiepileptic efficacy of eslicarbazepine acetate as adjunctive therapy or as monotherapy was maintained during longer-term extension studies, with each extension study period being up to 2 years. Oral eslicarbazepine acetate was generally well tolerated when administered as adjunctive therapy or monotherapy in adult patients and when administered as adjunctive therapy in paediatric patients, with most adverse events being of mild or moderate intensity. In conclusion, with the convenience of once-daily administration, eslicarbazepine acetate is an effective and generally well-tolerated treatment option for adults, adolescents and children aged > 6 years with focal-onset seizures.

Clinical outcomes of eslicarbazepine acetate monotherapy for focal-onset seizures: A multicenter audit

OBJECTIVE

To assess the effectiveness and tolerability of eslicarbazepine acetate (ESL) monotherapy in routine clinical practice for the treatment of focal-onset seizures.

METHODS

Multicenter, retrospective, observational study conducted in patients older than 16 years treated with ESL as first-line monotherapy or converted to ESL monotherapy from polytherapy or other monotherapy. Outcomes included 1-year retention rate, seizure-free rates after 6 and 12 months of monotherapy treatment, and safety/tolerability issues.

RESULTS

A total of 256 patients were included (106 first-line and 150 conversion to monotherapy; 56 patients aged >65 years). Overall, the 1-year retention rate was 79% (72.7% in the ≥65 years subgroup) and seizure-free rates at 6 and 12 months were 59.3% and 55.3% (72.2% and 67.3% in the ≥65 years subgroup), without significant differences when comparing first-line vs conversion-to-ESL monotherapy groups (P = .979). However, the conversion group was heterogeneous and included 43 (29.1%) patients that were seizure free the year prior ESL introduction. A substantially higher proportion of patients remained seizure free for the entire follow-up among those who initiated ESL due to tolerability problems compared with those treated due to inadequate seizure control (71.4% vs 37.3%). Overall, 62 of 256 (24.2%) patients reported AEs (39.3% in >65 years subgroup) and led to discontinuation in 20/256 (7.8%) patients (12.5% in >65 years subgroup). Commonly reported AEs were somnolence (6.6%), dizziness (6.3%), and headache (4.3%). Hyponatremia was recorded in five patients, the majority (4/5) of whom were older than 65 years.

CONCLUSIONS

Eslicarbazepine acetate was effective and well-tolerated as first-line or conversion to monotherapy in a clinical setting in adult and elderly patients with focal-onset seizures.

Effectiveness of eslicarbazepine acetate in dependency of baseline anticonvulsant therapy: Results from a German prospective multicenter clinical practice study

Eslicarbazepine acetate (ESL) is a third-generation antiepileptic drug (AED) approved as monotherapy for partial-onset seizures in adults and as adjunctive therapy in patients aged above 6 years in the European Union (EU). The prospective observational Zebinix Effects in DEpendency of BAseline Conditions (ZEDEBAC) study aimed at investigating the effectiveness of ESL in clinical practice, with ESL being administered as monotherapy (mono group), as only add-on to a current monotherapy (1+ group), or as add-on to ≥2 baseline AEDs (≥2+ group). In total, 237 patients were included, 35 in the mono group, 114 in the 1+, and 88 in the ≥2+ group. Six-month retention rates were 93.9%, 78.0%, and 75.3% in the mono, 1+, and ≥2+ group. There were 90.5%, 77.6%, and 48.3% of patients in the mono, 1+, and ≥2+ groups who were responders (patients with a ≥50% reduction in seizure frequency at follow-up vs. baseline). Seizure freedom rates were 81.5%, 47.9%, and 23.4%, respectively. Adverse drug reactions (ADRs) occurred in 11.4% of patients of the mono, 19.3% of the 1+, and 28.4% of patients of the ≥2+ group. Hyponatremia was reported as ADR in 3.4% of all patients. Although baseline variables differed considerably, with most elderly patients with tumor-related and vascular etiologies in the mono group and most patients with refractory epilepsies with pronounced use of concomitant sodium channel blockers (SCBs) in the ≥2+ group, retention as a measure of real-life effectiveness turned out not to be substantially different and favorable in all groups.

MONOZEB: Long-term observational study of eslicarbazepine acetate monotherapy

AIM

The aim of the study was to evaluate the effectiveness and tolerability of eslicarbazepine acetate (ESL) when used as monotherapy for 1 year or more in routine clinical use in patients with focal seizures in epilepsy clinics in Spain.

METHODS

This is a retrospective, observational, noninterventional study. Eligible patients were aged ≥18 years, had focal seizures, and started on ESL ≥1 year before database closure. Primary endpoint was the following: proportion seizure-free for ≥6 months at 1 and 2 years. Secondary endpoints included retention on ESL monotherapy at 1 and 2 years, seizure frequency change, seizure worsening, and side effects. Other analyses included seizure freedom from baseline to 1 and 2 years and outcomes in special populations.

RESULTS

Four hundred thirty-five patients were included (127 on first-line monotherapy and 308 converting to ESL monotherapy): median daily dose was 800 mg at all time points; 63.2% were seizure-free at 1 year, 65.1% at 2 years, and 50.3% for the entire follow-up. Mean duration of ESL monotherapy was 66.7 months; retention was 88.0% at 1 year and 81.9% at 2 years. Mean reduction in seizure frequency was 75.5% at last visit. Over the entire follow-up, seizure worsening was seen in 22 patients (5.1%), side effects in 28.0%, considered severe in 1.8%, and leading to discontinuation in 5.7%. Dizziness, hyponatremia (sodium <135 mEq/l), and somnolence were the most frequent side effects. Outcomes in special populations (patients aged ≥65 years and those with psychiatric history or learning difficulty) were consistent with the overall population.

CONCLUSIONS

Patients with focal seizures taking ESL monotherapy had excellent retention, high seizure-free rates, and good tolerability up to 2 years.

New anti-seizure medication for elderly epileptic patients

Introduction: Epilepsy treatment in older people requires specific consideration owing to more physical co-morbidities, the risk of drug-to-drug interactions through polypharmacy, and differences in pharmacodynamics and pharmacokinetics. There are many 'newer' antiepileptic drugs (AEDs) widely used for various seizure types and seizure disorders. However, there is limited specific evidence for the efficacy, safety, and tolerability of these treatments in the elderly population. Areas covered: This review summarises the current most robust evidence available for the use of the newer AEDs belonging to generation two and three in elderly people with epilepsy. The article provides practical evidenced based clinical information to help prescribers choose the most appropriate AED from the drugs discussed. Expert opinion: Diagnosing new onset epilepsy in the elderly population requires specialist assessment. Treatment plans need to be tailored to accommodate an individual's co-morbidities, concurrent medications, and general health status. To date, few clinical investigations consider the elderly population specifically despite the increased risk factors. There is a need for large quality trial data to assess the impact of the newest AEDs on seizure control and quality of life in this population with complex needs.

Effectiveness and Safety/Tolerability of Eslicarbazepine Acetate in Epilepsy Patients Aged ≥ 60 Versus < 60 Years: A Subanalysis from the Euro-Esli Study

Introduction

Clinical practice studies help guide antiepileptic drug (AED) therapy in patient groups routinely excluded from clinical trials, such as the elderly. The Euro-Esli study investigated the effectiveness and safety/tolerability of eslicarbazepine acetate (ESL) when used in everyday clinical practice in Europe. A subanalysis of data from elderly patients (≥ 60 years) included in the Euro-Esli study was conducted to assess these aspects of ESL use in this population.

Methods

Euro-Esli was a pooled analysis of 14 European clinical practice studies. Effectiveness parameters included responder (≥ 50% seizure frequency reduction) and seizure freedom rates after 3, 6 and 12 months of treatment and at last visit. Safety and tolerability were assessed throughout the follow-up by evaluating adverse events (AEs) and ESL discontinuation due to AEs, respectively. Data were compared for patients aged ≥ 60 versus those aged < 60 years at study entry.

Results

Euro-Esli included 2058 patients (mean age 44.0 years). Age at study entry was known for 2057 patients, of whom 358 (17.4%) and 1699 (82.6%) were aged ≥ 60 and < 60 years, respectively. Mean maximum ESL dose was   882.0 and 1008.2 mg/day in patients aged ≥ 60 and < 60 years, respectively  (p < 0.001). At all timepoints, responder and seizure freedom rates were significantly higher in patients aged ≥ 60 versus < 60 years; for example, at 12 months, responder rates were 83.9 and 73.7%, respectively (p = 0.002), and seizure freedom rates were 58.5 and 37.1%, respectively (p < 0.001). The incidence of AEs was significantly higher in patients aged ≥ 60 versus < 60 years (41.4 vs. 32.5%; p = 0.001), but the rate of discontinuation due to AEs was comparable between age groups (16.2 vs 13.1%; p = not significant). The safety/tolerability of ESL in patients aged ≥ 60 years was consistent with its known    profile.

Conclusion

Eslicarbazepine acetate was efficacious and generally well tolerated when used to treat elderly patients with focal epilepsy in clinical practice, with no new or unexpected safety signals emerging in this setting.

Funding

Eisai Ltd.