A randomized phase III trial of adjunctive zonisamide in pediatric patients with partial epilepsy

Zonisamide: A Comprehensive, Updated Review for the Clinician

Purpose of Review

Zonisamide (ZNS) was first approved in the United States in 2000 for the adjunctive treatment of patients aged 16 years or older with partial (focal) seizures. Although ZNS has been proven to treat multiple seizure types, it has been largely underutilized in US clinical practice.

Recent Findings

Published literature demonstrated that antiseizure medications (ASMs) acting on Na+ and Ca2+ channels may add beneficial effects in many seizure types by reducing seizure frequency and leading to overall improvements. In addition, effects of ZNS may lead to clinical improvements in Parkinson disease, alcohol and sleep disorders, pain, and migraine. ZNS is available in multiple formulations and is a safe and effective, broad spectrum ASM.

Summary

The purpose of this review was to provide an update to what is known about the efficacy of ZNS and where it shows benefits in the treatment of patients with epilepsy and other CNS disorders through its many unique mechanisms of action.

Isochromosome Mosaic Turner Syndrome With Epilepsy and Developmental Abnormalities: A Case Report

Turner syndrome (TS) is a genetic disorder resulting from the partial or complete absence of one X chromosome in females. This condition gives rise to a spectrum of physical and developmental characteristics. Isochromosome mosaic Turner syndrome (IMTS) is a distinct form of this disorder, characterized by genetically different cell lineages, where one or more of the lineages contain an isochromosome X consisting of either p or q arms. While IMTS is relatively common, the relationship between IMTS and epilepsy along with developmental abnormalities remains an area of further investigation. An eight-year-old female presented with a seizure lasting more than 10 minutes, subsequent bilateral hand weakness, and an abnormal gait. Neurologic evaluation revealed a 24-hour amplitude-integrated electroencephalogram (EEG) demonstrating generalized sharp and slow waves increased with hyperventilation and left-sided delta activity. Both the brain magnetic resonance imaging (MRI) and repeated EEG, conducted while the patient was sedated, showed normal results. The patient was diagnosed with generalized epilepsy with underlying left hemispheric dysfunction. Early medical history revealed acid reflux, heightened sensitivity or aversion to certain textures, swallowing difficulties, attention-deficit/hyperactivity disorder, extremity clumsiness, and a focal seizure one year prior. In the following months, the patient continued having generalized tonic-clonic seizures and developed bilateral muscle weakness in her arms and legs. This prompted genetic testing, which revealed a karyotype of 45,X,t(17;20)(q23;p13)/46,X,I(X)(q10),t(17;20)(q23;p13) consistent with IMTS and an additional chromosomal translocation. This rare case highlights the potential association between IMTS and the development of epilepsy, emphasizing the importance of a multidisciplinary approach in evaluating TS patients. There is a need for further research that explores the genetic link between TS variants and epilepsy, as well as other intellectual disorders.

Long-term safety and efficacy of adjunctive brivaracetam in pediatric patients with epilepsy: An open-label, follow-up trial

OBJECTIVE

This study was undertaken to evaluate the long-term safety, tolerability, and efficacy of adjunctive brivaracetam (BRV) treatment in pediatric patients with epilepsy.

METHODS

A phase 3, open-label, multicenter, long-term follow-up trial (N01266; NCT01364597) was conducted on patients (aged 1 month to <17 years at core trial entry; direct enrollers aged 4 to <17 years) treated with BRV. Outcomes included treatment-emergent adverse events (TEAEs), behavior assessments (Achenbach Child Behavior Checklist [CBCL], Behavior Rating Inventory of Executive Function [BRIEF]/BRIEF-Preschool version [BRIEF-P]), and efficacy outcomes (percent change in focal seizure frequency, 50% responder rate for all seizure types for patient subgroups <2 years and ≥2 years of age using daily record card data).

RESULTS

Of 257 patients with ≥1 dose of BRV (141 [54.9%] male; mean age = 8.0 years [SD = 4.5]), 36 patients were <2 years of age, and 72.0% of patients had a history of focal seizures. Mean BRV exposure was 3.2 patient-years. At least one TEAE occurred in 93.4% patients, and 32.3% had serious TEAEs. Seven patients died during the trial; no deaths were considered treatment-related. Patients ≥2 years of age had a median decrease in 28-day adjusted focal seizure frequency of 62.9%, and 50.9% had a ≥50% response in all seizures. Patients <2 years of age had a median decrease in 28-day adjusted focal seizure frequency of 96.9%, and 68.2% had a ≥50% response in all seizures. Kaplan-Meier estimated treatment retention was 72.7%, 64.5%, 57.8%, 53.3%, 50.1%, and 44.8% at 1, 2, 3, 4, 5, and 6 years, respectively. Mean changes (baseline to last evaluation) for all Achenbach CBCL and BRIEF-P/BRIEF subscale scores were negative, reflecting stability/slight improvement.

SIGNIFICANCE

Long-term adjunctive BRV treatment was generally well tolerated and efficacious in reducing seizure frequency, and had high retention rates, with generally stable cognitive/behavioral scores in pediatric patients with epilepsy.

Safety and efficacy of brivaracetam in children epilepsy: a systematic review and meta-analysis

Background

Epilepsy is one of the most common neurological diseases, affecting people of any age. Although the treatments of epilepsy are more and more diverse, the uncertainty regarding efficacy and adverse events still exists, especially in the control of childhood epilepsy.

Methods

We performed a systematic review and meta- analysis following the Cochrane Handbook and preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Four databases including PubMed, Embase, Web of Science and Cochrane library were searched. Studies reporting the use of brivaracetam monotherapy or adjuvant therapy in children (aged ≤18 years) were eligible for inclusion. Each stage of the review was conducted by two authors independently. Random-effects models were used to combine effect sizes for the estimation of efficacy and safety.

Results

A total of 1884 articles were retrieved, and finally 9 articles were included, enrolling 503 children with epilepsy. The retention rate of BRV treatment was 78% (95% CI: 0.64-0.91), the responder rate (reduction of seizure frequency ≥ 50%) was 35% (95% CI: 0.24-0.47), the freedom seizure rate (no seizure) was 18% (95% CI: 0.10-0.25), and the incidence rate of any treatment-emergent adverse events (TEAE) was 39% (95% CI: 0.09-0.68). The most common TEAE was somnolence, which had an incidence rate of 9% (95% CI: 0.07-0.12). And the incidence rate of mental or behavioral disorders was 12% (95% CI: 0.06-0.17).

Conclusion

Our systematic review and meta-analysis showed that BRV seemed to be safe and effective in the treatment of childhood epilepsy.

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.

Effectiveness of zonisamide in childhood refractory epilepsy

INTRODUCTION

Zonisamide (ZNS) is a new generation antiepileptic drug (AED) used in refractory epilepsy. This study assessed the effectiveness and reliability of ZNS in childhood refractory epilepsy.

METHOD

Sixty-eight epilepsy patients who were followed up in the paediatric neurology clinic, between 2013 and 2019, and in whom add-on therapy ZNS had been added as their seizures had continued despite multiple drugs being used, were included in this retrospective study. Their demographic findings, seizure aetiology, pre-treatment and post-treatment electroencephalography findings, treatment responses and any side effects of the drugs given were assessed in these patients.

RESULTS

There were 46 (67.6%) patients in the refractory generalized epilepsy (RGE) group using multiple AEDs and 22 (32.35%) patients in the refractory focal epilepsy (RFE) group. Of these patients, 12 (17.65%) were being followed up for idiopathic epilepsy and 8 (11.76%) were being followed up for epilepsy of unknown aetiology. Twenty-two (32.36%) patients were followed up for structural abnormality, 8 patients (11.77%) were followed up for genetic disease, 4 patients (5.88%) were followed up for infectious sequel, 14 patients (20.59%) were followed up for metabolic reasons. In the RGE group, a more than 50% reduction was found in the seizures of 26 (56.5%) patients, while the seizures of 7 (15.2%) patients were found to have terminated completely. In the RFE group, a more than 50% reduction was found in the seizures of 19 (86.4%) patients, while the seizures of 2 (9.1%) patients were found to have terminated completely. The termination or a more than 50% reduction in seizures in 4 of the 6 patients followed up for a diagnosis of tuberous sclerosis complex (TSC) was significant.

CONCLUSION

ZNS is an effective and reliable option as an add-on therapy in paediatric refractory epilepsy, especially in focal epilepsy. It can also be considered for treatment in TSC patients.

Treatment of Focal-Onset Seizures in Children: Should This Be More Etiology-Driven?

To accelerate the process of licensing antiseizure medication (ASM) in children, extrapolation of efficacy data for focal-onset seizures from adults to children ≥2 or ≥4 years of age is now accepted. We summarized the efficacy evidence from randomized, controlled trials that was used to grant approval for the pediatric indication of focal-onset seizures for the different ASMs available in Europe. Data from high-quality randomized, controlled trials in young children are limited, especially on the use of ASMs in monotherapy. Licensure trials are typically focused on seizure type irrespective of etiology or epilepsy syndrome. We elaborate on the importance of etiology- or syndrome-driven research and treatment, illustrating this with examples of childhood epilepsy syndromes characterized by predominantly focal-onset seizures. Some of these syndromes respond well to standard ASMs used for focal-onset seizures, but others would benefit from a more etiology- or syndrome-driven approach. Advances in molecular genetics and neuroimaging have made it possible to reveal the underlying cause of a child's epilepsy and tailor research and treatment. More high-quality randomized, controlled trials based on etiology or syndrome type are needed, including those assessing effects on cognition and behavior. In addition, study designs such as "N-of-1 trials" could elucidate possible new treatment options in rare epilepsies. Broadening incentives currently in place to stimulate the development and marketing of drugs for rare diseases (applicable to some epilepsy syndromes) to more common pediatric epilepsy types and syndromes might be a means to enable high-quality trials, and ultimately allow more evidence-based treatment in children.

Pharmacotherapy for Seizures in Tuberous Sclerosis Complex

Epilepsy is one of the main symptoms affecting the lives of individuals with tuberous sclerosis complex (TSC), causing a high rate of morbidity. Individuals with TSC can present with various types of seizures, epilepsies, and epilepsy syndromes that can coexist or appear in relation to age. Focal epilepsy is the most frequent epilepsy type with two developmental and epileptic encephalopathies: infantile spasms syndrome and Lennox-Gastaut syndrome. Active screening and early management of epilepsy is recommended in individuals with TSC to limit its consequences and its impact on quality of life, cognitive outcome and the economic burden of the disease. The progress in the knowledge of the mechanisms underlying epilepsy in TSC has paved the way for new concepts in the management of epilepsy related to TSC. In addition, we are moving from traditional "reactive" and therapeutic choices with current antiseizure medications used after the onset of seizures, to a proactive approach, aimed at predicting and preventing epileptogenesis and the onset of epilepsy with vigabatrin, and to personalized treatments with mechanistic therapies, namely mechanistic/mammalian target of rapamycin inhibitors. Indeed, epilepsy linked to TSC is one of the only epilepsies for which a predictive and preventive approach can delay seizure onset and improve seizure response. However, the efficacy of such interventions on long-term cognitive and psychiatric outcomes is still under investigation.

Clinical Trial Design for Disease-Modifying Therapies for Genetic Epilepsies

Although trials with anti-seizure medications (ASMs) have not shown clear anti-epileptogenic or disease-modifying activity in humans to date, rapid advancements in genomic technology and emerging gene-mediated and gene replacement options offer hope for the successful development of disease-modifying therapies (DMTs) for genetic epilepsies. In fact, more than 26 potential DMTs are in various stages of preclinical and/or clinical development for genetic syndromes associated with epilepsy. The scope of disease-modification includes but is not limited to effects on the underlying pathophysiology, the condition's natural history, epilepsy severity, developmental achievement, function, behavior, sleep, and quality of life. While conventional regulatory clinical trials for epilepsy therapeutics have historically focused on seizure reduction, similarly designed trials may prove ill-equipped to identify these broader disease-modifying benefits. As we look forward to this pipeline of DMTs, focused consideration should be given to the challenges they pose to conventional clinical trial designs for epilepsy therapeutics. Just as DMTs promise to fundamentally alter how we approach the care of patients with genetic epilepsy syndromes, DMTs likewise challenge how we traditionally construct and measure the success of clinical trials. In the following, we briefly review the historical and preclinical frameworks for DMT development for genetic epilepsies and explore the many novel challenges posed for such trials, including the choice of suitable outcome measures, trial structure, timing and duration of treatment, feasible follow-up period, varying safety profile, and ethical concerns.

Safety considerations selecting antiseizure medications for the treatment of individuals with Dravet syndrome

Introduction: Management of individuals with Dravet Syndrome has evolved significantly over the past 10 years. Progress has been made in understanding the pathophysiology, the long-term outcome and possible consequences of inappropriate therapies, new drugs have been approved by the regulatory authorities and patients and families expressed their needs beyond seizures' control.Areas covered: The authors aimed at providing an overview of the main antiseizure medications used in Dravet syndrome with a particular focus on safety considerations. As the highly active phase of seizures takes place before the age of 5 years, the characteristics of antiseizure medications in infancy and childhood have also been considered due to their impact on antiseizure medication safety.Expert opinion: Recent treatments, evaluated via randomized clinical trials, are promising in terms of efficacy and safety in individuals with DS. However, the balance between expected benefits and risks taken must be accurately assessed on an individual basis. There is a lack of data to understand the needs of patients and families, a major point particularly in this population, where the evaluation of efficacy and safety beyond seizures is difficult due to cognitive delay and behavioral disorders and where this evaluation is coming almost exclusively from caregivers.

Zonisamide add-on therapy for focal epilepsy

BACKGROUND

The majority of people with epilepsy have a good prognosis, and their seizures can be well controlled with the use of a single antiepileptic agent, but up to 30% develop dug-resistant epilepsy, especially those with focal seizures. In this review, we summarised the evidence from randomised controlled trials (RCT) of zonisamide, used as an add-on treatment for focal epilepsy uncontrolled by one or more concomitant antiepileptic drug. This is an updated version of the Cochrane review previously published in 2018.

OBJECTIVES

To evaluate the efficacy and tolerability of zonisamide, when used as an add-on treatment for people with focal epilepsy uncontrolled by one or more concomitant antiepileptic drugs.

SEARCH METHODS

For the latest update, we searched the Cochrane Register of Studies (CRS Web) and MEDLINE Ovid (September 2019). In addition, we contacted Eisai Limited (makers and licensees of zonisamide) and experts in the field, to seek any ongoing or unpublished studies.

SELECTION CRITERIA

Randomised controlled trials, in which add-on zonisamide was compared with placebo or another antiepileptic drug in people with focal epilepsy, uncontrolled by one or more concomitant antiepileptic drugs.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, extracted data, assessed for risk of bias using the Cochrane 'Risk of bias' tool, and assessed the certainty of the evidence, using the GRADE approach. The primary outcome was at least a 50% reduction in total seizure frequency; the secondary outcomes were (1) tolerability; and (2) adverse effects. We used an intention-to-treat approach for our primary analyses. We estimated summary risk ratios (RRs) for each outcome. We displayed a summary of the estimates of effects and certainty of the evidence for each outcome in a 'Summary of findings' table.

MAIN RESULTS

We did not find any new studies since the last version of this review. We included eight studies (1636 participants) from previous versions of this review. The overall RR with 95% confidence interval (CI) for at least a 50% reduction in seizure frequency for 300 mg to 500 mg/day of zonisamide compared to placebo was 1.90 (95% CI 1.63 to 2.22; 7 trials, 1371 participants; moderate-certainty evidence). The RR for 50% reduction in seizure frequency compared to placebo for any dose of zonisamide (100 mg to 500 mg/day) was 1.86 (95% CI 1.60 to 2.17; 7 trials, 1429 participants; moderate-certainty evidence). The number needed to treat for an additional beneficial outcome was six (95% CI 4.1 to 6.8). Two trials provided evidence of a dose-response relationship for this outcome. The RR for treatment withdrawal for 300 mg to 500 mg/day of zonisamide compared to placebo was 1.59 (95% CI 1.18 to 2.13; 6 trials, 1099 participants; moderate-certainty evidence), and for 100 mg to 500 mg/day was 1.44 (95% CI 1.08 to 1.93; 6 trials, 1156 participants; moderate-certainty evidence). The number needed to treat for an additional harmful outcome was 15 (95% CI 9.3 to 36.7). The following adverse effects were more likely to be associated with zonisamide than with placebo: ataxia (RR 3.85, 99% CI 1.36 to 10.93; 4 trials, 734 participants; low-certainty evidence); somnolence (RR 1.52, 99% CI 1.00 to 2.31; 8 trials, 1636 participants; moderate-certainty evidence); agitation (RR 2.35, 99% CI 1.05 to 5.27; 4 trials, 598 participants; low-certainty evidence); and anorexia (RR 2.74, 99% CI 1.64 to 4.60; 6 trials, 1181 participants; low-certainty evidence). Across the eight studies, we rated risk of bias domains at low or unclear risk of bias, apart from two studies, which we rated at high risk of attrition bias. Five of the eight studies were sponsored by the drug companies that produced zonisamide.

AUTHORS' CONCLUSIONS

When used as an add-on treatment in people with focal epilepsy, uncontrolled by one or more concomitant antiepileptic drugs, moderate-certainty evidence found that zonisamide was more successful than placebo at reducing the frequency of seizures by at least 50%. We were unable to identify minimum effective and maximum tolerated doses. The included trials evaluated a maximum stable-dose phase of 18 weeks, so results cannot be used to confirm longer periods of efficacy in seizure control. The results cannot be extrapolated to monotherapy, or to people with other seizure types or epilepsy syndromes.

Safety and tolerability of adjunctive brivaracetam in children with focal seizures: Interim analysis of pooled data from two open-label trials

OBJECTIVE

To evaluate long-term safety and tolerability of adjunctive brivaracetam (BRV) in children with epilepsy.

METHODS

This was an interim analysis (cut-off March 15, 2017) of pooled data from two open-label, single-arm, multicentre trials. N01263 (NCT00422422) was a 3-week trial of BRV 0.8-4 mg/kg/day in patients (1 month-<16 years) with epilepsy. Patients who completed this trial could continue into a long-term follow-up trial (N01266, NCT01364597) which also directly enrolled patients (4-<17 years) with focal seizures. After dose-escalation, patients received BRV 1-5 mg/kg/day (maximum 200 mg/day) during long-term evaluation. Data are reported for patients aged 4 to <16 years with focal seizures.

RESULTS

The safety set comprised 149 patients: 34 from the initial trial (26 entered long-term trial) and 115 directly enrolled into the long-term trial. At the cut-off, 90 patients were receiving BRV (total exposure: 299.4 patient-years). Treatment-emergent adverse events (TEAEs) were reported by 140/149 (94.0%) patients, most commonly (≥20%) nasopharyngitis (24.8%), pharyngitis (22.1%), convulsion (21.5%), and pyrexia (20.1%). TEAEs considered drug-related by the investigator were reported by 56/149 (37.6%) patients, most commonly somnolence (6.0%). Two patients died; neither death was considered related to BRV. Mean changes from baseline in child behaviour rating scales were small; most patients remained in their baseline category.

CONCLUSION

In this pooled analysis of two open-label trials including long-term data, adjunctive BRV was generally well tolerated in children aged 4 to <16 years with focal seizures. These findings supported approval of BRV as a new therapy option for children aged ≥4 years with focal seizures.

Efficacy and tolerability of adjunctive lacosamide in pediatric patients with focal seizures

Objective

To evaluate efficacy and tolerability of adjunctive lacosamide in children and adolescents with uncontrolled focal (partial-onset) seizures.

Methods

In this double-blind trial (SP0969; NCT01921205), patients (age ≥4–<17 years) with uncontrolled focal seizures were randomized (1:1) to adjunctive lacosamide/placebo. After a 6-week titration, patients who reached the target dose range for their weight (<30 kg: 8–12 mg/kg/d oral solution; ≥30–<50 kg: 6–8 mg/kg/d oral solution; ≥50 kg: 300–400 mg/d tablets) entered a 10-week maintenance period. The primary outcome was change in focal seizure frequency per 28 days from baseline to maintenance.

Results

Three hundred forty-three patients were randomized; 306 (lacosamide 152 of 171 [88.9%]; placebo 154 of 172 [89.5%]) completed treatment (titration and maintenance). Adverse events (AEs) were the most common reasons for discontinuation during treatment (lacosamide 4.1%; placebo 5.8%). From baseline to maintenance, percent reduction in focal seizure frequency per 28 days for lacosamide (n = 170) vs placebo (n = 168) was 31.7% (p = 0.0003). During maintenance, median percent reduction in focal seizure frequency per 28 days was 51.7% for lacosamide and 21.7% for placebo. Fifty percent responder rates (≥50% reduction) were 52.9% and 33.3% (odds ratio 2.17, p = 0.0006). During treatment, treatment-emergent AEs were reported by 67.8% lacosamide-treated patients (placebo 58.1%), most commonly (≥10%) somnolence (14.0%, placebo 5.2%) and dizziness (10.5%, placebo 3.5%).

Conclusions

Adjunctive lacosamide was efficacious in reducing seizure frequency and generally well tolerated in patients (age ≥4–<17 years) with focal seizures.

ClinicalTrials.gov identifier:

NCT01921205.

Classification of evidence

This trial provides Class I evidence that for children and adolescents with uncontrolled focal seizures, adjunctive lacosamide reduces seizure frequency.

[Clinical experience of using zonisamide in structural focal epilepsy in children with cerebral palsy]

AIM

To evaluate the efficacy and safety of zonisamide as an add-on therapy in structural focal epilepsy in children with cerebral palsy (CP).

MATERIAL AND METHODS

Sixty-four patients (36 boys and 28 girls) with spastic CP and structural focal epilepsy with refractory seizures were followed up. Patients received zonisamide in a dose of 6-8.8 mg/kg/day for ≥6 months. Treatment efficacy was assessed by the reduction of seizures depending on CP form, type of epileptic seizures, combination of zonisamide with other drugs and adverse-effects.

RESULTS AND CONCLUSION

A reduction of seizures by ≥50% was identified in 60.9% of children, 10.9% showed a better recovery. The best efficacy (35.9%) was demonstrated in the treatment of generalized seizures with focal onset and in the combination with levetiracetam (35.9%). Adverse effects of mild to moderate severity were noted in 26.5% of children. The treatment was discontinued in 7.8%. Therefore, zonisamide is an effective treatment for refractory structural focal epilepsy in children with CP and comorbid pathology, which reduces the frequency of seizures without severe side-effects.

Zonisamide add-on therapy for focal epilepsy

BACKGROUND

The majority of people with epilepsy have a good prognosis, and their seizures can be well controlled with the use of a single antiepileptic agent, but up to 30% develop refractory epilepsy, especially those with focal seizures. In this review, we summarised the evidence from randomised controlled trials (RCT) of zonisamide, used as an add-on treatment for focal epilepsy uncontrolled by one or more concomitant antiepileptic drug. This is an updated version of the Cochrane review previously published in 2013.

OBJECTIVES

To evaluate the efficacy and tolerability of zonisamide, when used as an add-on treatment for people with focal epilepsy uncontrolled by one or more concomitant antiepileptic drugs.

SEARCH METHODS

For this update, on 4 September 2017, we searched the Cochrane Epilepsy Group Specialised Register, Cochrane Register of Studies Online, MEDLINE Ovid, ClinicalTrials.gov, and the WHO International Clinical Trials Registry Platform ICTRP. We searched SCOPUS on 13 February 2013, but this is no longer necessary, because RCTs and quasi-RCTs in Embase are now included in CENTRAL. In addition, we contacted Eisai Limited (makers and licensees of zonisamide) and experts in the field to seek any ongoing or unpublished studies.

SELECTION CRITERIA

Randomised controlled trials, in which add-on zonisamide was compared with placebo or another antiepileptic drug in people with focal epilepsy, uncontrolled by one or more concomitant antiepileptic drugs.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, extracted data, assessed for risk of bias using the Cochrane 'Risk of bias' tool, and assessed the quality of the evidence, using the GRADE approach. The primary outcome was at least a 50% reduction in total seizure frequency; the secondary outcomes were (1) tolerability; and (2) adverse effects. We used an intention-to-treat approach for our primary analyses. We estimated summary risk ratios (RRs) for each outcome. We displayed a summary of the estimates of effects and quality of the evidence for each outcome in a 'Summary of findings' table.

MAIN RESULTS

We included eight studies (1636 participants). The overall RR with 95% confidence interval (CI) for at least a 50% reduction in seizure frequency compared to placebo for 300 mg to 500 mg/day of zonisamide was 1.90 (95% CI 1.63 to 2.22; 7 trials, 1371 participants; moderate-quality evidence). The RR for 50% reduction in seizure frequency compared to placebo for any dose of zonisamide (100 mg to 500 mg/day) was 1.86 (95% CI 1.60 to 2.17; 7 trials, 1429 participants; moderate-quality evidence). The number needed to treat for an additional beneficial outcome was six (95% CI 4.1 to 6.8) for this outcome. Two trials provided evidence of a dose-response relationship for this outcome. The RR for treatment withdrawal for 300 mg to 500 mg/day of zonisamide compared to placebo was 1.59 (95% CI 1.18 to 2.13; 6 trials, 1099 participants; moderate-quality evidence), and for 100 mg to 500 mg/day was 1.44 (95% CI 1.08 to 1.93; 6 trials, 1156 participants; moderate-quality evidence). The number needed to treat for an additional harmful outcome was 15 (95% CI 9.3 to 36.7). The CIs of the following adverse effects indicated that they were significantly associated with zonisamide: ataxia RR 3.85 (99% CI 1.36 to 10.93; 4 trials, 734 participants; low-quality evidence); somnolence RR 1.52 (99% CI 1.00 to 2.31; 8 trials, 1636 participants; moderate-quality evidence); agitation RR 2.35 (99% CI 1.05 to 5.27; 4 trials, 598 participants; low-quality evidence); and anorexia RR 2.74 (99% CI 1.64 to 4.60; 6 trials, 1181 participants; low-quality evidence).Across the eight studies, we rated risk of bias domains at low or unclear risk of bias apart from two studies which we rated at high risk of attrition bias. Five of the eight studies were sponsored by the drug companies that produced zonisamide.

AUTHORS' CONCLUSIONS

When used as an add-on treatment in people with focal epilepsy uncontrolled by one or more concomitant antiepileptic drugs, moderate-quality evidence found that zonisamide was more successful than placebo at reducing the frequency of seizures by at least 50%. We were unable to identify minimum effective and maximum tolerated doses. The included trials evaluated a maximum stable-dose phase of 18 weeks, so results cannot be used to confirm longer periods of efficacy in seizure control. The results cannot be extrapolated to monotherapy or to people with other seizure types or epilepsy syndromes.

Practice guideline update summary: Efficacy and tolerability of the new antiepileptic drugs II: Treatment-resistant epilepsy: Report of the American Epilepsy Society and the Guideline Development, Dissemination, and Implementation Subcommittee of the American Academy of Neurology

Objective: To update the 2004 American Academy of Neurology (AAN) guideline for managing treatment-resistant (TR) epilepsy with second- and third-generation antiepileptic drugs (AEDs). Methods: 2004 criteria were used to systematically review literature (January 2003 to November 2015), classify pertinent studies according to the therapeutic rating scheme, and link recommendations to evidence strength. Results: Forty-two articles were included. Recommendations: The following are established as effective to reduce seizure frequency (Level A): immediate-release pregabalin and perampanel for TR adult focal epilepsy (TRAFE); vigabatrin for TRAFE (not first-line treatment; rufinamide for Lennox-Gastuat syndrome (LGS) (add-on therapy). The following should be considered to decrease seizure frequency (Level B): lacosamide, eslicarbazepine, and extended-release topiramate for TRAFE (ezogabine production discontinued); immediate- and extended-release lamotrigine for generalized epilepsy with TR generalized tonic-clonic (GTC) seizures in adults; levetiracetam (add-on therapy) for TR childhood focal epilepsy (TRCFE) (1 month to 16 years), TR GTC seizures, and TR juvenile myoclonic epilepsy; clobazam for LGS (add-on therapy); zonisamide for TRCFE (6-17 years); oxcarbazepine for TRCFE (1 month to 4 years). The text presents Level C recommendations. AED selection depends on seizure/syndrome type, patient age, concomitant medications, and AED tolerability, safety, and efficacy. This evidence-based assessment informs AED prescription guidelines for TR epilepsy and indicates seizure types and syndromes needing more evidence. A recent FDA strategy allows extrapolation of efficacy across populations; therefore, for focal epilepsy, eslicarbazepine and lacosamide (oral only for pediatric use) as add-on or monotherapy in persons ≥4 years of age and perampanel as monotherapy received FDA approval.

Comparative efficacy of antiepileptic drugs in children and adolescents: A network meta-analysis

OBJECTIVE

To estimate the comparative efficacy among antiepileptic drugs in the pediatric population (0-18 years).

METHODS

Using the Embase and MEDLINE databases, we updated to February 2017 the search strategy of the National Institute for Health and Care Excellence guidelines for epilepsy. We only included randomized clinical trials conducted in children and mixed-age populations. According to the PRISMA network meta-analysis guideline, the study-level quality assessment was made with the Cochrane risk-of-bias tool. Three investigators independently selected articles. The efficacy outcome was considered to be seizure freedom or ≥50% seizure reduction.

RESULTS

We selected 46 randomized clinical trials. A total of 5652 individuals were randomized to 22 antiepileptic drugs and placebo. The point estimates of carbamazepine and lamotrigine efficacy showed their superiority with respect to all comparator antiepileptic drugs for the treatment of newly diagnosed focal epilepsy. In refractory focal epilepsy, levetiracetam (odds ratio [OR] = 3.3, 95% credible interval [CrI] = 1.3-7.6) and perampanel (OR = 2.5, 95% CrI = 1.1-5.8) were more effective compared to placebo. Ethosuximide and valproic acid were both superior to lamotrigine against absence seizures. The OR point estimate showed the superiority of adrenocorticotropic hormone over all comparators in infantile spasms. A wide heterogeneity in the length of follow-up was observed among the studies.

SIGNIFICANCE

This network meta-analysis suggests that the quality of studies should be improved through the use of comparative designs, relevant outcomes, appropriate follow-up length, and more reliable inclusion criteria.

Meta-analyses of newer antiepileptic drugs as adjunct for treatment of focal epilepsy in children

AIM

This study conducted a systematic review evaluating the effectiveness of newer antiepileptic drugs (AEDs) (namely, lamotrigine, levetiracetam, topiramate, vigabatrin, zonisamide, oxcarbazepine, perampanel, gabapentin, and stiripentol) as add-on for treatment of focal epilepsy in children.

METHODS

Articles were retrieved from EMBASE, Medline and Cochrane Library from inception to January 2016. Treatment outcomes were analysed based on responder, seizure-free, withdrawal and adverse event rates. Quality of each study was also assessed.

RESULTS

Twelve articles fulfilled the inclusion criteria. Heterogeneity and quality of the included studies were considered acceptable. Overall, newer AEDs as adjunct therapy in children with inadequate control of focal seizure showed a trend of better seizure outcomes. The pooled ORs for responder, seizure-free and withdrawal rates were 2.15 (95%CI:1.72, 2.69), 1.99 (95%CI:0.72, 5.48) and 0.69 (95%CI:1.13, 2.39) respectively. Adverse events of newer AEDs were comparatively higher than placebo (OR:1.64, 95%CI:1.13, 2.39).

CONCLUSION

In our updated review, newer AEDs as adjunct therapy for focal epilepsy in children have trends of better effectiveness compared to placebo. Newer AEDs are associated with statistically more children with >50% seizure reduction, and a trend of better seizure freedom. Their tolerability would also be considered acceptable with the observed low withdrawal rate. However, the relative lack of well-conducted RCTs evaluating their effectiveness against other active AED treatment in children would not facilitate evidence-based practice. This highlights the knowledge gap and the need for more well-conducted RCTs against active treatments to ascertain the long term effectiveness and the role of newer AEDs in managing epilepsy in children.

Reducing placebo exposure in trials: Considerations from the Research Roundtable in Epilepsy

The randomized controlled trial is the unequivocal gold standard for demonstrating clinical efficacy and safety of investigational therapies. Recently there have been concerns raised about prolonged exposure to placebo and ineffective therapy during the course of an add-on regulatory trial for new antiepileptic drug approval (typically ∼6 months in duration), due to the potential risks of continued uncontrolled epilepsy for that period. The first meeting of the Research Roundtable in Epilepsy on May 19-20, 2016, focused on "Reducing placebo exposure in epilepsy clinical trials," with a goal of considering new designs for epilepsy regulatory trials that may be added to the overall development plan to make it, as a whole, safer for participants while still providing rigorous evidence of effect. This topic was motivated in part by data from a meta-analysis showing a 3- to 5-fold increased rate of sudden unexpected death in epilepsy in participants randomized to placebo or ineffective doses of new antiepileptic drugs. The meeting agenda included rationale and discussion of different trial designs, including active-control add-on trials, placebo add-on to background therapy with adjustment, time to event designs, adaptive designs, platform trials with pooled placebo control, a pharmacokinetic/pharmacodynamic approach to reducing placebo exposure, and shorter trials when drug tolerance has been ruled out. The merits and limitations of each design were discussed and are reviewed here.

Epilepsy, Antiepileptic Drugs, and Aggression: An Evidence-Based Review

Antiepileptic drugs (AEDs) have many benefits but also many side effects, including aggression, agitation, and irritability, in some patients with epilepsy. This article offers a comprehensive summary of current understanding of aggressive behaviors in patients with epilepsy, including an evidence-based review of aggression during AED treatment. Aggression is seen in a minority of people with epilepsy. It is rarely seizure related but is interictal, sometimes occurring as part of complex psychiatric and behavioral comorbidities, and it is sometimes associated with AED treatment. We review the common neurotransmitter systems and brain regions implicated in both epilepsy and aggression, including the GABA, glutamate, serotonin, dopamine, and noradrenaline systems and the hippocampus, amygdala, prefrontal cortex, anterior cingulate cortex, and temporal lobes. Few controlled clinical studies have used behavioral measures to specifically examine aggression with AEDs, and most evidence comes from adverse event reporting from clinical and observational studies. A systematic approach was used to identify relevant publications, and we present a comprehensive, evidence-based summary of available data surrounding aggression-related behaviors with each of the currently available AEDs in both adults and in children/adolescents with epilepsy. A psychiatric history and history of a propensity toward aggression/anger should routinely be sought from patients, family members, and carers; its presence does not preclude the use of any specific AEDs, but those most likely to be implicated in these behaviors should be used with caution in such cases.

Advancing pharmacologic treatment options for pharmacologic treatment options for children with epilepsy

INTRODUCTION

The pharmacological management of epilepsy is continually modified by the increase in our knowledge about the efficacy and the safety on antiepileptic drugs.

AREAS COVERED

This review covers the published data (2010-2015) on the pharmacological management of epilepsy in children and adolescent. We review the data from the most recent randomized controlled and open-label trials.

EXPERT OPINION

Even if there is an increasing number of antiepileptic drugs approved for focal seizure in children and adolescent with epilepsy, each new approval would be considered as a significant addition to the current therapeutic options. Refractory epilepsy with focal seizure should not be regarded as a single disease but as numerous various patients. Because most of evidence of efficacy is primarily from placebo-controlled trials, there is no evidence to choose a treatment based on efficacy. In case of focal seizure, we explain how possible cognitive impact, mechanisms of action, pharmacologic characteristics and side effect profile are the factors taken into an account to propose a treatment. In case of childhood absence epilepsy, there are evidences showing the ethosuximide should be the first line treatment. Finally, we stress that trials in the pediatric epilepsy syndromes are required to propose better evidence-based pharmacological management.

Targeted Treatment in Childhood Epilepsy Syndromes

OPINION STATEMENT

The mainstay of treatment of epilepsy has been antiepileptic drugs; however, despite the emergence of new agents, a consistent proportion remain drug-resistant. Newer AEDs show promise. However, as it becomes clear that the epilepsies are a group of diseases rather than a single disorder the prospect of targeted treatment in some may become a reality.

Zonisamide: Review of Recent Clinical Evidence for Treatment of Epilepsy

Zonisamide is an orally administered antiepileptic drug that was first approved for clinical use in Japan in 1989. Since then, it has been licensed in Korea for a broad spectrum of epilepsies in adults and children, and in the USA for adjunctive therapy of adults with partial seizures, and in Europe for monotherapy of adults with newly diagnosed partial seizures and adjunctive therapy of adults and adolescents and children aged ≥6 years with partial seizures with or without secondary generalization. Zonisamide is a benzisoxazole derivative with a unique chemical structure, predictable dose-dependent pharmacokinetics, and multiple complementary mechanisms of action. Treatment with zonisamide is well tolerated and is not known to be associated with clinically significant drug-drug interactions, including with oral contraceptives or other antiepileptic drugs. There have been >2 million patient-years of experience with zonisamide for treatment of epilepsy, and this drug has International League Against Epilepsy level A evidence for efficacy/effectiveness as initial monotherapy for adults with partial-onset seizures. This review presents the evidence for zonisamide across the spectrum of epilepsy, with emphasis on real-world clinical practice and special populations of patients (children, elderly patients, and women of childbearing age) who are likely to be treated in daily clinical practice.

Effects of adjunctive zonisamide treatment on weight and body mass index in children with partial epilepsy

BACKGROUND

Zonisamide has been associated with weight loss in children and adults.

AIMS OF THE STUDY

To assess the effects of adjunctive zonisamide on weight and body mass index (BMI) in children with partial epilepsy.

METHODS

A subanalysis was conducted of a Phase III trial and extension study, in which children with partial epilepsy received adjunctive zonisamide (target dose 8 mg/kg/day; maximum 500 mg/day). Changes in weight were correlated with skeletal development and sexual maturation.

RESULTS

Overall, 179 children (93 male, 86 female; age 6-18 years) received zonisamide (mean duration 370.6 days). Weight loss ≥ 5% was reported for 64 of 179 (35.8%) zonisamide-treated children. Of these, 46.9% were overweight/obese at study entry, compared with 23.4% at study end (P = 0.0007); 48.4% had normal weight at study entry, compared with 65.6% at study end (P = 0.03). Three patients were underweight at study entry, and four more became underweight by study end. No consistent correlations between weight loss and skeletal development or sexual maturation were observed.

CONCLUSIONS

Approximately one-third of children treated with zonisamide experienced ≥ 5% weight loss. Weight loss was most apparent in children with high baseline BMI values and did not appear to be associated with any consistent effects on growth and development.

Efficacy and safety of zonisamide in Thai children and adolescents with intractable seizures

This retrospective study examined the efficacy and safety of zonisamide for Thai children and adolescents with intractable seizures. The medical records of 24 patients (13 male, 11 female), aged 2 to 18 years (median 11.5, mean 10.4) who received zonisamide were reviewed. The underlying illness, etiology of epilepsy, seizure types, previous and concomitant antiepileptic drugs, dosage, and adverse effects of the drug were collected. Zonisamide's efficacy was evaluated on the basis of seizure reduction rates. At final evaluation, 7 patients were still taking zonisamide from 4.7 to 10.3 mg/kg/d (median 8). One patient became seizure-free and the other 6 experienced favorable seizure control. The median duration of zonisamide therapy was 23.75 months (range 20.5-25 months). Minor adverse effects were reported in 41.6% of patients during the first 3 months of therapy. Zonisamide is an option for the treatment of intractable seizures with favorable seizure control in children and adolescents.

Possible association between moderate intellectual disability and weight gain in valproic acid-treated patients with epilepsy

BACKGROUND

Although patients with moderate intellectual disability (ID) are known to have higher rates of being overweight and obese than those without ID, there are no current data regarding the relationship between ID and weight gain in epilepsy patients treated with valproic acid (VPA).

PATIENTS AND METHODS

The possible association between moderate ID and an overweight status at the time of initiation of VPA therapy (baseline) was investigated using a logistic regression analysis in 143 patients with epilepsy. Among the 119 nonoverweight patients at baseline, the longitudinal association between moderate ID and the weight status during VPA therapy was retrospectively examined using a Cox hazards regression analysis and the generalized estimating equations approach, while also paying careful attention to associations with other patient characteristics.

RESULTS

The proportion of patients with moderate ID was 52.4% among the 143 study subjects. The presence of moderate ID was not associated with an overweight status at baseline (P=0.762). Among the nonoverweight patients at baseline, 16 subjects were newly diagnosed as being overweight during treatment with VPA (3.6±2.1 years). The presence of moderate ID was significantly associated with the incidence of an overweight status after starting VPA therapy (adjusted hazard ratio =6.72, P=0.007). The patient age at baseline and treatment with co-administered carbamazepine, clobazam, and zonisamide significantly influenced the degree of weight fluctuation during VPA therapy among the patients with moderate ID (P<0.001, P<0.001, P=0.002, and P=0.028, respectively), whereas only patient age at baseline affected this parameter among the patients without moderate ID (P=0.022).

CONCLUSION

The present findings suggest that the weight status should be carefully monitored in VPA-treated patients with moderate ID, especially those receiving other co-administered antiepileptic drugs that facilitate weight gain, such as carbamazepine.

Antiepileptic Drug Treatment in Children with Epilepsy

Most children with new-onset epilepsy achieve seizure freedom with appropriate antiepileptic drugs (AEDs). However, nearly 20 % will continue to have seizures despite AEDs, as either monotherapy or in combination. Despite the growing market of new molecules over the last 20 years, the proportion of drug-resistant epilepsies has not changed. In this review, we report the evidence of efficacy and safety based on phase III randomized controlled clinical trials (RCTs) of AEDs currently used in the paediatric population. We conducted a literature search using the PubMed database and the Cochrane Database of Systematic Reviews. We also analysed the RCTs of newer AEDs whose efficacy in adolescents and adults might suggest possible use in children. Most of the phase III trials on AEDs in children have major methodological limitations that considerably limit meaningful conclusions about comparative efficacy between old and new molecules. Since the efficacy of new drugs has only been reported versus placebo, the commonly held opinion that new and newer AEDs have a better safety profile than old ones does not appear to be supported by evidence. Despite limited solid evidence, pharmacological management has improved over the years as a consequence of increased awareness of some degree of specificity of treatment in relation to different epilepsy syndromes and attention to adverse events. Future research should be directed taking these factors, as well as the diversity of epilepsy, into consideration.

Pharmacological Management of Obesity in Pediatric Patients

Objective: To review current evidence of pharmacological options for managing pediatric obesity and provide potential areas for future research. Data Sources: A MEDLINE search (1966 to October 2014) was conducted using the following keywords: exenatide, liraglutide, lorcaserin, metformin, obesity, orlistat, pediatric, phentermine, pramlintide, topiramate, weight loss, and zonisamide. Study Selection and Data Extraction: Identified articles were evaluated for inclusion, with priority given to randomized controlled trials with orlistat, metformin, glucagon-like peptide-1 agonists, topiramate, and zonisamide in human subjects and articles written in English. References were also reviewed for additional trials. Data Synthesis: Whereas lifestyle modification is considered first-line therapy for obese pediatric patients, severe obesity may benefit from pharmacotherapy. Orlistat is the only Food and Drug Administration (FDA)-approved medication for pediatric obesity and reduced body mass index (BMI) by 0.5 to 4 kg/m2, but gastrointestinal (GI) adverse effects may limit use. Metformin has demonstrated BMI reductions of 0.17 to 1.8 kg/m2, with mild GI adverse effects usually managed with dose titration. Exenatide reduced BMI by 1.1 to 1.7 kg/m2 and was well-tolerated with mostly transient or mild GI adverse effects. Topiramate and zonisamide reduced weight when used in the treatment of epilepsy. Future studies should examine efficacy and safety of pharmacological agents in addition to lifestyle modifications for pediatric obesity. Conclusions: Lifestyle interventions remain the treatment of choice in pediatric obesity, but concomitant pharmacotherapy may be beneficial in some patients. Orlistat should be considered as second-line therapy for pediatric obesity. Evidence suggests that other diabetes and antiepileptic medications may also provide weight-loss benefits, but safety should be further evaluated.

Safety and tolerability of zonisamide in paediatric patients with epilepsy

BACKGROUND

Zonisamide has recently been approved in Europe for the adjunctive treatment of partial seizures (with or without secondary generalisation) in adolescents and children aged ≥6 years.

AIM

To further assess the safety of adjunctive zonisamide in paediatric epilepsy patients.

METHODS

A pooled analysis of data from 17 studies (including four randomised, double-blind trials) was conducted. The safety population comprised patients aged ≤16 years receiving at least one dose of study drug. Assessments included treatment-emergent adverse events (TEAEs), clinical laboratory parameters, vital signs and electrocardiography.

RESULTS

The analysis included 398 patients treated with zonisamide (<12 years, n = 191; 12-16 years, n = 207). All but seven patients received zonisamide as adjunctive therapy. Mean duration of exposure was 318.7 days (mean dose, 253.1 mg/day). Most TEAEs were of mild or moderate intensity. The most frequently reported treatment-related TEAEs were decreased appetite (15.6%), somnolence (12.1%), fatigue (9.3%), dizziness (6.0%), decreased weight (5.8%), irritability (5.8%) and headache (5.3%). Incidence of serious zonisamide-related TEAEs was low (3.5% overall). TEAEs most commonly leading to discontinuation were lethargy (1.0%) and fatigue (1.0%). TEAEs of decreased weight and decreased appetite occurred in 28 (7.0%) and 78 (19.6%) patients, respectively. Twenty-eight patients had decreased bicarbonate levels, but there were no reports of respiratory alkalosis or metabolic acidosis. No changes in vital signs of clinical concern were observed and there were no reports of clinically significant electrocardiogram abnormalities with zonisamide treatment.

CONCLUSION

Zonisamide demonstrated an acceptable safety profile when used as adjunctive treatment in paediatric patients.

[New aspects in the field of epilepsy]

Regarding epilepsy several new developments can be reported. The International League Against Epilepsy (ILAE) has suggested a new definition of epilepsy, for the first time including a definition of epilepsy resolution. Progress in the diagnosis relates to new genetic findings, improvements in magnetic resonance imaging (MRI) and the increasing use of stereo electroencephalograms (sEEG). Regarding treatment there are new clinically relevant data on the pathophysiology and prevention of sudden unexpected death in epilepsy (SUDEP). Zonisamide has been approved by the European Medicines Agency (EMA) for monotherapy in adults with focal seizures and combination therapy in children aged ≥ 6 years. Retigabin and perampanel have been approved but are currently taken off the market in Germany (only) because the Gemeinsamer Bundesausschuss (GBA, Joint Federal Committee) did not find any additional therapeutic value as compared to lamotrigine due to a lack of data. A decision regarding a new application for perampanel is pending. Regarding surgical treatment novel ablation techniques (e.g. stereotactic radiofrequency and laser ablation as well as focussed ultrasound ablation) and brain stimulation paradigms are under investigation. Experimental studies, generously supported by the European Union (EU) and the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) are focusing on (opto-)genetic (e.g. using lentoviral transfection), epigenetic (e.g. micro-RNA-related) approaches and on the investigation of neuronal micronetworks.

Zonisamide: a review of its use as adjunctive therapy in the management of partial seizures in pediatric patients aged ≥6 years

Oral zonisamide (Zonegran®) is a benzisoxazole derivative chemically unrelated to other antiepileptic drugs (AEDs). It is approved in the EU as an adjunct to other AEDs in the treatment of pediatric patients aged ≥6 years with partial seizures, with or without secondary generalization. In a randomized, double-blind, multinational, phase III study in pediatric patients aged 6-17 years with partial seizures, the proportion of patients achieving a ≥50 % reduction from baseline in seizure frequency per 28 days during the maintenance treatment period was significantly higher with adjunctive therapy with zonisamide than placebo. The antiepileptic efficacy of zonisamide was sustained during a 59-week extension study in this patient population. Zonisamide was generally well tolerated in these studies, with the majority of adverse events being mild or moderate in severity. Thus, oral zonisamide as an adjunctive therapy to other AEDs provides a useful option in the treatment of pediatric patients aged ≥6 years with partial seizures.

Zonisamide as a treatment for partial epileptic seizures: a systematic review

Although the majority of people with epilepsy have a good prognosis and their seizures can be well controlled with pharmacotherapy, up to one-third of patients can develop drug-resistant epilepsy, especially those patients with partial seizures. This unmet need has driven considerable efforts over the last few decades aimed at developing and testing newer antiepileptic agents to improve seizure control. One of the most promising antiepileptic drugs of the new generation is zonisamide, a benzisoxazole derivative chemically unrelated to other anticonvulsant agents. In this article, the authors present the results of a systematic literature review summarizing the current evidence on the efficacy and tolerability of zonisamide for the treatment of partial seizures. Of particular interest within this updated review are the recent data on the use of zonisamide as monotherapy, as they might open new therapeutic avenues.

Adjunctive zonisamide therapy in the long-term treatment of children with partial epilepsy: results of an open-label extension study of a phase III, randomized, double-blind, placebo-controlled trial

OBJECTIVE

To investigate the safety/tolerability and efficacy of long-term adjunctive zonisamide and its impact on growth and development in children (6-18 years) with partial epilepsy.

METHODS

Open-label extension of a phase III, placebo-controlled trial. Started with double-blind transition period (2-11 weeks), during which patients on zonisamide continued at the same dose and those on placebo switched to zonisamide 1 mg/kg/day, up-titrated to 8 mg/kg/day (maximum 500 mg/day). During the subsequent open-label period (45-57 weeks), zonisamide dosing could be adjusted according to tolerability/response. Safety assessments included treatment-emergent adverse events (TEAEs), clinical laboratory parameters, and vital signs. Efficacy assessments included responder rate (primary assessment) and seizure freedom rate during the open-label period. Growth and development assessments comprised Tanner stages, hand x-rays, Child Behavior Checklist (CBCL 6/18), School Performance questionnaire, Physician and Parent/Guardian Global Impression of Change, and Controlled Oral Word Association Test (COWAT).

RESULTS

One hundred forty-four children entered the study; 99 (68.8%) of 144 children completed it, and 108 (75.0%) of 144 received zonisamide for ≥1 year. TEAEs occurred in 39 (27.1%) of 144 patients. There were low incidences of serious TEAEs (2.1%) and TEAEs leading to discontinuation (2.8%). Bicarbonate level decreases >3.5 mm occurred in 64 patients (44.4%), and 24 patients (16.7%) had a weight decrease of ≥10% from baseline. During the open-label period, 81 (56.3%) of 144 patients were responders and 16 (11.1%) of 144 achieved seizure freedom. Tanner staging and skeletal development were as expected for the study population. Changes were minimal for CBCL 6/18 and School Performance scores. Most patients were "much improved"/"very much improved" on Physician (73.8%) and Parent/Guardian (75.4%) Global Impressions of Change. Median changes in COWAT Category and Letter Fluency scores were 2.0 and 0.5, respectively.

SIGNIFICANCE

Adjunctive zonisamide was well tolerated and efficacious over a period of at least 1 year in children with partial epilepsy, with no unexpected safety concerns and no consistent detrimental effects on growth and development. A PowerPoint slide summarizing this article is available for download in the Supporting Information section here.