Adjunctive therapy with oxcarbazepine in children with partial seizures. The Oxcarbazepine Pediatric Study Group

Long-term efficacy, safety, and tolerability, including behavior and executive functioning, during adjunctive lacosamide treatment in pediatric patients with uncontrolled epilepsy

OBJECTIVES

To evaluate long-term efficacy, safety, and tolerability, including behavior and executive functioning, during adjunctive lacosamide (LCM) treatment in pediatric patients (≥1 month to <18 years of age) with focal-onset or generalized seizures enrolled in 2 open-label, long-term follow-up trials.

METHODS

Two open-label extension trials (SP848: NCT00938912; EP0034: NCT01964560) were conducted in pediatric patients who had participated in previous trials of adjunctive LCM (SP0847/NCT00938431; SP0966/NCT01969851; EP0060/NCT02710890; SP0967/NCT02477839; SP0969/NCT01921205); SP848 also directly enrolled eligible pediatric patients who had not previously participated in a clinical trial of LCM. Outcomes included retention, efficacy, and safety/tolerability. Patient improvement was assessed with Clinician's and Caregiver's Global Impression of Change scale. Behavior and emotional function was assessed with Achenbach Child Behavior Checklist (CBCL) and executive functioning was assessed with Behavior Rating Inventory of Executive Function® (BRIEF).

RESULTS

The pooled dataset from both trials included 905 patients (851 in the focal-onset seizure population and 47 in the generalized seizure population). In the overall population, Kaplan-Meier-estimated 1-year retention was 80 %. From baseline to the end of the treatment period, patients in the focal-onset seizure population had a median percent reduction in focal-onset seizure frequency per 28 days of 60.4 %, 55.4 % of patients were 50 % responders, and 40.8 % of patients were 75 % responders. In patients with ≥12 months of LCM treatment, ≥12 month seizure freedom during the LCM treatment period was achieved by 29.9 % of patients in the focal-onset seizure population (median duration of first ≥12-month seizure-free interval: 641 days) and 24.4 % of patients in the generalized seizure population (median duration of first ≥12-month seizure-free interval: 665 days). Improvement during LCM treatment was reported in >75 % of patients by both physicians and caregivers. Treatment-emergent adverse events (TEAEs) were reported by 749 (82.8 %) patients, most commonly pyrexia (18.9 %), upper respiratory tract infection (18.6 %), nasopharyngitis (16.2 %), vomiting (15.7 %), and somnolence (11.8 %). The most common drug-related TEAEs were somnolence (8.5 %), dizziness (7.6 %), and vomiting (5.4 %). Behavioral and emotional function was generally stable in patients 1.5-5 years of age and slightly improved in patients ≥6 years of age, and executive functioning was stable in patients <5 years of age and generally slightly improved in patients 5-18 years of age.

CONCLUSIONS

In this analysis of a large patient pool from 2 open-label trials, long-term adjunctive LCM was efficacious and generally well tolerated in children with epilepsy and focal-onset or generalized seizures. Behavior and executive functioning were generally stable without observable worsening during long-term adjunctive LCM treatment.

Efficacy and safety of levetiracetam vs. oxcarbazepine in the treatment of children with epilepsy: a systematic review and meta-analysis

Background

Levetiracetam (LEV) and oxcarbazepine (OXC) are new antiseizure medications (ASMs). In recent years, OXC monotherapy is widely used in children with epilepsy; however, no consensus exists on applying LEV monotherapy among children with epilepsy.

Objective

The present work focused on comparing the efficacy and safety of LEV and OXC monotherapy in treating children with epilepsy.

Methods

We conducted a comprehensive search across multiple databases including PubMed, Cochrane Library, Embase, Web of Science, CNKI, Wanfang Database, VIP, and China Biology Medicine disc, covering studies from inception to August 26, 2023. We included randomized controlled trials (RCTs) and cohort studies evaluating the efficacy and safety of LEV and OXC monotherapy for treating epilepsy in children. We utilized Cochrane Risk of Bias Tool in RevMan 5.3 software for assessing included RCTs quality. In addition, included cohort studies quality was determined using Newcastle-Ottawa Scale (NOS). A random-effects model was utilized to summarize the results.

Results

This meta-analysis included altogether 14 studies, including 893 children with epilepsy. LEV and OXC monotherapy was not statistical different among children with epilepsy in seizure-free rate (relative risk [RR] = 1.010, 95% confidence interval [CI] [0.822, 1.242], P > 0.05) and seizure frequency decrease of ≥50% compared with baseline [RR = 0.938, 95% CI (0.676, 1.301), P > 0.05]. Differences in total adverse reaction rate [RR = 1.113, 95% CI (0.710, 1.744), P > 0.05] and failure rate because of serious adverse reaction [RR = 1.001, 95% CI (0.349, 2.871), P > 0.05] were not statistical different between LEV and OXC treatments among children with epilepsy. However, the effects of OXC monotherapy on thyroid among children with epilepsy was statistically correlated than that of LEV (thyroid stimulating hormone: standardized mean difference [SMD] = -0.144, 95% CI [-0.613, 0.325], P > 0.05; free thyroxine: SMD = 1.663, 95% CI [0.179, 3.147], P < 0.05).

Conclusion

The efficacy of LEV and OXC monotherapy in treating children with epilepsy is similar. However, OXC having a more significant effect on the thyroid than that of LEV. Therefore, LEV may be safer for children with epilepsy who are predisposed to thyroid disease than OXC.

Systematic Review Registration

https://www.crd.york.ac.uk/, PROSPERO (CRD42024514016).

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.

Comparative antiseizure medications of adjunctive treatment for children with drug-resistant focal-onset seizures: A systematic review and network meta-analysis

Purpose: In this study, we intended to compare and rank the efficacy and acceptability of antiseizure medications (ASMs) for adjunctive treatment of children with drug-resistant focal-onset seizures. Method: We conducted a computerized search of PubMed, EMBASE, Cochrane Library, Web of Science, and Google Scholar to identify eligible randomized controlled trials (RCTs) published before 31 May 2022. We included studies evaluating the efficacy and tolerability of antiseizure medications for children with drug-resistant focal-onset seizures. The efficacy and safety were reported in terms of responder and dropout rate along with serious adverse events, the outcomes were ranked with the surface under the cumulative ranking curve (SUCRA). Results: A total of 14 studies (16 trials) with 2,464 patients were included, involving 10 active antiseizure medications. For the primary endpoint of at least 50% reduction in focal-onset seizures, the surface under the cumulative ranking curve ranking suggested that lamotrigine and levetiracetam were more effective as compared with other antiseizure medications; moreover, levetiracetam had the highest probability of rank first for achieving seizure freedom. Concerning tolerability, oxcarbazepine and eslicarbazepine acetate were associated with higher dropout rates relative to other antiseizure medications and placebo, and topiramate was associated with higher occurrence of side effects. No significant differences were found between active antiseizure medications concerning dropout for side effects. Conclusion: According to the surface under the cumulative ranking curve ranking, lamotrigine, levetiracetam, and oxcarbazepine were more efficacious than other active antiseizure medications in terms of responder rate. Concerning tolerability, oxcarbazepine was more likely to lead to dropout and topiramate was associated with higher occurrence of side effects.

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.

Population pharmacokinetic model development and its relationship with adverse events of oxcarbazepine in adult patients with epilepsy

This study aimed to develop a pharmacokinetic (PK) model of oxcarbazepine (OXC) and analyse the relationship between monohydroxylated derivative (MHD), an active metabolite of OXC, and the adverse events of OXC. We obtained 711 OXC samples from 618 patients with epilepsy who were enrolled in the Epilepsy Registry Cohort of Seoul National University Hospital from February 2011 to January 2014. The plasma PK model was developed using a nonlinear mixed-effect modelling method with NONMEM (ver 7.3). A one-compartment model with a first-order absorption model and proportional residual error adequately described the MHD concentration–time profiles. The only covariate incorporated for CL/F and V/F was body weight. Of the 447 patients analysed, 28 (6.26%) had dose-related adverse events (DRAEs), which were dizziness, somnolence, headache, and diplopia. For DRAE occurrence, the cut-off values of the MHD trough and AUC were 12.27 mg/L (specificity 0.570, sensitivity 0.643) and 698.5 mg h/L (specificity, sensitivity 0.571), respectively. Multivariate analysis showed the sole dizziness symptom was significantly associated with both the MHD trough and the AUC (p = 0.013, p = 0.038, respectively). We newly developed a population PK model using sparse sampling data from patients with epilepsy, and the model better reflects the actual clinical situation.

Predicted Efficacy of Once-Daily Extended-Release Oxcarbazepine (Oxtellar XR®) Monotherapy in Adults and Children with Partial-Onset Seizures: Exposure-Response Modeling and Simulation

PURPOSE

We conducted exposure-response modeling and simulations to compare the predicted efficacy of extended-release oxcarbazepine (OXC-XR), an oral once-daily (qd) antiepileptic drug, with that of immediate-release (IR) OXC twice-daily (bid) when the agents are used as monotherapy or adjunctive therapy in patients with epilepsy characterized by partial-onset seizures (POS).

METHODS

Modeling assessed percent change from baseline 28-day seizure frequency (PCH) as a function of minimum concentration (Cmin) of monohydroxy derivative (MHD), the clinically relevant metabolite of OXC. For OXC-IR, the model used historical data; values for OXC-XR were derived from observed data. The model was simulated (N=100) to predict PCH at MHD Cmin concentrations achieved with 1200 and 2400 mg/day in adults and children receiving OXC-XR qd or OXC-IR bid. Mean PCH and 95% confidence intervals (CIs) were generated and compared.

RESULTS

Predicted efficacy was not different (ie, 95% CI of mean PCH overlapped) for OXC-XR qd vs OXC-IR bid at mean MHD Cmin concentrations achieved with 1200 and 2400 mg/day adjunctive OXC-XR (47.4 and 76.4 µmol/L) and at target MHD Cmin concentrations for OXC-IR monotherapy (59.1 and 112 µmol/L) in adults. Predicted efficacy in adults vs children was not different between formulations. Depending on MHD Cmin, the predicted mean PCH in adults ranged from -51.4% to -73.4% with OXC-XR qd and -53.2% to -78.5% with OXC-IR bid. In children, the predicted mean PCH ranged from -48.4% to -58.1% (OXC-XR qd) and -32.5% to -70.4% (OXC-IR bid).

CONCLUSION

This model-based analysis predicted comparable efficacy for OXC-XR qd vs OXC-IR bid at MHD Cmin concentrations corresponding to 1200 and 2400 mg/day as monotherapy or adjunctive therapy. Based on this analysis, the US Food & Drug Administration approved OXC-XR for use as monotherapy in adults and children ≥6 years of age with POS.

Oxcarbazepine add-on for drug-resistant focal epilepsy

BACKGROUND

Epilepsy is a common neurological disorder. In approximately 30% of epilepsy cases, seizures are uncontrolled by one antiepileptic drug (AED). These people require treatment with a combination of multiple AEDs and are described as having drug-resistant epilepsy. Oxcarbazepine is a keto-analogue of carbamazepine, an established AED, and can be used as an add-on treatment for drug-resistant epilepsy.

OBJECTIVES

To assess the efficacy and tolerability of oxcarbazepine as an add-on treatment for people with drug-resistant focal epilepsy.

SEARCH METHODS

The following databases were searched on 24 September 2018: Cochrane Register of Studies (CRS Web), which includes the Cochrane Epilepsy Group Specialized Register and the Cochrane Central Register of Controlled Trials (CENTRAL); Medline (Ovid) 1946 to 21 September 2018; ClinicalTrials.gov; and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). Originally, we also searched SCOPUS as a substitute for Embase, but this is no longer necessary, because randomised and quasi-randomised controlled trials in Embase are now included in CENTRAL.

SELECTION CRITERIA

Randomised controlled trials with parallel-group or cross-over design, recruiting people of any age with drug-resistant focal epilepsy. We accepted any level of blinding and trials could be placebo- or active-controlled.

DATA COLLECTION AND ANALYSIS

In accordance with the methodological procedures expected by the Cochrane Collaboration, two review authors independently assessed trial eligibility before extracting data and assessing risk of bias. We assessed the primary outcomes: median percentage seizure reduction per 28 days; 50% or greater reduction in seizure frequency; and adverse effects including ataxia, hyponatraemia, and somnolence. We assessed the secondary outcomes: seizure freedom; treatment withdrawal; cognitive effects; and quality of life. We used an intention-to-treat population for all primary analyses. We present results as risk ratios (RR) with 95% confidence intervals (CI), with the exception of adverse effects which we present with 99% CI.

MAIN RESULTS

We identified six eligible studies, involving 1593 participants. We judged that three studies were at unclear risk of bias and three were at high risk of bias. Bias mainly arose from lack of methodological details and from high attrition rates. Participants were aged 1 month to 65 years, with a diagnosis of drug-resistant focal epilepsy. All studies were either placebo- or alternative-dose-controlled with parallel-group design. The treatment period varied from 9 days to 26 weeks. The median percentage seizure reduction per 28 days (3 studies; moderate-certainty evidence) ranged from 26% to 83.3% for participants randomised to experimental oxcarbazepine compared to 7.6% to 28.7% for participants randomised to control treatment. Oxcarbazepine may increase the responder rate for 50% or greater reduction in seizure frequency compared to control treatment (RR 1.80, 95% CI 1.27 to 2.56; random-effects model; 6 studies; low-certainty evidence). For seizure freedom, the RR was 2.86 (95% CI 1.19 to 6.87; random-effects model; 5 studies; low-certainty evidence), suggesting an advantageous effectiveness of oxcarbazepine over control treatment. Treatment with oxcarbazepine was associated with an increased treatment withdrawal rate compared to control (RR 1.75, 95% CI 1.44 to 2.13; fixed-effect model; 6 studies; moderate-certainty evidence). The largest oxcarbazepine dose used, 2400 mg/d, was associated with a higher treatment withdrawal rate (RR 2.38, 95% CI 1.92 to 2.94; fixed-effect model; 2 studies) compared to control, than 1200 mg/d (RR 1.54, 95% CI 1.21 to 1.95; fixed-effect model; 3 studies) or 600 mg/d oxcarbazepine (RR 0.79, 95% CI 0.55 to 1.15; fixed-effect model; 1 study). Treatment with oxcarbazepine was associated with an increased incidence of multiple adverse effects including: ataxia (RR 2.54, 99% CI 0.86 to 7.54; random-effects model; 5 studies; moderate-certainty evidence); and somnolence (RR 2.03, 99% CI 1.17 to 3.54; random-effects model; 6 studies; low-certainty evidence). Hyponatraemia occurred more frequently with oxcarbazepine treatment but not significantly so (RR 2.53, 99% CI 0.27 to 23.85; fixed-effect model; 6 studies; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

Oxcarbazepine might be effective at reducing seizure frequency when used as an add-on for drug-resistant focal epilepsy. The efficacy outcomes - 50% or greater seizure reduction and seizure freedom - were derived from low-certainty evidence. We are, therefore, uncertain whether the estimated effect size is representative of the true effect. In contrast, the evidence for median percentage seizure reduction and treatment withdrawal were of moderate certainty: thus, we are fairly certain of the effect estimates' reliability. Overall, we are unsure of the true efficacy of oxcarbazepine, but have concerns about its tolerability.

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.

Potential Clinical Benefits of CBD-Rich Cannabis Extracts Over Purified CBD in Treatment-Resistant Epilepsy: Observational Data Meta-analysis

This meta-analysis paper describes the analysis of observational clinical studies on the treatment of refractory epilepsy with cannabidiol (CBD)-based products. Beyond attempting to establish the safety and efficacy of such products, we also investigated if there is enough evidence to assume any difference in efficacy between CBD-rich extracts compared to purified CBD products. The systematic search took place in February/2017 and updated in December/2017 using the keywords "epilepsy" or "Dravet" or "Lennox-Gastaut" or "CDKL5" combined with "Cannabis," "cannabinoid," "cannabidiol," or "CBD" resulting in 199 papers. The qualitative assessment resulted in 11 valid references, with an average impact factor of 8.1 (ranging from 1.4 to 47.8). The categorical data of a total of 670 patients were analyzed by Fischer test. The average daily dose ranged between 1 and 50 mg/kg, with treatment length from 3 to 12 months (mean 6.2 months). Two thirds of patients reported improvement in the frequency of seizures (399/622, 64%). There were more reports of improvement from patients treated with CBD-rich extracts (318/447, 71%) than patients treated with purified CBD (81/175, 46%), [corrected] with statistical significance (p < 0.0001). Nevertheless, when the standard clinical threshold of a "50% reduction or more in the frequency of seizures" was applied, only 39% of the individuals were considered "responders," and there was no difference (p = 0.52) [corrected] between treatments with CBD-rich extracts (122/330, 37%) [corrected] and purified CBD (94/223, 42%). Patients treated with CBD-rich extracts reported lower average dose (6.0 mg/kg/day) [DOSAGE ERROR CORRECTED] than those using purified CBD (25.3 mg/kg/day). [DOSAGE ERROR CORRECTED] The reports of mild (158/216 76% vs. 148/447, 33% p < 0.001) and severe (41/155, 26% vs. 23/328, 7% p < 0.0001) [corrected] adverse effects were more frequent in products containing purified CBD than in CBD-rich extracts. CBD-rich extracts seem to present a better therapeutic profile than purified CBD, at least in this population of patients with refractory epilepsy. The roots of this difference is likely due to synergistic effects of CBD with other phytocompounds (aka Entourage effect), but this remains to be confirmed in controlled clinical studies.

Oxcarbazepine oral suspension in young pediatric patients with partial seizures and/or generalized tonic-clonic seizures in routine clinical practice in China: a prospective observational study

BACKGROUND

This study aimed to assess efficacy and safety of oxcarbazepine (OXC) oral suspension in pediatric patients aged 2-5 years with partial seizures (PS) and/or generalized tonic-clonic seizures (GTCS) in real-world clinical practice in China.

METHODS

This 26-week, prospective, single-arm, multicenter, observational study recruited pediatric patients aged 2-5 years with PS or GTCS suitable for OXC oral suspension treatment based on physicians' judgments from 11 medical centers in China. Enrolled subjects started OXC oral suspension treatment as monotherapy or in combination with other antiepileptic drugs. Primary efficacy outcome was the percentage of pediatric subjects achieving ≥ 50% seizure frequency reduction at the end of the 26-week treatment. Secondary efficacy-related parameters and safety parameters such as adverse events (AEs) and serious AEs (SAEs) were also monitored during the 26-week treatment period.

RESULTS

Six hundred and six pediatric patients were enrolled and 531 (87.6%) completed the study. After 26 weeks of treatment, 93.3% subjects achieved ≥ 50% seizure frequency reduction, and 81.8% achieved 100% seizure frequency reduction compared to baseline. Among different seizure types, OXC was effective in all subjects with simple PS and in > 90% of subject with other type of seizure present in the study. AEs were observed in 49 (8.1%) subjects. Only three subjects experienced SAE. Rash (n = 18, 2.97%) was the most common AE. Only 17 subjects discontinued due to AEs.

CONCLUSION

This study, reporting the real-world data, further confirms the efficacy and good safety profile of OXC oral suspension in Chinese pediatric patients aged 2-5 years with PS and/or GTCS.

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.

Oxcarbazepine oral suspension in pediatric patients with partial seizures and/or generalized tonic-clonic seizures: a multi-center, single arm, observational study in China

BACKGROUND

To assess efficacy and safety of oxcarbazepine (OXC) oral suspension in pediatric patients aged 2-16 years with partial seizures (PS) and/or generalized tonic-clonic seizures (GTCS) in real-world clinical practice in China.

METHODS

This 26-week, single arm, multicenter and observational study recruited patients aged 2-16 years with PS or GTCS suitable for OXC oral suspension treatment. Enrolled patients received OXC oral suspension treatment for 26 weeks. Primary endpoints included mean seizure frequency at the end of the treatment and mean seizure frequency reduction at the end of the treatment vs. baseline. Secondary efficacy-related endpoints and safety parameters were also assessed.

RESULTS

Nine hundred and eighty-seven pediatric patients were enrolled and 912 (92.4%) completed the study. The mean seizure frequencies at baseline and the end of week 26 were 13.40±64.92 and 1.62±19.47 times/ month, respectively. The mean seizure frequency reduction was 10.03±63.67 times/month and the mean seizure frequency reduction percentage was 90.02%±5127.0% (P<0.0001). After 26 weeks of treatment, 82.36%, 7.24% and 3.86% of the patients became controlled, significantly improved and improved, respectively. Adverse events (AEs) were reported in 74 (7.65%) patients. Rash was the most common AE. The efficacy of OXC was not affected by seizure types, age or gender.

CONCLUSIONS

This study confirms the efficacy and good safety profile of OXC oral suspension in Chinese pediatric patients aged 2-16 years with PS and/or GTCS.

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.

Evaluation of Safety in Exceeding Maximum Adult Doses of Commonly Used Second-Generation Antiepileptic Drugs in Pediatric Patients

OBJECTIVE

Pediatric patients often require larger doses of antiepileptic drug (AED) than adults in order to attain therapeutic serum concentrations and/or achieve seizure control. Safety and efficacy data are often extrapolated from adult literature; hence, optimal dosage may only be determined anecdotally or based on expert opinion. With limited pediatric dosing guidelines, milligrams per day that are based on weight may exceed the maximum adult dose. The primary objective of this study is to evaluate the safety of exceeding maximum doses as specified by the US Food and Drug Administration or manufacturers of commonly used AEDs in pediatric patients.

METHODS

This study is a single-center, retrospective analysis of all pediatric patients seen in the outpatient clinic between October 2010 and October 2014 who were prescribed a dose that exceeds the maximum approved dose of oxcarbazepine, zonisamide, topiramate, levetiracetam, lamotrigine, or clobazam. Baseline demographics (ie, sex, age, race/ethnicity, weight, height, diagnosis), serum drug concentrations, and appropriate laboratory tests were collected. Side effects were reviewed.

RESULTS

During the 4-year study period, 41,137 prescriptions were included. A total of 2% of prescriptions exceeded the maximum dose of 1 of the included AEDs. The most common AED prescribed above the maximum dose was levetiracetam (53%), whereas lamotrigine was the least common (6%). The largest doses prescribed exceeded the maximum by 3-fold (i.e., levetiracetam dose of 9000 mg/day).

CONCLUSION

It appears safe to use doses exceeding the maximum approved dose of the evaluated AEDs in pediatric patients, with appropriate counseling and monitoring for adverse effects.

Efficacy and safety of oxcarbazepine in the treatment of children with epilepsy: a meta-analysis of randomized controlled trials

BACKGROUND

To assess the efficacy and safety of oxcarbazepine (OXC) in the treatment of children with epilepsy.

METHODS

Randomized controlled trials (RCTs) published in PubMed, Embase, Web of Science, Cochrane Library, Scopus, SinoMed (Chinese BioMedical Literature Service System, China), and Chinese National Knowledge Infrastructure (China) database were systematically reviewed. Eligible studies were those that compared the efficacy and safety of OXC with other antiepileptic drugs in epilepsy. Risk ratio (RR) with 95% confidence intervals (95% CIs) was calculated using fixed-effects or random-effects model.

RESULTS

Eleven RCTs with a total of 1,241 patients met the inclusion criteria and were included in this meta-analysis. Compared with other antiepileptic drugs (sodium valproate, levetiracetam, phenytoin, and placebo), OXC was associated with similar seizure-free rate (RR =1.06, 95% CI: 0.94, 1.20; P=0.366) and percentage reduction from baseline in seizure frequency (for ≥75% reduction: RR =1.15, 95% CI: 0.88, 1.49; P=0.310; for 50%-75% reduction: RR =1.12, 95% CI: 0.90, 1.39; P=0.301; for <50% reduction: RR =0.79, 95% CI: 0.56, 1.12; P=0.179). Moreover, patients treated with OXC had a comparable incidence of adverse events compared with those treated with other antiepileptic drugs (RR =1.01, 95% CI: 0.92, 1.11; P=0.760).

CONCLUSION

OXC showed similar effects and safety as other antiepileptic drugs in the treatment of children with epilepsy. Further well-conducted, large-scale RCTs are needed to validate these findings.

WITHDRAWN: Oxcarbazepine add-on for drug-resistant partial epilepsy

BACKGROUND

Most people with epilepsy have a good prognosis and their seizures can be well controlled with the use of a single antiepileptic drug, but up to 30% develop refractory epilepsy, especially those with partial seizures. In this review we summarize the current evidence regarding oxcarbazepine when used as an add-on treatment for drug-resistant partial epilepsy.

OBJECTIVES

To evaluate the effects of oxcarbazepine when used as an add-on treatment for drug-resistant partial epilepsy.

SEARCH METHODS

We searched the Cochrane Epilepsy Group's Specialized Register (28 March 2006), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2006), MEDLINE (1966 to March 2006). No language restrictions were imposed. We checked the reference lists of retrieved studies for additional reports of relevant studies. We also contacted Novartis (manufacturers of oxcarbazepine) and experts in the field.

SELECTION CRITERIA

Randomized, placebo-controlled, double-blinded, add-on trials of oxcarbazepine in patients with drug-resistant partial epilepsy.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and extracted the relevant data. The following outcomes were assessed : (a) 50% or greater reduction in seizure frequency; (b) treatment withdrawal (any reason); (c) side effects. Primary analyses were intention-to-treat. Summary odds ratios were estimated for each outcome.

MAIN RESULTS

Two trials were included representing 961 randomized patients.Overall Odds Ratio (OR) (95% Confidence Interval (CIs)) for 50% or greater reduction in seizure frequency compared to placebo 2.96 (2.20, 4.00).Treatment withdrawal OR (95% CIs) compared to placebo 2.17 (1.59, 2.97).Side effects: OR (99% CIs) compared to placebo, ataxia 2.93 (1.72, 4.99); dizziness 3.05 (1.99, 4.67); fatigue 1.80 (1.02, 3.19); nausea 2.88 (1.77, 4.69); somnolence 2.55 (1.84, 3.55); diplopia 4.32 (2.65, 7.04), were significantly associated with oxcarbazepine.

AUTHORS' CONCLUSIONS

Oxcarbazepine has efficacy as an add-on treatment in patients with drug-resistant partial epilepsy, both in adults and children. However, trials reviewed were of relatively short duration, and provide no evidence about the long-term effects of oxcarbazepine. Results cannot be extrapolated to monotherapy or to patients with other epilepsy types.

Hyponatremia induced by antiepileptic drugs in patients with epilepsy

INTRODUCTION

Hyponatremia induced by antiepileptic drugs (AEDs) has not received sufficient attention in patients with epilepsy. Areas covered: We reviewed articles between 1966 and 2015 about hyponatremia as an adverse effect of AEDs in patients with epilepsy. The incidence, clinical symptoms, onset times of AEDs-induced hyponatremia are discussed in detail, as are the risk factors associated with AEDs-induced hyponatremia and mechanisms underlying its development. We also briefly describe strategies for treating AED-induced hyponatremia. Expert opinion: Carbamazepine and oxcarbazepine are the most common AEDs which induce hyponatremia in patients with epilepsy. Recently, other AEDs, such as eslicarbazepine, sodium valproate, lamotrigine, levetiracetam and gabapentin have also been reported to cause hyponatremia. Understanding the risk associated with AED-induced hyponatremia and taking effective measures to combat serum sodium imbalance induced by AED therapy are necessary.

HLA-B*40:02 and DRB1*04:03 are risk factors for oxcarbazepine-induced maculopapular eruption

OBJECTIVE

Oxcarbazepine (OXC) is a widely used antiepileptic drug for the treatment of partial seizures that was developed through structural variation of carbamazepine. Although OXC has a lower risk of cutaneous adverse drug reactions (cADRs) than carbamazepine, cADRs ranging from maculopapular eruption (MPE) to the more severe Stevens-Johnson syndrome and toxic epidermal necrolysis still limit the use of OXC in some patients. A few human leukocyte antigen (HLA)-related genetic risk factors for carbamazepine-induced cADRs have been identified. However, the HLA-related genetic risk factors associated with OXC-induced cADRs are unknown.

METHODS

A total of 40 patients who experienced OXC-induced MPE and 70 patients who were tolerant to OXC treatment were included in the study. Genomic DNA was extracted from the peripheral blood of these patients, and high-resolution HLA genotyping was performed.

RESULTS

The HLA-B*40:02 and HLA-DRB1*04:03 alleles were significantly associated with OXC-induced MPE compared with the OXC-tolerant group (odds ratio [OR] 4.33, p = 0.018 and OR 14.64, p = 0.003, respectively) and the general Korean population (OR 4.04, p = 0.001 and OR 3.11, p = 0.019, respectively). The HLA-B*15:01 genetic frequency was significantly lower in the OXC-MPE group compared to the OXC-tolerant group (OR 0.18, p = 0.016) and the Korean population (OR 0.22, p = 0.030). The allele frequencies of well-known HLA-related risk factors for carbamazepine-induced cADRs (HLA-B*15:02, A*31:01 and B*15:11) were not different among the three groups.

SIGNIFICANCE

This study is the first to demonstrate an association of HLA-B*40:02 and HLA-DRB1*04:03 with OXC hypersensitivity using a large cohort of patients with OXC-induced MPE. These findings should be confirmed in future studies in different ethnic groups.

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.

Developing antiepileptic drugs in children: balancing protection and access

This chapter addresses the issue of the balance between protection of children submitted to research and children's access to new treatments, focusing on the field of antiepileptic drugs. Due to the lack of interest pharmaceutical companies have for such an unrewarding market, ethical and legal problems, difficulties recruiting patients, and in Europe insufficient public resources, many infants and children with epilepsy are still exposed to off-label drugs. The incentives and regulations specifically directed toward research in children in the United States and EU provided the first step to change this condition. The challenge is to perform trials determined by the needs of children and to obtain benefits in the same order of magnitude as for adults but with reduced risks. In order to optimize the development of new AEDs in pediatrics, the new European guidelines (2010) recommend the identification of adult clinical trial results that can be extrapolated to the pediatric population (i.e., those in partial epilepsies) and the use of innovative strategies that help limit the number of pediatric patients enrolled in trials (i.e., those with epileptic encephalopathies). A key step will be to develop international networks of pediatric epilepsy centers with the shared purpose of optimizing development and execution of clinical trials.

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.

A comparison of the efficacy and tolerability of oxcarbazepine oral suspension between infants and children with epilepsy: a retrospective chart review at a single medical center in Taiwan

BACKGROUND

Few clinical studies have assessed the efficacy and safety of oxcarbazepine (OXC) oral suspension in Asian pediatric patients and particularly in infants. The aim of this study was to investigate and compare the efficacy, tolerability, and side effects of OXC oral suspension in Taiwanese infants and children with various types of epilepsy.

METHODS

A retrospective review of the efficacy, tolerability, and side effects of OXC oral suspension in a tertiary medical center in Taiwan was conducted and included children (1-9 years old) and infants (<1 year old) diagnosed with epilepsy, which was classified into idiopathic partial, symptomatic partial, or multifocal subtypes. The OXC oral suspension (Trileptal(®); Novartis) was given in a gradual dose titration, from an initial 7.5 mg/kg/day to 30 mg/kg/day within 1 month in all cases.

RESULTS

A total of 20 infants and 38 children were identified. There were no statistically significant differences between the children and infants in efficacy (75 vs. 82 %, p = 0.734) and adverse effects (30 vs. 21 %, p = 0.525) after OXC oral suspension treatment. The efficacy was significantly correlated with the epilepsy subtype (p < 0.01) and the number of combined antiepileptic drugs (AEDs) before OXC treatment (p < 0.01) in both groups. The patients with idiopathic and symptomatic partial epilepsy responded better to OXC oral suspension than those with multifocal epilepsy.

CONCLUSIONS

OXC oral suspension is effective and well tolerated in both infants and children with partial epilepsy in Taiwan. Treatment efficacy was related to epilepsy subtype and number of combined AEDs before OXC treatment. Monotherapy had an excellent therapeutic response in partial epilepsy but not in multifocal epilepsy.

Oxcarbazepine extended-release formulation in epilepsy

Oxcarbazepine (OXC) is a 10-keto-analogue of carbamazepine, which was developed and labeled as a follow-up antiepileptic drug, that was intended to overcome some of the pharmacological drawbacks of carbamazepine with similar efficacy. The main advantage is the nonoxidative metabolic pathway that allows a lower enzyme-induction profile and fewer drug interactions. OXC is rapidly and extensively reduced by cytosolic hepatic enzymes to its monohydroxylated derivative (MHD), thus OXC may be regarded as a prodrug with MHD representing the active antiepileptic agent. The immediate-release (IR) formulation of OXC (Trileptal(®), Timox(®)) has an almost complete bioavailibilty. It is rapidly absorbed and reaches peak concentrations after 1-3 h. MHD peak concentrations are measured within 4-12 h. Elimination half-life in healthy subjects is 1-5 h for OXC and 7-20 h for MHD. The OXC plasma concentration peak may have been responsible for side effects, such as dizziness, vertigo, coordination problems or blurred vision, which appeared more often with this formulation in individual cases than with the formulation available prior to 2000, or with another formulation that has been distributed in Scandinavian countries. Both possibilities offer a profile approaching the characteristics of an extended-release (ER) formulation. ER OXC was labeled in Germany in 2008 (Apydan(®) extent, Desitin Arzneimittel GmbH, Hamburg, Germany). Under steady-state conditions, Phase I studies show bioequivalence between IR and ER OXC. With ER OXC, OXC plasma peak concentrations and both OXC and MHD peak-trough fluctuations are markedly reduced. In clinical trials, comparisons between IR OXC twice daily versus ER OXC once daily failed to show significant differences; efficacy tended to be better with IR OXC, whereas OXC ER showed insignificant tolerability advantages. Another study is currently ongoing to compare the tolerability of both formulations under twice-daily administration conditions in patients with difficult-to-treat epilepsies who require a dosage increase of OXC and who are randomized to IR or ER OXC.

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

PURPOSE

To assess the efficacy and safety/tolerability of adjunctive zonisamide treatment in pediatric patients with partial epilepsy.

METHODS

In this phase III, double-blind, randomized, placebo-controlled, multicenter trial, 207 patients (age 6-17 years) with partial epilepsy, receiving one or two antiepileptic drugs, were randomized to receive adjunctive zonisamide or placebo. Zonisamide was initiated at 1 mg/kg/day, titrated to a target dose of 8 mg/kg/day over 8 weeks (one down-titration permitted), and maintained for 12 weeks. The primary efficacy end point was the proportion of responders (≥ 50% seizure frequency reduction from baseline) during the 12-week maintenance period. Safety/tolerability assessments included the incidence of treatment-emergent adverse events (TEAEs).

KEY FINDINGS

In total, 93 (86.9%) of 107 patients randomized to zonisamide and 90 (90.0%) of 100 patients randomized to placebo completed the trial. Responder rates were 50% for zonisamide versus 31% for placebo (p = 0.0044; intention-to-treat population, last observation carried forward). The overall incidence of TEAEs was similar for zonisamide (55.1%) versus placebo (50.0%), with low rates of serious TEAEs with zonisamide and placebo (3.7% vs. 2.0%) and TEAEs leading to withdrawal (0.9% vs. 3.0%). TEAEs reported more frequently with zonisamide versus placebo were decreased appetite (6.5% vs. 4.0%), decreased weight (4.7% vs. 3.0%), somnolence (4.7% vs. 2.0%), vomiting (3.7% vs. 2.0%), and diarrhea (3.7% vs. 1.0%).

SIGNIFICANCE

Adjunctive zonisamide treatment was shown to be effective and well tolerated in pediatric patients with partial epilepsy. No new or unexpected safety findings emerged.

Advancing the management of childhood epilepsies

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

Pharmacotherapy of focal epilepsy in children: a systematic review of approved agents

BACKGROUND

Partial-onset seizures contribute the bulk of seizure burden in childhood epilepsy. The therapeutic decision making involves consideration of factors specific to drug, patient and socioeconomic situation.

OBJECTIVES

This paper systematically reviews the available efficacy/effectiveness evidence for various anti-epileptic drugs (AED) as monotherapy and adjunctive therapy for partial-onset seizures in children.

DATA SOURCES

Relevant randomized clinical trials (RCTs) were identified by a structured PubMed search, supplemented by an additional hand search of reference lists and authors' files.

STUDY APPRAISAL AND SYNTHESIS METHODS

Eligible studies were reviewed and data extracted into tables. Included RCTs were classified based on accepted published criteria.

OUTCOMES

Only efficacy and effectiveness outcome measures were evaluated since there is little scientifically rigorous comprehensive AED adverse effects data.

RESULTS

Oxcarbazepine is the only AED with Class I evidence for efficacy/effectiveness as initial monotherapy for partial-onset seizures in children. Carbamazepine, clobazam, lamotrigine, phenobarbital, phenytoin, topiramate, valproate, vigabatrin and zonisamide have, at best, Class III efficacy/effectiveness evidence for monotherapy of partial-onset seizures in children. For adjunctive therapy, gabapentin, lamotrigine, levetiracetam, oxcarbazepine and topiramate have Class I efficacy/effectiveness evidence for treatment of pediatric partial-onset seizures.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

This efficacy/effectiveness analysis must not be used in isolation when selecting therapy. AED selection for a specific child needs to integrate a drug's efficacy/effectiveness data with its safety and tolerability profile, pharmacokinetic properties, available formulations, and patient specific characteristics. It is critical that physicians and patients incorporate all these relevant variables when choosing AED therapy.

Oxcarbazepine Pharmacokinetics and Tolerability in Children With Inadequately Controlled Epilepsy

This two-part, open-label study evaluated the pharmacokinetics, safety, and tolerability of oxcarbazepine as combination therapy in 112 children 2 to 12 years old with inadequately controlled epilepsy. Part I was a pharmacokinetic study in children stratified by age (2-5 years and 6-12 years) and randomized to receive a single oxcarbazepine dose of 5 mg/kg or 15 mg/kg. Mean specific AUC and t(1/2) values of the active metabolite (MHD) were approximately 30% lower in younger children compared with older children, regardless of dose. Part II was a 4-month safety, tolerability, and pharmacokinetic study in which children received oxcarbazepine doses of 11 to 68 mg/kg/day. The mean specific oxcarbazepine daily dose was 38% higher in younger children compared with older children. Similarly, mean trough plasma MHD concentrations were 34% lower in younger children. Six (5%) children discontinued due to adverse events. Oxcarbazepine was safe and well tolerated. Younger children require higher oxcarbazepine doses because of rapid clearance.

Open study of pranlukast add-on therapy in intractable partial epilepsy

Innovative treatments of epileptic seizures are needed to improve the outcome of epilepsy. We studied the effect of pranlukast on seizure outcome in patients with intractable partial epilepsy. An open study was conducted to evaluate the clinical efficacy of 24-week pranlukast add-on therapy in 50 patients with intractable partial seizures. Serum concentrations of matrix metalloproteinase (MMP)-9 were determined using Biotrak Activity Assay System. Cytokines in cerebrospinal fluid (CSF) were measured by the BioPlex (BioRad) system and soluble TNF receptor1 (sTNFR1) in CSF was measured by the ELISA. Surface markers of lymphocytes in CSF were examined by cell-sorter. Seizure-free rate (SFR) was 13.6%, responder rate (RR) was 47.7%, and aggravation rate (AR) was 18.2% at the 13-24 week period after starting pranlukast. In patients with increased serum MMP-9 before pranlukast therapy (baseline), comparison of paired serum levels showed a significant decrease after pranlukast therapy. Baseline CSF levels of IL-1β and IL-6 were elevated in patients compared with disease controls. Of four patients with paired data, three (including a responder to pranlukast) showed decreased pro-inflammatory cytokines (IL-1β, IL-6, and TNFα), and four showed decreased sTNFR1, after pranlukast treatment, and only a responder had markedly decreased frequency of CD8+ T cells in CSF. Pranlukast reduces seizure frequencies probably by pleiotropic effects including normalization of MMP-9 in sera, reduced leakage of pro-inflammatory cytokines into CNS, and inhibition of extravasation of leucocytes from brain capillaries. Further investigations by double-blind control study and animal models are warranted.

A revisited strategy for antiepileptic drug development in children: designing an initial exploratory step

BACKGROUND

Randomized controlled trials (RCTs) in refractory paediatric epilepsy usually involve the two main types of epilepsy shared by children and adults, focal epilepsy and Lennox-Gastaut syndrome (LGS). Most other epilepsy syndromes, specifically paediatric, are excluded from drug development. In order to identify among them the candidate(s) for dedicated RCTs with a new drug, the European Medicine Agency (EMA) recently recommended proceeding in two steps: (1) an exploratory (prospective-observational) trial (POT) including a large variety of paediatric epilepsy syndromes and (2) a subsequent RCT in each of those that disclose a signal for possible efficacy.

OBJECTIVE

Our objective was to address the three following issues that have not been addressed by the EMA: (1) to determine a minimal threshold for this signal; (2) to establish a list of epilepsies to evaluate; and (3) to estimate the number of patients to include in such POTs.

METHODS

We extensively reviewed the POTs (including various syndromes) and RCTs reported in paediatric patients with uncontrolled epilepsy using MEDLINE (from 1990 to 2011) and the Cochrane library. We determined the threshold as the lowest percentage of responders observed in a POT with a positive corresponding RCT. The syndromes that reached this threshold in a POT were those to evaluate in an RCT. The minimal number of patients to include for each syndrome for a POT with a new antiepileptic drug was estimated in order to reach at least this threshold of responders with a 95 % confidence interval.

RESULTS

We found the minimal responder threshold to be 25 %. We identified eight epilepsy types/syndromes reaching this threshold and estimated for each of them the minimal sample needed: refractory focal epilepsy (n = 40), Lennox-Gastaut syndrome (n = 32), infantile spasms (n = 50), Dravet syndrome (n = 32), childhood absence epilepsy (n = 12), other symptomatic generalized epilepsy (n = 38), epileptic encephalopathy with continuous spikes and waves during sleep (n = 7) and epilepsy with myoclonic-astatic seizures (n = 4) [the two last samples may be underestimated due to the lack of RCTs in these conditions].

CONCLUSION

Among the eight epilepsy types/syndromes that we recommend to systematically include in exploratory trials using the POT procedure, we assume that, for the minimal sample given above, a responder threshold of 25 % will provide a reliable efficacy signal, to be confirmed by a dedicated RCT. This strategy should avoid missing new therapeutic possibilities for children with epilepsy and reduce the off-label use of drugs in paediatric neurology.

Treatment strategies

There has been important progress in the identification of antiepileptic compounds and their indications in children over the past 15 years: their number has doubled and specific pediatric trials are being performed to document their effect according to seizures and syndromes as well as their tolerability in pediatrics. The improved understanding of pharmacokinetics and drug-drug interactions has helped to optimize treatment. Specific issues specific of infants have also been studied although new antiepileptic drugs are still dramatically lacking for this age group. Before reaching a syndromic diagnosis, the choice of a first- line agent goes to compounds with the largest range of efficacy and least identified risks. Subsequent choices are mainly based on the epilepsy syndrome and seizure type in addition to good clinical practice to determine dose, adverse effect profile, risk of aggravating seizures and drug interactions, clinician's experience, cultural habits, and availability of drugs. If there are several options, preference is given to the compound that exhibits the best risk/benefit ratio, or the most rapid titration when seizure frequency is the major issue. For new antiepileptic compounds, price is often a limiting factor in countries with poor insurance coverage. Third generation anti-epileptic drugs are emerging which also seem to be promising.

Preliminary efficacy and safety of lacosamide in children with refractory epilepsy

BACKGROUND

Despite the introduction of multiple new antiepileptic drugs (AEDs) in the past 20 years, about 30% of patients with epilepsy continue to experience uncontrolled seizures or significant side effects.

AIMS

To present our experience with lacosamide therapy in children with drug-resistant epilepsy.

METHODS

We retrospectively reviewed the medical charts of all patients receiving oral lacosamide until October 2010. Efficacy was determined according to seizure frequency during the week prior to treatment initiation and the week after the maximal dosage of lacosamide was attained.

RESULTS

Seventeen patients (10 boys) aged 1.5-16 (mean - 8 ± 4.7) years were identified. Nine patients had epilepsy attributed to a structural cause, six patients had epilepsy of unknown cause, and two had Lennox-Gastaut syndrome. Mean epilepsy duration was 5.4 ± 3.3 years. The mean number of previous AEDs was 6.6 ± 2. Lacosamide was added to the baseline AEDs in13 patients. The mean duration of follow-up was 9.1 ± 4.4 months. Six (35%) patients had at least a 50%.seizure reduction (mean - 76%). Social, behavioral, and/or motor improvement were noted in seven (41%) patients. Lacosamide was discontinued in six (35%) patients because of inefficacy. Side effects were reported in 10 (59%) patients.

CONCLUSIONS

Lacosamide seems to be effective and safe according to the data in our small cohort. Further prospective studies on lacosamide efficacy and safety in a large number of children are warranted.

Does one more medication help? Effect of adding another anticonvulsant in childhood epilepsy

OBJECTIVES

To study adding an anticonvulsant in children with uncontrolled epilepsy on ≥ 1 appropriate anticonvulsants.

METHODS

Chart review, patients with intractable epilepsy in a neurology clinic July 1, 2004 to December 31, 2007. Inclusion: Children on ≥ 1 stable anticonvulsant who had a second, third, or fourth anticonvulsant added.

EXCLUSIONS

Noncompliance, subtherapeutic doses, and/or serum anticonvulsant levels, inappropriate anticonvulsant for seizure type, inadequate documentation, infantile spasms, or significant dosage changes in the baseline anticonvulsant(s) over the follow-up period. Patients were followed until further therapeutic changes occurred or September 30, 2008, whichever came first.

OUTCOME

≥ 50% decrease in seizure frequency.

RESULTS

Charts reviewed: 1886. Patients who met criteria: 84. Time to assessment: 4 weeks to 42 months (median = 7 months). ≥ 50% reduction in seizure frequency: 35 of 52 patients with second agent added; 5 of 30 patients with third agent added (P = .0001).

CONCLUSIONS

Worthwhile seizure reduction is reasonably likely with the addition of a second anticonvulsant, but much less likely with the addition of third anticonvulsant.

New drugs for pediatric epilepsy

The last 2 decades have witnessed an unprecedented period of new antiepileptic drug (AED) development. Newer-generation AEDs have been developed with the intention of improving the ease of use, decreasing drug interactions, decreasing adverse side effects, and identifying drugs with unique mechanisms of action, some of which may bear relevance to potential neuroprotective activity. Drug trials have also been refined in some cases to evaluate AED efficacy in children and against distinct epilepsy syndromes. This progress provides many new treatment options for the child neurologist facing children with epilepsy but also introduces the burden of determining appropriate AED choices. Here we highlight 6 new antiepileptic medications recently approved or pending approval for use in the United States: lacosamide, rufinamide, vigabatrin, retigabine, brivaracetam, and clobazam. For each of these medications, we present information regarding the history of drug development, proposed mechanism(s) of action, pharmacokinetics and recommended dosing, evidence for clinical efficacy, tolerability, and when, available, any unique features that are relevant for the pediatric population.

The safety and tolerability of newer antiepileptic drugs in children and adolescents

The newer antiepileptic drugs (AEDs) provide more therapeutic options and overall improved safety and tolerability for patients. To provide the best care, physicians must be familiar with the latest tolerability and safety data. This is particularly true in children, given there are relatively fewer studies examining the effects of AEDs in children compared with adults. Since we now have significant paediatric literature on each of these agents, we provide a comprehensive and current literature review of the newer AEDs, focusing on safety and tolerability data in children and adolescents. Because the safety profiles in children differ from those in adults, familiarity with this literature is important for child neurologists and other paediatric caregivers. We have organized the data by organ system for each AED for easier reference.

[Therapeutic drug monitoring of oxcarbazepine]

Oxcarbazepine is an analogue of carbamazepine, used for the treatment of partial seizure with or without secondary generalization. The two forms R and S of the mono-hydroxylated derivatives (MHD) are responsible for most of the anti-convulsant activity and it is the concentrations of MHD that are relevant in therapeutic drug monitoring (TDM). Analysis of currently literature provides no well-established relationship between plasma concentration of MHD and efficiency or toxicity. Although there is not a validated therapeutic range, the residual concentrations of usually observed therapeutic MHD are situated between 12 and 30 mg/L. In certain pathological or physiological circumstances, the pharmacokinetic variability of the oxcarbazepine can be considerable, but this strong unpredictability does not nevertheless justify the TDM of the MHD. Based on the available evidence, TDM of MHD is not routinely warranted but may be possibly useful in specific situations such as pregnancy or renal insufficiency.

Short-term impact of the switch from immediate-release to extended-release oxcarbazepine in epilepsy patients on high dosages

Extended-release oxcarbazepine (OXC) was introduced in Germany in January of 2008. In principle, this formulation should allow a better tolerability due to the less marked serum peak concentration of OXC prior to metabolization to its monohydroxy derivate (MHD) that is the active compound. Twenty-seven in-patients who had been referred to our epilepsy centre because of their difficult-to-treat localization-related epilepsies and had been on immediate-release OXC were abruptly switched to extended-release OXC at identical dosages. The adverse event profile (AEP) and the QOLIE-10 questionnaire were obtained immediately prior to and 5 days after this switch. On both days MHD fasting serum concentrations were also measured. After the switch a significant improvement of tolerability and quality of life was reported according to AEP and QOLIE-10 (p<0.001). Ameliorations were apparent in almost every patient (AEP: 26 of 27 patients, QOLIE-10: 23 of 27 patients). The improvement not explained by a drop of MHD levels. On the contrary and in line with preclinical data, serum levels of MHD rose significantly (p<0.001). We suggest that patients on extended-release OXC experience a lower serum concentration peak of the pro-drug OXC.

Placebo-corrected efficacy of modern antiepileptic drugs for refractory epilepsy: systematic review and meta-analysis

Although adjunctive treatment with modern antiepileptic drugs (AEDs) is standard care in refractory epilepsy, it is unclear how much of the effect can be attributed directly to the AEDs and how much to the beneficial changes seen with placebo. Therefore, we performed a systematic review and meta-analysis of the evidence to determine the placebo-corrected net efficacy of adjunctive treatment with modern AEDs on the market for refractory epilepsy. Of 317 potentially eligible articles reviewed in full text, 124 (39%) fulfilled eligibility criteria. After excluding 69 publications, 55 publications of 54 studies in 11,106 adults and children with refractory epilepsy form the basis of evidence. The overall weighted pooled-risk difference in favor of AEDs over placebo for seizure-freedom in the total sample of adults and children was 6% [95% confidence interval (CI) 4-8, z = 6.47, p < 0.001] and 21% (95% CI 19-24, z = 17.13, p < 0.001) for 50% seizure reduction. Although the presence of moderate heterogeneity may reduce the validity of the results and limit generalizations from the findings, we conclude that the placebo-corrected efficacy of adjunctive treatment with modern AEDs is disappointingly small and suggest that better strategies of finding drugs are needed for refractory epilepsy, which is a major public health problem.

Drug treatment of epilepsy in the century of the ILAE: the second 50 years, 1959-2009

The drug therapy of epilepsy evolved enormously in this 50 year period. Advances in therapeutics included the incorporation of pharmacokinetics into clinical practice, enormous advances in neurochemistry, a trend to antiepileptic drug monotherapy, better drug assessment, better understanding of therapeutic outcomes, and the recognition of the large epilepsy treatment gap in many countries. An unprecedented range of new drugs was introduced in this period. Before 1989, these included carbamazepine, valproate, ethosuximide, and the benzodiazepines. Since 1989, 13 more new drugs have been licensed and marketed and there are others in the pipeline. The International League Against Epilepsy and its leading figures have played an important role in these developments. In this period, too, there has been a rapid expansion in research and development within the pharmaceutical industry and a rise in the value of the antiepileptic drug market. In parallel, governmental regulation of pharmaceuticals has greatly increased. To what extent the overall prognosis of epilepsy has improved as a result of these activities is an interesting and perplexing question.