The cost effectiveness of rufinamide in the treatment of Lennox-Gastaut syndrome in the UK

The burden of illness in Lennox-Gastaut syndrome: a systematic literature review

BACKGROUND

Lennox-Gastaut syndrome (LGS) is a severe developmental and epileptic encephalopathy characterized by drug-resistant epilepsy with multiple seizure types starting in childhood, a typical slow spike-wave pattern on electroencephalogram, and cognitive dysfunction.

METHODS

We performed a systematic literature review according to the PRISMA guidelines to identify, synthesize and appraise the burden of illness in LGS (including "probable" LGS). Studies were identified by searching MEDLINE, Embase and APA PsychInfo, Cochrane's database of systematic reviews, and Epistemonikos. The outcomes were epidemiology (incidence, prevalence or mortality), direct and indirect costs, healthcare resource utilization, and patient and caregiver health-related quality of life (HRQoL).

RESULTS

The search identified 22 publications evaluating the epidemiology (n = 10), direct costs and resource (n = 10) and/or HRQoL (n = 5). No studies reporting on indirect costs were identified. With no specific ICD code for LGS in many regions, several studies had to rely upon indirect methods to identify their patient populations (e.g., algorithms to search insurance claims databases to identify "probable" LGS). There was heterogeneity between studies in how LGS was defined, the size of the populations, ages of the patients and length of the follow-up period. The prevalence varied from 4.2 to 60.8 per 100,000 people across studies for probable LGS and 2.9-28 per 100,000 for a confirmed/narrow definition of LGS. LGS was associated with high mortality rates compared to the general population and epilepsy population. Healthcare resource utilization and direct costs were substantial across all studies. Mean annual direct costs per person varied from $24,048 to $80,545 across studies, and home-based care and inpatient care were significant cost drivers. Studies showed that the HRQoL of patients and caregivers was adversely affected, although only a few studies were identified. In addition, studies suggested that seizure events were associated with higher costs and worse HRQoL. The risk of bias was low or moderate in most studies.

CONCLUSIONS

LGS is associated with a significant burden of illness featuring resistant seizures associated with higher costs and worse HRQoL. More research is needed, especially in evaluating indirect costs and caregiver burden, where there is a notable lack of studies.

Anti-seizure medications for Lennox-Gastaut syndrome

BACKGROUND

Lennox-Gastaut syndrome (LGS) is an age-specific epilepsy syndrome characterised by multiple seizure types, including drop seizures. LGS has a characteristic electroencephalogram, an onset before age eight years and an association with drug resistance. This is an updated version of the Cochrane Review published in 2013.

OBJECTIVES

To assess the efficacy and tolerability of anti-seizure medications (ASMs) for LGS.

SEARCH METHODS

We searched the Cochrane Register of Studies (CRS Web) and MEDLINE (Ovid, 1946 to 28 February 2020) on 2 March 2020. CRS Web includes randomised controlled trials (RCTs) or quasi-RCTs from the Cochrane Central Register of Controlled Trials (CENTRAL); the Specialised Registers of Cochrane Review Groups, including Cochrane Epilepsy; PubMed; Embase; ClinicalTrials.gov; and the World Health Organization's International Clinical Trials Registry Platform (ICTRP). We imposed no language restrictions. We contacted pharmaceutical companies and colleagues in the field to seek any unpublished or ongoing studies.

SELECTION CRITERIA

We considered RCTs, including cross-over trials, of ASMs for LGS in children and adults. We included studies of ASMs used as either monotherapy or as an add-on (adjunctive) therapy. We excluded studies comparing different doses of the same ASM.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures, including independent, dual assessment for risk of bias and application of the GRADE approach to rate the evidence certainty for outcomes.

MAIN RESULTS

We found no trials of ASM monotherapy. The review included 11 trials (1277 participants; approximately 11 weeks to 112 weeks follow-up after randomisation) using add-on ASMs for LGS in children, adolescents and adults. Two studies compared add-on cannabidiol (two doses) with add-on placebo in children and adolescents only. Neither study reported overall seizure cessation or reduction. We found high-certainty evidence that 72 more people per 1000 (confidence interval (CI) 4 more to 351 more) had adverse events (AE) leading to study discontinuation with add-on cannabidiol, compared to add-on placebo (two studies; 396 participants; risk ratio (RR) 4.90, 95% CI 1.21 to 19.87). One study compared add-on cinromide with add-on placebo in children and adolescents only. We found very low-certainty evidence that 35 more people per 1000 (CI 123 fewer to 434 more) had 50% or greater average reduction of overall seizures with add-on cinromide compared to add-on placebo (one study; 56 participants; RR 1.15, 95% CI 0.47 to 2.86). This study did not report participants with AE leading to study discontinuation. One study compared add-on clobazam (three doses) with add-on placebo. This study did not report overall seizure cessation or reduction. We found high-certainty evidence that 106 more people per 1000 (CI 0 more to 538 more) had AE leading to study discontinuation with add-on clobazam compared to add-on placebo (one study; 238 participants; RR 4.12, 95% CI 1.01 to 16.87). One study compared add-on felbamate with add-on placebo. No cases of seizure cessation occurred in either regimen during the treatment phase (one study; 73 participants; low-certainty evidence). There was low-certainty evidence that 53 more people per 1000 (CI 19 fewer to 716 more) with add-on felbamate were seizure-free during an EEG recording at the end of the treatment phase, compared to add-on placebo (RR 2.92, 95% CI 0.32 to 26.77). The study did not report overall seizure reduction. We found low-certainty evidence that one fewer person per 1000 (CI 26 fewer to 388 more) with add-on felbamate had AE leading to study discontinuation compared to add-on placebo (one study, 73 participants; RR 0.97, 95% CI 0.06 to 14.97). Two studies compared add-on lamotrigine with add-on placebo. Neither study reported overall seizure cessation. We found high-certainty evidence that 176 more people per 1000 (CI 30 more to 434 more) had ≥ 50% average seizure reduction with add-on lamotrigine compared to add-on placebo (one study; 167 participants; RR 2.12, 95% CI 1.19 to 3.76). We found low-certainty evidence that 40 fewer people per 1000 (CI 68 fewer to 64 more) had AE leading to study-discontinuation with add-on lamotrigine compared to add-on placebo (one study; 169 participants; RR 0.49, 95% CI 0.13 to 1.82). Two studies compared add-on rufinamide with add-on placebo. Neither study reported seizure cessation. We found high-certainty evidence that 202 more people per 1000 (CI 34 to 567 more) had ≥ 50% average seizure reduction (one study; 138 participants; RR 2.84, 95% CI 1.31 to 6.18). We found low-certainty evidence that 105 more people per 1000 (CI 17 fewer to 967 more) had AE leading to study discontinuation with add-on rufinamide compared to add-on placebo (one study; 59 participants; RR 4.14, 95% CI 0.49 to 34.86). One study compared add-on rufinamide with another add-on ASM. This study did not report overall seizure cessation or reduction. We found low-certainty evidence that three fewer people per 1000 (CI 75 fewer to 715 more) had AE leading to study discontinuation with add-on rufinamide compared to another add-on ASM (one study; 37 participants; RR 0.96, 95% CI 0.10 to 9.57). One study compared add-on topiramate with add-on placebo. This study did not report overall seizure cessation. We found low-certainty evidence for ≥ 75% average seizure reduction with add-on topiramate (one study; 98 participants; Peto odds ratio (Peto OR) 8.22, 99% CI 0.60 to 112.62) and little or no difference to AE leading to study discontinuation compared to add-on placebo; no participants experienced AE leading to study discontinuation (one study; 98 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

RCTs of monotherapy and head-to-head comparison of add-on ASMs are currently lacking. However, we found high-certainty evidence for overall seizure reduction with add-on lamotrigine and rufinamide, with low-certainty evidence for AE leading to study discontinuation compared with add-on placebo or another add-on ASM. The evidence for other add-on ASMs for overall seizure cessation or reduction was low to very low with high- to low-certainty evidence for AE leading to study discontinuation. Future research should consider outcome reporting of overall seizure reduction (applying automated seizure detection devices), impact on development, cognition and behaviour; future research should also investigate age-specific efficacy of ASMs and target underlying aetiologies.

Rufinamide add-on therapy for drug-resistant epilepsy

BACKGROUND

Epilepsy is a central nervous system disorder (neurological disorder). Epileptic seizures are the result of excessive and abnormal cortical nerve cell electrical activity in the brain. Despite the development of more than 10 new antiepileptic drugs (AEDs) since the early 2000s, approximately a third of people with epilepsy remain resistant to pharmacotherapy, often requiring treatment with a combination of AEDs. In this review, we summarised the current evidence regarding rufinamide, a novel anticonvulsant medication, which, as a triazole derivative, is structurally unrelated to any other currently used anticonvulsant medication when used as an add-on treatment for drug-resistant epilepsy. In January 2009, rufinamide was approved by the US Food and Drug Administration for the treatment of children four years of age and older with Lennox-Gastaut syndrome. It is also approved as an add-on treatment for adults and adolescents with focal seizures. This is an updated version of the original Cochrane Review published in 2018.

OBJECTIVES

To evaluate the efficacy and tolerability of rufinamide when used as an add-on treatment for people with drug-resistant epilepsy.

SEARCH METHODS

We imposed no language restrictions. We contacted the manufacturers of rufinamide and authors in the field to identify any relevant unpublished studies.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled, add-on trials of rufinamide, recruiting people (of any age or gender) with drug-resistant epilepsy.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion and extracted the relevant data. We assessed the following outcomes: 50% or greater reduction in seizure frequency (primary outcome); seizure freedom; treatment withdrawal; and adverse effects (secondary outcomes). Primary analyses were intention-to-treat (ITT) and we presented summary risk ratios (RRs) with 95% confidence intervals (CIs). We evaluated dose response in regression models. We carried out a risk of bias assessment for each included study using the Cochrane 'Risk of bias' tool and assessed the overall certainty of evidence using the GRADE approach.

MAIN RESULTS

The review included six trials, representing 1759 participants. Four trials (1563 participants) included people with uncontrolled focal seizures. Two trials (196 participants) included individuals with established Lennox-Gastaut syndrome. Overall, the age of adults ranged from 18 to 80 years and the age of children ranged from 4 to 16 years. Baseline phases ranged from 28 to 56 days and double-blind phases from 84 to 96 days. Five of the six included trials described adequate methods of concealment of randomisation, and only three described adequate blinding. All analyses were by ITT. Overall, five studies were at low risk of bias and one had unclear risk of bias due to lack of reported information around study design. All trials were sponsored by the manufacturer of rufinamide and therefore were at high risk of funding bias. The overall RR for 50% or greater reduction in seizure frequency was 1.79 (95% CI 1.44 to 2.22; 6 randomised controlled trials (RCTs), 1759 participants; moderate-certainty evidence), indicating that rufinamide (plus conventional AED) was significantly more effective than placebo (plus conventional AED) in reducing seizure frequency by at least 50% when added to conventionally used AEDs in people with drug-resistant focal epilepsy. Data from only one study (73 participants) reported seizure freedom: RR 1.32 (95% CI 0.36 to 4.86; 1 RCT, 73 participants; moderate-certainty evidence). The overall RR for treatment withdrawal (for any reason and due to AED) was 1.83 (95% CI 1.45 to 2.31; 6 RCTs, 1759 participants; moderate-certainty evidence), showing that rufinamide was significantly more likely to be withdrawn than placebo. Most adverse effects were significantly more likely to occur in the rufinamide-treated group. Adverse events significantly associated with rufinamide were headache, dizziness, somnolence, vomiting, nausea, fatigue, and diplopia. The RRs for these adverse effects were as follows: headache 1.36 (95% Cl 1.08 to 1.69; 3 RCTs, 1228 participants; high-certainty evidence); dizziness 2.52 (95% Cl 1.90 to 3.34; 3 RCTs, 1295 participants; moderate-certainty evidence); somnolence 1.94 (95% Cl 1.44 to 2.61; 6 RCTs, 1759 participants; moderate-certainty evidence); vomiting 2.95 (95% Cl 1.80 to 4.82; 4 RCTs, 777 participants; low-certainty evidence); nausea 1.87 (95% Cl 1.33 to 2.64; 3 RCTs, 1295 participants; moderate-certainty evidence); fatigue 1.46 (95% Cl 1.08 to 1.97; 3 RCTs, 1295 participants; moderate-certainty evidence); and diplopia 4.60 (95% Cl 2.53 to 8.38; 3 RCTs, 1295 participants; low-certainty evidence). There was no important heterogeneity between studies for any outcomes. Overall, we assessed the evidence as moderate to low certainty due to wide CIs and potential risk of bias from some studies contributing to the analysis.

AUTHORS' CONCLUSIONS

For people with drug-resistant focal epilepsy, rufinamide when used as an add-on treatment was effective in reducing seizure frequency. However, the trials reviewed were of relatively short duration and provided no evidence for long-term use of rufinamide. In the short term, rufinamide as an add-on was associated with several adverse events. This review focused on the use of rufinamide in drug-resistant focal epilepsy, and the results cannot be generalised to add-on treatment for generalised epilepsies. Likewise, no inference can be made about the effects of rufinamide when used as monotherapy.

Cost-Effectiveness of Cannabidiol Adjunct Therapy versus Usual Care for the Treatment of Seizures in Lennox-Gastaut Syndrome

BACKGROUND

Cannabidiol (CBD) is a novel therapy for the treatment of Lennox-Gastaut Syndrome (LGS), a rare, treatment-refractory epileptic encephalopathy. Two pivotal trials found CBD 20 mg/kg/day conferred a reduction from baseline in median drop seizure frequency of 44% and 42%, respectively, compared with 22% and 17%, respectively, in the usual care arms. No economic evaluations have been published to date. This analysis assessed the cost effectiveness of CBD adjunct therapy compared with usual care alone in LGS from the US payer perspective.

METHODS

We developed a lifetime horizon Markov decision analytic model. Efficacy, healthcare costs (2020 US$), and health state utilities were ascertained from published clinical trials, retrospective analyses, and time trade-off interviews conducted in the UK, respectively. Fifteen-year-old patients entering the model transitioned to states representing a percentage reduction in drop seizure frequency from baseline, where they remained until reverting back to baseline drop seizure frequency, or death. One-way and probabilistic sensitivity analyses were conducted to evaluate parameter uncertainty, and scenario analyses investigated the impact of various assumptions. Costs and outcomes were discounted at 3%.

RESULTS

Compared with usual care alone, CBD yielded 0.7 additional quality-adjusted life-years (QALYs) and $314,900 additional healthcare expenditure, resulting in $451,800 per QALY. Uncertainty in health state utilities were the largest contributor to uncertainty in the results. Results from the 5000-simulation probabilistic sensitivity analysis indicated a 0% chance of CBD being cost effective at a $150,000 per QALY willingness-to-pay threshold, with a 95% credible range for the incremental cost-effectiveness ratio of $325,300-$690,000 per QALY.

CONCLUSION

CBD does not appear to be a cost-effective therapeutic option in LGS patients at a willingness-to-pay threshold of $150,000/QALY.

Economic Evaluation of Cannabinoid Oil for Dravet Syndrome: A Cost-Utility Analysis

INTRODUCTION

Cannabinoid oils are being increasingly used to treat Dravet syndrome, yet the long-term costs and outcomes of this approach are unknown. Thus, we examined the cost effectiveness of cannabinoid oil as an adjunctive treatment (added to clobazam and valproate), compared with adjunctive stiripentol or with clobazam and valproate alone, for the treatment of Dravet syndrome in children.

METHODS

We performed a probabilistic cost-utility analysis from the perspective of the Canadian public health care system, comparing cannabinoid oil and stiripentol (both on a background of clobazam and valproate) with clobazam and valproate alone. Costs and quality-adjusted life-years (QALYs) were estimated using a Markov model that followed a cohort of children aged from 5 to 18 years through model states related to seizure frequency. Model inputs were obtained from the literature. The cost effectiveness of adjunctive cannabinoid oil, adjunctive stiripentol, and clobazam/valproate alone was assessed through sequential analysis. The influence of perspective and other assumptions were explored in scenario analyses. All costs are expressed in 2019 Canadian dollars, and costs and QALYs were discounted at a rate of 1.5% per year.

RESULTS

The incremental cost per QALY gained with the use of adjunctive cannabinoid oil, from the health care system perspective, was $32,399 compared with clobazam and valproate. Stiripentol was dominated by cannabinoid oil, producing fewer QALYs at higher costs. At a willingness-to-pay threshold of $50,000, cannabinoid oil was the optimal treatment in 76% of replications. From a societal perspective, cannabinoid oil dominated stiripentol and clobazam/valproate. The interpretation of the results was insensitive to model and input assumptions.

CONCLUSION

Compared with clobazam/valproate, adjunctive cannabinoid oil may be a cost-effective treatment for Dravet syndrome, if a decision maker is willing to pay at least $32,399 for each QALY gained. The opportunity costs of continuing to fund stiripentol, but not cannabinoid oil, should be considered.

Decision Models for Assessing the Cost Effectiveness of Treatments for Pediatric Drug-Resistant Epilepsy: A Systematic Review of Economic Evaluations

BACKGROUND

Drug-resistant epilepsy affects about one-third of children with epilepsy and is associated with high costs to the healthcare system, yet the cost effectiveness of most treatments is unclear. Use of cannabis-based products for epilepsy is increasing, and the cost effectiveness of such strategies relative to conventional pharmacologic treatments must be considered.

OBJECTIVE

The objective of this systematic review was to identify economic evaluations of cannabis-based treatments for pediatric drug-resistant epilepsy. We also sought to identify and appraise decision models that have been used in economic evaluations of pharmacologic treatments (i.e., antiepileptic drugs) in this population.

METHODS

Electronic searches of MEDLINE, EMBASE, and the Cochrane library, as well as a targeted grey literature search, were undertaken (11 June 2018). Model-based full economic evaluations involving cannabis-based treatments or pharmacologic treatments for drug-resistant epilepsy in children were eligible for inclusion. Two independent reviewers selected studies for inclusion, and study quality was assessed by use of the Drummond and Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklists. Study findings, as well as model characteristics, are narratively summarized.

RESULTS

Nine economic evaluations involving children with drug-resistant epilepsy were identified; however, none involved cannabis-based treatments. All studies involved pharmacologic treatments compared with other pharmacologic treatments or non-pharmacologic treatments (i.e., ketogenic diet, epilepsy surgery, vagus nerve stimulation). Few studies have assessed the cost effectiveness of pharmacologic treatments in specific drug-resistant epilepsy syndromes, including Dravet and Lennox-Gastaut syndromes. Five included studies involved use of Markov models with a similar structure (i.e., health states based on seizure frequency relative to baseline). There was a wide range of methodological quality, and few studies fully addressed context-specific issues such as weight gain and treatment switching.

CONCLUSION

Whether cannabis-based treatments for pediatric drug-resistant epilepsy represent good value for money has yet to be investigated. Economic evaluations of such treatments are needed and should address issues of particular importance in pediatric epilepsy, including weight gain over time, switching or discontinuation of treatments, effectiveness of interventions and comparators, and long-term effectiveness beyond the duration of available clinical studies.

PROSPERO REGISTRATION

CRD42018099591.

Development of a classifier to identify patients with probable Lennox-Gastaut syndrome in health insurance claims databases via random forest methodology

Objective: Describe the development of a claims-based classifier utilizing machine learning to identify patients with probable Lennox-Gastaut syndrome (LGS) from six state Medicaid programs. Methods: Patients were included if they had ≥2 medical claims ≥30 days apart for specified or unspecified epilepsy, excluding those with ≥1 claim for petit mal status. The LGS classifier utilized a random forest algorithm, a compilation of thousands of binary decision trees in which machine-generated predictor variables split the data set into branches that predict the presence or absence of LGS. To construct the splitting rules, the importance of each candidate variable was determined by calculating the mean decrease in Gini impurity. Training and testing were performed on two data sets (30% and 70%) using a "true" LGS and non-LGS patient population. Performance was compared with logistic regression and single tree methodology. Results: Using a 60% probability threshold, which yielded the highest sensitivity (97.3%) and specificity (95.6%), the classifier identified approximately 4% of patients with epilepsy as probable LGS. The most important input variables included number of distinct antiepileptic drugs received, epilepsy-related outpatient/inpatient visits, electroencephalogram procedures and claims for delayed development. The random forest methodology outperformed logistic regression and single tree methodology. Most of the important LGS predictor characteristics identified by the classifier were statistically significantly associated with LGS status (p < .05). Conclusions: The claims-based LGS classifier showed high sensitivity and specificity, outperformed single tree and logistic regression methodologies and identified a prevalence of probable LGS that was similar to previously published estimates.

Rufinamide add-on therapy for refractory epilepsy

BACKGROUND

Epilepsy is a central nervous system disorder (neurological disorder). Epileptic seizures are the result of excessive and abnormal cortical nerve cell electrical activity in the brain. Despite the development of more than 10 new antiepileptic drugs (AEDs) since the early 2000s, approximately a third of people with epilepsy remain resistant to pharmacotherapy, often requiring treatment with a combination of AEDs. In this review, we summarised the current evidence regarding rufinamide, a novel anticonvulsant medication, which, as a triazole derivative, is structurally unrelated to any other currently used anticonvulsant medication, when used as an add-on treatment for refractory epilepsy. In January 2009, rufinamide was approved by the US Food and Drug Administration for treatment of children four years of age and older with Lennox-Gastaut syndrome. It is also approved as an add-on treatment for adults and adolescents with focal seizures.

OBJECTIVES

To evaluate the efficacy and tolerability of rufinamide when used as an add-on treatment in people with refractory epilepsy.

SEARCH METHODS

On 2 October 2017, we searched the Cochrane Epilepsy Group Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL) via the Cochrane Register of Studies Online (CRSO), MEDLINE (Ovid, 1946), ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP). We imposed no language restrictions. We also contacted the manufacturers of rufinamide and authors in the field to identify any relevant unpublished studies.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled, add-on trials of rufinamide, recruiting people (of any age or gender) with refractory epilepsy.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion and extracted the relevant data. We assessed the following outcomes: 50% or greater reduction in seizure frequency (primary outcomes); seizure freedom; treatment withdrawal; and adverse effects (secondary outcomes). Primary analyses were intention-to-treat (ITT) and we presented summary risk ratios (RR) with 95% confidence intervals (CI). We evaluated dose response in regression models. We carried out a risk of bias assessment for each included study using the Cochrane 'Risk of bias' tool and assessed the overall quality of evidence using the GRADE approach, which we presented in a 'Summary of findings' table.

MAIN RESULTS

The review included six trials, representing 1759 participants. Four trials (1563 participants) included people with uncontrolled focal seizures. Two trials (196 participants) included established Lennox-Gastaut syndrome. Overall, the age of the adults ranged from 18 to 80 years and the age of the infants ranged from four to 16 years. Baseline phase ranged from 28 to 56 days and double-blind phases from 84 to 96 days. Five of the six included trials described adequate methods of concealment of randomisation and only three described adequate blinding. All analyses were by ITT. Overall, five studies were at low risk of bias, and one had unclear risk of bias due to lack of reported information around study design. All trials were sponsored by the manufacturer of rufinamide, and therefore, were at high risk of funding bias.The overall RR for 50% or greater reduction in seizure frequency was 1.79 (95% CI 1.44 to 2.22; 6 RCTs; moderate-quality evidence) indicating that rufinamide (plus conventional AED) was significantly more effective than placebo (plus conventional AED) in reducing seizure frequency by at least 50%, when added to conventionally used AEDs in people with refractory focal epilepsy. The overall RR for treatment withdrawal (for any reason and due to AED) was 1.83 (95% CI 1.45 to 2.31; 6 RCTs; moderate-quality evidence) showing that rufinamide was significantly more likely to be withdrawn than placebo. In respect of adverse effects, most were significantly more likely to occur in the rufinamide-treated group. The adverse events significantly associated with rufinamide were: headache, dizziness, somnolence, vomiting, nausea, fatigue and diplopia. The RRs of these adverse effects were: headache 1.36 (95% Cl 1.08 to 1.69; 3 RCTs; high-quality evidence); dizziness 2.52 (95% Cl 1.90 to 3.34; 3 RCTs; moderate-quality evidence); somnolence 1.94 (95% Cl 1.44 to 2.61; 6 RCTs; moderate-quality evidence); vomiting 2.95 (95% Cl 1.80 to 4.82; 4 RCTs; low-quality evidence); nausea 1.87 (95% Cl 1.33 to 2.64; 3 RCTs; moderate-quality evidence); fatigue 1.46 (95% Cl 1.08 to 1.97; 3 RCTs; moderate-quality evidence); and diplopia 4.60 (95% Cl 2.53 to 8.38; 3 RCTs; low-quality evidence). There was no important heterogeneity between studies for any of the outcomes. Overall, we assessed the evidence as moderate to low quality, due to potential risk of bias from some studies contributing to the analysis and wide CIs.

AUTHORS' CONCLUSIONS

In people with drug-resistant focal epilepsy, rufinamide when used as an add-on treatment was effective in reducing seizure frequency. However, the trials reviewed were of relatively short duration and provided no evidence for the long-term use of rufinamide. In the short term, rufinamide as an add-on was associated with several adverse events. This review focused on the use of rufinamide in drug-resistant focal epilepsy and the results cannot be generalised to add-on treatment for generalised epilepsies. Likewise, no inference can be made about the effects of rufinamide when used as monotherapy.

Assessment of treatment patterns and healthcare costs associated with probable Lennox-Gastaut syndrome

Lennox-Gastaut syndrome (LGS) is a chronic and severe form of epilepsy characterized by intractable seizures, cognitive impairment, and abnormal electroencephalogram findings with slow spike-wave complexes. It typically presents before age 8, but symptoms continue into adulthood and require lifelong treatment associated with significant clinical burden. Data on LGS-associated healthcare utilization and costs are limited. In this study we use a claims-based LGS classifier based on random forest methodology to identify patients with probable LGS from the a Medicaid multi-state database and assess its prevalence across the age spectrum, healthcare utilization, treatment patterns, costs, and comorbid conditions. The classifier identified patients with probable LGS across all ages, with up to 8% of 10-year-old patients with epilepsy identified as having probable LGS. The prevalence of probable LGS was lower in older age cohorts, indicating that it may be under-recognized in older patients. Our analysis showed that probable LGS is associated with considerably higher total healthcare and medical costs than non-LGS patients. The costs were generally consistent between age cohorts, suggesting that the cost burden extends beyond childhood and has a lifelong impact. Analysis of treatment patterns suggest that while the majority of probable LGS patients in this study received widest-spectrum AEDs, a considerable proportion did not and therefore may have been inadequately treated. Further, usage of clobazam and rufinamide was decreased in older compared to younger patient cohorts, indicating that older patient cohorts are less likely to be receiving optimum treatment for LGS. These findings indicate the need for increased clinical attention to LGS beyond pediatric years, with a focus on optimization of treatment for LGS patients of all ages with widest-spectrum AEDs. Timely recognition and adequate treatment of LGS are likely to result in improved outcomes and less costly management of this condition.

A systematic review of economic evaluations of treatments for patients with epilepsy

The increasing number of treatment options and the high costs associated with epilepsy have fostered the development of economic evaluations in epilepsy. It is important to examine the availability and quality of these economic evaluations and to identify potential research gaps. As well as looking at both pharmacologic (antiepileptic drugs [AEDs]) and nonpharmacologic (e.g., epilepsy surgery, ketogenic diet, vagus nerve stimulation) therapies, this review examines the methodologic quality of the full economic evaluations included. Literature search was performed in MEDLINE, EMBASE, NHS Economic Evaluation Database (NHS EED), Econlit, Web of Science, and CEA Registry. In addition, Cochrane Reviews, Cochrane DARE and Cochrane Health Technology Assessment Databases were used. To identify relevant studies, predefined clinical search strategies were combined with a search filter designed to identify health economic studies. Specific search strategies were devised for the following topics: (1) AEDs, (2) patients with cognitive deficits, (3) elderly patients, (4) epilepsy surgery, (5) ketogenic diet, (6) vagus nerve stimulation, and (7) treatment of (non)convulsive status epilepticus. A total of 40 publications were included in this review, 29 (73%) of which were articles about pharmacologic interventions. Mean quality score of all articles on the Consensus Health Economic Criteria (CHEC)-extended was 81.8%, the lowest quality score being 21.05%, whereas five studies had a score of 100%. Looking at the Consolidated Health Economic Evaluation Reporting Standards (CHEERS), the average quality score was 77.0%, the lowest being 22.7%, and four studies rated as 100%. There was a substantial difference in methodology in all included articles, which hampered the attempt to combine information meaningfully. Overall, the methodologic quality was acceptable; however, some studies performed significantly worse than others. The heterogeneity between the studies stresses the need to define a reference case (e.g., how should an economic evaluation within epilepsy be performed) and to derive consensus on what constitutes "standard optimal care."

Comprehensive overview: efficacy, tolerability, and cost-effectiveness of clobazam in Lennox-Gastaut syndrome

Clobazam is the newest medication approved by the US Food and Drug Administration (FDA) for the treatment of Lennox–Gastaut syndrome (LGS) in patients at least 2 years of age, although the medication has been available in countries around the world to treat epilepsy and anxiety disorders for many years. Though classified as a benzodiazepine, the drug differs structurally from other drugs in the class as it possesses nitrogen atoms at the 1 and 5 positions within the heterocyclic ring rather than at the 1 and 4 positions. This difference and the classification of clobazam as a partial agonist are believed to be responsible for the decreased incidence of sedative effects compared to other benzodiazepines. Adverse events associated with clobazam use in clinical trials have generally been mild to moderate in nature. Data from an open-label extension trial have confirmed that clobazam is efficacious for the treatment of seizures associated with LGS, particularly atonic seizures (drop seizures), over the long term. Tolerance to the drug’s antiepileptic effects does not seem to be a common occurrence. The drug has proven to be a cost-effective option for therapy, particularly due to its ability to decrease the number of seizures that require medical treatment. Clobazam represents a welcome addition to the treatment options for LGS.

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.

Cost-effectiveness analysis of antiepileptic drugs in the treatment of Lennox-Gastaut syndrome

An economic model evaluated the costs and outcomes of adjunctive clobazam therapy for Lennox-Gastaut syndrome (LGS) compared with adjunctive lamotrigine, rufinamide, and topiramate. Clinical data were used to estimate baseline frequency and the percentage of drop-seizure reductions over 3 months (all comparators) and 2 years (rufinamide). Claims data from a large US health care plan were employed to estimate costs. After 3 months, 21.5% of those receiving clobazam were drop-seizure-free. Over a 3-month horizon, clobazam was more effective and less expensive than comparators, with the assumption that >0.77% of drop seizures required medical care. Below this threshold, topiramate was less costly than clobazam. With the base-case assumption that 2.3% of drop seizures were medically attended, costs for patients receiving clobazam totaled $30,147 versus $34,223-$35,378 for comparators. Clobazam was more efficacious and less costly than rufinamide over a 2-year horizon. The percentage of medically attended drop seizures was a driver of results. Clobazam treatment may be cost-saving.

Indirect comparison of clobazam and other therapies for Lennox-Gastaut syndrome

OBJECTIVE

In the absence of head-to-head trials, it is not feasible to make direct comparisons of antiepileptic therapies for the treatment of Lennox-Gastaut syndrome (LGS). We conducted indirect comparisons of the relative efficacies of clobazam, felbamate, lamotrigine, topiramate, and rufinamide as adjunctive treatments for LGS.

METHODS

Clinical studies of LGS patients were identified in a 2009 Cochrane review and by electronic database search. Five randomized controlled trials were included in this systematic review, which reports findings from indirect comparisons between clobazam and other approved adjunctive LGS therapies (felbamate, lamotrigine, topiramate, rufinamide) in the United States and Europe. As outcomes were not uniformly reported across studies, the primary efficacy endpoint from each trial was transformed into Cohen's d effect size, to facilitate indirect comparisons. Typical interpretations of Cohen's d results are as follows: d < 0.2, change not detectable; 0.2 ≤ d < 0.5, small change; 0.5 ≤ d < 0.8, moderate change; and 0.8 ≤ d, large change.

RESULTS

High-dosage clobazam (1.0 mg/kg/day) was found to have the strongest treatment effect vs placebo (effect size 0.80), with moderate effects (effect sizes >0.50) for medium-dosage clobazam (0.5 mg/kg/day) and rufinamide. Felbamate, lamotrigine, and topiramate had low effect sizes. Indirect comparisons of numbers of total seizures and tonic-atonic seizures ('drop attacks') demonstrated superiority of both clobazam dosages over all comparators.

CONCLUSIONS

High- and medium-dosage clobazam was estimated to be more efficacious than other LGS treatments. Our analysis relied on published data and could not draw on direct head-to-head data of clobazam with alternatives. Further comparative research is ongoing to assess the usefulness of clobazam for LGS.

The cost effectiveness of newer epilepsy treatments: a review of the literature on partial-onset seizures

BACKGROUND AND OBJECTIVE

Epilepsy is one of the most common neurological disorders, affecting more than 3 million people in Europe. This paper reviews the published evidence regarding the cost effectiveness of second-generation antiepileptic drugs (AEDs).

METHODS

A systematic literature search was performed, using the databases Academic Search Complete, Econlit, EMBASE and MEDLINE. Health economic evaluations of newer (second-generation) AEDs, published as full-length journal articles, were searched for. We focused on evaluations of newer AEDs as treatment for partial-onset seizures. 470 studies were initially identified and 19 were finally included. Information regarding (i) AEDs studied, (ii) cost effectiveness, and (iii) a variety of health economic modelling specifics was extracted from each study. Then, the included studies were summarized and a quality assessment was performed, according to the British Medical Journal's guidelines for economic studies.

RESULTS

The results were as follows: (i) the cost per additional QALY for newer AEDs used as adjunctive treatment, compared with standard therapy, ranged between $US19 139 (levetiracetam) and $US57 210 (pregabalin) [year 2010 values]; no cost-effectiveness evidence was identified for felbamate, eslicarbazepine, oxcarbazepine or tiagabine; and (ii) all studies met at least 60% of the British Medical Journal's guidelines criteria, and seven studies were found to satisfy more than 80% of the criteria. Guidelines criteria not met involve inadequate reporting of input data and modelling details, including validation and availability of models used for cost-effectiveness calculations.

CONCLUSIONS

Although failure to meet good practice guidelines influences the reliability of the presented evidence adversely, a sufficient number of the included studies were found to comply enough with the guidelines in order for the qualitative content of the cost-effectiveness results - that some of the newer AEDs are cost effective - to be reliable. In fact, this conclusion is likely to be relatively robust, since the effect of improved seizure control on labour market performance was not included in the base-case results in any of the included studies and improved seizure control need only to have a moderate effect on sickness absenteeism in order for the corresponding treatment to be cost effective even when willingness to pay for an additional QALY is low. However, the cost effectiveness of newer AEDs has only been studied for a small number of settings, and hence future studies incorporating additional settings are needed.

Rufinamide: a pharmacoeconomic profile of its use as adjunctive therapy in Lennox-Gastaut syndrome

Rufinamide (Inovelon®), a triazole derivative, is an oral antiepileptic drug approved in the EU as adjunctive therapy in the treatment of seizures associated with Lennox-Gastaut syndrome (LGS) in patients aged ≥4 years. The efficacy of oral rufinamide as adjunctive therapy in patients with LGS uncontrolled on one to three concomitant antiepileptic drugs was demonstrated in a pivotal, 12-week, randomized, double-blind trial. Rufinamide significantly reduced the 28-day frequency of both drop attacks and total seizures compared with placebo, and significantly increased the proportions of patients experiencing a ≥50% reduction in each seizure frequency. A significantly higher proportion of rufinamide than placebo recipients recorded an improvement in seizure severity at the end of treatment. Reductions in the frequency of drop attacks and total seizures were maintained in a long-term (up to 3 years), open-label extension study. Oral rufinamide was generally well tolerated in patients with LGS. Somnolence and vomiting were the most common adverse events occurring more frequently with rufinamide than with placebo. Two pharmacoeconomic analyses, using decision-analysis models with 3-month cycles over a time horizon of 3 years, assessed the cost effectiveness and cost utility, respectively, of rufinamide compared with topiramate and lamotrigine as adjunctive therapy in patients with LGS from the perspective of the UK NHS. The cost-effectiveness analysis suggested that rufinamide would be associated with incremental costs of £62 (drop attacks) or £2151 (total seizures) per 1% increase in the number of patients achieving a >50% reduction in seizure frequency over 3 years. The cost-utility analysis predicted that the incremental cost per QALY gained for rufinamide compared with the next less-costly and undominated therapy would be more than 5-fold higher than the commonly accepted willingness-to-pay threshold range in the UK. In conclusion, the available pharmacoeconomic data indicate that rufinamide is more effective, but more expensive, than alternative adjunctive therapies approved for use in patients with LGS in the UK. Rufinamide would appear to be a cost-effective alternative to topiramate. Although rufinamide exceeds conventional cost-effectiveness thresholds when compared with lamotrigine, it may still be considered a valuable treatment option for a devastating orphan disease such as LGS.