Lamotrigine versus levetiracetam or zonisamide for focal epilepsy and valproate versus levetiracetam for generalised and unclassified epilepsy: two SANAD II non-inferiority RCTs

BACKGROUND

Levetiracetam (Keppra^®, UCB Pharma Ltd, Slough, UK) and zonisamide (Zonegran^®, Eisai Co. Ltd, Tokyo, Japan) are licensed as monotherapy for focal epilepsy, and levetiracetam is increasingly used as a first-line treatment for generalised epilepsy, particularly for women of childbearing age. However, there is uncertainty as to whether or not they should be recommended as first-line treatments owing to a lack of evidence of clinical effectiveness and cost-effectiveness.

OBJECTIVES

To compare the clinical effectiveness and cost-effectiveness of lamotrigine (Lamictal^®, GlaxoSmithKline plc, Brentford, UK) (standard treatment) with levetiracetam and zonisamide (new treatments) for focal epilepsy, and to compare valproate (Epilim^®, Sanofi SA, Paris, France) (standard treatment) with levetiracetam (new treatment) for generalised and unclassified epilepsy.

DESIGN

Two pragmatic randomised unblinded non-inferiority trials run in parallel.

SETTING

Outpatient services in NHS hospitals throughout the UK.

PARTICIPANTS

Those aged ≥ 5 years with two or more spontaneous seizures that require anti-seizure medication.

INTERVENTIONS

Participants with focal epilepsy were randomised to receive lamotrigine, levetiracetam or zonisamide. Participants with generalised or unclassifiable epilepsy were randomised to receive valproate or levetiracetam. The randomisation method was minimisation using a web-based program.

MAIN OUTCOME MEASURES

The primary outcome was time to 12-month remission from seizures. For this outcome, and all other time-to-event outcomes, we report hazard ratios for the standard treatment compared with the new treatment. For the focal epilepsy trial, the non-inferiority limit (lamotrigine vs. new treatments) was 1.329. For the generalised and unclassified epilepsy trial, the non-inferiority limit (valproate vs. new treatments) was 1.314. Secondary outcomes included time to treatment failure, time to first seizure, time to 24-month remission, adverse reactions, quality of life and cost-effectiveness.

RESULTS

Focal epilepsy. A total of 990 participants were recruited, of whom 330 were randomised to receive lamotrigine, 332 were randomised to receive levetiracetam and 328 were randomised to receive zonisamide. Levetiracetam did not meet the criteria for non-inferiority (hazard ratio 1.329) in the primary intention-to-treat analysis of time to 12-month remission (hazard ratio vs. lamotrigine 1.18, 97.5% confidence interval 0.95 to 1.47), but zonisamide did meet the criteria (hazard ratio vs. lamotrigine 1.03, 97.5% confidence interval 0.83 to 1.28). In the per-protocol analysis, lamotrigine was superior to both levetiracetam (hazard ratio 1.32, 95% confidence interval 1.05 to 1.66) and zonisamide (hazard ratio 1.37, 95% confidence interval 1.08 to 1.73). For time to treatment failure, lamotrigine was superior to levetiracetam (hazard ratio 0.60, 95% confidence interval 0.46 to 0.77) and zonisamide (hazard ratio 0.46, 95% confidence interval 0.36 to 0.60). Adverse reactions were reported by 33% of participants starting lamotrigine, 44% starting levetiracetam and 45% starting zonisamide. In the economic analysis, both levetiracetam and zonisamide were more costly and less effective than lamotrigine and were therefore dominated. Generalised and unclassifiable epilepsy. Of 520 patients recruited, 260 were randomised to receive valproate and 260 were randomised to receive to levetiracetam. A total of 397 patients had generalised epilepsy and 123 had unclassified epilepsy. Levetiracetam did not meet the criteria for non-inferiority in the primary intention-to-treat analysis of time to 12-month remission (hazard ratio 1.19, 95% confidence interval 0.96 to 1.47; non-inferiority margin 1.314). In the per-protocol analysis of time to 12-month remission, valproate was superior to levetiracetam (hazard ratio 1.68, 95% confidence interval 1.30 to 2.15). Valproate was superior to levetiracetam for time to treatment failure (hazard ratio 0.65, 95% confidence interval 0.50 to 0.83). Adverse reactions were reported by 37.4% of participants receiving valproate and 41.5% of those receiving levetiracetam. Levetiracetam was both more costly (incremental cost of £104, 95% central range -£587 to £1234) and less effective (incremental quality-adjusted life-year of -0.035, 95% central range -0.137 to 0.032) than valproate, and was therefore dominated. At a cost-effectiveness threshold of £20,000 per quality-adjusted life-year, levetiracetam was associated with a probability of 0.17 of being cost-effective.

LIMITATIONS

The SANAD II trial was unblinded, which could have biased results by influencing decisions about dosing, treatment failure and the attribution of adverse reactions.

FUTURE WORK

SANAD II data could now be included in an individual participant meta-analysis of similar trials, and future similar trials are required to assess the clinical effectiveness and cost-effectiveness of other new treatments, including lacosamide and perampanel.

CONCLUSIONS

Focal epilepsy - The SANAD II findings do not support the use of levetiracetam or zonisamide as first-line treatments in focal epilepsy. Generalised and unclassifiable epilepsy - The SANAD II findings do not support the use of levetiracetam as a first-line treatment for newly diagnosed generalised epilepsy. For women of childbearing potential, these results inform discussions about the benefit (lower teratogenicity) and harm (worse seizure outcomes and higher treatment failure rate) of levetiracetam compared with valproate.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN30294119 and EudraCT 2012-001884-64.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 75. See the NIHR Journals Library website for further project information.

The SANAD II study of the effectiveness and cost-effectiveness of levetiracetam, zonisamide, or lamotrigine for newly diagnosed focal epilepsy: an open-label, non-inferiority, multicentre, phase 4, randomised controlled trial

BACKGROUND

Levetiracetam and zonisamide are licensed as monotherapy for patients with focal epilepsy, but there is uncertainty as to whether they should be recommended as first-line treatments because of insufficient evidence of clinical effectiveness and cost-effectiveness. We aimed to assess the long-term clinical effectiveness and cost-effectiveness of levetiracetam and zonisamide compared with lamotrigine in people with newly diagnosed focal epilepsy.

METHODS

This randomised, open-label, controlled trial compared levetiracetam and zonisamide with lamotrigine as first-line treatment for patients with newly diagnosed focal epilepsy. Adult and paediatric neurology services across the UK recruited participants aged 5 years or older (with no upper age limit) with two or more unprovoked focal seizures. Participants were randomly allocated (1:1:1) using a minimisation programme with a random element utilising factor to receive lamotrigine, levetiracetam, or zonisamide. Participants and investigators were not masked and were aware of treatment allocation. SANAD II was designed to assess non-inferiority of both levetiracetam and zonisamide to lamotrigine for the primary outcome of time to 12-month remission. Anti-seizure medications were taken orally and for participants aged 12 years or older the initial advised maintenance doses were lamotrigine 50 mg (morning) and 100 mg (evening), levetiracetam 500 mg twice per day, and zonisamide 100 mg twice per day. For children aged between 5 and 12 years the initial daily maintenance doses advised were lamotrigine 1·5 mg/kg twice per day, levetiracetam 20 mg/kg twice per day, and zonisamide 2·5 mg/kg twice per day. All participants were included in the intention-to-treat (ITT) analysis. The per-protocol (PP) analysis excluded participants with major protocol deviations and those who were subsequently diagnosed as not having epilepsy. Safety analysis included all participants who received one dose of any study drug. The non-inferiority limit was a hazard ratio (HR) of 1·329, which equates to an absolute difference of 10%. A HR greater than 1 indicated that an event was more likely on lamotrigine. The trial is registered with the ISRCTN registry, 30294119 (EudraCt number: 2012-001884-64).

FINDINGS

990 participants were recruited between May 2, 2013, and June 20, 2017, and followed up for a further 2 years. Patients were randomly assigned to receive lamotrigine (n=330), levetiracetam (n=332), or zonisamide (n=328). The ITT analysis included all participants and the PP analysis included 324 participants randomly assigned to lamotrigine, 320 participants randomly assigned to levetiracetam, and 315 participants randomly assigned to zonisamide. Levetiracetam did not meet the criteria for non-inferiority in the ITT analysis of time to 12-month remission versus lamotrigine (HR 1·18; 97·5% CI 0·95-1·47) but zonisamide did meet the criteria for non-inferiority in the ITT analysis versus lamotrigine (1·03; 0·83-1·28). The PP analysis showed that 12-month remission was superior with lamotrigine than both levetiracetam (HR 1·32 [97·5% CI 1·05 to 1·66]) and zonisamide (HR 1·37 [1·08-1·73]). There were 37 deaths during the trial. Adverse reactions were reported by 108 (33%) participants who started lamotrigine, 144 (44%) participants who started levetiracetam, and 146 (45%) participants who started zonisamide. Lamotrigine was superior in the cost-utility analysis, with a higher net health benefit of 1·403 QALYs (97·5% central range 1·319-1·458) compared with 1·222 (1·110-1·283) for levetiracetam and 1·232 (1·112, 1·307) for zonisamide at a cost-effectiveness threshold of £20 000 per QALY. Cost-effectiveness was based on differences between treatment groups in costs and QALYs.

INTERPRETATION

These findings do not support the use of levetiracetam or zonisamide as first-line treatments for patients with focal epilepsy. Lamotrigine should remain a first-line treatment for patients with focal epilepsy and should be the standard treatment in future trials.

FUNDING

National Institute for Health Research Health Technology Assessment programme.

The SANAD II study of the effectiveness and cost-effectiveness of valproate versus levetiracetam for newly diagnosed generalised and unclassifiable epilepsy: an open-label, non-inferiority, multicentre, phase 4, randomised controlled trial

BACKGROUND

Valproate is a first-line treatment for patients with newly diagnosed idiopathic generalised or difficult to classify epilepsy, but not for women of child-bearing potential because of teratogenicity. Levetiracetam is increasingly prescribed for these patient populations despite scarcity of evidence of clinical effectiveness or cost-effectiveness. We aimed to compare the long-term clinical effectiveness and cost-effectiveness of levetiracetam compared with valproate in participants with newly diagnosed generalised or unclassifiable epilepsy.

METHODS

We did an open-label, randomised controlled trial to compare levetiracetam with valproate as first-line treatment for patients with generalised or unclassified epilepsy. Adult and paediatric neurology services (69 centres overall) across the UK recruited participants aged 5 years or older (with no upper age limit) with two or more unprovoked generalised or unclassifiable seizures. Participants were randomly allocated (1:1) to receive either levetiracetam or valproate, using a minimisation programme with a random element utilising factors. Participants and investigators were aware of treatment allocation. For participants aged 12 years or older, the initial advised maintenance doses were 500 mg twice per day for levetiracetam and valproate, and for children aged 5-12 years, the initial daily maintenance doses advised were 25 mg/kg for valproate and 40 mg/kg for levetiracetam. All drugs were administered orally. SANAD II was designed to assess the non-inferiority of levetiracetam compared with valproate for the primary outcome time to 12-month remission. The non-inferiority limit was a hazard ratio (HR) of 1·314, which equates to an absolute difference of 10%. A HR greater than 1 indicated that an event was more likely on valproate. All participants were included in the intention-to-treat (ITT) analysis. Per-protocol (PP) analyses excluded participants with major protocol deviations and those who were subsequently diagnosed as not having epilepsy. Safety analyses included all participants who received one dose of any study drug. This trial is registered with the ISRCTN registry, 30294119 (EudraCt number: 2012-001884-64).

FINDINGS

520 participants were recruited between April 30, 2013, and Aug 2, 2016, and followed up for a further 2 years. 260 participants were randomly allocated to receive levetiracetam and 260 participants to receive valproate. The ITT analysis included all participants and the PP analysis included 255 participants randomly allocated to valproate and 254 randomly allocated to levetiracetam. Median age of participants was 13·9 years (range 5·0-94·4), 65% were male and 35% were female, 397 participants had generalised epilepsy, and 123 unclassified epilepsy. Levetiracetam did not meet the criteria for non-inferiority in the ITT analysis of time to 12-month remission (HR 1·19 [95% CI 0·96-1·47]); non-inferiority margin 1·314. The PP analysis showed that the 12-month remission was superior with valproate than with levetiracetam. There were two deaths, one in each group, that were unrelated to trial treatments. Adverse reactions were reported by 96 (37%) participants randomly assigned to valproate and 107 (42%) participants randomly assigned to levetiracetam. Levetiracetam was dominated by valproate in the cost-utility analysis, with a negative incremental net health benefit of -0·040 (95% central range -0·175 to 0·037) and a probability of 0·17 of being cost-effectiveness at a threshold of £20 000 per quality-adjusted life-year. Cost-effectiveness was based on differences between treatment groups in costs and quality-adjusted life-years.

INTERPRETATION

Compared with valproate, levetiracetam was found to be neither clinically effective nor cost-effective. For girls and women of child-bearing potential, these results inform discussions about benefit and harm of avoiding valproate.

FUNDING

National Institute for Health Research Health Technology Assessment Programme.

Study protocol for a pragmatic randomised controlled trial comparing the effectiveness and cost-effectiveness of levetiracetam and zonisamide versus standard treatments for epilepsy: a comparison of standard and new antiepileptic drugs (SANAD-II)

INTRODUCTION

Antiepileptic drugs (AEDs) are the mainstay of epilepsy treatment. Over the past 20 years, a number of new drugs have been approved for National Health Service (NHS) use on the basis of information from short-term trials that demonstrate efficacy. These trials do not provide information about the longer term outcomes, which inform treatment policy. This trial will assess the long-term clinical and cost-effectiveness of the newer treatment levetiracetam and zonisamide.

METHODS AND ANALYSIS

This is a phase IV, multicentre, open-label, randomised, controlled clinical trial comparing new and standard treatments for patients with newly diagnosed epilepsy. Arm A of the trial randomised 990 patients with focal epilepsy to standard AED lamotrigine or new AED levetiracetam or zonisamide. Arm B randomised 520 patients with generalised epilepsy to standard AED sodium valproate or new AED levetiracetam. Patients are recruited from UK NHS outpatient epilepsy, general neurology and paediatric clinics. Included patients are aged 5 years or older with two or more spontaneous seizures requiring AED monotherapy, who are not previously treated with AEDs. Patients are followed up for a minimum of 2 years. The primary outcome is time to 12-month remission from seizures. Secondary outcomes include time to treatment failure (including due to inadequate seizure control or unacceptable adverse reactions); time to first seizure; time to 24-month remission; adverse reactions and quality of life. All primary analyses will be on an intention to treat basis. Separate analyses will be undertaken for each arm. Health economic analysis will be conducted from the perspective of the NHS to assess the cost-effectiveness of each AED.

ETHICS AND DISSEMINATION

This trial has been approved by the North West-Liverpool East REC (Ref. 12/NW/0361). The trial team will disseminate the results through scientific meetings, peer-reviewed publications and patient and public involvement.

TRIAL REGISTRATION NUMBERS

EudraCT 2012-001884-64; ISRCTN30294119.

Shared Genetic Risk Factors Across Carbamazepine-Induced Hypersensitivity Reactions

Carbamazepine (CBZ) causes life‐threating T‐cell‐mediated hypersensitivity reactions, including serious cutaneous adverse reactions (SCARs) and drug‐induced liver injury (CBZ‐DILI). In order to evaluate shared or phenotype‐specific genetic predisposing factors for CBZ hypersensitivity reactions, we performed a meta‐analysis of two genomewide association studies (GWAS) on a total of 43 well‐phenotyped Northern and Southern European CBZ‐SCAR cases and 10,701 population controls and a GWAS on 12 CBZ‐DILI cases and 8,438 ethnically matched population controls. HLA‐A*31:01 was identified as the strongest genetic predisposing factor for both CBZ‐SCAR (odds ratio (OR) = 8.0; 95% CI 4.10–15.80; P = 1.2 × 10⁻⁹) and CBZ‐DILI (OR = 7.3; 95% CI 2.47–23.67; P = 0.0004) in European populations. The association with HLA‐A*31:01 in patients with SCAR was mainly driven by hypersensitivity syndrome (OR = 12.9; P = 2.1 × 10⁻⁹) rather than by Stevens‐Johnson syndrome/toxic epidermal necrolysis cases, which showed an association with HLA‐B*57:01. We also identified a novel risk locus mapping to ALK only for CBZ‐SCAR cases, which needs replication in additional cohorts and functional evaluation.

Genetics of epilepsy: epilepsy research foundation workshop report

The Sixth Epilepsy Research Foundation workshop, held in Oxford in March 2006, brought together basic scientists, geneticists, epidemiologists, statisticians, pharmacologists and clinicians to consider progress, issues and strategies for harnessing genetics to improve the understanding and treatment of the epilepsies. General principles were considered, including the fundamental importance of clear study design, adequate patient numbers, defi ned phenotypes, robust statistical data handling, and follow-up of genetic discoveries. Topics where some progress had been made were considered including chromosomal abnormalities, neurodevelopment, hippocampal sclerosis, juvenile myoclonic epilepsy, focal cortical dysplasia and pharmacogenetics. The ethical aspects of epilepsy genetics were reviewed. Principles and limitations of collaboration were discussed. Presentations and their matched discussions are produced here. There was optimism that further genetic research in epilepsy was not only feasible, but might lead to improvements in the lives of people with epilepsy.

Pharmacokinetics and Drug Interactions with Zonisamide

Polypharmacy is a widely employed treatment strategy in epilepsy, particularly for individuals with poorly controlled seizures. Drug combinations should be carefully considered to minimize the potential for unfavorable interactions. Older-generation antiepileptic drugs (AEDs) are well known for their pharmacokinetic interaction potential, which generally results from alterations in the metabolism of concomitant drugs due to effects on the cytochrome P450 (CYP) and uridine glucuronyl transferase enzyme systems. Newer agents, such as zonisamide, are less likely to cause adverse drug interactions. A series of interaction studies has revealed zonisamide to be without effect on the steady-state pharmacokinetics of carbamazepine, phenytoin, sodium valproate, or lamotrigine. However, zonisamide is principally inactivate by CY3A4-dependent reduction. Consequently, carbamazepine, phenytoin, and phenobarbital all increase its clearance, an interaction that may necessitate a dosage increase, but which will also permit more rapid attainment of steady-state zonisamide concentrations. Otherwise, zonisamide is essentially devoid of clinically significant interactions with other AEDs, oral contraceptives and, indeed, all other classes of therapeutic agents investigated to date. As a result, it is reasonable to conclude that zonisamide has a favorable pharmacokinetic profile and that it may be a useful and uncomplicated agent when employed as adjunctive therapy in refractory epilepsy.

Impact of electrokinetic remediation on microbial communities within PCP contaminated soil

Electrokinetic techniques have been used to stimulate the removal of organic pollutants within soil, by directing contaminant migration to where remediation may be more easily achieved. The effect of this and other physical remediation techniques on the health of soil microbial communities has been poorly studied and indeed, largely ignored. This study reports the impact on soil microbial communities during the application of an electric field within ex situ laboratory soil microcosms contaminated with pentachlorophenol (PCP; 100mg kg(-1) oven dry soil). Electrokinetics reduced counts of culturable bacteria and fungi, soil microbial respiration and carbon substrate utilisation, especially close to the acidic anode where PCP accumulated (36d), perhaps exacerbated by the greater toxicity of PCP at lower soil pH. There is little doubt that a better awareness of the interactions between soil electrokinetic processes and microbial communities is key to improving the efficacy and sustainability of this remediation strategy.