Developing antiepileptic drugs in children: balancing protection and access

Safety and efficacy of levetiracetam and carbamazepine monotherapy in the management of pediatric focal epilepsy: a randomized clinical trial

Due to the limited number of studies in children with focal epilepsy and the importance of choosing the most suitable drug to control seizures in children, the administration of the most effective medication with the most negligible adverse events is vital. This study aimed to evaluate the effectiveness and adverse events of carbamazepine vs. levetiracetam monotherapy in children with focal seizures. A monocentric, randomized, controlled, double-blind, parallel-group clinical trial was designed. This study was approved by the Iranian Registry of Clinical Trials (registration number: IRCT20170216032603N2) on June 19, 2020, and conducted at the neurology department of Imam Ali Hospital, Karaj, Iran, from February 2020 to March 2021. This study assessed 120 patients with recently diagnosed focal seizures aged 2 to 14. Patients were randomly divided into two groups, who received carbamazepine (CBZ) 15 to 20 mg/kg and levetiracetam (LEV) 20 to 40 mg/kg daily, respectively. Patients were evaluated for improvement and complications at weeks 4, 12, and 24. Out of 120 patients included in the study, six patients were excluded due to various complications of CBZ. The mean number of seizures at the end of the fourth, twelfth, and twenty-fourth weeks were 1.09 ± 0.75, 0.62 ± 0.27, and 0.39 ± 0.12 in the carbamazepine group and 1.11 ± 0.63, 0.52 ± 0.21, and 0.37 ± 0.11 in the LEV group, respectively (P > 0.05). Similarly, the number of seizure-free patients was 34, 44, and 48 in the CBZ group compared to 41, 50, and 54 in the LEV group, respectively (P > 0.05). On the other hand, the frequency of somnolence, dermatologic complications, and agitation was considerably higher in the CBZ group (P < 0.05). Although both medicines were equally effective in seizure control, CBZ was associated with considerably more adverse events and less patient compliance. Physicians should be aware of this difference to prevent unwanted consequences.

Sleep and epilepsy: unfortunate bedfellows

The relationship between sleep and seizure disorders is a particularly vicious cycle. Nocturnal seizures can interrupt sleep while a number of factors, including antiepileptics and sleep disorders that cause sleep fragmentation, can worsen seizures. Understanding and managing seizures and related sleep disturbance is therefore an important and treatable intervention target that could potentially improve children's sleep, but also their learning, mood, behaviour, seizures and parental quality of life.

A Review of the New Antiepileptic Drugs for Focal-Onset Seizures in Pediatrics: Role of Extrapolation

Most antiepileptic drugs (AEDs) receive regulatory approval for children years after the drug is available in adults, encouraging off-label use of the drug in children and hindering attempts to obtain quality pediatric data in controlled trials. Extrapolating adult efficacy data to pediatrics can reduce the time between approval in adults and that in children. To extrapolate efficacy from adults to children, several assumptions must be supported, such as (1) a similar disease progression and response to interventions in adults and children, and (2) similar exposure response in adults and children. The Pediatric Epilepsy Academic Consortium for Extrapolation (PEACE) addressed these assumptions in focal-onset seizures (FOS), the most common seizure type in both adults and children. PEACE reviewed the biological and clinical evidence that supported the assumptions that children with FOS have a similar disease progression and response to intervention as adults with FOS. After age 2 years, the pathophysiological underpinnings of FOS and the biological milieu in which seizures are initiated and propagated in children, seizure semiology, electroencephalographic features, etiology and AED response to FOS in children are similar to those in adults with FOS. PEACE concluded that extrapolation of efficacy data in adults to pediatrics in FOS is supported by strong scientific and clinical evidence. However, safety and pharmacokinetic (PK) data cannot be extrapolated from adults to children. Based on extrapolation, eslicarbazepine is now approved for children with FOS, down to age 4 years. Perampanel, lacosamide and brivaracetam are now undergoing PK and safety studies for the purposes of extrapolation down to age 2 or 4 years. When done in conjunction with PK and safety investigations in children, extrapolation of adult data from adults to children can reduce the time delay between approval of effective and safe AEDs in adults and approval in children.

Investigator-initiated randomized controlled trials in children with epilepsy: Mission impossible?

Objective

In children many antiepileptic drugs (AEDs) are prescribed off‐label due to a lack of well‐designed randomized controlled trials (RCTs). We conducted a multicenter RCT in the Netherlands to compare levetiracetam and valproic acid as monotherapy in children with newly diagnosed epilepsy. After 2 years, we had to stop this investigator‐initiated trial prematurely because the inclusion rate was too low. We analyzed the reasons for this failure, assessed the various issues involved in performing RCTs in children, and now give recommendations for future studies.

Methods

A questionnaire was completed by all investigators involved in the study. It included questions about the motivation to participate and the perceived reasons for recruitment failure. We also studied literature about financial, logistic, legal, and ethical aspects of RCTs in children.

Results

Main reasons for recruitment failure were overestimation of the number of eligible AED‐naive children referred by general pediatricians; personal preferences of investigators for specific antiepileptic drugs; and the extensive administrative load due to extra regulations and guidelines for children. Fundraising for investigator‐initiated trials is difficult and the majority of RCTs concerning AEDs are sponsored by pharmaceutical companies. Involving children requires balancing between protection and participation; the randomization procedure and obtaining informed consent are complex for both children and parents.

Significance

Performing RCTs with AEDs in children is important but complicated by logistic, regulatory, legal, and ethical restrictions. Based on our recent experience, our advice to colleagues who are planning a similar trial would be to perform a feasibility pilot study; to set up intensive collaboration with referring pediatricians; to arrange support of a clinical trials unit and a local research nurse during the complete trial period; and to incorporate the possibility of extending the recruitment period. Major investments, both financially from governmental organizations and in time, are imperative for independent RCTs in children.

Levetiracetam Monotherapy in Children with Epilepsy: A Systematic Review

BACKGROUND

Levetiracetam, a second-generation anti-epileptic drug (AED) with a good efficacy and safety profile, is licensed as monotherapy for adults and children older than 16 years with focal seizures with or without secondary generalization. However, it is increasingly being used off-label in younger children.

OBJECTIVES

We critically reviewed the available evidence and discuss the present status of levetiracetam monotherapy in children 0-16 years old.

DATA SOURCES

We systematically searched the literature using PubMed, Web of Science and Embase up to August 2014 for articles on levetiracetam monotherapy in children. Keywords were levetiracetam, monotherapy and child*. The titles and abstracts of 532 articles were evaluated by AW, of which 480 were excluded. The full texts of the other 52 articles were assessed for relevance.

RESULTS

We covered one review, one opinion statement and 32 studies in this review, including four randomized controlled trials, ten open-label prospective studies, eight retrospective studies, and ten case reports. The formal evidence for levetiracetam monotherapy in children is minimal: it is potentially efficacious or effective as initial monotherapy in children with benign epilepsy with centrotemporal spikes. In all of the published studies, however, efficacy and tolerability of levetiracetam seemed to be good and comparable to other AEDs.

CONCLUSION

The data of 32 studies on levetiracetam monotherapy in children were insufficient to confirm that levetiracetam is effective as initial monotherapy for different types of seizures and/or epilepsy syndromes. There is still an urgent need for well designed trials to justify the widespread use of levetiracetam monotherapy in children of all ages.