Network meta-analysis of antiepileptic drugs in focal drug-resistant epilepsy

A prospective, observational, multicentre study to evaluate the efficacy of brivaracetam as adjuvant therapy for epilepsy: The Bravo study

Background

Epilepsy is a persistent tendency to experience epileptic seizures and can lead to various neurobiological disorders, with an elevated risk of premature mortality. This study evaluates the efficacy of brivaracetam adjuvant therapy in patients with epilepsy.

Methods

A prospective observational multicentre study that was conducted in Pakistan from March to September 2022, by using a non-probability convenience sampling technique. The population consisted of 543 individuals with a diagnosis of epilepsy for whom adjunctive brivaracetam (Brivera; manufactured by Helix Pharma Pvt Ltd., Sindh, Pakistan) was recommended by the treating physician. The research sample was drawn from various private neurology clinics of Karachi, Lahore, Rawalpindi, Islamabad and Peshawar. Data originating from routine patient visits, and assessments at three study time points, were recorded in the study case report form.

Results

Across 18 clinical sites, 543 individuals participated, with a mean age of 32.9 years. The most prescribed dosages were 50 mg BD, followed by 100 mg BD. Notably, brivaracetam combined with divalproex sodium was the most prevalent treatment, followed by brivaracetam with levetiracetam. At both the 14th and 90th day assessments, a significant reduction in seizure frequency was observed, with 63.1% of individuals showing a favourable response by day 90. Treatment-naive individuals exhibited higher rates of seizure freedom and response compared with treatment-resistant individuals.

Conclusions

The study demonstrates the effectiveness of brivaracetam combination therapy in epilepsy management, with notable reductions in seizure frequency and favourable clinical responses observed, particularly in treatment-naive individuals.

Further advances in epilepsy

In 2017, one of us reviewed advances in epilepsy (Manford in J Neurol 264:1811-1824, 2017). The current paper brings that review up to date and gives a slight change in emphasis. Once again, the story is of evolution rather than revolution. In recognition that most of our current medications act on neurotransmitters or ion channels, and not on the underlying changes in connectivity and pathways, they have been renamed as antiseizure (ASM) medications rather than antiepileptic drugs. Cenobamate is the one newly licensed medication for broader use in focal epilepsy but there have been a number of developments for specific disorders. We review new players and look forward to new developments in the light of evolving underlying science. We look at teratogenicity; old villains and new concerns in which clinicians play a vital role in explaining and balancing the risks. Medical treatment of status epilepticus, long without evidence, has benefitted from high-quality trials to inform practice; like buses, several arriving at once. Surgical treatment continues to be refined with improvements in the pre-surgical evaluation of patients, especially with new imaging techniques. Alternatives including stereotactic radiotherapy have received further focus and targets for palliative stimulation techniques have grown in number. Individuals' autonomy and quality of life continue to be the subject of research with refinement of what clinicians can do to help persons with epilepsy (PWE) achieve control. This includes seizure management but extends to broader considerations of human empowerment, needs and desires, which may be aided by emerging technologies such as seizure detection devices. The role of specialist nurses in improving that quality has been reinforced by specific endorsement from the International League against Epilepsy (ILAE).

Clinical Outcome Data of Children Treated with Cannabis-Based Medicinal Products for Treatment Resistant Epilepsy - Analysis from the UK Medical Cannabis Registry

BACKGROUND

 There is a paucity of high-quality evidence of the efficacy and safety of cannabis-based medicinal products in treatment of treatment-resistant epilepsy (TRE) in children.

METHODS

 A case series of children (<18 years old) with TRE from the UK Medical Cannabis Registry was analyzed. Primary outcomes were ≥50% reduction in seizure frequency, changes in the Impact of Pediatric Epilepsy Score (IPES), and incidence of adverse events.

RESULTS

 Thirty-five patients were included in the analysis. Patients were prescribed during their treatment with the following: CBD isolate oils (n = 19), CBD broad-spectrum oils (n = 17), and CBD/Δ⁹-THC combination therapy (n = 17). Twenty-three (65.7%) patients achieved a ≥50% reduction in seizure frequency. 94.1% (n = 16) of patients treated with CBD and Δ⁹-THC observed a ≥50% reduction in seizure frequency compared to 31.6% (n = 6) and 17.6% (n = 3) of patients treated with CBD isolates and broad-spectrum CBD products, respectively (p< 0.001). Twenty-six (74.3%) adverse events were reported by 16 patients (45.7%). The majority of these were mild (n = 12; 34.2%) and moderate (n = 10; 28.6%).

CONCLUSION

 The results of this study demonstrate a positive signal of improved seizure frequency in children treated with Cannabis-based medicinal products (CBMPs) for TRE. Moreover, the results suggest that CBMPs are well-tolerated in the short term. The limitations mean causation cannot be determined in this open-label, case series.

Comparative Efficacy and Safety of Lacosamide and Oxcarbazepine for Seizure Control in Children with Newly Diagnosed Solitary Neurocysticercosis

BACKGROUND

In newly diagnosed neurocysticercosis (NCC) with seizures, the choice of anti-seizure medication (ASM) seems to be arbitrary due to a lack of comparative studies. Although oxcarbazepine (OXC) is often considered efficacious for focal seizures in NCC, due to adverse effects, newer ASMs like levetiracetam (LCM) and lacosamide are also being explored.

METHODS

This study was performed by case record review of children with newly diagnosed solitary viable parenchymal NCC aged 4-18years who received lacosamide and OXC at least for 12 weeks between August 2019 and April 2021, from a prospective registry of a tertiary care teaching hospital in north India. Seizure control, electroencephalographic abnormalities, resolution of inflammatory granulomas and adverse effects were compared between two arms at 12 and 24 weeks.

RESULTS

Total 31 (8.3 ± 4.7 years, 19 boys) and 72 (8.6 ± 4.2 years, 43 boys) completed at least 12 weeks follow-up in LCM and OXC groups, out of which 2 and 51 completed at least 24 weeks follow-up in LCM and OXC groups, respectively. The occurrence of breakthrough seizure was comparable in both arms at 12 and 24 weeks (1/31 and 2/22 in lacosamide group vs. 2/72 and 4/51 in OXC group, p = 0.66 and 0.59, respectively). Patients receiving OXC had more frequent treatment-emergent adverse events (p = 0.0001) and four patients required discontinuation due to severe adverse events (SAEs), while none in the lacosamide group had SAEs.

CONCLUSIONS

Lacosamide appears to be efficacious and safe for achieving seizure freedom in patients with solitary viable parenchymal neurocysticercosis.

Pregabalin add-on for drug-resistant focal epilepsy

BACKGROUND

This is an updated version of the Cochrane Review last published in Issue 7, 2019; it includes two additional studies. Epilepsy is a common neurological disease that affects approximately 1% of the UK population. Approximately one-third of these people continue to have seizures despite drug treatment. Pregabalin is one of the newer antiepileptic drugs that has been developed to improve outcomes. In this review we summarised the current evidence regarding pregabalin when used as an add-on treatment for drug-resistant focal epilepsy.

OBJECTIVES

To assess the efficacy and tolerability of pregabalin when used as an add-on treatment for drug-resistant focal epilepsy.

SEARCH METHODS

For the latest update we searched the following databases on 16 November 2020: Cochrane Register of Studies (CRS Web), and MEDLINE (Ovid, 1946 to 16 November 2020). CRS Web includes randomised or quasi-randomised, controlled trials from PubMed, Embase, ClinicalTrials.gov, the World Health Organisation International Clinical Trials Registry Platform (ICTRP), the Cochrane Central Register of Controlled Trials (CENTRAL), and the Specialised Registers of Cochrane Review Groups, including Epilepsy. We imposed no language restrictions. We contacted the manufacturers of pregabalin and authors in the field to identify any relevant unpublished studies.

SELECTION CRITERIA

We included randomised controlled trials comparing pregabalin with placebo or an alternative antiepileptic drug as an add-on for people of any age with drug-resistant focal epilepsy. Double-blind and single-blind trials were eligible for inclusion. The primary outcome was 50% or greater reduction in seizure frequency; secondary outcomes were seizure freedom, treatment withdrawal for any reason, treatment withdrawal due to adverse effects, and proportion of individuals experiencing adverse effects.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion and extracted the relevant data. Primary analyses were intention-to-treat (ITT). We presented summary risk ratios (RRs) and odds ratios (ORs) 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

We included 11 randomised controlled trials (3949 participants). Nine trials compared pregabalin to placebo. For the primary outcome, participants randomised to pregabalin were significantly more likely to attain a 50% or greater reduction in seizure frequency compared to placebo (RR 1.95, 95% CI 1.40 to 2.72, 9 trials, 2663 participants, low-certainty evidence). The odds of response doubled with an increase in dose from 300 mg/day to 600 mg/day (OR 1.99, 95% CI 1.74 to 2.28), indicating a dose-response relationship. Pregabalin was significantly associated with seizure freedom (RR 3.94, 95% CI 1.50 to 10.37, 4 trials, 1125 participants, moderate-certainty evidence). Participants were significantly more likely to withdraw from pregabalin treatment than placebo for any reason (RR 1.33, 95% CI 1.10 to 1.60; 9 trials, 2663 participants; moderate-certainty evidence) and for adverse effects (RR 2.60, 95% CI 1.86 to 3.64; 9 trials, 2663 participants; moderate-certainty evidence). Three trials compared pregabalin to three active-control drugs: lamotrigine, eventrate and gabapentin. Participants allocated to pregabalin were significantly more likely to achieve a 50% or greater reduction in seizure frequency than those allocated to lamotrigine (RR 1.47, 95% CI 1.03 to 2.12; 1 trial, 293 participants) but not those allocated to eventrate (RR 0.94, 95% CI 0.80 to 1.11; 1 trial, 509 participants) or gabapentin (RR 0.96, 95% CI 0.82 to 1.12; 1 trial, 484 participants). We found no significant differences between pregabalin and lamotrigine for seizure freedom (RR 1.39, 95% CI 0.40 to 4.83). However, significantly fewer participants achieved seizure freedom with add-on pregabalin compared to eventrate (RR 0.50, 95% CI 0.30 to 0.85). No data were reported for this outcome for pregabalin versus gabapentin. We detected no significant differences in treatment withdrawal rate for any reason or due to adverse effects, specifically, during either pooled analysis or subgroup analysis. Ataxia, dizziness, somnolence, weight gain, headache and fatigue were significantly associated with pregabalin than in active control. We rated the overall risk of bias in the included studies as low or unclear due to the possibility of publication bias and lack of methodological details provided. We assessed all the studies to be at a high risk of funding bias as they were all sponsored by Pfizer. We rated the certainty of the evidence as very low to moderate using the GRADE approach.

AUTHORS' CONCLUSIONS

For people with drug-resistant focal epilepsy, pregabalin when used as an add-on treatment was significantly more effective than placebo at producing a 50% or greater seizure reduction and seizure freedom. Results demonstrated efficacy for doses from 150 mg/day to 600 mg/day, with increasing effectiveness at 600 mg doses, although there were issues with tolerability at higher doses. However, the trials included in this review were of short duration, and longer-term trials are needed to inform clinical decision-making. This review focused on the use of pregabalin 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 pregabalin when used as monotherapy.

The ups and downs of alkyl-carbamates in epilepsy therapy: How does cenobamate differ?

Since 1955, several alkyl-carbamates have been developed for the treatment of anxiety and epilepsy, including meprobamate, flupirtine, felbamate, retigabine, carisbamate, and cenobamate. They have each enjoyed varying levels of success as antiseizure drugs; however, they have all been plagued by the emergence of serious and sometimes life-threatening adverse events. In this review, we compare and contrast their predominant molecular mechanisms of action, their antiseizure profile, and where possible, their clinical efficacy. The preclinical, clinical, and mechanistic profile of the prototypical γ-aminobutyric acidergic (GABAergic) modulator phenobarbital is included for comparison. Like phenobarbital, all of the clinically approved alkyl-carbamates share an ability to enhance inhibitory neurotransmission through modulation of the GABA_A receptor, although the specific mechanism of interaction differs among the different drugs discussed. In addition, several alkyl-carbamates have been shown to interact with voltage-gated ion channels. Flupirtine and retigabine share an ability to activate K⁺ currents mediated by KCNQ (Kv7) K⁺ channels, and felbamate, carisbamate, and cenobamate have been shown to block Na⁺ channels. In contrast to other alkyl-carbamates, cenobamate seems to be unique in its ability to preferentially attenuate the persistent rather than transient Na⁺ current. Results from recent randomized controlled clinical trials with cenobamate suggest that this newest antiseizure alkyl-carbamate possesses a degree of efficacy not witnessed since felbamate was approved in 1993. Given that ceno-bamate's mechanistic profile is unique among the alkyl-carbamates, it is not clear whether this impressive efficacy reflects an as yet undescribed mechanism of action or whether it possesses a unique synergy between its actions at the GABA_A receptor and on persistent Na⁺ currents. The high efficacy of cenobamate is, however, tempered by the risk of serious rash and low tolerability at higher doses, meaning that further safety studies and clinical experience are needed to determine the true clinical value of cenobamate.