Comparative short-term efficacy and safety of add-on anti-seizure medications in Dravet syndrome: An indirect treatment comparison

Update on Cannabidiol in Drug-Resistant Epilepsy

Cannabidiol (CBD) has arisen as a promising therapeutic option for children with drug-resistant epilepsy (DRE). CBD has received regulatory nod from different regulatory authorities in the United States, Europe, and India for children with DRE particularly, Dravet syndrome (DS), Lennox Gastaut syndrome (LGS), and Tuberous sclerosis complex (TSC). Recent clinical trials and observational studies highlight the potential of CBD to lower seizure frequency and provide better quality of life in children affected by these disorders. The safety profile is generally favorable with minor common adverse events such as somnolence, diarrhea, and gastrointestinal issues. Furthermore, the expense associated with CBD remains a notable concern, especially in low- and middle-income countries such as India, where access to this promising treatment may be constrained. This draws attention to the cost-effective perspective of CBD. This review aims to explore the pharmacological properties of CBD, its mechanisms of action, and the clinical evidence supporting its use in various pediatric epilepsies, including LGS, DS, and TSC. Additionally, this review sheds light on the current regulatory landscape in India where CBD use is still in its nascent stages, and discusses the challenges and opportunities for integrating CBD into clinical practice.

A comprehensive review of evolving treatment strategies for Dravet syndrome: Insights from randomized trials, meta-analyses, real-world evidence, and emerging therapeutic approaches

Dravet syndrome (DS) is a severe genetic developmental and epileptic encephalopathy, primarily caused by SCN1A gene mutations. Historically, treatments like clobazam and valproate have been used without evidence from randomized controlled trials (RCTs). However, the therapeutic landscape of DS has evolved with multiple RCTs demonstrating the efficacy and safety of three antiseizure medications (ASMs): stiripentol, cannabidiol (CBD), and fenfluramine. In the absence of direct comparisons between these therapies, several network meta-analyses have been conducted to compare the ASMs, while expert consensus has independently been developed to formulate treatment guidelines. While these three ASMs show promise in reducing seizures, increasing awareness of non-seizure outcomes-such as cognitive development and quality of life-has shifted the focus of evaluation. Some recent real-world studies of these ASMs have reported improvements in these non-seizure outcomes, alongside sustained efficacy and safety. However, natural history studies continue to underscore persistent deficits in these areas and highlight suboptimal long-term seizure control despite the use of these therapies. This review addresses these gaps by first discussing network meta-analyses and treatment guidelines, along with the practical limitations of these approaches. It then examines the long-term efficacy, safety, non-seizure effects, and cost-effectiveness from real-world studies of these ASMs. Finally, emerging research on novel therapeutic approaches, including genetic and serotonergic modulation, is explored. By evaluating these developments, this review aims to guide clinical decision-making and propose future directions for optimizing DS care.

Use of Stiripentol in Dravet Syndrome: A Guide for Clinicians

Dravet syndrome is a developmental and epileptic encephalopathy characterized by frequent, prolonged convulsive seizures and status epilepticus. Symptoms usually appear in the first year of life, and in addition to ongoing severe and intractable epilepsy, children with Dravet syndrome experience neurodevelopmental, behavioral, and motor impairments, along with high rates of mortality, especially in the first 12 years of life. Prompt diagnosis and initiation of treatment with broad-spectrum antiseizure medications are recommended to reduce seizure frequency and status epilepticus, and to potentially minimize the comorbidities associated with the epileptic encephalopathy. Stiripentol is an antiseizure medication approved for adjunctive use in Dravet syndrome in patients aged as young as six months. Data from randomized clinical trials and real-world studies demonstrate that stiripentol added to first-line therapy with clobazam and/or valproate is associated with high rates of seizure control, including freedom from status epilepticus, for extended periods of time including into adulthood. Stiripentol has multiple mechanisms of action and also inhibits several metabolic drug-metabolizing enzymes that can enhance the efficacy of coadministered antiseizure medications. Stiripentol is well tolerated, and treatment-emergent adverse events can often be managed by dose adjustments of comedications. This review updates the use of stiripentol in the modern era.

First-choice hormonal therapies for children with infantile epileptic spasms syndrome in South Asia: A network meta-analysis of randomized controlled trials

Considering the peculiar challenges with infantile epileptic spasms syndrome (IESS) in South Asia and a wide variation in the usage of hormonal therapies, we compared the efficacy and safety of various hormonal therapies for children with IESS in South Asia. We searched PubMed, Embase, Scopus, and Web of Science databases from the inception until April 2024. We included only randomized clinical trials (RCTs) evaluating the efficacy and safety of hormonal therapies for IESS in the South Asian region. Complete cessation of epileptic spasms (ES), electro-clinical response, and time taken to be spasm-free at 2 or 6 weeks of therapy were efficacy outcomes, while the occurrence of adverse events was the safety outcome. Effect estimates were reported as odds ratio (OR) or mean difference (MD) with 95% confidence intervals (CI) and Cochrane risk of bias 2.0 (ROB 2.0) used for quality assessment of each study. The surface under the cumulative ranking curve (SUCRA) was used to rank the different therapies and reported as a p-score ranging from 0 to 1. Of 747 citations, nine RCTs comprising 566 children with IESS were included. After 2-week treatment, dexamethasone (OR: 6.72; 95% CI: 1.47, 30.72), adrenocorticotropic hormone therapy (ACTH) high dose (HD) (OR: 5.30; 95% CI: 1.05, 26.91), and prednisolone HD (OR: 2.41; 95% CI:1.07, 5.46) had shown significantly greater efficacy for cessation of EScompared with ACTH low dose (LD). Similarly, for electroclinical response, dexamethasone (OR: 9.63; 95% CI: 1.99, 46.70) and prednisolone HD (OR: 3.46; 95% CI: 1.38, 8.68) had greater efficacy compared with ACTH LD. Safety outcomes revealed that hypertension was significantly less common with ACTH LD and prednisolone HD as compared with ACTH HD. This study provides quality evidence on preferred first-choice hormonal therapy for managing IESS in South Asia. ACTH HD, dexamethasone, and prednisolone HD are the most effective hormonal therapy options with dose-dependent therapeutic efficacy. PLAIN LANGUAGE SUMMARY: This study provides insights into the selection of first-line hormonal therapies among the various treatments for managing infantile epileptic spasms syndrome (IESS) in South Asia. The study findings suggested that the effectiveness of these therapies is dose-dependent, with high doses of ACTH, dexamethasone, and prednisolone being the most effective for achieving cessation of epileptic spasms.

Evaluation of burden of SCN1A pathogenicity in North Indian children with Dravet syndrome

BACKGROUND

Dravet syndrome is an infantile-onset developmental and epileptic encephalopathy with limited data on the frequency of SCN1A in Indian children. The study aimed to identify and characterize the burden of SCN1A pathogenic variants associated with the Dravet syndrome phenotype through genetic testing in the North Indian population.

METHOD

In this prospective, cross-sectional study from March 2015 to February 2019, we enrolled 52 children with Dravet syndrome phenotype who underwent genetic testing for SCN1A gene pathogenicity. We assessed variant effect using multiple algorithms, and genetic test results were reported based on recommendations from the American College of Medical Genetics and Genomics guidelines. Additionally, we performed multiplex-ligation dependent probe amplification (MLPA) to detect copy number variations of the SCN1A gene in children without identified genetic pathogenicity (n = 22) and analysed the results using Coffalyser.net.

RESULTS

Of the 52 probands studied, pathogenic variants in the SCN1A gene were identified in 30 children. Among these variants, 11 truncating variants (3 frame-shift variants, 3 intronic variants in splice site regions, and 5 nonsense variants) in 12 unrelated probands, and 17 missense variants in 18 unrelated probands were found. The genetic yield of SCN1A pathogenicity in our cohort (n = 52) was 58 %. Additionally, two of the identified variants were novel. Furthermore, MLPA analysis of the SCN1A gene in 22 children without pathogenic variants yielded no results.

CONCLUSION

This work represents a genetic analysis of a Dravet syndrome cohort, revealing a 58 % burden of SCN1A variants in children with the Dravet syndrome phenotype from the North Indian population.

Practical considerations for the use of fenfluramine to manage patients with Dravet syndrome or Lennox-Gastaut syndrome in clinical practice

Fenfluramine (FFA), an antiseizure medication (ASM) with serotonergic and sigma-1 receptor activity, is used to manage patients with developmental and epileptic encephalopathies (DEEs). It is approved in the US for treating seizures associated with Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS) in patients ≥2 years old and as add-on therapy for seizures associated with DS and LGS in the EU, UK, and Japan in similarly aged patients. Consensus guidelines for treatment of DS have recommended FFA to be an early-line ASM, and it has also shown efficacy in managing seizures associated with LGS. DS and LGS are DEEs associated with a range of seizure types, developmental impairments, and multiple comorbidities. Here we provide case vignettes describing 4 patients (3 DS and 1 LGS) aged 4-29 years old in whom up to 14 ASMs had previously failed, to illustrate real-world practice issues encountered by neurologists. This review provides guidance on the use of FFA in the context of ASM polytherapy and drug-drug interactions (DDIs), behavioral issues, dose titration, and adverse events. Along with data from the clinical trial program, these case vignettes emphasize the low risk of DDIs, a generally well-tolerated safety profile, and other seizure and nonseizure benefits (eg, improved cognition and sleep) associated with the use of FFA in DS or LGS. PLAIN LANGUAGE SUMMARY: Fenfluramine is used to treat seizures in individuals with Dravet syndrome and Lennox-Gastaut syndrome, but there are a range of issues that clinicians may face when treating patients. This review highlights four patients from the authors' everyday clinical work and offers guidance and practical considerations by neurologists with expertise in managing these complex conditions related to drug interactions, dosing, and side effects associated with fenfluramine.

Utilizing an acute hyperthermia-induced seizure test and pharmacokinetic studies to establish optimal dosing regimens in a mouse model of Dravet syndrome

OBJECTIVE

The current standard of care for Dravet syndrome (DS) includes polytherapy after inadequate seizure control with one or more monotherapy approaches. Treatment guidelines are often based on expert opinions, and finding an optimal balance between seizure control and adverse drug effects can be challenging. This study utilizes the efficacy and pharmacokinetic assessment of a second-line treatment regimen that combines clobazam and sodium valproate with an add-on drug as a proof-of-principle approach to establish an effective therapeutic regimen in a DS mouse model.

METHODS

We evaluated the efficacy of add-on therapies stiripentol, cannabidiol, lorcaserin, or fenfluramine added to clobazam and sodium valproate against hyperthermia-induced seizures in Scn1aA1783V/WT mice. Clobazam, N-desmethyl clobazam (an active metabolite of clobazam), sodium valproate, stiripentol, and cannabidiol concentrations were quantified in plasma and brain using liquid chromatography-tandem mass spectrometry for the combinations deemed effective against hyperthermia-induced seizures. The concentration data were used to calculate pharmacokinetic parameters via noncompartmental analysis in Phoenix WinNonLin.

RESULTS

Higher doses of stiripentol or cannabidiol, in combination with clobazam and sodium valproate, were effective against hyperthermia-induced seizures in Scn1aA1783V/WT mice. In Scn1aWT/WT mice, brain clobazam and N-desmethyl clobazam concentrations were higher in the triple-drug combinations than in the clobazam monotherapy. Stiripentol and cannabidiol brain concentrations were greater in the triple-drug therapy than when given alone.

SIGNIFICANCE

A polypharmacy strategy may be a practical preclinical approach to identifying efficacious compounds for DS. The drug-drug interactions between compounds used in this study may explain the potentiated efficacy of some polytherapies.

Comprehensive scoping review of fenfluramine's role in managing generalized tonic-clonic seizures in developmental and epileptic encephalopathies

Developmental and epileptic encephalopathies (DEEs) are characterized by pharmacoresistant seizures and developmental delay. Patients with DEEs experience multiple seizure types, including tonic-clonic seizures (TCS) that can be generalized tonic-clonic (GTCS) or focal evolving to bilateral tonic-clonic (FBTCS). Fenfluramine (FFA) has demonstrated efficacy in reduction of TCS in patients with Dravet syndrome (DS), Lennox-Gastaut syndrome (LGS), and other DEEs. Using the PRISMA-ScR (Preferred Reporting Items for Systematic Review and Meta-Analyses extension for Scoping Review) guidelines, we performed a scoping review to describe changes in TCS in patients treated with FFA. A comprehensive search of five literature databases was conducted up to February 14, 2023. Studies were included if they reported change in GTCS or TCS (but not FBTCS) after treatment with FFA in patients with DEEs. Duplicate patients and studies with unclear efficacy data were excluded. Fourteen of 422 studies met the eligibility criteria. Data extracted and evaluated by expert clinicians identified 421 unique patients with DS (in nine studies), CDKL5 deficiency disorder, SCN8A-related disorder, LGS, SCN1B-related disorder, and other DEEs. The median percent reduction in GTCS or TCS from baseline was available in 10 studies (n = 328) and ranged from 47.2% to 100%. Following FFA treatment, 10 studies (n = 144) reported ≥50% reduction in GTCS or TCS from baseline in 72% of patients; in nine of those (n = 112), 54% and 29% of patients achieved ≥75% and 100% reduction in GTCS or TCS from baseline, respectively. Overall, this analysis highlighted improvements in GTCS or TCS frequency when patients were treated with FFA regardless of the DEE evaluated. Future studies may confirm the impact of FFA on TCS reduction and on decreased premature mortality risk (including sudden unexpected death in epilepsy), improvement in comorbidities and everyday executive function, decreased health care costs, and improvement in quality of life.

Comparative efficacy and safety of stiripentol, cannabidiol and fenfluramine as first-line add-on therapies for seizures in Dravet syndrome: A network meta-analysis

OBJECTIVES

Stiripentol, fenfluramine, and cannabidiol are licensed add-on therapies to treat seizures in Dravet Syndrome (DS). There are no direct or indirect comparisons assessing their full licensed dose regimens, across different jurisdictions, as first-line add-on therapies in DS.

METHODS

We conducted a systematic review and frequentist network meta-analysis (NMA) of randomized controlled trial (RCT) data for licensed add-on DS therapies. We compared the proportions of patients experiencing: reductions from baseline in monthly convulsive seizure frequency (MCSF) of ≥50% (clinically meaningful), ≥75% (profound), and 100% (seizure-free); serious adverse events (SAEs); discontinuations due to AEs.

RESULTS

We identified relevant data from two placebo-controlled RCTs for each drug. Stiripentol 50 mg/kg/day and fenfluramine 0.7 mg/kg/day had similar efficacy in achieving ≥50% (clinically meaningful) and ≥75% (profound) reductions from baseline in MCSF (absolute risk difference [RD] for stiripentol versus fenfluramine 1% [95% confidence interval: -20% to 22%; p = 0.93] and 6% [-15% to 27%; p = 0.59], respectively), and both were statistically superior (p < 0.05) to licensed dose regimens of cannabidiol (10 or 20 mg/kg/day, with/irrespective of clobazam) for these outcomes. Stiripentol was statistically superior in achieving seizure-free intervals compared to fenfluramine (RD = 26% [CI: 8% to 44%; p < 0.01]) and licensed dose regimens of cannabidiol. There were no significant differences in the proportions of patients experiencing SAEs. The risk of discontinuations due to AEs was lower for stiripentol, although the stiripentol trials were shorter.

SIGNIFICANCE

This NMA of RCT data indicates stiripentol, as a first-line add-on therapy in DS, is at least as effective as fenfluramine and both are more effective than cannabidiol in reducing convulsive seizures. No significant difference in the incidence of SAEs between the three add-on agents was observed, but stiripentol may have a lower risk of discontinuations due to AEs. These results may inform clinical decision-making and the continued development of guidelines for the treatment of people with DS.

PLAIN LANGUAGE SUMMARY

This study compared three drugs (stiripentol, fenfluramine, and cannabidiol) used alongside other medications for managing seizures in a severe type of epilepsy called DS. The study found that stiripentol and fenfluramine were similarly effective in reducing seizures and both were more effective than cannabidiol. Stiripentol was the best drug for stopping seizures completely based on the available clinical trial data. All three drugs had similar rates of serious side effects, but stiripentol had a lower chance of being stopped due to side effects. This information can help guide treatment choices for people with DS.

Fenfluramine: A Review in Dravet and Lennox-Gastaut Syndromes

Fenfluramine (Fintepla®) is an oral anti-seizure medication (ASM) with a novel mechanism of action consisting of activity in the serotonergic system coupled with positive allosteric modulation effects at sigma-1 receptors. Originally approved for use at high doses as an appetite suppressant, it was subsequently withdrawn after being linked to valvular heart disease (VHD) and pulmonary arterial hypertension (PAH), before being investigated for use at low doses as an adjunctive ASM in patients with developmental epileptic encephalopathies, including Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS) who have pharmacoresistant seizures. In clinical trials, treatment with adjunctive fenfluramine markedly reduced convulsive seizure frequency in patients with DS that were sustained for up to 3 years, and reduced drop seizure frequency in patients with LGS that were sustained for up to 1 year. Notably, fenfluramine was also associated with clinically meaningful improvements in aspects of everyday executive functioning (EF) not entirely explainable by seizure reduction alone. Furthermore, it was generally well tolerated with, importantly, no reports of VHD or PAH. Thus, adjunctive fenfluramine is a novel and effective treatment for pharmacoresistant seizures associated with DS and LGS that may also improve aspects of everyday EF in some patients.

Efficacy and Safety of Dietary Therapies for Childhood Drug-Resistant Epilepsy: A Systematic Review and Network Meta-analysis

Importance

Despite advances in the understanding of dietary therapies in children with drug-resistant epilepsy, no quantitative comparison exists between different dietary interventions.

Objective

To evaluate the comparative efficacy and safety of various dietary therapies in childhood drug-resistant epilepsy.

Data Sources

Systematic review and network meta-analysis (frequentist) of studies in PubMed, Embase, Cochrane, and Ovid published from inception to April 2022 using the search terms ketogenic diet, medium chain triglyceride diet, modified Atkins diet, low glycemic index therapy, and refractory epilepsy.

Study Selection

Randomized clinical trials comparing different dietary therapies (ketogenic diet, modified Atkins diet, and low glycemic index therapy) with each other or care as usual in childhood drug-resistant epilepsy were included. Abstract, title, and full text were screened independently by 2 reviewers.

Data Extraction and Synthesis

Data extraction was conducted following Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline. Cochrane risk-of-bias tool was used to assess the study quality. Effect sizes were calculated as odds ratio with 95% CI using random-effects model. The hierarchy of competing interventions was defined using the surface under the cumulative ranking curve.

Main Outcomes and Measures

Short-term (≤3 months) 50% or higher and 90% or higher reduction in seizure frequency and treatment withdrawal due to adverse events were the primary efficacy and safety outcomes.

Results

Of 2158 citations, 12 randomized clinical trials (907 patients) qualified for inclusion. In the short term, all dietary interventions were more efficacious than care as usual for 50% or higher seizure reduction (low glycemic index therapy: odds ratio [OR], 24.7 [95% CI, 5.3-115.4]; modified Atkins diet: OR, 11.3 [95% CI, 5.1-25.1]; ketogenic diet: OR, 8.6 [95% CI, 3.7-20.0]), while ketogenic diet (OR, 6.5 [95% CI, 2.3-18.0]) and modified Atkins diet (OR, 5.1 [95% CI, 2.2-12.0]) were better than care as usual for seizure reduction of 90% or higher. However, adverse event-related discontinuation rates were significantly higher for ketogenic diet (OR, 8.6 [95% CI, 1.8-40.6]) and modified Atkins diet (OR, 6.5 [95% CI, 1.4-31.2]) compared with care as usual. Indirectly, there was no significant difference between dietary therapies in efficacy and safety outcomes.

Conclusions and Relevance

This study found that all dietary therapies are effective in the short term. However, modified Atkins diet had better tolerability, higher probability for 50% or higher seizure reduction, and comparable probability for 90% or higher seizure reduction and may be a sounder option than ketogenic diet. Direct head-to-head comparison studies are needed to confirm these findings.

Efficacy and safety of adjunctive antiseizure medications for dravet syndrome: A systematic review and network meta-analysis

Purpose: Recently, the U.S. Food and Drug Administration (FDA) approved stiripentol, cannabidiol, and fenfluramine to treat patients with Dravet syndrome (DS). Moreover, soticlestat was determined as a promising new drug for the treatment of DS as it has good efficacy and safety. However, the efficacy and safety of these drugs have not yet been evaluated in "head-to-head" trials. This study aimed to compare and evaluate the efficacy and safety of these adjunctive antiseizure medications in the treatment of DS. Methods: We searched in PubMed, Embase, Cochrane Library, and Web of Science databases for randomized controlled trials (RCTs) and open-label extension (OLE) studies in patients with DS. We performed a random-effect meta-analysis of OLE studies and a network meta-analysis for RCTs to evaluate the efficacy and safety of antiseizure medications in the treatment of DS. Primary efficacy outcomes were defined as a ≥50% reduction in seizure frequency compared with baseline. Furthermore, safety evaluation indicators were defined as the incidence of adverse events (AEs) and serious adverse events (SAEs) during treatment. Relative ranking was assessed using the surface under the cumulative ranking curve (SUCRA) probabilities. Results: Seven RCTs involving four antiseizure medications (stiripentol, cannabidiol, fenfluramine, and soticlestat) and a total of 634 patients were included in the analysis. According to the SUCRA results, all four drugs significantly reduced the frequency of seizures compared with the placebo. Soticlestat was the most likely to reduce seizure frequency by ≥50% compared to the baseline [risk ratio (RR): 19.32; 95% confidence interval (CI): 1.20-311.40], followed by stiripentol and fenfluramine. Stiripentol was ranked highest for the near percentage reduction in the seizure rate from baseline [RR: 12.33; 95% CI: 1.71-89.17] and the occurrence of any treatment-emergent adverse events [RR: 3.73; 95% CI: 1.65-8.43] and serious adverse events [RR: 4.76; 95% CI: 0.61-37.28]. A total of ten OLE studies containing 1,121 patients were included in our study. According to the results of the meta-analysis, the order of probability of reducing seizure frequency by ≥50% was fenfluramine (0.715, 95% CI: 0.621-0.808), stiripentol (0.604, 95% CI: 0.502-0.706), cannabidiol (0.448, 95% CI: 0.403-0.493). And the probability of occurrence of AEs is ranked as fenfluramine(0.832, 95% CI: 0.795-0.869), cannabidiol (0.825, 95% CI:0.701-0.950), stiripentol (0.823, 95% CI: 0.707-0.938), soticlestat (0.688, 95% CI: 0.413-0.890). Conclusion: According to the results of indirect comparison of efficacy and safety, cannabidiol is slightly inferior to the other three antiseizure medications in terms of efficacy and safety. Soticlestat, fenfluramine, and stripentol may have little difference in efficacy, but soticlestat and fenfluramine are safer. Soticlestat is probably the best adjunctive antiseizure medication, followed by fenfluramine. This conclusion is consistent with the comparison of long-term efficacy and safety.

Short-term and long-term efficacy and safety of antiseizure medications in Lennox Gastaut syndrome: A network meta-analysis

PURPOSE

To assess the short-term and long-term comparative efficacy and safety of ASMs for Lennox-Gastaut syndrome (LGS).

METHODS

Following a systematic literature search, randomized controlled trial (RCT) and open-label extension (OLE) studies on LGS comparing ASMs with placebo or other ASMs were included. ≥50% reduction in drop seizure frequency from baseline and occurrence of treatment-emergent adverse events (TEAEs) were the primary efficacy and safety outcomes. For short-term outcomes, a network meta-analysis (NMA) reporting odds ratio (OR) with 95% confidence intervals (CIs) and hierarchy of competing interventions [surface under the cumulative ranking curve(SUCRA)] was done. Long-term outcomes were reported as proportion with 95% CIs using the random-effects model.

RESULTS

Fifteen studies including 1263 participants with LGS (aged 2-54years) receiving any of six ASMs [cannabidiol (CBD), clobazam (CLB), felbamate (FLB), lamotrigine (LTG), rufinamide (RFM), topiramate (TPM)] or placebo were included. High-dose CLB (1.0 mg/kg/day; CLB_H) [OR: 4.9; 95% CI: 2.3-10.8] was significantly associated with ≥50% reduction in drop seizure frequency as compared with placebo, and achieved the highest-ranking probability (0.89) based on SUCRA values (although there was an overlap between confidence intervals of effect sizes of CLB, RFM and CBD), while high-dose CBD (20 mg/kg/day; CBD_H) [OR: 3.8; 95% CI:1.6-9.0] had significantly higher odds for occurrence of any TEAEs and had the highest-ranking probability (0.85). Furthermore, the long-term treatment with CLB [78%; 95% CI: 70-85%] was associated with a significantly higher proportion of patients with reduction in drop-seizures, and long-term use of CBD [96%; 95% CI: 95-98%] was associated with a higher frequency of TEAEs.

CONCLUSION

The study findings suggest that CLB_H, CBD and RFM are the most efficacious and safest in terms of both short and long-term outcomes with CLB_H probably leading the hierarchy. Future head-to-head trials comparing these ASMs are needed.

1,3-Benzodioxole Derivatives Improve the Anti-Tumor Efficiency of Arsenicals

Arsenicals have been widely used in the treatment of cancers such as leukemia and other tumors. However, their side effects limit their clinical application. Stiripentol, a second-line adjunctive treatment for epilepsy with a good safety profile, inhibits microsomal cytochrome-P450-family enzymes to extend the retention time of co-administration. Inspired by the metabolism of stiripentol, the 1,3-benzodioxole responsible for the inhibition and its metabolic derivatives were conjugated with arsenical precursors. The fabricated arsenicals were eliminated much slower in mice and maintained an efficient concentration in the blood for a longer time than that of the arsenical precursors. They also performed better in anti-proliferation by inhibiting the thioredoxin system to induce oxidative stress, and concomitantly to initiate apoptosis in vitro and in vivo. The fabricated arsenicals reversed the hemogram of tumor-bearing mice to normal and eliminated the tumor without causing damage to any organs, exhibiting a good design strategy and pre-clinical application for leukemia and other tumors.

Serotonin receptors in epilepsy: novel treatment targets?

Despite the availability of over 30 antiseizure medications (ASMs), there is no “one size fits it all,” so there is a continuing search for novel ASMs. There are divergent data demonstrating that modulation of distinct serotonin (5‐hydroxytryptamine, 5‐HT) receptors subtypes could be beneficial in the treatment of epilepsy and its comorbidities, whereas only a few ASM, such as fenfluramine (FA), act via 5‐HT. There are 14 different 5‐HT receptor subtypes, and most epilepsy studies focus on one or a few of these subtypes, using different animal models and different ligands. We reviewed the available evidence of each 5‐HT receptor subtype using MEDLINE up to July 2021. Our search included medical subject heading (MeSH) and free terms of each “5‐HT subtype” separately and its relation to “epilepsy or seizures.” Most research underlines the antiseizure activity of 5‐HT_{1A,1D,2A,2C,3} agonism and 5‐HT₆ antagonism. Consistently, FA, which has recently been approved for the treatment of seizures in Dravet syndrome, is an agonist of 5‐HT_1D,2A,2C receptors. Even though each study focused on a distinct seizure/epilepsy type and generalization of different findings could lead to false interpretations, we believe that the available preclinical and clinical studies emphasize the role of serotonergic modulation, especially stimulation, as a promising avenue in epilepsy treatment.