Treatment Guidelines for Rare, Early-Onset, Treatment-Resistant Epileptic Conditions: A Literature Review on Dravet Syndrome, Lennox-Gastaut Syndrome and CDKL5 Deficiency Disorder

Antiseizure medications for Lennox-Gastaut Syndrome: Comprehensive review and proposed consensus treatment algorithm

Lennox-Gastaut syndrome (LGS) is a severe, childhood-onset developmental and epileptic encephalopathy characterized by multiple drug-resistant seizure types, specific electroencephalogram (EEG) patterns, and significant cognitive and behavioral impairments. To date, eight anti-seizure medications (ASMs) have been specifically approved by the U.S. Food and Drug Administration (FDA) for the treatment of LGS: clonazepam, felbamate, lamotrigine, topiramate, rufinamide, clobazam, cannabidiol, and fenfluramine. Additionally, several other ASMs, including valproate, are frequently used off-label for LGS management. As the therapeutic landscape for LGS expands, clinicians are increasingly faced with complex decisions regarding optimal ASM selection. This narrative review explores evolving treatment strategies, offering a consensus-based treatment algorithm designed by a panel of U.S.- based experts. We analyze both FDA-approved and off-label ASMs, drawing on data from randomized controlled trials, open-label extensions, and real-world studies to assess each drug's efficacy and safety profile. A key challenge in comparing ASMs lies in the heterogeneity of study designs and outcome measures. This review addresses these limitations and considers crucial factors influencing ASM selection, such as seizure outcomes, safety profiles, cognitive and behavioral outcomes, drug-drug interactions, and rational polypharmacy. Barriers to access, including economic and regulatory hurdles, are also discussed. The proposed treatment algorithm emphasizes a personalized approach to LGS management, recommending valproate or clobazam as first-line treatments, followed by individualized combinations based on the specific patient profile and associated comorbidities.

Development of cohort definitions and algorithms to identify patients with Lennox-Gastaut syndrome or Dravet syndrome from real-world administrative healthcare databases

Objective

To develop cohort definitions and algorithms that can be applied to a range of real-world retrospective data sources in the United States, France, Germany, Italy, Spain, United Kingdom, China, and Japan to identify patients with Lennox-Gastaut syndrome (LGS) or Dravet syndrome (DS) to aid future research.

Methods

The study was conducted in 3 stages. A targeted literature review was used to identify retrospective healthcare database studies identifying LGS or DS populations and develop overall draft cohort definitions and algorithms. Country-specific research explored the diagnosis codes and antiseizure medications (ASMs) with available indications for LGS or DS, with the findings used to adapt the cohort definitions and algorithms to country-specific settings. Physician interviews were conducted to validate and refine the draft country-specific cohort definitions and algorithms, and better understand the diagnosis and treatment of patients with LGS and DS in each country.

Results

Forty-eight publications were reviewed; 25 focused on LGS only and 14 on DS only. LGS-specific and DS-specific diagnosis codes were identified in the United States, Spain, and United Kingdom; local codes in France, China, and Japan; and no LGS-specific or DS-specific diagnosis codes in Germany or Italy. ASMs only indicated for LGS or DS were available across all countries except China. Multiple seizure types, developmental delay, and intellectual disabilities were considered by the physicians to be key diagnostic features. The country-specific definitions for all 3 approaches (specific diagnostic codes, ASM indicated for LGS or DS only, and broader epilepsy diagnostic codes) were refined further using consensus from the physician interviews.

Conclusions

To our knowledge, this is the first study to comprehensively develop country-specific definitions and algorithms for LGS and DS across several countries that provide a solid foundation toward identifying such patients from real-world retrospective databases. However, additional research and validation using real-world data sources are warranted.

Efficiency and safety of cannabinoid medical use: an analysis of discussions and observed trends on Instagram

Background

Cannabis and its derivatives show encouraging therapeutic effects in the treatment of various diseases. However, further studies are needed to better assess their efficacy and safety. A promising base for research in the field of medicine and additional pharmacovigilance is social networks, in which experience and knowledge are exchanged between researchers, doctors, and patients, as well as information about the potential risks and benefits of using drugs for medical purposes is disseminated. The aim of this study was to investigate the reported efficiency and safety of medical use of cannabinoids in patients using posts on the social media Instagram and analyze the observed trends.

Methods

Social media listening platform Apify was used to collect data with hashtags as of June 4, 2024, including posts from 2023 and 2024, with some data extending into later periods, in compliance with a systematic approach to data collection. The analysis of the data obtained from the research was conducted using the RStudio platform.

Results

The analysis covered 1,466 posts containing hashtags related to cannabinoids. The posts studied were categorized as follows: 33.08% focused on advertising and commercialization, 25.58% on personal experience, 21.35% on other topics, and 19.99% contained educational content. An analysis of overall content relevance found that the majority of Instagram posts (81.79%) related to cannabis and cannabinoid hashtags are relevant. Most of the Instagram posts studied were posters, followed by personal photos and videos. The analysis shows that English dominates the studied category (70.74% of posts), while German, French, Spanish, and other languages also occupy a significant place, emphasizing the importance of a multilingual approach in content analysis. It has been revealed that organizations publish a larger percentage of posts under this study, with a higher percentage of relevance. Personal experience stories receive a significant number of "likes" indicating a strong emotional connection between audience and content. Instagram discussions about cannabinoid treatment support evidence from scientific studies about their effectiveness in treating a range of diseases, such as epilepsy with Lennox-Gastaut and Dravet syndromes, multiple sclerosis, cancer, and HIV-cachexia, nausea and vomiting caused by chemotherapy. At the same time, they emphasize the need for further clinical studies to better assess safety, side effects, and optimal dosages. Advertising and commercial posts can contribute to increased cannabis use, highlighting the need to raise awareness of risks and strengthen preventive measures.

Conclusion

Analysis of content on the social media Instagram can complement traditional scientific research by providing information on the real use of cannabis and its derivatives, contributing to the development of safe and effective recommendations for its use.

Comparison of various doses of oral cannabidiol for treating refractory epilepsy indications: a network meta-analysis

Aim

To evaluate the comparative efficacy and safety of various doses of oral cannabidiol (CBD) in treating refractory epilepsy indications, thus providing more informative evidence for clinical decision-making.

Methods

A literature search of PubMed, Embase, the Cochrane library, and Web of Science (WoS) was performed to retrieve relevant randomized controlled trials (RCTs) that compared different doses of oral CBD with placebo or each other in refractory epilepsy indications. The search was limited from the inception of each database to January 3, 2023. Relative risk [RR] with a 95% confidence interval [CI] was used to express results. STATA/SE 14 was employed for network meta-analysis.

Results

Six RCTs involving 972 patients were included in the final data analysis. Network meta-analysis showed that, CBD10 (10 mg/kg/day) (RR: 1.77, 95%CI: 1.28 to 2.44), CBD20 (20 mg/kg/day) (RR: 1.91, 95%CI: 1.49 to 2.46), CBD25 (25 mg/kg/day) (RR: 1.61, 95%CI: 0.96 to 2.70), and CBD50 (50 mg/kg/day) (RR: 1.78, 95%CI: 1.07 to 2.94) were associated with higher antiseizure efficacy although the pooled result for CBD25 was only close to significant. In addition, in terms of the risk of treatment-emergent adverse events (TEAEs), the difference between different doses is not significant. However, CBD20 ranked first in terms of antiseizure efficacy, followed by CBD50, CBD10, and CBD25. For TEAEs, CBD25 ranked first, followed by CBD10, CBD50, CBD5, and CBD20.

Conclusion

For refractory indications, CBD20 may be optimal option for antiseizure efficacy; however, CBD25 may be best for TEAEs. Therefore, an appropriate dose of oral CBD should be selected based on the actual situation. Due to the limitations of eligible studies and the limited sample size, more studies are needed in the future to validate our findings.

Treatment guidelines for rare, early-onset conditions associated with epileptic seizures: a literature review on Rett syndrome and tuberous sclerosis complex

BACKGROUND

Rett syndrome (RTT) and tuberous sclerosis complex (TSC) are two rare disorders presenting with a range of different epileptic seizures. Seizure management requires careful therapy selection, thereby necessitating development of high-quality treatment guidelines. This targeted literature review (TLR) aimed to characterise country-specific and international treatment guidelines available for pharmacological management of seizures in RTT and TSC.

METHODS

A TLR was performed between 25-Jan and 11-Mar 2021. Manual searches of online rare disease and guideline databases, and websites of national heath technology assessment bodies were conducted for the following countries: Australia, Canada, France, Germany, Israel, Italy, Japan, Spain, Switzerland, UK, and US as defined by pre-specified eligibility criteria. Search terms were developed for each condition and translated into local languages where appropriate. Eligible publications were defined as guidelines/guidance reporting pharmacological management of seizures in patients with RTT and TSC. Guideline development methodology, geographical focus, author information and treatment recommendations were extracted from guidelines. An author map was generated using R version 3.5.1 to visualise extent of collaboration between authors.

RESULTS

24 total guidelines were included, of which three and six contained only recommendations for RTT and TSC, respectively (some provided recommendations for ≥ 1 condition). Guideline development processes were poorly described (50% [12 guidelines] had unclear/absent literature review methodologies); reported methodologies were variable, including systematic literature reviews (SLRs)/TLRs and varying levels of expert consultation. Most (83% [20/24]) were country-specific, with guideline authors predominantly publishing in contained national groups; four guidelines were classified as 'International,' linking author groups in the US, UK, Italy and France. High levels of heterogeneity were observed in the availability of treatment recommendations across indications, with 13 and 67 recommendations found for RTT and TSC, respectively. For RTT, all treatment recommendations were positive and sodium valproate had the highest number of positive recommendations (Khwaja, Sahin (2011) Curr Opin Pediatr 23(6):633-9). All TSC treatments (21 medications) received either exclusively negative (National Organization for Rare Disorders (2019)) or positive (Chu-Shore et al. (2010) Epilepsia 51(7):1236-41) recommendations; vigabatrin received the highest number of positive recommendations (Kaur, Christodoulou (2019)).

CONCLUSIONS

This review highlights the need for the development of international high-quality and comprehensive consensus-based guidance for the management of seizures with pharmacological therapy in RTT and TSC.

TRIAL REGISTRATION

Not applicable.

Cannabis for medicinal use in patients with rare diseases

BACKGROUND: Patients with Rare Diseases (RDs) present with chronic and debilitating symptoms such as pain, anxiety and epileptic seizures. Symptoms can be unresponsive to conventional treatment and may lead to a decreased Quality of Life for patients. Cannabinoids have been reported to be efficacious against chronic pain refractory to conventional analgesics, anxiety and seizures. OBJECTIVE: Identification of RDs for which Medicinal Cannabis (MC) can be used and identification of issues related to RDs and perceptions on the use of MC in patients with RDs. METHODS: Study was divided into 2 phases. Phase 1: Literature Review to identify RDs in which cannabis or cannabinoids are used Phase 2: Development, validation and dissemination of 2 questionnaires for: (i) Health Care Professionals (HCPs) and (ii) RD patients. RESULTS: Cannabinoids were described as possible therapeutic agents in 20 RDs. The questionnaires were completed by 101 HCPs and 38 RD patients. Thirty-three HCPs had no experience on use of MC but would consider using it in their practice for management of RDs. Most patients (n = 29) did not have experience with use of MC and 20 patients would consider using MC to treat their condition or relieve symptoms of their disease. CONCLUSION: The study helps identify the potential of MC use in RDs associated with chronic symptoms such as pain, muscle spasticity, seizures and anxiety.

Are OMERACT recommendations followed in clinical trials on fibromyalgia? A systematic review of patient-reported outcomes and their measures

PURPOSE

Patient-Reported Outcomes (PROs) and its measures (PROMs) are key to outcome assessment in Fibromyalgia (FM) trials. The aim of this review was to investigate which domains and instruments were assessed in recent FM trials and to compare them to recommendations by the Outcome Measures in Rheumatology (OMERACT) initiative. In addition, we investigated the overlap with a generic health assessment approach, i.e. eight domains suggested by the Patient-Reported Outcome Measurement Information System® (PROMIS®).

METHODS

In compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic literature search in scientific databases including PubMed, PsycInfo, and Embase was conducted to identify studies that assessed at least two dimensions of health-related quality of life (HRQoL) from 2015 to June 2022. Non-randomized and randomized controlled trials were included in the analysis. We extracted PROs and PROMs used in each study.

RESULTS

From 1845 identified records, 107 records out of 105 studies met the inclusion criteria. Studies investigated 50 PROs using 126 different PROMs. Most frequently assessed domains were pain, depression, fatigue, and anxiety (> 95% of the studies). The disease-specific FIQ was the most frequently applied PROM (82%). Overall, only 9% of the studies covered all domains deemed mandatory by OMERACT. Very few studies covered all eight generic health domains suggested by PROMIS.

CONCLUSION

The majority of trials covered most OMERACT domains or generic PROMIS health domains. There was, however, great variability in the instruments used to assess the domains, which points at a limited degree of standardization in the field.

Clinical efficacy and safety of cannabidiol for pediatric refractory epilepsy indications: A systematic review and meta-analysis

Antiseizure medications (ASMs) are the mainstay for the treatment of seizure disorders. However, about one-third of people with epilepsy remain refractory to current ASMs. Cannabidiol (CBD) has recently been approved as ASM for three refractory epilepsy syndrome indications in children and adults. In this study, we evaluated the overall clinical potential of an oral CBD to treat refractory epilepsy in patients with Dravet syndrome (DS), Lennox-Gastaut syndrome (LGS), and tuberous sclerosis complex (TSC) through a systematic review and meta-analysis. A comprehensive search of databases was conducted, including randomized controlled trials (RCTs) assessing the effect of CBD in epilepsy patients. The review was conducted as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The review focused on RCTs involving patients receiving highly purified oral CBD (Epidiolex, 10 to 50 mg/kg/day) for up to 16 weeks. A subgroup analysis by syndrome and CBD with or without concomitant clobazam was conducted. The key outcomes were reduction in seizure frequency, differences in 50% responder rates, adverse events, and interactions with clobazam as co-therapy. Odds ratio (OR) with 95% confidence interval (CI) were estimated. Of 1183 articles screened, we included 6 RCTs meeting our eligibility criteria. All studies were considered to have a low risk of bias. In the pooled analysis, CBD treatment was found to be more efficacious compared to placebo (OR = 2.45, 95% CI =1.81-3.32, p < 0.01). Subgroup analysis by syndrome demonstrated the odds of ≥50% reduction in seizures with CBD treatment in patients with DS (OR = 2.26, 95% CI:1.38-3.70), LGS (OR = 2.98, 95% CI:1.83-4.85) and TSC (OR = 1.99, 95% CI = 1.06-3.76). Compared with placebo, CBD was associated with increased adverse events (OR = 1.81, 95% CI = 1.33-2.46) such as diarrhea, somnolence, and sedation, and any serious adverse events (OR = 2.86, 95% CI = 1.63-5.05). Other factors, including dosage and clobazam co-therapy, were significantly associated with a greater effect on seizure control and side effects of CBD. In conclusion, the study shows that CBD is highly efficacious both as standalone and adjunct therapy with clobazam for controlling seizures in DS, LGS, and TSC conditions while limiting side effects. Further pharmacodynamic investigation of CBD actions, drug interaction assessments, and therapeutic management guidelines are warranted.

Reversibility and therapeutic development for neurodevelopmental disorders, insights from genetic animal models

Neurodevelopmental Disorders (NDDs) encompass a broad spectrum of conditions resulting from atypical brain development. Over the past decades, we have had the fortune to witness enormous progress in diagnosis, etiology discovery, modeling, and mechanistic understanding of NDDs from both fundamental and clinical research. Here, we review recent neurobiological advances from experimental models of NDDs. We introduce several examples and highlight breakthroughs in reversal studies of phenotypes using genetically engineered models of NDDs. The in-depth understanding of brain pathophysiology underlying NDDs and evaluations of reversibility in animal models paves the foundation for discovering novel treatment options. We discuss how the expanding property of cutting-edge technologies, such as gene editing and AAV-mediated gene delivery, are leveraged in animal models for the therapeutic development of NDDs. We envision opportunities and challenges toward faithful modeling and fruitful clinical translation.

Treatment-Refractory Dravet Syndrome: Considerations for Novel Medications

Before 2018, there were no U.S. Food and Drug Administration-approved medications for managing seizures in Dravet syndrome (DS). Common agents used in the antiepileptic drug regimens of patients with DS included clobazam, valproic acid, topiramate, and levetiracetam, among others; however, these agents alone rarely provide adequate seizure control. Management of seizures in DS changed in recent years with the approval of cannabidiol and stiripentol in 2018 and fenfluramine in 2020. This continuing education article summarizes available efficacy and safety data involving cannabidiol, stiripentol, and fenfluramine and provides a practical review of dosing strategies, pharmacokinetics, and monitoring interventions relevant to their use.

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.