Optimizing clobazam treatment in patients with Lennox-Gastaut syndrome

Application of ensemble learning for predicting GABAA receptor agonists

BACKGROUND

Over the past few decades, agonists binding to the benzodiazepine site of the GABAA receptor have been successfully developed as clinical drugs. Different modulators (agonist, antagonist, and reverse agonist) bound to benzodiazepine sites exhibit different or even opposite pharmacological effects, however, their structures are so similar that it is difficult to distinguish them based solely on molecular skeleton. This study aims to develop classification models for predicting the agonists.

METHODS

306 agonists or non-agonists were collected from literature. Six machine learning algorithms including RF, XGBoost, AdaBoost, GBoost, SVM, and ANN algorithms were employed for model development. Using six descriptors including 1D/2D Descriptors, ECFP4, 2D-Pharmacophore, MACCS, PubChem, and Estate fingerprint to characterize chemical structures. The model interpretability was explored by SHAP method.

RESULTS

The best model demonstrated an AUC value of 0.905 and an MCC value of 0.808 for the test set. The PubMac-based model (PubMac-GB) achieved best AUC values of 0.935 for test set. The SHAP analysis results emphasized that MaccsFP62, ECFP_624, ECFP_724, and PubchemFP213 were the crucial molecular features. Applicability domain analysis was also performed to determine reliable prediction boundaries for the model. The PubMac-GB model was applied to virtual screening for potential GABAA agonists and the top 100 compounds were given.

CONCLUSION

Overall, our ensemble learning-based model (PubMac-GB) achieved comparable performance and would be helpful in effectively identifying agonists of GABAA receptors.

The new International League Against Epilepsy (ILAE) definition of Lennox-Gastaut syndrome: Practical implications and limitations

PURPOSE

There are three major changes in the new definition of Lennox-Gastaut syndrome (LGS) compared with the traditional definition: (1) onset prior to 18 years, (2) must include tonic seizure, (3) generalized slow spike-waves (SSW) and (instead of or) generalized paroxysmal fast activity (GPFA) on electroencephalography (EEG). We investigated the practical implications and potential limitations of the new LGS definition based on a large cohort of patients in an exploratory study.

METHODS

This was a retrospective database study. All patients with an electro-clinical diagnosis of LGS (based on its traditional definition) at the outpatient epilepsy clinic at Shiraz University of Medical Sciences, Shiraz, Iran were included (from 2008 until 2020). Patients were reclassified based on the new definition of LGS.

RESULTS

In total, 3737 patients were registered. Based on its traditional definition, 300 patients were diagnosed as having LGS. According to the new definition of LGS, only 96 patients (32% of the traditional cohort) had LGS. One patient, who had other criteria, had and age at onset of 21 years; 29 patients (9.7%) did not have SSW in their EEGs; 139 people (46.3%) did not have GPFA in their EEGs; and, 111 patients (37%) did not report having tonic seizures.

CONCLUSION

The new International League Against Epilepsy (ILAE) definition of LGS has some important practical implications and limitations. Before reinforcing and making this new definition compulsory in future research and clinical practice, more work is needed to enlighten various aspects of such changes in the definition of this epilepsy syndrome.

CLB add-on treatment in patients with epileptic encephalopathy: a single center experience with long-term follow-up

Clobazam (CLB) is an effective anticonvulsant used as an adjunctive treatment for several seizures and epilepsy syndromes. Data are limited on efficacy and safety of CLB as add-on therapy for epileptic encephalopaties (EEs) other than Lennox-Gastaut syndrome (LGS). This retrospective study aimed to assess efficacy and safety of long-term CLB add-on therapy for various EE syndromes. Data on CLB add-on therapy were assessed in 74 children (60.8% male) after 3 months (early) and 12 months (late) follow-up as well as in 57 (77%) patients who had been on CLB therapy longer than 12 months (mean:39.11 ± 30.29; range:12-129 months) (very late) were reported. Data on CLB add-on therapy were assessed in 74 children (60.8% male) after 3 months (early) and 12 months (late) follow-up as well as in 57 (77%) patients who had been on CLB therapy longer than 12 months (mean:39.11 ± 30.29; range:12-129 months) (very late) were reported. Good response rate (> 50%) for seizures was achieved in 24% at early follow-up, 30% at late follow-up, and 35% during very late follow-up. Complete seizure remission was achieved for 15% seizures; 72.7% occurred at very late follow-up. Myoclonic seizures were the most responsive (35%); this response increased during late follow-up (46%), whereas 27.3% of myoclonic-atonic/atonic seizures had good response at early and very late follow-up. At late follow-up, comparison of mean effective doses of CLB did not show significant difference among types of seizures with good response. Adverse effects reported in 15% of patients did not require stopping CLB therapy. Generalized epileptogenic potentials significantly decreased while focal epileptogenic potentials significantly increased at first year of treatment in comparison to basal EEG findings (p < 0.001). CLB should be considered as an optional antiepileptic that is well tolerated, particularly in EEs with myoclonic and myoclonic-atonic/atonic seizures.

Management of Lennox-Gastaut syndrome beyond childhood: A comprehensive review

Lennox-Gastaut syndrome (LGS) is a childhood-onset epileptic encephalopathy characterized by multiple types of medically intractable seizures, cognitive impairment, and generalized slow spike-wave discharges in electroencephalography (EEG). Although the onset of this epileptic syndrome occurs typically before eight years of age with a peak age between 3 and 5 years, lifelong persistence of the syndrome is usual. The evolution of clinical features, EEG findings, and paucity of knowledge about LGS among adult health care providers can make LGS significantly underdiagnosed in the adult population. Management of LGS remains problematic beyond childhood due to intractable seizures, the difficult transition from pediatric to adult neurologists, challenging behaviors, impaired cognition, poor quality of life, and disabled social life. In focusing on the management of LGS beyond childhood, this narrative review describes medical and surgical management of epilepsy, the transition from pediatric to adult care, and management of other common comorbidities associated with LGS. Several antiepileptic drugs (AEDs) such as lamotrigine, topiramate, felbamate, rufinamide, clobazam, and Epidiolex (pure pharmaceutical grade cannabidiol (CBD) oil) have been noted to be effective in well-designed, randomized controlled trials. Other non-pharmacological therapies, such as vagus nerve stimulation, ketogenic diet, and epilepsy surgery, have been frequently utilized in the management of intractable seizures associated with LGS. However, effective management of LGS requires a broader perspective to not only control seizures but improve the quality of life by addressing cognitive and behavioral problems, sleep disturbances, physical disability, social disability, and educational and employment challenges.

Expanding the Treatment Landscape for Lennox-Gastaut Syndrome: Current and Future Strategies

Lennox-Gastaut syndrome (LGS), a childhood-onset severe developmental and epileptic encephalopathy (DEE), is an entity that encompasses a heterogenous group of aetiologies, with no single genetic cause. It is characterised by multiple seizure types, an abnormal EEG with generalised slow spike and wave discharges and cognitive impairment, associated with high morbidity and profound effects on the quality of life of patients and their families. Drug-refractory seizures are a hallmark and treatment is further complicated by its multiple morbidities, which evolve over the patient's lifetime. This review provides a comprehensive overview of the current and future options for the treatment of seizures associated with LGS. Six treatments are specifically indicated as adjunct therapies for the treatment of seizures associated with LGS in the US: lamotrigine, clobazam, rufinamide, topiramate, felbamate and most recently cannabidiol. These therapies have demonstrated reductions in drop seizures in 15%-68% of patients across trials, with responder rates (≥ 50% reduction in drop seizures) of 37%-78%. Valproate is still the preferred first-line treatment, generally in combination with lamotrigine or clobazam. Other treatments frequently used off-label include the broad spectrum anti-epileptic drugs (AED) levetiracetam, zonisamide and perampanel, while recent evidence from observational studies has indicated that a newer AED, the levetiracetam analogue brivaracetam, may be effective and well tolerated in LGS patients. Other treatments in clinical development include fenfluramine in late phase III, perampanel, soticlestat-OV953/TAK-953, carisbamate and ganaxolone. Non-pharmacologic interventions include the ketogenic diet, vagus nerve stimulation and surgical interventions; these are also expanding, with the potential for less invasive techniques for corpus callosotomy that have promise for reducing complications. However, despite these advancements, patients continue to experience a significant burden. Because LGS is not a single entity, tailoring of treatment is needed as opposed to a 'one size fits all' approach. Further research is needed into the underlying aetiologies and pathophysiology of LGS, together with advancements in treatments that encompass the spectrum of seizures associated with this complex syndrome.

Therapeutic approach to Lennox-Gastaut syndrome: a systematic review

Lennox-Gastaut syndrome (LGS) is a rare, age-related syndrome, characterized by multiple seizure types, mental regression, and specific EEG abnormalities. It is one of the most challenging epilepsy: treatment is rarely effective and the final prognosis remains poor, despite the availability of several antiepileptic drugs, validated through well-designed, randomized, controlled trials. However, it is reasonable to consider non-medical treatments, such as surgery, after failure of two-to-three drugs. This review has as goal to describe systematically the different therapeutic options for LGS, including, not only recognized antiepileptic drugs, but also new oral drugs, immune therapy, diet, surgery, and neurostimulation techniques.

An evaluation of clobazam tablets and film (AQST-120) for the treatment of Lennox-Gastaut syndrome

Introduction: Lennox-Gastaut syndrome (LGS) is a chronic, epileptic encephalopathy, characterized by multiple seizure types, distinctive slow spike-wave patterns in the electroencephalogram (EEG), and severe cognitive and behavioral comorbidities. Seizures are typically refractory and long-term prognosis is poor. No antiseizure drug (ASD) is fully effective as a monotherapy. Clobazam (CLB) was licensed in the United States in 2011 as an adjunctive therapy for seizures in LGS. In 2018, a new formulation, CLB oral soluble film (COSF) (AQST-120), was approved by the Federal Drug Administration (FDA) for the same indication. Areas covered: The authors summarize current pharmacological options and guidelines for the management of seizures in LGS and efficacy and safety findings from phase II and III randomized controlled trials of adjunctive CLB in patients with LGS. An open-label extension trial is also considered. A pharmacokinetic comparison of COSF and CLB tablets is also undertaken. Expert opinion: CLB is partly effective as an add-on therapy in treating seizures in LGS. Adverse effects, pharmacokinetic interactions and the potential for tolerance with long-term treatment should be weighed against the clinical benefit when considering the introduction of CLB in this population. COSF has a similar pharmacokinetic profile to CLB tablets and may help to improve adherence to treatment.