Citations

Abstract This article summarizes data for 13 investigational treatments for which at least preliminary seizure outcome data in patients with epilepsy were reported at the Eighteenth Eilat Conference on New Antiepileptic Drugs and Devices held in Madrid, Spain, on May 3–6, 2026. The treatments reviewed include bexicaserin, a selective 5‐hydroxytryptamine (5‐HT, serotonin) type 2C (5‐HT 2C ) receptor superagonist investigated as a treatment for developmental and epileptic encephalopathies (DEEs); BMB‐101, a selective 5‐HT 2C receptor agonist investigated for the treatment of absence seizures and DEEs; elsunersen, an antisense oligonucleotide designed for the treatment of early‐onset SCN2A ‐DEE; EPX‐100 (clemizole hydrochloride), an antihistamine endowed with agonist activity at 5‐HT 2A and 5‐HT 2B receptors, repurposed as a treatment for DEEs; ES‐481, an antagonist of α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid (AMPA) receptors containing the transmembrane AMPA receptor regulatory protein γ8 (TARP‐γ8), under investigation for the treatment of drug‐resistant epilepsy; ETX‐101, a gene therapy in development for the treatment of SCN1A ‐positive Dravet syndrome; PrevEp‐006 (intranasal seletracetam), a synaptic vesicle glycoprotein 2A (SV2A) ligand under investigation as an acute seizure rescue therapy; radiprodil, a negative allosteric modulator that binds to the GluN2B subunit of the N ‐methyl‐ D ‐aspartate (NMDA) receptor, in development for the treatment of seizures and other symptoms associated with GRIN‐related neurodevelopmental disorder, tuberous sclerosis complex, and focal cortical dysplasia type II; RAP‐219, a selective negative allosteric modulator of TARP‐γ8, in development for drug‐resistant focal epilepsy; relutrigine, a selective disease‐state sodium channel modulator investigated as a treatment for SCN2A ‐ and SCN8A ‐DEE; Staccato Alprazolam, a breath‐actuated device that delivers alprazolam to the lungs for rapid seizure termination; vormatrigine, a functionally selective sodium channel modulator in development for the treatment of focal seizures; and zorevunersen, an antisense oligonucleotide engineered to restore endogenous Nav1.1 protein expression, investigated for the treatment of Dravet syndrome. Overall, the evidence reviewed justifies expectations for improved health outcomes for the millions of children and adults with epilepsy who do not fully benefit from existing therapies.

Abstract Over the last 34 years, the Eilat Conference on New Antiepileptic Drugs and Devices has provided an interactive forum for stakeholders to discuss investigational and recently licensed treatments for seizures and epilepsy. The Eighteenth Eilat Conference on New Antiepileptic Drugs and Devices (EILAT XVIII) took place in Madrid, Spain, on May 3–6, 2026. This article provides summaries of eight treatments in preclinical and early clinical development that were presented at EILAT XVIII. These include AUT00206, a positive allosteric modulator of Kv3.1 and Kv3.2 voltage‐gated potassium channels in development for the treatment of rare epilepsy syndromes as well as neurodevelopmental and neuropsychiatric disorders; ION283, an antisense oligonucleotide designed to suppress the expression of glycogen synthase 1, under investigation for the treatment of Lafora disease; MSCA‐7136, a selective allosteric RAS/mitogen‐activated protein kinase—extracellular signal regulated kinase (MEK) inhibitor being developed for the treatment of focal seizures associated with mesial temporal lobe epilepsy and seizures associated with tuberous sclerosis complex; OV329, a selective inhibitor of γ‐aminobutyric acid (GABA) aminotransferase, in development for the treatment of drug‐resistant focal seizures; PTI5803 (probenecid), an uricosuric agent and a blocker of pannexin 1 channels, repurposed as a treatment for seizures associated with focal cortical dysplasia; simufilam, a filamin A modulator under investigation for the treatment of tuberous sclerosis complex‐related epilepsy; SN‐2000, a selective allosteric phosphodiesterase 4B inhibitor, in development for the treatment of focal seizures; and sodium selenate, a promoter of the dephosphorylation of pathological hyperphosphorylated tau in the brain, under investigation as a disease‐modifying agent in mesial temporal lobe epilepsy. Treatments in more advanced clinical development are discussed in an accompanying article.

Abstract A variety of terms, such as “antiepileptic,” “anticonvulsant,” and “antiseizure” have been historically applied to medications for the treatment of seizure disorders. Terminology is important because using terms that do not accurately reflect the action of specific treatments may result in a misunderstanding of their effects and inappropriate use. The present International League Against Epilepsy (ILAE) position paper used a Delphi approach to develop recommendations on English‐language terminology applicable to pharmacological agents currently approved for treating seizure disorders. There was consensus that these medications should be collectively named “antiseizure medications”. This term accurately reflects their primarily symptomatic effect against seizures and reduces the possibility of health care practitioners, patients, or caregivers having undue expectations or an incorrect understanding of the real action of these medications. The term “antiseizure” to describe these agents does not exclude the possibility of beneficial effects on the course of the disease and comorbidities that result from the downstream effects of seizures, whenever these beneficial effects can be explained solely by the suppression of seizure activity. It is acknowledged that other treatments, mostly under development, can exert direct favorable actions on the underlying disease or its progression, by having “antiepileptogenic” or “disease‐modifying” effects. A more‐refined terminology to describe precisely these actions needs to be developed.

AbstractEpilepsy syndromes have been recognized for >50 years, as distinct electroclinical phenotypes with therapeutic and prognostic implications. Nonetheless, no formally accepted International League Against Epilepsy (ILAE) classification of epilepsy syndromes has existed. The ILAE Task Force on Nosology and Definitions was established to reach consensus regarding which entities fulfilled criteria for an epilepsy syndrome and to provide definitions for each syndrome. We defined an epilepsy syndrome as “a characteristic cluster of clinical and electroencephalographic features, often supported by specific etiological findings (structural, genetic, metabolic, immune, and infectious).” The diagnosis of a syndrome in an individual with epilepsy frequently carries prognostic and treatment implications. Syndromes often have age‐dependent presentations and a range of specific comorbidities. This paper describes the guiding principles and process for syndrome identification in both children and adults, and the template of clinical data included for each syndrome. We divided syndromes into typical age at onset, and further characterized them based on seizure and epilepsy types and association with developmental and/or epileptic encephalopathy or progressive neurological deterioration. Definitions for each specific syndrome are contained within the corresponding position papers.

AbstractThe goal of this paper is to provide updated diagnostic criteria for the epilepsy syndromes that have a variable age of onset, based on expert consensus of the International League Against Epilepsy Nosology and Definitions Taskforce (2017–2021). We use language consistent with current accepted epilepsy and seizure classifications and incorporate knowledge from advances in genetics, electroencephalography, and imaging. Our aim in delineating the epilepsy syndromes that present at a variable age is to aid diagnosis and to guide investigations for etiology and treatments for these patients.

Abstract The International League Against Epilepsy (ILAE) Task Force on Nosology and Definitions proposes a classification and definition of epilepsy syndromes in the neonate and infant with seizure onset up to 2 years of age. The incidence of epilepsy is high in this age group and epilepsy is frequently associated with significant comorbidities and mortality. The licensing of syndrome specific antiseizure medications following randomized controlled trials and the development of precision, gene‐related therapies are two of the drivers defining the electroclinical phenotypes of syndromes with onset in infancy. The principal aim of this proposal, consistent with the 2017 ILAE Classification of the Epilepsies, is to support epilepsy diagnosis and emphasize the importance of classifying epilepsy in an individual both by syndrome and etiology. For each syndrome, we report epidemiology, clinical course, seizure types, electroencephalography (EEG), neuroimaging, genetics, and differential diagnosis. Syndromes are separated into self‐limited syndromes, where there is likely to be spontaneous remission and developmental and epileptic encephalopathies , diseases where there is developmental impairment related to both the underlying etiology independent of epileptiform activity and the epileptic encephalopathy. The emerging class of etiology‐specific epilepsy syndromes, where there is a specific etiology for the epilepsy that is associated with a clearly defined, relatively uniform, and distinct clinical phenotype in most affected individuals as well as consistent EEG, neuroimaging, and/or genetic correlates, is presented. The number of etiology‐defined syndromes will continue to increase, and these newly described syndromes will in time be incorporated into this classification. The tables summarize mandatory features, cautionary alerts, and exclusionary features for the common syndromes. Guidance is given on the criteria for syndrome diagnosis in resource‐limited regions where laboratory confirmation, including EEG, MRI, and genetic testing, might not be available.

Abstract In 2017, the International League Against Epilepsy (ILAE) Classification of Epilepsies described the “genetic generalized epilepsies” (GGEs), which contained the “idiopathic generalized epilepsies” (IGEs). The goal of this paper is to delineate the four syndromes comprising the IGEs, namely childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy, and epilepsy with generalized tonic–clonic seizures alone. We provide updated diagnostic criteria for these IGE syndromes determined by the expert consensus opinion of the ILAE’s Task Force on Nosology and Definitions (2017–2021) and international external experts outside our Task Force. We incorporate current knowledge from recent advances in genetic, imaging, and electroencephalographic studies, together with current terminology and classification of seizures and epilepsies. Patients that do not fulfill criteria for one of these syndromes, but that have one, or a combination, of the following generalized seizure types: absence, myoclonic, tonic‐clonic and myoclonic‐tonic‐clonic seizures, with 2.5–5.5 Hz generalized spike‐wave should be classified as having GGE. Recognizing these four IGE syndromes as a special grouping among the GGEs is helpful, as they carry prognostic and therapeutic implications.

Abstract The 2017 International League Against Epilepsy classification has defined a three‐tier system with epilepsy syndrome identification at the third level. Although a syndrome cannot be determined in all children with epilepsy, identification of a specific syndrome provides guidance on management and prognosis. In this paper, we describe the childhood onset epilepsy syndromes, most of which have both mandatory seizure type(s) and interictal electroencephalographic (EEG) features. Based on the 2017 Classification of Seizures and Epilepsies, some syndrome names have been updated using terms directly describing the seizure semiology. Epilepsy syndromes beginning in childhood have been divided into three categories: (1) self‐limited focal epilepsies, comprising four syndromes: self‐limited epilepsy with centrotemporal spikes, self‐limited epilepsy with autonomic seizures, childhood occipital visual epilepsy, and photosensitive occipital lobe epilepsy; (2) generalized epilepsies, comprising three syndromes: childhood absence epilepsy, epilepsy with myoclonic absence, and epilepsy with eyelid myoclonia; and (3) developmental and/or epileptic encephalopathies, comprising five syndromes: epilepsy with myoclonic–atonic seizures, Lennox–Gastaut syndrome, developmental and/or epileptic encephalopathy with spike‐and‐wave activation in sleep, hemiconvulsion–hemiplegia–epilepsy syndrome, and febrile infection‐related epilepsy syndrome. We define each, highlighting the mandatory seizure(s), EEG features, phenotypic variations, and findings from key investigations.

SummaryObjectiveTo evaluate safety, tolerability, seizure frequency, and regional variations in treatment responses with the AMPA antagonist, perampanel, in a large extension study during up to 3 years of treatment.MethodsPatients ≥12 years old with partial‐onset seizures despite treatment with 1–3 antiepileptic drugs at baseline completed a perampanel phase III trial and entered extension study 307 (NCT00735397). Patients were titrated to 12 mg/day (or their individual maximum tolerated dose) during the blinded conversion period, followed by open‐label maintenance. Exposure, safety (adverse events [AEs], vital signs, weight, electrocardiography [ECG], laboratory values) and seizure outcomes were analyzed; key measures were assessed by geographic regions.ResultsAmong 1,216 patients, median exposure was 1.5 years (range 1 week to 3.3 years), with >300 patients treated for >2 years. Treatment retention was 58.5% at cutoff. AEs reported in ≥10% of patients were dizziness, somnolence, headache, fatigue, irritability, and weight increase. Only dizziness and irritability caused discontinuation in >1% of patients (3.9% and 1.3%, respectively). The only serious AEs reported in >1% of patients were epilepsy‐related (convulsion, 3.0%; status epilepticus, 1.1%). No clinically relevant changes in vital signs, ECG or laboratory parameters were seen. After titration/conversion, responder rate and median percentage change from baseline in seizure frequency were stable: 46% for both measures at 9 months (in 980 patients with ≥9 months' exposure) and 58% and 60%, respectively, at 2 years (in the 337 patients with 2 years' exposure). Median percentage reduction in frequency of secondarily generalized (SG) seizures ranged from 77% at 9 months (N = 422) to 90% at 2 years (N = 141). Among the 694 patients with maintenance data ≥1 year, 5.3% were seizure‐free for the entire year.SignificanceNo new safety signals emerged during up to 3 years of perampanel exposure in 39 countries. Seizure responses remained stable, with marked reductions, particularly in SG seizures.A PowerPoint slide summarizing this article is available for download in the Supporting Information section here.