epilepsy
Epilepsy clinical trials increasingly focus on treatment-resistant epilepsy (TRE) β€” defined as failure of two adequate antiseizure medication (ASM) trials β€” where one-third of patients remain uncontrolled. Genetic stratification has driven trials in specific epilepsy syndromes (Dravet, Lennox-Gastaut, SCN1A, KCNQ2) where disease-modifying gene therapy approaches are now being tested.
Active trials investigate fenfluramine for treatment-resistant focal epilepsy, KCNQ2/SCN1A antisense oligonucleotides, sodium selenate for progressive myoclonic epilepsy, novel mTOR inhibitors for TSC-related epilepsy, and responsive neurostimulation (RNS). Seizure frequency and seizure-free rates remain primary endpoints, with ESES and status epilepticus trials gaining traction.
Disease Burden & Epidemiology
Epilepsy is one of the most common serious neurological conditions, affecting approximately 50 million people worldwide — about 1 in 100 people globally. In the United States, the CDC estimates that 3.4 million Americans have active epilepsy, including 470,000 children. Epilepsy is not a single disease but a spectrum of disorders characterized by a predisposition to recurrent unprovoked seizures, with over 40 distinct epilepsy syndromes recognized. Approximately one-third of all people with epilepsy — roughly 17 million globally — have treatment-resistant epilepsy (TRE), defined by failure of two or more appropriately chosen and dosed antiseizure medications. TRE is associated with disproportionate mortality, cognitive decline, social isolation, unemployment, and reduced quality of life. People with epilepsy are 2–3 times more likely to die prematurely than the general population, including from sudden unexpected death in epilepsy (SUDEP), which claims approximately 1 in 1,000 adults with epilepsy annually. Genetic causes are identified in an increasing proportion of epilepsy cases through next-generation sequencing, enabling syndrome-specific trials; this has particularly transformed management of rare pediatric epilepsies such as Dravet syndrome, KCNQ2 encephalopathy, and TSC-related epilepsy.
Key Research Trends & Landmark Studies
The GWPCARE trials established cannabidiol (Epidiolex) as an effective adjunctive therapy for Dravet syndrome and Lennox-Gastaut syndrome, earning FDA approval in 2018 β€” the first plant-derived pharmaceutical approved in the US and validating a novel mechanism beyond traditional antiseizure drugs. The FINTEPLA trials demonstrated fenfluramine's efficacy in Dravet syndrome, with a 63% reduction in convulsive seizure frequency versus placebo. The PCDH19 trial (international registry-based) established important natural history data enabling future trials in this X-linked condition. For gene therapy, the Phase 1/2 trial of ETX101 (AAV9-delivered GABAa modulator) in SCN1A-positive Dravet syndrome showed seizure reduction and safety signals that are advancing to Phase 3. Responsive neurostimulation (RNS System) trials in mesial temporal and neocortical TRE have demonstrated durability of effect at five years with continued improvement, expanding the surgical epilepsy toolkit. The RESPOND trial is currently evaluating carisbamate in TRE across multiple focal epilepsy syndromes.
Patient Guide: How to Find & Join a Trial
People with epilepsy who continue to have seizures despite trying two or more medications should discuss clinical trial eligibility with a neurologist specializing in epilepsy (epileptologist). Comprehensive epilepsy centers β€” typically located at academic medical centers β€” offer the full range of trial participation options, including surgical evaluations that serve as a prerequisite for some neuromodulation trials. Before your appointment, document your seizure diary (frequency, type, and duration), your complete antiseizure medication history (all drugs tried, doses, duration, and reason for stopping), and any prior EEG or MRI findings. Genetic testing with an epilepsy gene panel is increasingly recommended for treatment-resistant patients, as identification of a specific genetic etiology (SCN1A, KCNQ2, CDKL5, etc.) may open eligibility for genotype-targeted trials not available to uncharacterized TRE patients. The Epilepsy Foundation (epilepsy.com) maintains a clinical trial finder and a helpline (1-800-332-1000) that can assist patients in navigating the trial search process.