Are Genetic Therapies for Epilepsy Ready for the Clinic?

Established and emerging GABAA receptor pharmacotherapy for epilepsy

Drugs that modulate the GABAA receptor are widely used in clinical practice for both the long-term management of epilepsy and emergency seizure control. In addition to older medications that have well-defined roles for the treatment of epilepsy, recent discoveries into the structure and function of the GABAA receptor have led to the development of newer compounds designed to maximise therapeutic benefit whilst minimising adverse effects, and whose position within the epilepsy pharmacologic armamentarium is still emerging. Drugs that modulate the GABAA receptor will remain a cornerstone of epilepsy management for the foreseeable future and, in this article, we provide an overview of the mechanisms and clinical efficacy of both established and emerging pharmacotherapies.

Viral Vector-Based Gene Therapy for Epilepsy: What Does the Future Hold?

In recent years, many pre-clinical studies have tested gene therapy approaches as possible treatments for epilepsy, following the idea that they may provide an alternative to conventional pharmacological and surgical options. Multiple gene therapy approaches have been developed, including those based on anti-sense oligonucleotides, RNA interference, and viral vectors. In this opinion article, we focus on translational issues related to viral vector-mediated gene therapy for epilepsy. Research has advanced dramatically in addressing issues like viral vector optimization, target identification, strategies of gene expression, editing or regulation, and safety. Some of these pre-clinically validated potential gene therapies are now being tested in clinical trials, in patients with genetic or focal forms of drug-resistant epilepsy. Here, we discuss the ongoing translational research and the advancements that are needed and expected in the near future. We then describe the clinical trials in the pipeline and the further challenges that will need to be addressed at the clinical and economic levels. Our optimistic view is that all these issues and challenges can be overcome, and that gene therapy approaches for epilepsy will soon become a clinical reality.

Response to Singh et al. 2023: It is premature for a unified hypothesis of sudden unexpected death in epilepsy: A great amount of research is still needed to understand the multisystem cascade

In response to the comments by Singh and colleagues about our recent paper proposing a unified hypothesis of SUDEP, we definitely agree that more research is needed. This research should include studies in other models, including Dravet mice, emphasized by Singh et al. However, we strongly believe the hypothesis is timely, because it is based on the continuing progress on SUDEP-related research on serotonin (5-HT) and adenosine as well as neuroanatomical findings.We propose testing of 5-HT enhancing drugs, neurotoxicity blocking drugs, such as N-methyl-D-aspartate (NMDA) antagonists and periaqueductal gray (PAG) electrical stimulation for SUDEP prevention. There are FDA-approved drugs that enhance the action of 5-HT, including fluoxetine and fenfluramine, which is approved for Dravet syndrome. NMDA antagonists, including memantine and ketamine, are also approved for other disorders. PAG electrical stimulation, which is proposed to activate a suffocation alarm, is also approved to treat other conditions and is known to enhance respiration. Experiments using these methods are currently being carried out in animal studies. If these approaches are validated in SUDEP models, treatments could be evaluated relatively quickly in patients with epilepsy (PWE) who exhibit a biomarker for high SUDEP risk, such as peri-ictal respiratory abnormalities. An example of such a study is the ongoing clinical trial of a selective serotonin reuptake inhibitor in PWE. Although, gene-based therapies may ultimately become treatments of choice to prevent SUDEP, as Singh et al suggested, one or more of the approaches we proposed could become temporizing treatments before gene-based therapies can be available. Establishing genetic treatments would require extensive time for each of the genetic abnormalities associated with SUDEP, and too many PWE are likely to die in the meantime.The temporizing treatments may help to reduce the incidence of SUDEP sooner, which is urgently needed.