Gene Therapy for Chronic Neuropathic Pain: How Does It Work and Where Do We Stand Today?

Abstract

Chronic neuropathic pain has been an enigma to physicians and researchers for decades. A better understanding of its pathophysiology has given us more insight into its various mechanisms and possible treatment options. We now have an understanding of the role of various ionic channels, biologically active molecules involved in pain, and also the intricate pain pathways where possible interventions might lead to substantial pain relief. The recent research on laboratory animals using virus-based vectors for gene transfer at targeted sites is very promising and may lead to additional human clinical trials. However, one needs to be aware that this "novel" approach is still in its infancy and that many of its details need to be further elucidated. The purpose of this article is to thoroughly review the current available literature and analyze the deficiencies in our current knowledge. Literature review. After an extensive online literature search, a total of 133 articles were selected to synthesize a comprehensive review about chronic neuropathic pain and gene therapy in order to understand the concepts and mechanisms. Most of the studies have shown benefits of gene therapy in animal models, and recently, phase 1 human trials using herpes simplex virus vector have started for intractable cancer pain. Although animal data have shown safety and efficacy, and initial human trials have been promising, additional studies in humans are required to more completely understand the actual benefits and risks of using gene therapy for the treatment of chronic neuropathic pain.