Safety and Tolerability Study of ST-503 for Refractory Pain Due to Peripheral Neuropathy (Small Fiber Predominant, SFN)

This research is being done to study a possible treatment for refractory pain due to small fiber neuropathy (SFN). Small fiber neuropathy happens when something damages small nerve fibers in your skin, causing symptoms like painful tingling or burning sensations in your hands and feet. Pain originating in the nerves outside of the brain and spinal cord is defined by doctors as neuropathic pain. Scientists have discovered that certain proteins in our bodies called sodium channels are important for communicating pain signals in nerves, specifically, Nav1.7, Nav1.8 and Nav1.9. This first-in-human study will test the use of a type of experimental treatment called "gene therapy." The primary goal is to determine if it is safe and well tolerated. The second goal is to determine if it reduces the level of refractory pain due to SFN disease. The gene will be delivered into your cells using a special delivery tool called a vector.