Additional Study Information: Small fiber neuropathy is a painful condition caused by damage to the small nerves in your arms andlegs. This damage causes burning, sharp-stabbing and aching pain, amongst other types of pain. It can be sometimes difficult to know the cause of the damage to the small nerves in your arms and legs. In most cases, treatment for small fiber neuropathy is focused on alleviating the pain, usually the most severe symptom of small fiber neuropathy. The research study you are invited to take part in is focused on treating pain caused by small fiber neuropathy. This study is being done to learn more about the safety and effects of VX-150 in subjects with pain caused by small fiber neuropathy. VX-150 is an investigational drug. Investigational means VX-150 is not yet approved for use by the Food and Drug Administration (FDA) or your local Regulatory Authority and is still being tested for safety and effectiveness. VX-150 blocks the channels on pain sensing neurons. By blocking these channels, these neurons cannot send the pain signal to the brain. As a result, there is a decrease or potentially loss of pain sensation. Please contact the research team on 212-305-6035 if you're interested to know more about the study.