Study to Evaluate the Safety and Analgesic Activity of ATx08-001 in Subjects With Postherpetic Neuralgia

Aestus has identified a novel selective peroxisome proliferator-activated receptor modulator (SPPARM), with promising potential for the treatment of neuropathic pain. PPARs are nuclear receptors that control many cellular and metabolic processes and are readily modulated by a variety of different drugs. Drugs modulating this target have been shown to improve blood glucose levels and levels of blood lipids, and may reduce the risk of atherosclerosis. The primary objective of the study is to evaluate the safety and analgesic efficacy of ATx08-001 at doses of 2.5 mg bid and 7.5 mg bid compared to placebo for the control of moderate-to-severe postherpetic neuralgia (PHN) pain. The secondary objectives are: * To determine the approximate time to onset of analgesia following administration of study drug * To determine the approximate duration of analgesia following study drug administration * To determine the percentage of treatment responders among subjects receiving ATx08-001 Subjects will be given a diary and instructed to record their postherpetic neuralgia pain severity on a Numerical Pain Rating Scale (NPRS - 12) "over the past 12 hours" on a 0 - 10 scale with "0" being no pain and "10" being the most severe pain the subject could imagine, each morning and night for three consecutive days prior to returning for the Treatment Visit. The Treatment Visit will consist of an in-clinic 6-hour observation period. To be eligible for dosing, immediately before dosing subjects must report a baseline score of 4 or greater on the following Numerical Pain Rating Scale (NPRS-NOW) question: "How would you rate your pain RIGHT NOW using a zero to ten scale, where zero equals no pain and ten is the worst pain you can imagine." Qualified subjects will be administered study drug followed by a 6-hour observation in-clinic period. In addition to the Baseline pain intensity assessment conducted just prior to drug administration (Time 0), pain intensity scores (pain right now) will be assessed using the NPRS-NOW at 30 minutes, 1, 2, 3, 4, and 6 hours following study drug administration. Pain relief compared with Baseline will be assessed at those same time points using a 5-point numerical pain relief (NPR) scale, where 0 = no relief, 1 = a little relief, 2 = some relief, 3 = a lot of relief, and 4 = complete relief. Subjects will be discharged from the clinic at the end of the 6-hour observation period and will be instructed to record postherpetic neuralgia pain severity (NPRS-NOW scores) and pain relief (PAR scores) at 8, 10 and 12 hours following dosing in a diary.