Dose-Finding Study of REN-1654 in Patients With Post-Herpetic Neuralgia

This is a multi-center, double-blind, randomized, placebo-controlled, dose-finding study. After screening and baseline clinical assessments, subjects will be randomly assigned to receive 30 or 100 mg REN-1654 by mouth (p.o.), or matching placebo, once daily for 3 weeks. After 3 weeks of treatment, the clinical assessments will be repeated. Subjects who complete the 3 week placebo-controlled segment may enter the 3-week active-treatment extension segment, during which subjects in the REN-1654 30 mg group will remain on that dose, subjects who were given placebo in the previous segment will receive REN-1654 100 mg daily, and subjects who received REN 1654 100 mg in the first 3 week study segment will discontinue dosing. Double-blind conditions will be maintained through the placebo-controlled active treatment period (primary efficacy endpoint) and for those continuing dosing into the 3-week second active treatment period. The clinical assessments will be repeated at the end of 6 weeks, after which all subjects will discontinue treatment and return 2 weeks later for the final clinical assessment.