GlaxoSmithKline and XenoPort, Inc. achieved positive results from a Phase IIb trial evaluating the safety and efficacy of GSK1838262/XP13512 (gabapentin enacarbil) for neuropathic pain associated with post-herpetic neuralgia (PHN) in adults. The 14-week, double-blind, placebo-controlled study enrolled 376 subjects with PHN. Subjects were randomized to receive placebo, 1200, 2400 or 3600 mg/day of the drug, dosed twice a day. All doses of GSK1838262 demonstrated statistically significant impr...