Xenon Pharmaceuticals Inc., of Burnaby, British Columbia, said development and commercialization partner Teva Pharmaceutical Industries Ltd., of Jerusalem, plans to initiate a phase IIb trial of TV-45070 in patients with postherpetic neuralgia. The double-blind, placebo-controlled study will enroll approximately 330 patients to evaluate the efficacy and safety of TV-45070, with three treatment groups randomized to doses of 4 percent or 8 percent of TV-45070 or placebo, dosed twice daily.