SANTA CLARA, Calif.--(BUSINESS WIRE)--XenoPort, Inc. (Nasdaq:XNPT) announced plans to initiate an exploratory Phase 2 clinical trial of XP19986 in patients with acute back spasms, which is a debilitating condition affecting approximately two-thirds of patients experiencing lower back pain. XenoPort intends to initiate this two-week, multi-center, double-blind, placebo controlled trial in the fourth quarter of this year. The primary objective of the study will be to evaluate the safety and tolerability of XP19986 in subjects with acute back spasms, and the secondary objectives will include the evaluation of efficacy measures and pharmacokinetics.