A Double-Blind, Placebo-Controlled, Multicenter Phase IIb Extension Study to Evaluate the Safety and Efficacy of Multiple Alvimopan Dosage Regimens for the Treatment of Opioid-Induced Bowel Dysfunction in Cancer Pain Subjects.

Primary objectives: To compare the safety among the treatment regimens, while offering continued access to blinded investigational product to subjects who have completed a prior GSK alvimopan OBD study in cancer pain subjects.
Primary endpoints: Incidence of reported adverse events, including serious adverse events.