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

Primary objectives: To identify at least one alvimopan treatment regimen that improves spontaneous complete bowel movement (SCBM) frequency compared to placebo while maintaining an acceptable tolerability profile.
Primary endpoints: Changes in weekly spontaneous complete bowel movement (SCBM) frequency during the 3-week Treatment Period.