Comparison of ATI-5923, a Novel Vitamin K Antagonist, With Warfarin in Patients Requiring Chronic Anticoagulation

The primary study objective is to evaluate whether ATI-5923 is superior to adjusted dose warfarin in the quality of anticoagulation as measured by interpolated INR time in therapeutic range. This is a Phase II/III multi-center, randomized, stratified, double blind, parallel group, active control study comparing ATI-5923 with Coumadin in patients who require chronic, oral anticoagulation. Up to 600 patients who successfully complete all screening assessments and meet all eligibility criteria will be enrolled in the study and receive study drug treatment for 6-12 months depending on time of study entry.