- Subjects may not be enrolled with any of the following: History of a significant bleeding disorder unrelated to cancer, including diagnosed congenital bleeding disorders (e.g., von Willebrand's disease), and diagnosed acquired bleeding disorder within one year (e.g., acquired anti-factor VIII antibodies); GI bleeding from any cause within 3 months; Concomitant use of anticoagulants, except for low-dose warfarin (for prophylaxis to prevent catheter thrombosis) or heparin flushes (for IV lines), is prohibited (Note that chronic use of aspirin is prohibited)