This is a phase 2, single-arm, open-label, multi-center study to establish the safety and efficacy of Troxatyl™ (troxacitabine) administered as a continuous infusion for 5 days to subjects with AML. The study will primarily assess the complete response (CR) rate of a 5-day continuous infusion of troxacitabine at 12 mg/m2/day given as second salvage therapy in adult patients with AML, with secondary objectives to determine the overall, relapse-free and event-free survival and remission duration; to determine the duration of response; to determine the complete response with incomplete platelet recovery (CRp) rate; to evaluate the tolerability and safety of 5-day continuous intravenous (IV) infusion of troxacitabine; and to determine the relationship between troxacitabine plasma concentrations, anti-leukemic activity and adverse events. Additional cycles of treatment may be given at the investigator’s discretion, provided that the subject does not have progressive disease or experience a dose limiting toxicity. Bone marrow transplantation in responding subjects will be allowed.