Sequential cohorts of 3 to 6 subjects will receive escalating doses of TKM 080301 according to a pre-specified dose escalation scheme. Assessment of dose-limiting toxicities (DLTs) will be made during Cycle 1 to determine the maximum tolerated dose (MTD). Once the MTD level is established, approximately 20 subjects will be enrolled in an expansion cohort to further confirm the safety and tolerability of TKM-080301 at the MTD.