The initial dose of TH-302 will be one dose level higher than the MTD established in Part A. The dose of TH-302 will be escalated in cohorts of 3-6 subjects. A Dose Level at the MTD established in Part A will be built into the study in the event that subjects experience excessive toxicity at the initial dose. Dose escalation will continue with approximately 40% increases from the previous dose level; however lower dose increases of 20-39% may be implemented after consultation between the Investigators, Medical Monitor and Sponsor with the percent increase dependent on the current dose level and the cumulative safety data.