Arm 2 serves as a control and will serve as a bridge to the ARC 1 study performed in 2006/2007. Patients in Arm 1 will receive a relatively low "standard" dose, and patients in Arm 2 will receive the intermediate dose of 4 mg/kg that was used in the ARC1 study. Patients in Arm 3 will receive an experimental "high-dose" regimen. Currently available safety data extends to subjects who have received the 28 mg/Kg total dose over 7 days and to another study administering 8 mg/Kg/day for 3 days (total dose 24 mg/Kg). Subjects randomized into this study's 'high-dose' Arm 3 will, therefore, receive a total dose that is higher than has been previously studied in humans.