At the beginning of the study, one to three patients may be enrolled at each dose level, and dose will be doubled between groups until the first occurrence of intolerable side effects during Cycle 1. At the first occurrence of less severe side effects, groups will be expanded to 3-4 patients. Dose escalation (increasing) will continue in this way until researchers learn the highest dose that is best tolerated. You will remain at the same dose level that you started on for at least 2 cycles. After at least 2 cycles, your dose may be increased to another dose that has been determined to be safe. If your disease gets worse or you experience any intolerable side effects, you will be taken off this study.