 The study has 3 parts. The first phase of the study, Phase 1, has 2 parts. In the first part of Phase 1, patients with select myeloid leukemias or advanced MDS will receive increasing doses of study drug on different schedules in order to achieve the highest dose possible that will not cause unacceptable side effects. Approximately 30 patients per schedule from the US will be enrolled in Part 1 Completed. In the second part of Phase 1, patients with advanced MDS will receive the best dose of study drug and schedule determined from the first part of the study. Approximately 10 patients from the US will be enrolled in Part 2 Completed. 