- Phase I: Patients receive decitabine IV over 1 hour once daily on days 1-5 followed by oral tretinoin twice daily on days 10-19. Treatment repeats every 28 days for a minimum of 4 courses in the absence of disease progression or excessive toxicity. Patients who achieve a partial or complete response after completing 6 courses of treatment may receive 4 additional courses up to a total of 10 courses. Patients with stable disease or hematologic improvement are removed from study.