The dose of azacitidine that you receive will depend on when you enroll in this study. You will be part of a study group "cohort" (6 patients will be enrolled in each cohort). All members of a cohort receive the same dose of azacitidine when they begin receiving the study drug. Each new cohort will receive a higher dose than the cohort before. The dose of azacitidine that you receive may be adjusted depending on how well you tolerate it. The starting dose of valproic acid is fixed for all the patients, but this dose may be adjusted by your physician based on the results of your blood work.