Inclusion Criteria:

- Age ≥ 18 years

- Must understand and voluntarily sign an informed consent form

- Must be able to adhere to the study visit schedule and other protocol requirements

- Documented diagnosis of MDS according to WHO classification, that meets IPSS criteria
for intermediate-2 or high-risk disease

- Must have achieved a response (CR, PR, mCR or HI according to IWG 2006 criteria)
after 6 cycles of Azacitidine.

- Patients must have ECOG performance status (PS) of 0 - 2.

- Women of child-bearing potential (i.e., women who are pre-menopausal or not
surgically sterile) must have a negative serum or urine pregnancy test within 2 weeks
prior to beginning treatment on this study. Nursing patients are excluded.

- Creatinine clearance >50 ml/min

- Serum aspartate aminotransferase (AST)/serum glutamic-oxaloacetic transaminase (SGOT)
or alanine transaminase (ALT)/serum glutamate pyruvate transaminase (SGPT) < 3.0 x
upper limit of normal (ULN)

- Serum total bilirubin < 1.5 mg/dL. (except for unconjugated hyperbilirubinemia due to
Gilbert's disease or secondary to MDS).

Exclusion Criteria:

- Known positive status for human immunodeficiency virus (HIV) or hepatitis B or C

- Uncontrolled intercurrent illness including, but not limited to uncontrolled
infection, symptomatic congestive heart failure, cardiac arrhythmia, or psychiatric
illness/social situations that would limit compliance with study requirements

- Patients receiving any other standard or investigational cytotoxic treatment for
their hematologic malignancy

- Any medical condition which in the opinion of the investigator places the patient at
an unacceptably high risk for toxicities

- Prior history of malignancy other than MDS (except basal cell or squamous cell
carcinoma or carcinoma in situ of the cervix or breast) unless the subject has been
free of disease for ≥ 3 years

- Class III or IV cardiac disease, hypotension or severe hypertension, vasomotor
instability, serious or uncontrolled cardiac dysrhythmias (including ventricular
arrhythmias) at any time, acute myocardial infarction within the past 12 months,
active uncontrolled angina pectoris or symptomatic arteriosclerotic blood vessel
disease

- History of seizures, central nervous disorders, stroke within the last 12 months, or
psychiatric disability thought to be clinically significant in the opinion of the
investigator

- Prior history of autoimmune disease (including but not limited to systemic lupus,
inflammatory bowel disease, and psoriasis)

- Patients with active peptic or esophageal ulcer disease or with past peptic ulcer or
esophageal disease with a history of bleeding

- Patients continuing systemic treatment with clonidine, steroids, and/or H2 receptor
blocking agents Patients with a history of hypersensitivity to histamine or histamine
products, severe allergies to food or contrast media requiring treatment within the
last five years.