Inclusion Criteria

Eligibility Criteria:

- Age >18 with untreated MDS by FAB or WHO criteria (note: FAB criteria for MDS
includes <29% blasts; FAB criteria includes CMML).

- Patients with therapy related disease (t-MDS).

- If the patient has co-morbid medical illness, life expectancy attributed to this must
be greater than 6 months.

- Eastern Cooperative Oncology Group (ECOG) performance status <2.

- Must have adequate organ function as defined below:

- total bilirubin <2.0mg/dL

- AST(SGOT)/ALT(SGPT) <2.5 X institutional upper limit of normal

- creatinine <2.0mg/dL

- NYHA CHF Class II or better

- Women of child-bearing potential and men must agree to use adequate contraception
(hormonal or barrier method of birth control; abstinence).

- Ability to understand and willingness to sign the written informed consent document.

- CD33 expression is required on at least 25% of left shifted dysplastic myeloid cells,
including blasts. This testing will be done on bone marrow aspirate, but for patients
whose CD33 expression in this cellular compartment cannot be ascertained, peripheral
blood will be allowed to determine this.

Exclusion Criteria:

- Patients who have had chemotherapy or radiotherapy within 6 months (for other
cancers) prior to entering the study.

- Patients receiving any other investigational agents or patients that have received
other investigational agents within 1 month of enrollment.

- Patients with active central nervous system disease or with granulocytic sarcoma as
sole site of disease.

- Patients with history of allergic reactions attributed to compounds of similar
chemical or biologic composition to AZA or lintuzumab that are not easily managed are
excluded. Patients with hypersensitivity to mannitol are excluded.

- Uncontrolled intercurrent illness including, but not limited to, symptomatic
congestive heart failure, unstable angina pectoris, serious cardiac arrhythmia, or
psychiatric illness/social situations that would limit compliance with study
requirements. As infection is a common feature of MDS, patients with active infection
are permitted to enroll provided that the infection is under control. Myocardial
infarction within 6 months prior to enrollment or has New York Heart Association
(NYHA) Class III or IV heart failure, uncontrolled angina, severe uncontrolled
ventricular arrhythmias, or electrocardiographic evidence of acute ischemia or active
conduction system abnormalities.

- Psychiatric conditions that prevent compliance with protocol or consent.

- Pregnant women or women who are breastfeeding are excluded from this study.

- HIV-positive patients on combination antiretroviral therapy are ineligible.

- Patients with serious medical or psychiatric illness likely to interfere with
participation in this clinical study.

- Patients with serious medical or psychiatric illness likely to interfere with
participation in this clinical study.

- Patients with baseline fibrinogen <100mg/dL, or those with clinically significant
disseminated intravascular coagulation, are excluded.

- Patients who require ongoing therapeutic anticoagulation with warfarin, lovenox, or
similar agent are excluded. This does not apply to patients on low dose prophylaxis
therapy.

- Patients who require ongoing clopidogrel therapy are excluded. In cases where
clopidogrel use at screening is subsequently discontinued due to ongoing or future
risk of drug and treatment related cytopenias, such patients will be eligible.

- Patients with platelet <10,000/uL who are refractory to platelet transfusion are not
eligible (must bump to at least >10,000/uL after transfusion)

- Patients who have previously received lenalidomide or thalidomide are excluded.