Determination of Safe and Effective Dose of Romiplostim (AMG 531) in Subjects With Myelodysplastic Syndrome (MDS)Receiving Hypomethylating Agents

Inclusion Criteria: - Diagnosis of MDS by bone marrow biopsy based on the World Health
Organization (WHO) classification - Low, Intermediate-1 or Intermediate-2 risk category MDS
using the IPSS (International Prognostic Scoring System) - Planned to receive either
azacytidine 75 mg/m2 by subcutaneous administration each day for 7 days or decitabine 20
mg/m2 by intravenous administration each day for 5 days for at least 4 cycles Exclusion
Criteria:

   - Prior exposure to >3 cycles hypomethylating agents

   - Prior history of leukemia or aplastic anemia

   - Prior history of bone marrow transplantation

   - Prior malignancy (other than in situ cervical cancer or basal cell cancer of the skin)
   unless treated with curative intent and without evidence of disease for ³ 3 years
   before randomization

   - Active or uncontrolled infections

   - Unstable angina, congestive heart failure [NYHA (New York Heart Association) > class
   II], uncontrolled hypertension [diastolic > 100 mmHg], uncontrolled cardiac
   arrhythmia, or recent (within 1 year) myocardial infarction

   - History of arterial thrombosis ( eg, stroke or transient ischemic attack) in the past
   year

   - History of venous thrombosis that currently requires anti-coagulation therapy

   - Received IL-11 within 4 weeks of screening

   - Less than 4 weeks since receipt of any therapeutic drug or device that is not FDA
   approved for any indication

   - Have previously received any other thrombopoietic growth factor