A Study of Lenalidomide Versus Placebo in Subjects With Transfusion Dependent Anemia in Lower Risk Myelodysplastic Syndrome (MDS) Without Del 5q

Inclusion Criteria:

• 18 years or older

• Diagnosis of low or intermediate-1 risk Myelodysplastic (MDS) with any chromosomekaryotype except del 5q[31]

• Anemia that requires red blood cell transfusions

• Resistant to erythropoiesis stimulating agents (ESAs) or blood erythropoietin level > 500 mU/mL

• Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) ≤ 2

• Must agree to follow pregnancy precautions as required by the protocol.

• Must agree to receive counseling related to teratogenic and other risks oflenalidomide

• Must agree not to donate blood or semen

• Must be willing to consent to two or more bone marrow aspirate procedures to becompleted during study

Exclusion Criteria:

• Subjects previously receiving immunomodulating or immunosuppressive agents, orepigenetic or deoxyribonucleic acid (DNA) modulation agents

• Allergic reaction to thalidomide

• Renal insufficiency creatinine clearance (CrC1)<40 mL/min by Cockcroft-Gault method)

• Prior history of cancer, other than MDS, unless the subject has been free of thedisease for ≥ 5 years. (Basal cell carcinoma of the skin, carcinoma in situ of thecervix, or stage Tumor (T) 1a or T1b prostate cancer is allowed)

• Absolute neutrophil count (ANC) < 500/uL

• Platelets < 50,000/uL

• Aspartate aminotransferase (AST) or alanine aminotransferase (ALT) > 3X upper limit ofnormal

• Uncontrolled hyperthyroidism or hypothyroidism

• Significant neuropathy

• Prior stem cell transplantation

• Anemia due to reasons other than MDS

• History of deep venous thrombosis (DVT) or pulmonary embolus (PE) within past 3 years

• Significant active cardiac disease within the past 6 months

• Known Human Immunodeficiency Virus (HIV) infection; known Hepatitis C infection oractive Hepatitis B infection