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 chromosome
karyotype 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 of
lenalidomide

- Must agree not to donate blood or semen

- Must be willing to consent to two or more bone marrow aspirate procedures to be
completed during study

Exclusion Criteria:

- Subjects previously receiving immunomodulating or immunosuppressive agents, or
epigenetic 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 the
disease for ≥ 5 years. (Basal cell carcinoma of the skin, carcinoma in situ of the
cervix, 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 of
normal

- 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 or
active Hepatitis B infection