Safety Study of Lenalidomide With and Without Dexamethasone in Japanese Subjects With Previously Treated Multiple Myeloma

Inclusion Criteria: * Subjects with previously treated multiple myeloma * Measurable levels of m-protein in serum \>= 0.5 g/dL \[5g/L\]) or urine (\>= 0.2 g excreted in a 24-hour collection sample) * ECOG performance status of 0 - 2 * Willing to follow pregnancy precautions Exclusion Criteria: * Patients with acute an myocardial infarction (MI) within the past 6 months, or patients with a history of deep vein thrombosis (DVT) or pulmonary embolism (PE) within the past 3 years * Patients with tuberculous diseases, herpes simplex keratitis, systemic mycosis or other active infectious diseases * Patients with non-controlled diabetes, hypertension, digestive ulcer or glaucoma * Patients with posterior subcapsular cataracts * Patients with mental illness * Patients with past histories or complications which make the Investigator or other staff member deem them inappropriate for this study * Pregnant or lactating females * Grade 2 or worse neuropathy * Any of the following laboratory abnormalities: Absolute neutrophil count (ANC) \< 1,000cells/mL Platelet count \< 75,000/mL Serum creatinine \> 2.5 mg/dL Serum SGOT/AST or SGPT/ALT \> 3.0 x upper limit of normal (ULN) * Prior history of malignancies, other than multiple myeloma, unless the subject has been free of the disease for \>= 3 years. - Patients who received radiation therapy within 14 days of the start of study drug * Patients with scars from a recent viscus operation * Patients with history of a desquamating (blistering) rash while taking thalidomide * Patients with prior use of lenalidomide * Patients with known HIV positivity. * Patients who used cytotoxic chemotherapeutic agents, immunomodulating agents, or other experimental agents (agents that are not commercially available) intended for the treatment of MM within 28 days of the start of lenalidomide therapy. * Patients with known history of hypersensitivity to dexamethasone.