A Phase 2 Study of Lenalidomide to Evaluate the Efficacy in Japanese Patients With Newly Diagnosed Multiple Myeloma

Inclusion Criteria: * Age ≥ 20 years at the time of signing the informed consent document * Understand and voluntarily sign an informed consent document prior to any study related assessments/procedures are conducted * Able to adhere to the study visit schedule and other protocol requirements * Previously untreated, symptomatic multiple myeloma * Have measurable disease by protein electrophoresis analyses * At least 65 years of age or older or, if younger than 65 years of age, not candidates for hematopoietic stem cell transplantation * Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1, or 2 * Must agree to comply to Lenalidomide Pregnancy Prevention Risk Management Plan Exclusion Criteria: * Any significant medical condition, laboratory abnormality, or psychiatric illness that would prevent the subject from participating in the study * Any condition including the presence of laboratory abnormalities, which places the subject at unacceptable risk if he/she were to participate in the study * Any condition that confounds the ability to interpret data from the study * Previous treatment with anti-myeloma therapy * Pregnant or lactating females * Any of the following laboratory abnormalities: * Absolute neutrophil count (ANC) \< 1,000/microL (1.0 × 10\^9/L ) * Untransfused platelet count (a platelet count drawn at least 7 days after the administration of the last platelet transfusion) \< 50,000 cells/microL (50 × 10\^9/L) * Aspartate aminotransferase (AST) or alanine aminotransferase (ALT) \> 3.0 × upper limit of normal * Renal failure requiring hemodialysis or peritoneal dialysis * Prior history of malignancies, other than MM, unless the subject has been free of the disease for ≥ 5 years * Subjects who are unable or unwilling to undergo antithrombotic therapy. * Peripheral neuropathy of ≥ grade 2 severity. * Uncontrolled systemic fungal, bacterial, or viral infection * Known human immunodeficiency virus (HIV) positivity (subjects who are receiving antiretroviral therapy for HIV disease) * Hepatitis Bs (HBs) antigen-positive, or hepatitis C virus (HCV) antibody-positive. In case HBc antibody and/or HBs antibody is positive even if HBs antigen-negative, a Hepatitis B virus (HBV) DNA test should be performed and if positive the subject will be excluded. * Primary AL (immunoglobulin light chain) amyloidosis and myeloma complicated by amyloidosis. * Ineligible for dexamethasone or dexamethasone is contraindicated.