Phase 2 Study of Autologous Followed by Nonmyeloablative Allogeneic Transplantation Using TLI & ATG

PARTICIPANT INCLUSION CRITERIA * Stage II-III multiple myeloma or have progression after initial treatment of Stage I disease (Durie Salmon Staging). Patients with plasma cell leukemia are also included. * Multiple myeloma / plasma cell leukemia diagnosis confirmed by pathology reviewed at Stanford University Medical Center. * 18 to ≤ 75 years of age * Karnofsky Performance Status \> 70%. * Corrected Carbon monoxide diffusing capacity (Dlco) \> 60% * Left ventricle ejection fraction (LVEF) \> 50%. * Alanine aminotransferase (ALT) ≤ 2 x normal * Aspartate aminotransferase (AST) ≤ 2 x normal * Total bilirubin ≤ 2 mg/dL, unless hemolysis or Gilbert's disease. * Estimated creatinine clearance \> 50 mL/min. * Identified related or unrelated Human leukocyte antigen (HLA)-identical donor or donor with one antigen/allele mismatch in (HLA-A, B, C or DRB1). * Signed informed consent. DONOR INCLUSION CRITERIA * At least 17 years of age * HIV-seronegative * Must be capable of giving signed, informed consent * No contraindication to the administration of filgrastim * Willing to have a central venous catheter placed for apheresis if peripheral veins are inadequate PARTICIPANT EXCLUSION CRITERIA * Prior allogeneic hematopoietic cell transplantation * Uncontrolled active infection * Uncontrolled congestive heart failure or angina * HIV-positive * Pregnant or nursing DONOR EXCLUSION CRITERIA * Serious medical or psychological illness * Pregnant or lactating * Prior malignancies within the last 5 years except for non-melanoma skin cancers