Rituximab in Treating Patients With Multiple Myeloma

DISEASE CHARACTERISTICS: Histologically proven, newly diagnosed multiple myeloma Eligible if pancytopenia related to multiple myeloma At least 50% plasma cells in the bone marrow OR Splenomegaly OR Plasma cell leukemia No solitary extramedullary plasmacytoma or plasma cell dyscrasia

PATIENT CHARACTERISTICS: Age: Not specified Performance status: ECOG 0-2 Life expectancy: At least 3 months Hematopoietic: If less than 50% plasma cells in bone marrow: WBC at least 2,500/mm3 OR Absolute neutrophil count at least 1,000/mm3 (greater than 500/mm3 if platelet count at least 75,000/mm3) Platelet count greater than 45,000/mm3 (thrombocytopenia related to idiopathic thrombocytopenic purpura or vitamin B12 or folate deficiency allowed) Hepatic: Bilirubin no greater than 2 times upper limit of normal (ULN) ALT or AST less than 2 times ULN (if greater than one third of liver involved, then no greater than 5 times ULN) No severe hepatic disease Renal: Creatinine no greater than 2.0 mg/dL Other: No severe infection requiring intravenous antibiotics Not pregnant or nursing Fertile patients must use effective contraception No prior malignancy within 5 years except for treated basal cell or squamous cell skin cancer, or carcinoma in situ of the cervix No Type I hypersensitivity or anaphylactic reactions to murine proteins or to any component of rituximab

PRIOR CONCURRENT THERAPY: Biologic therapy: No prior bone marrow transplantation Concurrent sargramostim (GM-CSF) allowed for severe, symptomatic neutropenia Chemotherapy: At least 4 weeks since investigational drugs Endocrine therapy: Not specified Radiotherapy: Not specified Surgery: Not specified Other: No concurrent use of investigational drugs or devices Concurrent epoetin alfa allowed for anemia Plasmapheresis allowed at study onset to treat renal failure