DISEASE CHARACTERISTICS: Histologically or cytologically confirmed stage I, II, or III multiple myeloma with protein criteria present Quantifiable M-components of IgG, IgA, IgD, IgE AND/OR Urinary kappa or lambda light chain excretion No IgM peaks Quantifiable monoclonal proteins Received at least 1, but no more than 4 prior treatment regimens, including the following: Chemotherapy Bone marrow transplantation Biologic therapy Radiotherapy Interferon therapy or steroid pulsing given as maintenance therapy after transplantation or chemotherapy is not considered a separate treatment regimen Progressive disease