RATIONALE: Vaccines may make the body build an immune response to and kill tumor cells. Colony-stimulating factors such as GM-CSF increase the number of immune cells found in bone marrow or peripheral blood.

PURPOSE: Phase I trial to study the effectiveness of vaccine therapy plus GM-CSF in treating patients with multiple myeloma undergoing bone marrow or peripheral stem cell transplantation.

OBJECTIVES: I. Determine the safety of multiple subcutaneous vaccination with myeloma Id-KLH with adjuvant sargramostim (GM-CSF) in posttransplant myeloma patients. II. Evaluate patients' pre- and post-bone marrow transplants for evidence of endogenous idiotype specific immune response. III. Characterize the time course, specificity and persistence of antibody and T cell immune response to myeloma idiotype and to KLH induced by myeloma Ig (Id) immunization. IV. Clone, expand, and characterize T cell clones specific for the tumor idiotype. V. Monitor myeloma involvement in bone marrow and serum paraprotein level following vaccination.

OUTLINE: Patients more than 60 days posttransplant are vaccinated with autologous idiotype vaccine at 0, 2, 6, and 10 weeks. Allogeneic recipients are vaccinated after they are off corticosteroids and on a stable or tapering dose of cyclosporine or tacrolimus (FK506). A series of 4 subcutaneous injections of autologous Id-KLH is given with 3 additional daily injections of GM-CSF subcutaneously at the same site.

PROJECTED ACCRUAL: 35-40 patients will be entered.

• Biological: keyhole limpet hemocyanin
• Biological: sargramostim

DISEASE CHARACTERISTICS: Histologically proven multiple myeloma of late stage B cells Eligible for a FHCRC protocol using high dose therapy with syngeneic, allogeneic, or autologous marrow or stem cell transplantation Achievement of partial or greater remission for patients transplanted in relapse

PATIENT CHARACTERISTICS: Age: 18 to 65 Performance status: Karnokfsky 60-100% Life expectancy: Not specified Hematopoietic: Absolute neutrophil count greater than 1000/mm3 Platelet count greater than 50,000/mm3 without transfusions or growth factors RBC supportable to hematocrit greater than 25 with less than 2 units of packed RBC/week Hepatic: Not specified Renal: Creatinine no greater than 3.0 mg/dL Other: Must have pretransplant sera available with IgG, IgA, or IgM monoclonal paraprotein with a level of 1.5 g/dL or greater identifiable on serum protein electrophoresis Successful isolation and production of an autologous idiotype vaccine from pre-BMT sera Must be off corticosteroids prior to vaccination No infections No disease progression after transplant No graft versus host disease (GVHD) at vaccination No medical conditions that would result in inability to tolerate the vaccination No prior history of serious adverse reactions to GM-CSF

PRIOR CONCURRENT THERAPY: No concurrent posttransplant immunomodulation with IL-2