RATIONALE: Drugs used in chemotherapy use different ways to stop cancer cells from dividing so they stop growing or die. Thalidomide may stop the growth of tumor cells by stopping blood flow to the tumor. It is not yet known if combination chemotherapy is more effective with or without thalidomide for multiple myeloma. PURPOSE: Randomized phase III trial to compare the effectiveness of combination chemotherapy with or without thalidomide in treating patients who have refractory multiple myeloma.

OBJECTIVES: I. Compare the overall and progression-free survival and remission rates in patients with refractory multiple myeloma treated with dexamethasone, cyclophosphamide, etoposide, cisplatin, and filgrastim (G-CSF) with or without thalidomide. II. Compare the qualitative and quantitative toxic effects of these regimens in these patients. OUTLINE: This is a randomized, multicenter study. Patients are stratified according to prior transplantation (yes vs no), prior treatment failure (resistant vs relapsing), prior treatment regimens (1-2 vs 3-4), and prior thalidomide (no vs some). Patients are randomized to one of two treatment arms. Arm I: Patients receive oral dexamethasone daily and cyclophosphamide, etoposide, and cisplatin (DCEP) IV continuously on days 1-4. Patients also receive filgrastim (G-CSF) subcutaneously daily beginning on day 5 and continuing until blood counts recover. Treatment continues every 3-4 weeks for 3 courses. Patients achieving stable disease or better proceed to maintenance chemotherapy with DCEP administered every 8 weeks for 3 additional courses. Arm II: Patients receive chemotherapy with DCEP as in arm I plus oral thalidomide daily. Thalidomide continues with maintenance chemotherapy and then continues after chemotherapy is completed until disease progression. Patients are followed every 3 months for 1 year, every 6 months for 1 year, and then annually for 3 years. PROJECTED ACCRUAL: A total of 320 patients will be accrued for this study within 4 years.