OBJECTIVES: I. Determine the toxicity and potential efficacy of intensive high dose chemotherapy consisting of melphalan, topotecan, and etoposide phosphate followed by autologous stem cell transplantation in patients with stage II or III multiple myeloma or stage I with evidence of progressive disease. II. Determine the maximum tolerated dose of topotecan in combination with melphalan and etoposide phosphate in this patient population. III. Determine response rates and time to treatment failure in these patients when treated with this regimen. IV. Determine the pharmacokinetic profiles of these drugs and investigate the pharmacodynamic relationships with respect to the efficacy and toxicity of this regimen in these patients. V. Determine whether the sequencing of this chemotherapy regimen is appropriate and optimal in these patients.