A Study of Intensive-Dose Melphalan, Topotecan, and VP-16 Phosphate (MTV) Followed by Autologous Stem Cell Rescue in Patients With Multiple Myeloma

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.

OUTLINE: This is a dose escalation study of topotecan. Patients are primed with cyclophosphamide IV over 2 hours for 2 days. Peripheral blood stem cells (PBSC) are collected. Approximately 4 weeks after PBSC collection, patients receive melphalan IV over 30 minutes and topotecan IV over 30 minutes on days -7 to -5. Etoposide phosphate IV is administered over 4 hours on days -4 and -3. PBSC are reinfused on day 0. Cohorts of 4-12 patients receive escalating doses of topotecan until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 6 of 12 patients experience dose limiting toxicities. Patients are followed 2-3 times a week for approximately 1 month, then at 3, 6, and 12 months.

PROJECTED ACCRUAL: A total of 34-60 patients will be accrued for this study within 24-36 months.