UARK 98-035, A Phase III Study of D.T. PACE Versus High Dose Melphalan and Autologous Transplant in Patients With Previously Treated Multiple Myeloma

All patients will receive two cycles, 4-6 weeks apart, of a combination of chemotherapy drugs (a regimen called D.T. PACE) and collection of peripheral blood stem cells. D.T. PACE consists of 6 chemotherapy drugs (Dexamethasone, Thalidomide, CisPlatin, Adriamycin, Cyclophoshamide, and Etoposide). Four to six weeks after the last cycle of D.T. PACE, each patient with no evidence of myeloma progression will be randomly assigned to receive 1) Autologous Transplant as described below or 2) Additional cycles of D.T. PACE. Since it is not known at this time which treatment is the best, patients will be placed by chance in one of the two groups. If tests show that myeloma is in remission at the time of randomization, 2 additional cycles of D.T. PACE will be given. If myeloma is not in remission, 2 additional cycles of D.T. PACE will be given, then the myeloma will be re-assessed. If the patients myeloma protein has decreased by 90% since baseline or better, 2 more cycles are given. If it has not decreased that much or has gotten worse, the patient will be offered autologous transplantation. Patients with no financial coverage for transplant, or those that have inadequate stem cell collections to support two transplants, will not be randomized and will proceed directly to treatment 2, continued D.T. PACE. If it is determined that the myeloma did not respond adequately to the first 2 cycles of D.T. PACE, then the patient will not be randomized and will proceed directly to autologous transplant. Between 2 and 4 months after the first PBSC transplant, the patient will undergo a second course of high-dose Melphalan and PBSC transplant. In order for all patients to receive the maximum possible benefit, patients may "cross-over" to the other treatment arm if the myeloma does not go into complete remission or at any time myeloma progresses after randomization. When the physician feels that the maximum benefit from chemotherapy has been received (best partial or complete remission) the last phase of the study will start, which is maintenance. Patients will be randomly assigned to receive either low dose (50 mg) or higher dose (200 mg) thalidomide with the dexamethasone.