Improved survival duration with combination chemotherapy induction for multiple myeloma: a Southwest Oncology Group Study.

Four hundred forty previously untreated patients with active multiple myeloma were entered into a randomized trial (Southwest Oncology Group SWOG study 7927/28) comparing vincristine, melphalan, Cytoxan (Mead Johnson & Company, Evansville, Ind), and prednisone (VMCP) alternating with vincristine, BCNU, Adriamycin (Adria Laboratories, Columbus, Ohio) and prednisone (VBAP) with or without levamisole with vincristine, Cytoxan, and prednisone (VCP) with or without levamisole for induction therapy. The treatment groups were well balanced for all of the known major prognostic factors. Patients receiving VMCP-VBAP responded (greater than or equal to 75% regression) more frequently to induction therapy, both without (54%) and with (44%) levamisole v VCP without (28%) or with (28%) levamisole (P less than .001). In addition, patients receiving VMCP-VBAP (+/- levamisole) had a survival duration determined to be significantly increased by all forms of analysis: 48 and 33 months for VMCP-VBAP without and with levamisole v 29 and 26 months for VCP without and with levamisole (P = .011 overall). Levamisole did not improve response rates or survival duration (P greater than or equal to .1), nor did it prolong remission in the maintenance phase (P = .85). Analysis of SWOG study 7704/05 (updated April 1985) confirmed improved survival for combination therapy v MP, but no benefit for levamisole. The overall findings support the use of VMCP-VBAP as an excellent treatment option for remission induction in patients with active myeloma of all stages and prognostic categories.