Alternating combination chemotherapy and levamisole improves survival in multiple myeloma: a Southwest Oncology Group Study.

Previously untreated patients with multiple myeloma were entered on a randomized clinical trial to determine whether the use of alternating combination chemotherapy, including vincristine, doxorubicin, alkylating agents, and prednisone (160 patients) was more effective than conventional chemotherapy with melphalan and prednisone (77 patients), and whether the addition of the immunomodulating agent levamisole to maintenance chemotherapy enhanced the survival of patients achieving remission. The treatment groups were well matched for all major factors. The more aggressive chemotherapy was more effective at inducing remission, with a significantly higher proportion of patients achieving at least 75% tumor mass regression (53% with alternating combinations versus 32% with melphalan-prednisone, p = 0.002). Furthermore, the median survival was increased to 43 months with alternating combination chemotherapy as compared to 23 months with melphalan-prednisone (p = 0.004). After six to 12 months of induction therapy, 84 patients achieving remission were rerandomized to receive maintenance chemotherapy alone or with the addition of levamisole. The survival from the start of maintenance therapy was longer in patients receiving the added levamisole than with chemotherapy alone (p = 0.01). These findings support the use of aggressive multiagent chemotherapy for remission induction in patients with advanced-stage multiple myeloma.