High-dose therapy and innovative approaches to treatment of multiple myeloma

Abstract

High-dose therapy in multiple myeloma (MM) appears to be superior in terms of event-free survival and overall survival compared with conventional therapy. Melphalan-based high-dose therapy increases complete remission rates from 5% to 50% and extends event-free survival beyond 3 years and overall survival beyond 6 years. Critical disease features associated with durable complete remission, event-free survival, and overall survival include the absence of chromosome 13 deletion, low β 2-microglobulin, and low C-reactive protein levels. Data on 1,000 patients enrolled in tandem high-dose trials show that chromosome 13 deletion is an important prognostic feature. The timely application of a second cycle of high-dose therapy extends event-free survival and overall survival markedly in MM patients with low β 2-microglobulin levels. Long-term results of the total therapy trial indicate that patients who do not have chromosome 13 deletions and present with low C-reactive protein and β 2-microglobulin levels have longer complete remissions than patients lacking these prognostic factors. Thalidomide shows clear evidence of antitumor activity possibly because of its antiangiogenic activity. Magnetic resonance imaging (MRI) indicates that bone marrow lesions become smaller or disappear while patients receive dexamethasone, cyclophosphamide, etoposide, and cisplatin (DCEP) consolidation chemotherapy and that patients who have a compete remission after diagnostic MRI have a superior event-free and overall survival than those who still have persistent MRI lesions. Prospective trials are underway to evaluate the effectiveness of consolidation therapy (total therapy II).